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HomeMy WebLinkAbout2017-08-16-PB-packet-releasedAGENDA Lexington Planning Board Wednesday, August 16, 2017 Selectmen's Meeting Room 7:00 PM Staff Reports 1. Comprehensive Plan Update 2. Economic Development Recommended Strategies Memo Upcoming Meetings & Anticipated Schedule 1. Anticipated Meetings Development Administration 1. Oakmount Circle - ANR Plan 2. Cedar Street Subdivision - Proposed Street Names I Brookhaven - Site Plan Review (Public Hearing) 4. 45 -65 Hayden Ave - Potential Planned Development District Board Administration 1. Board and Committee Assignments Adjourn L &d Meeting broadcast by LexMedia AGENDA ITEM SUMMARY LEXINGTON PLANNING BOARD AGENDA ITEM TITLE: Comprehensive Plan Update PRESENTER: ITEM NUMBER: Aaron Henry SUMMARY: Staff to provide update on status of Comprehensive Plan as well as creation of the Comprehensive Plan Advisory Committee. SUGGESTED MOTION: FOLLOW-UP: No Follow -up DATE AND APPROXIMATE TIME ON AGENDA: 8/16/2017 AGENDA ITEM SUMMARY LEXINGTON PLANNING BOARD AGENDA ITEM TITLE: Economic Development Recommended Strategies Memo PRESENTER: ITEM NUMBER: Aaron Henry SUMMARY: Update Planning Board Members on Economic Development Presentation to the Board of Selectmen SUGGESTED MOTION: FOLLOW-UP: DATE AND APPROXIMATE TIME ON AGENDA: 8/16/2017 ATTACHMENTS: Description Type D Econorric Development Recommended 'Strategies Ekackup Material D I larowell Area Map Ekackup Material D Forbes Road Area Map Ekackup Material D Suburban ED Real Estate I landout CA)Ver Merno Town of Lexington Memorandum To: Carl Valente, Town Manager CC: Carol Kowalski, Asst. Town Manager for Development; Aaron Henry, Planning Director From: Melisa Tintocalis, Economic Development Director Date: August 14, 2017 RE: Recommended Economic Development Strategies In response to the Economic Development Summit on June 22, 2017, the Town Manger requested staff to develop recommendations on initial zoning changes for the Selectmen to consider in an effort to spur investment in the Town's commercial districts. Based on the review of the existing constraints, the Lexington Commercial Zone Analysis and Build - Out Study by the Cecil Group, discussions with the Economic Development Advisory Committee, and preliminary discussions with property owners, staff recommends the following strategies that could be undertaken: Create a new overlay district which includes 12 properties in the Commercial Manufacturing District at the north end of Harwell Avenues, as well as 7 Harwell, 475 & 459 Bedford, 482 Bedford. The overlay would allow for by -right mixed -use development and allow for limited small-scale residential units when certain conditions of flexible commercial and retail - amenity uses are included in the project and there is a commitment to transportation management. • The overlay would eliminate the floor area ratios or be set to 0.9 and setbacks would be adjusted to allow for increase development opportunity. • To offset potential traffic impacts, the new overlay would require a high level of transportation management and contributions to the transportation mitigation fund. It would also include a requirement for membership to the transportation management association and financial support of the REV shuttle bus. The mitigation funds would enable the Town to implement turning- movement and access restrictions to calm traffic and protect neighborhoods from cut - through traffic. Increase the floor area ratio in the Commercial Regional Office District to 0.9 and add explicit language to include flexible commercial use. Support the smaller existing commercial nodes by updating the uses, in particular examine the uses in the Commercial Service District. In addition, The Town should consider supporting the rezone effort proposed by King Street Properties for 75 Hayden. The proposed project would add approximately 200K square feet of lab office and is estimated to generate approximately $1.8M annually in tax revenue based on the final fiscal analysis by Fougere Planning & Development. Addresses of the Commercial Manufacturing District parcels: 12, 17, 24, 25, 29, 32, 35, 45, 32, & 40 Hartwell Avenue; 70 & 60 Westview c�C'y 84-80, 25 8 27 9 a- 11 71 l ii Ir WIN# 40 '7o Ii 5-16 ............... 101 ®R/@ — ZONE EM HAR IE Z I'l l—H �,'OODED DEI DI011 co ^3 4) "lE_'EEl lft -OODE-11'l "" W.tl d Setback m Fret J v/'m Z mmgDis ftt. _2016 COMMERCIALIINOUSTWAL DI—ICTS C1,1 l3nul'a, ,,,,n', c� PARCEL MAP —ER �C PLANNED —ELOPMENTDIST—TS D I C =1 �D 670 335 0 b7�0 -D "IF, NN i AN�`mi -1 `mzol W Q U) I� w 7 co cn `�` 4i rill % ✓ii }' Al rr, p S�USEfiS pVE i MPs s i "ON %/ IS V / r oi�r it � IV In aF, 11O IMAI<hF1'I ROAD IN 4 �rcl) 4� °�o /poi /rr�/ �V /i �'\ 9\ Legentl f ozP�, <NN�AI��AN�EIIOOO�z «o \ 35 /1 �INCOL �� �� %i �� �/� W tl d Setback n Fret a 1 B fDi.t Zon gD Ali.te_2016 r COMMERCIAL INDUSTRIAL DISTRICTS PARCEL MAP o� omaa OTHER cwemmenicvc PLANNEDDEVELOPMENTDISTRICTS Ro \440 220 0 "440 Celt �7J�aw 0 W 1 Z� 4NC356sr PN , a G w 11 m o- 0. 00 co N 0 w r 6, III U L x 4. C) O W O cc O O O cc 91 LU as IIAM 6 Z r-0 �Wi 00 41 EO X 0 -0 x 0 U) a E o CLO a) 'n u 4�0 a Bm z -- , m 6. wq —M fn a) m 4� = r-,z 0 C) u c .2 V)w 4--O>O-�2 uw Ln "<> OU UU< 07- w -50 0 uj lu LU as IIAM 6 Z �Wi > AGENDA ITEM SUMMARY LEXINGTON PLANNING BOARD AGENDA ITEM TITLE: Anticipated Meetings PRESENTER: ITEM NUMBER: Aaron Henry SUMMARY: This recurring agenda item is to inform the Board and public of the proposed meeting schedule. At this time, the Board has discussed a schedule out to this fall's Special Town Meeting (2017 STM -2) set for October 16 and 18, 2017. The proposed meeting dates are: • Monday, August 28 (Joint BO S /PB Meeting) • Wednesday, August 30 • Wednesday, September 13 • Friday, September 22 8AM Estabrook Hall (Joint 2020 Committee /BOS /PB /School Committee Meeting) • Wednesday, September 27 • Wednesday, October 4 • Monday, October 16 (short, pre -Town Meeting) • Wednesday, October 18 (short, pre -Town Meeting) SUGGESTED MOTION: There is no need for the Board to act on this item. FOLLOW-UP: Should Board members have any known conflicts with any of the proposed dates or wish to request an item be placed on a meeting agenda, please follow up with staff. DATE AND APPROXIMATE TIME ON AGENDA: 8/16/2017 AGENDA ITEM SUMMARY LEXINGTON PLANNING BOARD AGENDA ITEM TITLE: Oakmount Circle - ANR Plan PRESENTER: ITEM NUMBER: SUMMARY: Applicant has submitted a revised ANR plan with a few minor dimensional changes and no material lot line changes. The reason for the dimensional change is to go from tenths to hundredths due to the adjoining registered land in land court. SUGGESTED MOTION: Board endorse revised ANR plan as they are minor adjustments to an already endorsed ANR. FOLLOW-UP: DATE AND APPROXIMATE TIME ON AGENDA: 8/16/2017 ATTACHMENTS: Description Type D Oakrrrunt Circle Revised ANR Plan CAxver Merno f ° D D n -� - n o xo Dc zKo _ \\ �D A .. 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SUGGESTED MOTION: FOLLOW-UP: The Board will see the applicant again at its next meeting to deal with accepting the required performance guarantee and plan endorsement. DATE AND APPROXIMATE TIME ON AGENDA: 8/16/2017 ATTACHMENTS: Description Type D Developer street Name Suggestions & Fationale Ekackup Material D R Ganale'Street Name Suggestions & Ritionale Ekackup Material memo appreciate We sincerely preference remains Abbey Road (the longer road which would intersect Cedar Streetj • '- nny Lane (the shorter road). MrAgam Dear Ben, You asked rne for our reactions to the meeting last night regarding the discussion on street naming in the Cedar Street parcel. Well h was aninteresting and diverse commentary and vve would like tm express our thanks tothe Planning Board for having an open (if not public) discussion on this issue. Specifically, we would like to thank those members of the Planning Board who placed value on the inputs of the applicant and owners either by accepting the first two choices (Penny Ln, Abbey Rd — Mr. Hornig\,nrbystating that our inputs should matter (k8s. Concoron-Ronchetti).|n addition, xve thank the Chair, Mr. Canale, who after some independent research suggested the name wolf tree, based on the historical incidence of those trees on our property. In fact, there may be current examples of wolf trees on our lot, although many are of the multiple-stem variety that may not be long-lived. We appreciate your efforts to employ an arborist to help identify such trees, and to protect them when possible. The name and the image ufwolf tree' captures the strength and timeless beauty of the environment in this area. To continue with our reactions to the meeting, a few words' about the naming of Lexington MA: The origin of Lexington is somewhat in dispute, but two contenders for the name are: • in honor of Lord Lexington, an English peer, and • the town of Laxton in Nottinghamshire, England. b was asserted again in last night's meeting that the suggestions Penny Lane and Abbey Rd are nothing but cute references toan English pop singing group, but in light of the historical lineage of the town's name itself, vve respectfully disagree with Ms. Johnson. indeed, as we (44-year residents on this parcel of land) and our neighbors in Lexington move into our 3 rd century of acknowledging the history and values of our town, isn't it fitting to recognize a6U+ year old British (and international) cultural icon of peace as an important and positive contemporary link to our neighbor across the pond? Another note of historical significance which you have raised before: The land in this part of the town was denoted as ministerial land' denoting the church's privilege to acquire revenue from harvesting and selling trees onit. If we were to live on Abbey Road, we could have both a historical and contemporary link to our address. In closing, we repeat our thanks for the positive words that came from the Board, and continue our support for Penny Lane and Abbey Rd as the street names for the proposed new neighborhood. Yours truly, Peter and Susan Staecker �The biological origin ofwolf trees is briefly discussed here: zReference: The town of Lexington was founded (and given its present name) in17l3. 3 Reference: Tom 5i|eo's Historic Guide tm Open Space /n Lexington (excerpts provided by Lester Savage); Ch 11, Poor Farm. MUIRRIM As a 16-year Lexington resident and potential home-owner in the new streets being constructed by Finnegan Development, I'm writing to support the naming of Abbey Road and Penny Lane, I understand there was a question raised about the relevance of these names to Lexington since the genesis is a connection to The Beatles, a British rock band. I see man� connections to Lexin- ,.Ion's histopf and communit, and a ve ,, ersonal connection for our My husband, Dave, is originally British and is now a US citizen and Lexington resident since 2000. He's also a musician who's been greatly inspired by The Beatles. Dave performs in public and private venues around Lexington, and for the last 4 years his band has headlined the annual LEF fundraiser. In addition to bringing joy to the community through musical performances, his band has been an LEF auction item that raises thousands of dollars each year. Beyond this small example of how The Beatles music has contributed Lexington's community, I think it's safe to say The Beatles have brought happiness to a majority of Lexington residents over the years, inspiring generations of music lovers and performers. Another relevant connection Is that The Beatles are considered to have revolutionized modern day music, just as our founding fathers started a revolution, A recent PBS special called "Sgt. Pepper's Musical Revolution" explored the creation of this album and The Beatles profound musical influence. In this documentary, you'll find a very interesting segment on the construction of the song Penny Lane. Paul and John specifically sought out instruments from the past, including a &h century reed organ and an 18tt' century piccolo trumpet, which has a prominent solo in the song. Band instruments of this era, such as the "fife and drum", played an important communications role on the revolutionary battlefield, Finally, I'd like to point out that The Beatles are credited with inspiring a cultural revolution by promoting freedom, peace, love, inclusion and diversity. These ideals are represented In current day Lexington culture. Like the global influence of the American Revolution with the "shot heard round the world", The Beatles havz-� had a global impact on music and culture. Fundamentally, music is the common language of all societies and enhances happy occasions of life. The new Lexington families moving to these streets. Naming of two streets in the Cedar Street subdivision. Richard Canale The Planning Board has the statutory responsibility for naming the street(s) in subdivisions. Traditionally, applicants have requested names for streets, from which the Board has sought justification from the applicant. The Board typically wishes to have streets named which have a nexus to the property. Place names, historical events, or other nexus -based factors ate all important. Naming streets after Minutemen has been a tradition, and we have not run out of all such names. If the applicants are unable to propose suitable names, the Board has typically researched names, with or without external help. The present -day Cedar Street lots on the northerly side of Cedar were once part of Poor Farm. The Town sold these lots to returning World War 2 veterans (see Historical Commission ComErehensive Cultural Resources Survey for documentation - "Lots for veterans housing were set aside on Hill and Cedar Streets, land that was originally part of the town's Poor Farm "). It then seems that there are two themes that form a nexus, Poor Farm or World War 2 veterans. I haven't figured two potential street names that would signify a prestigious street name for the WW2 veteran's story, but anyone is welcome to try. There seems to be two such prestigious street names that are related to Poor Farm. One is the name Poor Farm Lane itself — both new -to -be streets were once part of Poor Farm. Additionally, several streets in Massachusetts, New England, and the USA are named Poor Farm Road or Lane (see partial listings below). htt�se // patch ,com /massachusetts /lexin� ton /the -poor- farms- �o�ulation The other is Wolf Tree Lane. There are documented street names that are Wolf Tree Road in other US states, and several tree nurseries and farms that contain the Wolf Tree name. The July, 2010 Patch Article that follows suggests that a few trees identified within Poor Farm are being overcome by smaller succession plants. The name place for Wolf Tree lane here links the historical story of succession from colonial wilderness to tamed farm to succession moderate World Wart veteran housing to newer substantial present- future housing on the Poor Farm site. htt�e / /northernwoodlands,or� /articles /article /a- glace- for -wolf -trees Examples of Existing Street Names Poor Farm Ln. Julian, PA Poor House Farm Ln, Wytheville, VA Poor House Farm Lane. New Bedford, MA Poor Farm Ln, Chinook, MT Poor Farm Rd, Harvard, MA Poor Farm Rd, Gilford, NH Poor Farm Rd, New Ipswich, NH Poor Farm Rd Deerfield, New Hampshire Old Poor Farm Rd, Ware, MA Poor Farm Rd, Nottingham, NH Wolf Tree Roads in SC, AGENDA ITEM SUMMARY LEXINGTON PLANNING BOARD AGENDA ITEM TITLE: Brookhaven - Site Plan Review (Public Hearing) PRESENTER: ITEM NUMBER: SUMMARY: This item deals with Brookhaven's recently approved expansion project. Per the Zoning Bylaw, the site must come to the Board for Site Plan Approval. The scope of the review is limited to ensuring that the proposal approved by Town Meeting is substantially the same as that before the Board now. Most of the recently submitted documents are attached to the Board packet. However due to the size of the full plan set they cannot be uploaded but can be viewed by clicking here. Recent changes have been made to the proposal based on comments received from the Conservation Commission. Engineering and Conservation staff are in the process of resolving some issues with the applicant associated with the placement of water utilities. SUGGESTED MOTION: Board open the hearing with discussion but continue the hearing to allow a resolution of the issues. FOLLOW-UP: Staff will provide additional materials to the Board once plans have been modified. DATE AND APPROXIMATE TIME ON AGENDA: 8/16/2017 ATTACHMENTS: Description Type D Brookhaven .-list of Plan Changes REVISED Backup Material D Brookhaven ... List of Plan Changes Backup Material D Brookhaven ... C2.2 DEMO REVISED PLAN 8...7...17 Backup Material D Brookhaven - C3.1 E.A. REVISED PLAN 8.7-17 Backup Material D Brookhaven - C3.2 FScS REVISED PLAN 8.7-17 Backup Material D Brookhaven - NOI Subirittal 7.18-17 Backup Material D Brookhaven - 1-1,11) Memo Backup Material D Brookhaven - Accentecli Sound Evaluation Backup Material OF11, 44 Wood Avenue Engineering, Inc. Mansfield, MA 02048 Tel (508) 339 -3929 n�u "in rrrr �x Ianviirc�r7ime��1 1. ir;�:i�u�ti�al:� Fax (508) 339 -3140 www.ohiengineering.com SITE PLAN CHANGES MADE TO PLAN THAT WAS APPROVED AT APRIL 2017 TOWN MEETING August 10, 2017 North Building: • Emergency Access: The emergency access entrance off Waltham St shifted south, increasing separation to the north abutter from 15 feet to approximately 33 feet This modification required modification to storm water, utilities, parking, sidewalks and landscaping. No net loss of parking spaces resulted from re- alignment of the emergency access. See Plan Sheets C.3.3, C.4.1, C.5.1 and C.6.2. • Arch Culvert: Arch Culvert Wing Walls removed in favor of continuous Redi- Rock retaining walls providing clean, consistent facade across arch culvert opening. Arch Culvert lengthened from —34' to —41' due to safety barriers and fencing at the crossing, coupled with manufacturer's fabrication constraints. See Plan Sheets C.3.3, C.4.2, C.5.2, and C.8.4. • Building Footprint: Garage entrance wall was adjusted to increase separation from Waltham St. by approximately 10 feet. See Plan Sheets C.3.3, C.4.1 and C.5.1. • Stormwater Management System: Stormwater system components and sizing revised as needed per updated Stormwater Design Calculations. See Sheets C.3.3, C.5.1, and C.5.2. • Water Service: Water loop connection was revised to pass beneath Chester Brook intermittent stream instead of over arch culvert, per Lexington Water and Engineering Departments. See Plan Sheet C.6.1.We have requested that the Water and Engineering Departments reconsider this requirement to allow the privately owner /maintained water line to pass over the arch culvert. The water line would be provided with an insulating sleeve wherever cover may be less than 4.5 feet. Sanitary Sewer: North Building sanitary sewer realigned to provide in -line grinder chamber as required by Brookhaven /Lexington MOU. Sanitary sewer connection to Waltham Street sewer main now includes re- alignment of existing drainage structures and piping at crossing due to conflicts with existing utilities. See Plan Sheets C.4.1 and C.8.11. Electrical Service: Transformer and generator pads moved and consolidated to area adjacent to NW building corner. Primary electrical feed duct bank was re- aligned and additional electrical manhole vault was provided. See Plan Sheets C.4.1 and C.4.2. Landscape Plan: Landscape Plan was revised to accommodate layout changes. See Plan Sheet C.7.3. Mansfield, MA Amherst, MA Chester, VT 2 Commons Expansion: • Skilled Nursing Porte Cochere: Addition of this element resulted in parking reconfiguration. Parking in this area was modified to preserve existing telecom manhole vault, existing electric transformer, existing boiler room entrance, existing gas meter works, existing chiller fence line, and existing grease trap. No net loss of parking spaces resulted. See Plan Sheets C.3.3, C.4.3, C.4.4, C.5.3 and C.5.4. • Building Footprint: Minor architectural modifications were made to the Commons Expansion building footprint. The architectural changes resulted in site modifications to storm water, utilities, parking, drop off loop, sidewalks, crosswalks, and landscaping. No net loss of parking spaces resulted. See Plan Sheets C.3.3, C.4.3, C.4.4, C.5.3 and C.5.4. • Stormwater Management System: Portions of the sidewalks will be constructed with pervious pavement for stormwater management purposes. Stormwater system components and sizing revised as needed per updated Stormwater Design Calculations. See Plan Sheets C.3.3, C.5.3 and C.5.4. • Utility Services: Emergency generator pad removed from Vernal Pool Buffer on north side of driveway in favour of using existing concrete pad adjacent to the Loading Dock. Electric and telecom duct banks, gas service, water loop reconfigured per M /E /P engineers' coordination, and layout changes above. See Plan Sheets C.3.3, C.4.3, C.4.4, C.5.3 and C.5.4. • Vernal Pool: Certified Vernal Pool noted and 100' Vernal Pool buffer zone added to plan. Pervious pavement added for sidewalks Commons Expansion area. Sidewalk on north side of driveway aisle east of the connector drive was eliminated to avoid work within the Vernal Pool buffer zone. See Plan Sheets C.3.1, C.3.3, C.4.3, C.4.4, C.5.3 and C.5.4. • Landscape Plan: Landscape Plan was revised to accommodate layout changes. See Plan Sheet C.7.4. Mansfield, MA Amherst, MA Chester, VT OF11, 44 Wood Avenue Engineering, Inc. Mansfield, MA 02048 Tel (508) 339 -3929 n�u "in rrrr �x Ianviirc�r7ime��1 1. ir;�:i�u�ti�al:� Fax (508) 339 -3140 www.ohiengineering.com SITE PLAN CHANGES MADE TO PLAN THAT WAS APPROVED AT APRIL 2017 TOWN MEETING July 2017 North Building: • Emergency Access: The emergency access entrance off Waltham St shifted south, increasing separation to the north abutter from 15 feet to approximately 33 feet This modification required modification to storm water, utilities, parking, sidewalks and landscaping. No net loss of parking spaces resulted from re- alignment of the emergency access. See Plan Sheets C.3.3, C.4.1, C.5.1 and C.6.2. • Arch Culvert: Arch Culvert Wing Walls removed in favor of continuous Redi- Rock retaining walls providing clean, consistent facade across arch culvert opening. Arch Culvert lengthened from —34' to —41' due to safety barriers and fencing at the crossing, coupled with manufacturer's fabrication constraints. See Plan Sheets C.3.3, C.4.2, C.5.2, and C.8.4. • Building Footprint: Garage entrance wall was adjusted to increase separation from Waltham St. by approximately 10 feet. See Plan Sheets C.3.3, C.4.1 and C.5.1. • Stormwater Management System: Stormwater system components and sizing revised as needed per updated Stormwater Design Calculations. See Sheets C.3.3, C.5.1, and C.5.2. • Water Service: Water loop connection was revised to pass beneath Chester Brook intermittent stream instead of over arch culvert, per Lexington Water and Engineering Departments. See Plan Sheet C.6.1. • Sanitary Sewer: North Building sanitary sewer realigned to provide in -line grinder chamber as required by Brookhaven /Lexington MOU. Sanitary sewer connection to Waltham Street sewer main now includes re- alignment of existing drainage structures and piping at crossing due to conflicts with existing utilities. See Plan Sheets C.4.1 and C.8.11. • Electrical Service: Transformer and generator pads moved and consolidated to area adjacent to NW building corner. Primary electrical feed duct bank was re- aligned and additional electrical manhole vault was provided. See Plan Sheets C.4.1 and C.4.2. • Landscape Plan: Landscape Plan was revised to accommodate layout changes. See Plan Sheet C.7.3. Commons Expansion: Skilled Nursing Porte Cochere: Addition of this element resulted in parking reconfiguration. Parking in this area was modified to preserve existing telecom manhole vault, existing electric transformer, existing boiler room entrance, existing gas meter works, existing chiller fence line, and existing Mansfield, MA Amherst, MA Chester, VT grease trap. No net loss of parking spaces resulted. See Plan Sheets C.3.3, C.4.3, C.4.4, C.5.3 and C.5.4. • Building Footprint: Minor architectural modifications were made to the Commons Expansion building footprint. The architectural changes resulted in site modifications to storm water, utilities, parking, drop off loop, sidewalks, crosswalks, and landscaping. No net loss of parking spaces resulted. See Plan Sheets C.3.3, C.4.3, C.4.4, C.5.3 and C.5.4. • Stormwater Management System: Portions of the sidewalks will be constructed with pervious pavement for stormwater management purposes. Stormwater system components and sizing revised as needed per updated Stormwater Design Calculations. See Plan Sheets C.3.3, C.5.3 and C.5.4. • Utility Services: Emergency generator pad removed from Vernal Pool Buffer on north side of driveway in favour of using existing concrete pad adjacent to the Loading Dock. Electric and telecom duct banks, gas service, water loop reconfigured per M /E /P engineers' coordination, and layout changes above. See Plan Sheets C.3.3, C.4.3, C.4.4, C.5.3 and C.5.4. • Vernal Pool: Certified Vernal Pool noted and 100' Vernal Pool Buffer added to plan. Pervious pavement path on north side of driveway aisle pulled farther away from Vernal Pool to back of curb, to minimize buffer impact. See Plan Sheets C.3.3, C.4.3, C.4.4, C.5.3 and C.5.4. • Landscape Plan: Landscape Plan was revised to accommodate layout changes. See Plan Sheet C.7.4. Mansfield, MA Amherst, MA Chester, VT ien cloo ho All 1 still ■ III � Ty, 2i sopo pit IL & Wal ODA v L lid zNp ---------- ... ch h T . . .... m z z O K Z lie _- htE h =o m �a �o ulii n e 0 2 W �n 3 a a ry C q a �w � 1 I \ I �Qyn I I i I I n I 1\ / lw �o 2 W �n 3 lie htE -Ye z �� o � ?��mN � or �� , . N -N-4-T 91 00 Q 0 El IN M 0 ---- -- ------ O Engineering, Inc. Faun u: k.irrvircaurrri atxl,r a uht.i.a�. SUBMITTAL TO: LEXINGTON CONSERVATION COMMISSION AND MASSDEP - BUREAU OF RESOURCE PROTECTION FORM 3 - NOTICE OF INTENT FOR BROOKHAVEN AT LEXINGTON 960 -1010 WALTHAM STREET LEXINGTON, MA 02421 Prepared for: SYMMES LIFECARE DBA BROOKHAVEN AT LEXINGTON, INC. 1010 WALTHAM STREET LEXINGTON, MA 02421 Prepared by: OH1 ENGINEERING, INC. 44 WOOD AVENUE MANSFIELD, MA 02048 508 - 339 -3929 508 - 339 -3140 (FAX) OHI PROJECT # 15 -1664 Submittal Date: JULY 18, 2017 Mansfield, MA Amherst MA Chester, VT 0 .1 r Engineering, Inc, FngCheer W & Environnnenta[ Sdenti httn July 18, 2017 Town of Lexington Conservation Commission 1625 Massachusetts Avenue Lexington, MA 02420 Re: Notice of Intent Brookhaven at Lexington 960 -1010 Waltham Street Dear Commissioners: 44 Wood Avenue Mansfield, MA 02048 Tel (508) 339 -3929 Fax (508) 339 -3140 www.ohiengineering.com Symmes Lifecare d /b /a Brookhaven at Lexington, Inc. (Brookhaven) and CHI Engineering, Inc. are pleased to submit the attached Notice of Intent (NOI) filed in accordance with the Massachusetts Wetlands Protection Act (WPA) at MGL c131 §140 and its implementing regulations (310 CMR 10.00) and the Code of the Town of Lexington for Wetland Protection, Chapter 130. Abutters to the Property have been notified in accordance with state and local regulations. Proof of mailing will be provided to the Lexington Conservation Commission at the public hearing. Brookhaven was incorporated in December 1984 as a Massachusetts Not - for - Profit corporation to meet the housing and health care needs of the elderly. It acquired 26 acres (Assessor Map 5, Parcel 16A) of property at 1010 Waltham Street, which was subsequently rezoned by Town Meeting in 1986 to an RD Planned Residential District, enabling Brookhaven to become a full - service life care retirement community. In 1987, following Town Meeting approval, the Zoning Board of Appeals approved a retirement community of 205 dwelling units with 41 -bed nursing care units and 316 parking spaces. Special permits for minor deviations of the Brookhaven RD were approved in 1994 (8 additional nursing care beds) and in 1999 (nine units of assisted care). In 2004, Brookhaven obtained Town Meeting approval to add a cluster of 48 independent living units while repurposing 6 existing independent living units, adding 11 assisted care units, and creation of additional space for a Health and Wellness Center. The current facility totals 240 independent living units, 20 assisted care units and 49 beds in the Nursing Center. In 2012, Brookhaven acquired adjoining property at 960 and 990 Waltham Street consisting of approximately 6 acres. The new property includes Town Assessor Map 5, Parcels 19C, 20 and 21A. Overall, Brookhaven owns approximately 32 acres of land. In 2013, Brookhaven appeared before the Conservation Commission seeking approval to excavate lead based paint- impacted soil that was associated with the former greenhouse use of the property and was located within 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent Bordering Vegetated Wetland (BVW) and associated buffer zone. The Lexington Conservation Commission issued an Order of Conditions under MassDEP File Number 201 -912, and a Certificate of Compliance upon completion of the work. In 2017, Brookhaven obtained Town Meeting approval to add 49 Independent Living units on the recently acquired property, and expansion of the existing Commons Building along with associated access drives, parking, utilities, landscaping and sidewalks. After construction of the proposed project, the Brookhaven facility will include 289 Independent Living units, 50 Assisted Care units and 12 Nursing Care beds for a total of 351 units with 422 parking spaces. As you may recall, Brookhaven and its engineering team met with the Conservation Commission and its staff in 2015, 2016 and 2017 to discuss the project prior to the 2017 Town Meeting. Activities subject to the Commission's jurisdiction are limited to: • Altering 513 square feet of bordering vegetated wetlands (BVW); • Altering 7,685 square feet of area within the 25 -foot buffer zone to BVW including 1,132 square feet of BVW replication; • Altering 85,305 square feet of area within the 100 -foot buffer zone to BVW; • Altering 77 square feet within the buffer zone to a vernal pool; and, • Temporary alteration of 15 linear feet of bank to an Intermittent Stream. To mitigate for the alteration of 513 square feet of BVW, Brookhaven proposes on -Site replication areas totaling 1,132 square feet resulting in greater than 2:1 ratio of replication to impact area. The attached NOI describes the existing conditions, alternatives considered and measures employed to avoid and minimize impacts to those resource areas identified above. Given the overall scope of the project, Brookhaven has advanced a plan that minimizes unavoidable wetland impacts, and which is designed in accordance with the applicable general performance standards presented in the Wetland Protection Regulations at 310 CMR 10.53, and the Lexington Wetland Bylaw. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent The attached NOI is being submitted for the Commission's review at the August 7, 2017 public hearing. If you have questions or comments regarding this application, please do not hesitate tO contact n0e3t5O8-339-3929x35OOr via email at Very truly yours, (]H| ENGINEERING, INC. Cc: K8assDEP— Northeast Region Lexington Town Clerk Brookhaven at Lexington � � 96O-1O20 Waltham Street Brookhaven otLexington Lexington, MA Notice of Intent Table of Contents WPA Form 3 — Notice of Intent ATTACHMENT A PROJECT NARRATIVE ATTACHMENT B FEE TRANSMITTAL AND FEE CALCULATION WORKSHEET ATTACHMENT C ABUTTER NOTIFICATIONS AND AFFIDAVIT OF SERVICE ATTACHMENT D FIGURES ATTACHMENT E PERMIT DRAWINGS ATTACHMENT F STORMWATER REPORT ATTACHMENT G STORMWATER POLLUTION PREVENTION PLAN ATTACHMENT H STORMWATER OPERATIONS AND MAINTENANCE PLAN ATTACHMENT I FIELD DATA FORMS 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent C)FiI 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent Massachusetts Department of Environmental Provided by MassDEP: * Protection MassDEP File #: „w Bureau of Resource Protection - Wetlands eDEPTransaction #:931321 WPA Form 3 - Notice of Intent City /fown:LEXINGTON Massachusetts Wetlands Protection Act M.G.L. c. 131, §40 A.General Information 1. Project Location: a. Street Address b. City/Town d. Latitude f Map /Plat # 2. Applicant: I- Individual Fv Organization 960- 10 10 WALTHAM STREET LEXINGTON c. Zip Code 42.41633N e. Longitude 5 g. Parcel/Lot # 02421 71.23035W 16A, 19C, 20, 21 A a. First Name JAMES b.Last Name FREEHLING c. Organization SYMMES LIFECARE DBA BROOKHAVEN AT LEXINGTON, INC. d, Mailing Address 960- 10 10 WALTHAM STREET e. City/Town LEXINGTON f State MA g. Zip Code 02421 h. Phone Number 781 -863 -9660 i. Fax 781 - 863 -9944 j. Email jfreehling @brookhavenatlexington.org 3.Property Owner: F- more than one owner a. First Name JAMES b. Last Name FREEHLING c. Organization SYMMES LIFECARE DBA BROOKHAVEN AT LEXINGTON, INC. d. Mailing Address 960- 10 10 WALTHAM STREET e. City/Town LEXINGTON f State MA g. Zip Code 02421 h. Phone Number 781 - 863 -9660 i. Fax 781 - 863 -9944 j.Email jfreeblinggbrookhavenatlexington .org 4.Representative: a. First Name JAMES b. Last Name BORRE13ACH c. Organization OHI ENGINEERING, INC. d. Mailing Address 44 WOOD AVENUE e. City/Town MANSFIELD f State MA g. Zip Code 02048 h.Phone Number 508 -339 -3929 i.Fax j.Email jborrebach @i ohiengineering.com 5.Total WPA Fee Paid (Automatically inserted from NOI Wetland Fee Transmittal Form),, a.Total Fee Paid 2,500.00 b.State Fee Paid 1,237.50 c.City/Town Fee Paid 1,262.50 6.General Project Description: BROOKHAVEN AT LEXINGTON IS A MASSACHUSETTS NOT - FOR - PROFIT CORPORATION FORMED IN 1984 TO MEET THE HOUSING AND HEALTH CARE NEEDS OF THE ELDERLY. THE PROJECT INVOLVES THE DEVELOPMENT OF 49 INDEPENDENT LIVING UNITS ON RECENTLY ACQUIRED PROPERTY, THE EXPANSION OF THE EXISTING COMMONS BUILDING, AND THE CONSTRUCTION OF ASSOCIATED ACCESS DRIVES, PARKING, UTILITIES, LANDSCAPING, AND SIDEWALKS. 7a.Project Type: 1.1 "" Single Family Home 2. r Residential Subdivision 3. f Limited Project Driveway Crossing gip, Fv Commercial/Industrial 5.F- Dock/Pier fi. F Utilities Page 1 of 7 * ELECTRONIC COPY Massachusetts Department of Environmental Provided by MassDEP L3Protection MassDEP File #: Bureau of Resource Protection - Wetlands eDEP Transaction #:931321 w� WPA Form 3 - Notice of Intent City/Town:LEXINGTON t ., ,.,,.... Massachusetts Wetlands Protection Act M.G.L. c. 131, §40 7. F Coastal Engineering Structure 8. r Agriculture (eg., cranberries, forestry) 9. f Transportation 10. f Other 7b.ls any portion of the proposed activity eligible to be treated as a limited project subject to 310 CMR 10.24 (coastal) or 310 CMR 10.53 (inland)? 1. F Yes r No If yes, describe which limited project applies to this project: 2. Limited Project 8.Property recorded at the Registry of Deeds for: a.County: b.Certificate: c.Book: tl.Page: SOUTHERN MIDDLESEX 17744 12, SOUTHERN MIDDLESEX 58589 450 B. Buffer Zone & Resource Area Impacts (temporary & permanent) 1.Buffer Zone & Resource Area Impacts (temporary & permanent): F This is a Buffer Zone only project - Check if the project is located only in the Buffer Zone of a Bordering Vegetated Wetland, Inland Bank, or Coastal Resource Area. 2.lnland Resource Areas: (See 310 CMR 10.54 - 1 Q.58, if not applicable, go to Section 13.3. Coastal Resource Areas) Resource Area a. W, Bank b. Fv Bordering Vegetated Wetland c. f Land under Waterbodies and Waterways d. r Bordering Land Subject to Flooding e. F Isolated Land Subject to Flooding Size of Proposed Alteration Proposed Replacement (if any) 15 15 1. linear feet 2. linear feet 513 1132 1. square feet 2. square feet 1. Square feet 2. square feet 3. cubic yards dredged I. square feet 2. square feet 3. cubic feet of flood storage lost 4. cubic feet replaced 1. square feet 2. cubic feet of flood storage lost 3. cubic feet replaced E F Riverfiont Area 1. Name of Waterway (if any) 2. Width of Riverfront Area (check one) o- 25 ft. - Designated Densely Developed Areas only F 100 ft. - New agricultural projects only F' 200 ft. - All other projects 3. Total area of Rivertront Area on the site of the proposed project square feet Page 2 of 7 * ELECTRONIC COPY Massachusetts Department of Environmental Provided by MassDEP: Protection MassDEP File #: •.', Bureau of Resource Protection - Wetlands eDEP Transaction #:931321 " WPA Form 3 - Notice of Intent Ciry/Iown:LExINGTON Massachusetts Wetlands Protection Act M.G.L. c. 131, §40 4. Proposed Alteration of the Riverfront Area: a. total square feet b. square feet within 100 ft. c. square feet between 100 ft. and 200 ft. 5. Has an alternatives analysis been done and is it attached to this NOI? I- Yesf' No 6. Was the lot where the activity is proposed created prior to August 1, 1996? f"` Yesf° No 3.Coastal Resource Areas: (See 310 CMR 10.25 - 10.35) Resource Area Size of Proposed Alteration Proposed Replacement (if any) a. f- Designated Port Areas Indicate size under Land under the ocean below, b. F" Land Under the Ocean 1. square feet 2. cubic yards dredged c. f- Barrier Beaches Indicate size under Coastal Beaches and/or Coatstal Dunes, below d.F Coastal Beaches e. r- Coastal Dunes f. F- Coastal Banks g. r Rocky Intertidal Shores h. f- Salt Marshes L I- Land Under Salt Ponds 1, square feet 2. cubic yards beach nourishment 1. square feet 2. cubic yards dune nourishment 1. linear feet 1. square feet I. square feet 2. sq ft restoration, rehab, crea. 1. square feet 2. cubic yards dredged j. F Land Containing Shellfish 1. square feet k. I__ Fish Runs Indicate size under Coastal Banks, Inland Bank, Land Under the Ocean, and/or inland Land Under Waterbodies and Waterways, above 1. cubic yards dredged I. f- Land Subject to Coastal Storm Flowage I. square feet 4. Restoration/Enhancement I Restoration/Replacement If the project is for the purpose of restoring or enhancing a wetland resource area in addition to the square footage that has been entered in Section B.2.b or B.3.h above, please entered the additional amount here. Page 3 of 7 * ELECTRONIC COPY Massachusetts Department of Environmental Provided by MassDEP: ...M Protection MassDEP File #: y .k. Bureau of Resource Protection - Wetlands eDEP Transaction #:931321 WPA Form 3 - Notice of Intent c;ry/Iown:LExINGTON Massachusetts Wetlands Protection Act M.G.L. c. 131, §40 a. square feet of $V W b. square feet of Salt Marsh 5.Projects Involves Stream Crossings Fv Project Involves Streams Crossings If the project involves Stream Crossings, please enter the number of new stream crossings/number of replacement stream crossings. I a. number of new stream crossings b. number of replacement stream crossings C. Other Applicable Standards and Requirements Streamlined Massachusetts Endangered Species Act/Wetlands Protection Act Review 1. Is any portion of the proposed project located in Estimated Habitat of Rare Wildlife as indicated on the most recent Estimated Habitat Map of State - Listed Rare Wetland Wildlife published by the Natural Heritage of Endangered Species program ( NHESP)? a. F_ Yes F4-oNo If yes, include proof of mailing or hand delivery of NOI to. Natural Heritage and Endangered Species Program Division of Fisheries and Wildlife 1 Rabbit Hill Road Westborough, MA 01581 b. Date of map: FROM MAP VIEWER If yes, the project is also subject to Massachusetts Endangered Species Act (MESA) review (321 CMR 10.18).... c. Submit Supplemental Information for Endangered Species Review * (Check boxes as they apply) r` Percentage /acreage of property to be altered: (a) within Wetland Resource Area (b) outside Resource Area percentage /acreage percentage /acreage 2. r- Assessor's Map or right- of-way plan of site 3. r` Project plans for entire project site, including wetland resource areas and areas outside of wetland jurisdiction, showing existing and proposed conditions, existing and proposed tree /vegetation clearing line, and clearly demarcated limits of work ** a, F_ Project description (including description of impacts outside of wetland resource area & buffer zone) b. r Photographs representative of the site c. F- MESA filing fee (fee information available at: h : / /www.mass. ov /eea/a encies/ 1I." dfw /natura - en , u! &(A review /Fisra s. dan ered -s ecies- act - mesa/mesa- fee- schedule.html ) Make check payable to "Natural Heritage & Endangered Species Fund" and mail to NHESP at above address Projects altering, 10 or more acres of land, also submit: d. F Vegetation cover type map of site e, F- Project plans showing Priority & Estimated Habitat boundaries d. OR Check One of the following I. f- Project is exempt from MESA review. Attach applicant letter indicating which MESA exemption applies. (See 321 CMR 10. 14, h : / /www.mass. ov /eea/a encies/df dfw /laws -re ulations/cmr 321 -emr- 1000- massachusetts -endan ered- Page 4 of 7 * ELECTRONIC COPY Massachusetts Department of Environmental Provided by MassDEP: Protection MassDEP File #: L WPA Bureau of Resource Protection - Wetlands eDEPTransaction4:931321 City/ own:LEX[NGTON Fora 3 - Notice of Intent M Massachusetts Wetlands Protection Act M.G.L. c. 131, §40 soecies- ac t.html #10.14; the NOI must still be sent to NHESP if the project is within estimated habitat pursuant to 310 CMR 10.37 and 10.59.) 2. f Separate MESA review ongoing. a. NHESP Tracking Number b. Date submitted to NHESP 3. r Separate MESA review completed. Include copy of NHESP "no Take" determination or valid Conservation & Management Permit with approved plan. * Some projects not in Estimated Habitat may be located in Priority Habitat, and require NHESP review... 2. For coastal projects only, is any portion of the proposed project located below the mean high waterline or in a fish run? a. 9— Not applicable - project is in inland resource area only b. [—Yes F- No If yes, include proof of mailing or hand delivery of NOI to either: South Shore - Cohasset to Rhode Island, North Shore - Hull to and the Cape & Islands: New Hampshire: Division of Marine Fisheries - Southeast Marine Fisheries Station Attn: Environmental Reviewer 1213 Purchase street - 3rd floor New Bedford, MA 02740 -6694 Division of Marine Fisheries - North Shore Office Attn: Environmental Reviewer 30 Emerson Avenue Gloucester, MA 01930 If yes, it may require a Chapter 91 license. For coastal towns in the Northeast Region, please contact MassDEP's Boston Office. For coastal towns in the Southeast Region, please contact MassDEP's Southeast Regional office. 3. Is any portion of the proposed project within an Area of Critical Environmental Concern (ACEC)? I " If yes, provide name of ACEC (see instructions to WPA Form 3 or a. Yes FYI No DEP Website for ACEC locations). Note: electronic filers click on Website. b. ACEC Name 4. Is any portion of the proposed project within an area designated as an Outstanding Resource Water (ORW) as designated in the Massachusetts Surface Water Quality Standards, 314 CMR 4.00? a. F Yes Fv No 5. Is any portion of the site subject to a Wetlands Restriction Order under the Inland Wetlands Restriction Act (M.G.L.c. 131, § 40A) or the Coastal Wetlands Restriction Act (M.G.L.c. 130, § 105)? a. F Yes iw No 6. Is this project subject to provisions of the MassDEP Stormwater Management Standards? a. Fv Yes, Attach a copy of the Stormwater Report as required by the Stormwater Management Standards per 310 CMR 10.05(6)(k) -(q) and check if, I. Applying for Low Impact Development (LID) site design credits (as described in Stormwater Management Handbook F Vol.2, Chapter 3) p _ A Imitioii rwl"fhe rilecurblil Ines ,i?odev "elol °m witt Page 5 of 7 * ELECTRONIC COPY Massachusetts Department of Environmental Provided by MassDEP: Protection Mas$DEP File #: Bureau of Resource Protection - Wetlands eDEP Transaction #:931321 L WPA Form 3 - Notice of Intent city/-Iown:LExINGTON Massachusetts Wetlands Protection Act M.G.L. c. 131, §40 Proprietary BMPs are included in the Stormwater Management System b. r No, Explain why the project is exempt: M ,'-An le f'anul Home ome 2. Emergency Road Repair F_ 3. Small Residential Subdivision (less than or equal to 4 single - family houses or less than or equal to 4 units in multi - family F housing project) with no discharge to Critical Areas. D. Additional Information Applicants must include the following with this Notice of Intent (NOI). See instructions for details. Online Users: Attach the document transaction number (provided on your receipt page) for any of the following information you submit to the Department by regular mail delivery. . USGS or other map of the area (along with a narrative description, if necessary) containing sufficient information for the W Conservation Commission and the Department to locate the site. (Electronic filers may omit this item.) 2. Plans identifying the location of proposed activities (including activities proposed to serve as a Bordering Vegetated Wetland W [BVW] replication area or other mitigating measure) relative to the boundaries of each affected resource area. 3. Identify the method for BVW and other resource area boundary delineations (MassDEP BVW Field Data Form(s). W, Determination of Applicability, Order of Resource Area Delineation, etc.), and attach documentation of the methodology, 4. List the titles and dates for all plans and other materials submitted with this NOI. W, a. Plan Title: b. Plan Prepared By: c. Plan Signed /Stamped By: c, Revised Final Date: e. Scale: PLAN SET CONSISTING OF 30 ENGINEERING GPR, INC, DOUGLAS MILLER, P.E. 7/17/2017 VARIES PLANS AND DETAIL SHEETS LANDSCAPE PLANS FISHER DESIGN AND DETAILS - 3 GROUP DAVID FISHER, RLA 7/17/2017 VARIES SHEETS S. If there is more than one property owner, please attach a list of these property owners not listed on this form. 1,.. 6. Attach proof of mailing for Natural Heritage and Endangered Species Program, if needed. I_., 7. Attach proof of mailing for Massachusetts Division of Marine Fisheries, if needed. C 8. Attach NOI Wetland Fee Transmittal Form. r 9. Attach Stormwater Report, if needed. Page 6 of 7 * ELECTRONIC COPY Massachusetts Department of Environmental Provided by MassDEP: LI Prote ction MassDEP File Bureau of Resource Protection - Wetlands eDEP Transaction #:931321 City/Town:LEXINGTON WPA Form 3 - Notice of Intent Massachusetts Wetlands Protection Act M.G.L. c. 131, §40 E. Fees. I Fee Exempt No filing fee shall be assessed for projects of any city, town, county, or district of the Commonwealth, federally recognized Indian tribe housing authority, municipal housing authority, or the Massachusetts Bay Transportation Authority. Applicants must submit the following information (in addition to pages I and 2 of the NOI Wetland Fee Transmittal Form) to confirm fee payment: 2. Mun i al Check Number - 3. Ch c date. 4. Slate Check Number 5. Check date Cpl N 1 &4 ivies r t !1wt e 6. Payer name on cbe : First Name 7. Payer name on check Last Name F. Signatures and Submittal Requirements I hereby certify under the penalties of perjury that the foregoing Notice of Intent and accompanying plans, documents, and supporting data are true and complete to the best of my knowledge. 1 understand that the Conservation Commission will place notification of this Notice in a local newspaper at the expense of the applicant in accordance with the wetlands regulations, 310 CMR 10.05(5)(a). I further certify under penalties of perjury that all abutters were notified of this application, pursuant to the requirements of MG.L, c. 131, § 40. Notice must be made by CIrtificate of Mailing or in writing by hand delivery or certified mail ('return receipt requested) to all abutters within 100 feet of the property line of e Project lot it Nif t S,grlature 3. Signature of Property &AncNir V L 11 a (.10 of Representative (if any) For Conservation Commission: m Date 4. Date 6 Dare Two copies of the completed Notice of Intent (Form 3), including supporting plans and documents, two copies of the Not Wetland Fee Transmittal Form, and the city/town fee payment, to the Conservation Commission by certified mail or hand delivery. For MassDEP: One copy of the completed Notice of Intent (Form 3), including supporting plans and documents, one copy of the NOI Wetland Fee Transmittal Form, and a copy of the state fee payment to the MassDEP Regional Office (see Instructions) by certified mail or hand delivery. r Other: If the applicant has checked the "yes" box in Section C, Items l above, refer to that section and the Instructions for additional submittal requirements. The original and copies must be sent simultaneously. Failure by the applicant to send copies in a timely manner may result in dismissal of the Notice of Intent. Page 7 of 7 * ELECTRONIC COPY O!H...'I O. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent ATTACHMENT A - PROJECT NARRATIVE 1.0 INTRODUCTION Symmes Lifecare d /b /a Brookhaven at Lexington, Inc. (Brookhaven) owns property shown on Lexington Assessors Map 5, Parcels 5 -16A, 5 -19C, 5 -20, and 5 -21A. These four properties contain a total of approximately 32.14 acres. A Site Locus Plan is provided as Figure 1. Brookhaven was incorporated in December 1984 as a Massachusetts Not - for - Profit corporation to meet the housing and health care needs of the elderly. It acquired 26 acres (Parcel 5 -16A) of property at 1010 Waltham Street, which was subsequently rezoned by Town Meeting in 1986 to an RD Planned Residential District, enabling Brookhaven to become a full- service life care retirement community. In 1987, following Town Meeting approval, the Zoning Board of Appeals approved a retirement community of 205 dwelling units with 41 -bed nursing care units and 316 parking spaces. Special permits for minor deviations of the Brookhaven RD were approved in 1994 (8 additional nursing care beds) and in 1999 (nine units of assisted care). In 2004, Brookhaven obtained Town Meeting approval to add a cluster of 48 independent living units while repurposing 6 existing independent living units, adding 11 assisted care units, and creation of additional space for a Health and Wellness Center. The current facility totals 240 independent living units, 20 assisted care units and 49 beds in the Nursing Center. In 2012, Brookhaven acquired adjoining property at 960 and 990 Waltham Street, consisting of approximately 6 acres (Parcels 5 -19C, 5 -20 and 5 -21A). In 2013, Brookhaven appeared before the Conservation Commission seeking approval to excavate lead based paint- impacted soil associated with the former greenhouse use of the property and located within Bordering Vegetated Wetland (BVW) and associated buffer zone. The Lexington Conservation Commission issued an Order of Conditions under file number 201 -912, and issued a Certificate of Compliance upon completion of the work. As you may recall, Brookhaven and its engineering team met with the Conservation Commission in 2015, 2016 and 2017 to discuss the project prior to the 2017 Town Meeting. In March 2017, the Lexington Town Meeting approved a zoning change for Parcels 5 -16A, 5 -19C. 5 -20 and 5 -21A from RD and RO zoning districts to a Planned Development District (PDD -1). The PDD -1 involves the construction of a new building (North Building) comprising 49 Independent Living units, and expansion of the existing Commons Building along with associated access drives, parking, utilities, landscaping and sidewalks. After construction of the proposed project, the Brookhaven facility will include 289 Independent Living units, 50 Assisted Care units and 12 Nursing Care beds for a total of 351 units with 422 parking spaces. Construction of the proposed project will include activities within Bordering Vegetated Wetland (BVW), and buffer zone to the BVW. The project will include activities near an intermittent stream (Chester Brook) and land shown on FEMA Flood Map #25017C0411E as Zone X. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 2.0 EXISTING CONDITIONS The Subject Property is located on the easterly side of Waltham Street south of Concord Road. The Subject Property comprises four parcels shown on the Lexington Assessors' Map 5, Parcels 16A, 19C, 20 and 21 -A (see Figure 1— Site Locus). These four parcels comprise a total of approximately 32.14 acres of land. The existing Brookhaven campus is located on Parcel 16A. The three recently acquired lots are located to the north of Parcel 16A and total roughly 6 acres. The Subject Property is located north of and abutting the Waltham City Line in an area of dense residential and commercial development, south of residential and commercial areas in Lexington, east of Waltham Street, and west of land owned by the Town of Lexington. Town of Lexington Topographic Map is provided as Figure 2 — Topographic Map. Flood zone map of the project vicinity is shown on Figure 3 — Flood Map. Portions of the project area are located within Zone X — minimal to moderate flood hazard with a 0.2% annual possibility of occurrence, otherwise known as the 500 -year storm, which would not be considered as Bordering Land Subject to Flooding. On the recently acquired parcels, a moderately dense canopy consists primarily of red maple (Acer rubrum), white ash (Fraxinus americana), black cherry (Prunus serotina), Norway maple (Acer platanoides), smooth sumac (Rhus glabra), and slippery elm (Ulmus rubra). The understory and shrub layers are comprised of saplings from the canopy, Japanese honeysuckle (Lonciera japonica), common blackberry (Rubus allegheniensis), eastern white pine (Pinus Strobus), Japanese barberry (Berberis thunbergii), eastern hemlock (Tsuga canadensis), oriental bittersweet (Celastrus orbiculatus), poison ivy (Toxicodendron radicans), and multiflora rose (Rosa multiflora). Observed ground cover species include seedlings from the canopy and understory, hay- scented fern (Dennstaedtia punctilobula), Japanese knotweed (Polygonum cuspidatum), and small - flowered crowfoot (Ranunculus arbortivus). Much of the existing vegetation at the Site consists of invasive species of limited value. Applied Ecological Sciences (AES) conducted a habitat assessment at the Project Site on December 8, 2015. Specifically, the northern - forested portion of the Site was traversed on foot and general observations were made about landscape features, cover types and existing habitat. White tailed deer (droppings) and gray squirrels were observed during the evaluation. Topography of the Site slopes gently to steeply southerly with extensive ledge outcrops and numerous surface stones and boulders evident throughout. Residential development abuts the Site to the north. Town of Lexington conservation land lies to the east. According to the Massachusetts Natural Heritage and Endangered Species Program (NHESP) 2008 habitat map, the Site is not located within an "Estimated Habitat of Rare Wildlife" or a "Priority Habitat of Rare Species" (see Figure 4 — Estimated Habitat Map). 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent No trees with large cavities ( >18" tree diameter at cavity entrance) were observed. Several large oaks are present on the Site; however, no evidence of nesting activity was observed. The Site does not appear to offer suitable turtle nesting habitat due to the preponderance of ledge at or near the surface. No vertical sandy banks suitable for barn swallows, rough- winged swallows or kingfishers were observed. No burrowing activity in- ground and in voids in ledge was observed. Fieldstone walls traverse the southern and eastern portions of the Site and can provide habitat for small mammals such as mice, chipmunks, etc. In general, the Site does not provide significant habitat opportunities. Nonetheless, Brookhaven will utilize existing fieldstone walls for construction of a wall along the northerly side of the trail east of the access drive. Brookhaven will develop and implement an invasive species control program to be implemented after construction of the Project. Based on the limited habitat opportunities, the reconstruction of fieldstone walls, and implementation of an Invasive Species Management Plan, the Project will have no significant deleterious effects on wildlife habitat. The existing Brookhaven campus was initially constructed in the late 1980s with several modifications having been made over the years. The recently acquired parcels were previously used for commercial green house space; the greenhouse business was discontinued in the early 2000s and the greenhouses were subsequently demolished. The parcels also contained two residential dwellings, which have also been demolished. In 2013, Brookhaven filed an NOI with the Lexington Conservation Commission to allow excavation and off -Site disposal of lead - impacted soil resulting from the historical application of lead based paint to the greenhouse structures. The work included alteration and restoration of approximately 2,600 square feet of BVW and removal of a decrepit structure previously used to house pump equipment for the greenhouses. The work was tracked under MassDEP File No. 201 -912. The Lexington Conservation Commission issued a Certificate of Compliance for the project in 2016. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 3.0 WETLAND RESOURCE AREAS Wetland resource associated with the Site includes the following: Bordering Vegetated Wetland and Buffer Zone A Site evaluation was conducted at the above referenced property on April 11, 2012. Wetland resource areas protectable under the Massachusetts Wetlands Protection Act (M.G.L. c. 131, § 40), the implementing Regulations (310 CMR 10.00), and the Code of the Town of Lexington for Wetland Protection, Chapter 130 were identified and characterized. Additionally, the upland /wetland boundary of BVW was confirmed, flagged and located in the field based on a wetland delineation approved on July 25, 2006 as shown on plan entitled: Existing Conditions, prepared by Kallstrom Landscape Architects dated 7 February 2008. The upland /wetland boundary was informally reviewed with Ms. Karen Mullins, Conservation Agent, in May 2017. Mr. Russell Waldron, wetland scientist from Applied Ecological Sciences (AES), subsequently evaluated portions of the wetland boundary in detail. Five wetland flags were relocated based on Mr. Waldron's evaluation. Wetland sheets are provided in Attachment K. The wetland boundary is shown on the Permit Drawings (Attachment E). Inland Bank Inland Bank is present on the property associated with Chester Brook, an intermittent stream. The designation of Chester Brook was made by the Lexington Conservation Commission as part of a filing by Lyman Property Holdings under File No. 201 -724, BL 681 based on a Positive Determination of Applicability issued by the Lexington Conservation Commission on January 26, 2006, which found that the stream was intermittent. Vernal Pool A NHESP- certified vernal pool is located on abutting Town of Lexington property. The limits of the vernal pool along with its buffer zone are shown on the engineering drawings. Additional Findings Based on the Federal Emergency Management Agency Flood Insurance Rate Map for the town of Lexington, Massachusetts (Community Panel 25017CO411 E), portions of the property are located within Zone X. This area would not be considered as Bordering Land Subject to Flooding. According to the 2008 edition of the Massachusetts Natural Heritage Atlas, the Site is not located within an Estimated or Priority Habitat of Rare Species. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 4.0 PROPOSED WORK The main components of the proposed project include the construction of the North Building with 49 Independent Living units on the recently acquired property (total six acres at 960- 990 Waltham Street), the expansion of the existing Commons Building, and the construction of an access roadway to connect the two buildings along with the associated access drives, parking areas, utilities, landscaping, and sidewalks. The proposed project will also include the installation of Stormwater Best Management Practices (BMPs) that are further explained in the Stormwater Management Report provided as Attachment F. Brookhaven and its engineering team have met with the Lexington Conservation Commission and staff in 2015, 2016, and 2017, prior to the 2017 Town Meeting, to discuss the proposed project. The proposed project has been designed to avoid and minimize impact to the wetland resource areas, including the BVW and inland bank, to the greatest extent possible. The activities stated above subject to the Commission's jurisdiction are limited to: • Altering 513 square feet of bordering vegetated wetlands (BVW); • Altering 7,685 square feet of area within the 25 -foot buffer zone to BVW including 1,132 square feet of BVW replication; • Altering 85,305 square feet of area within the 100 -foot buffer zone to BVW; • Altering 77 square feet within the buffer zone to a vernal pool; and, • Temporary alteration of 15 linear feet of bank to an Intermittent Stream. The main project components are further described below. 4.1 North Building The proposed North Building consists of a multi -story building with 49 Independent Units and an underground garage. The proposed building will be constructed into the hillside of the property, with the garage below the surface. The garage entrance is located along the westerly building face leading to the underground garage located on the northern side of the building. The garage is partially located under the proposed building. The proposed building comprises three stories under the southern portion of the underground garage. A landscaped plaza consisting of a vegetated roof with pavers, common terraces, and planters will be located above the northern portion of the underground garage. The south side of the building will consist of five stories with units, common areas, and the main entrance. The main entrance for the North Building will be in the center of the building and accessed through the south side. The access drive will extend from the outer ring road of the existing Brookhaven Campus, north across Chester Brook and thence westerly in front of the south side of the building. The Chester Brook crossing will consist of a 31 -foot 6 -inch aluminum arch culvert spanning the brook. The access road will be faced with Redi - Rock'" pre -cast segmental retaining walls in order to reduce the extent of work within wetland jurisdictional areas. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent Emergency access for the North Building will be in the northwest corner of the Property from Waltham Street with an access drive running west to east along the north side of the building with a fire truck turnaround. A sidewalk will run parallel to the main access drive and connect to a trail running along the east side of the building. Paved parking areas will be located east and southeast of the building. The parking areas consist of 22 parking spaces and four handicap parking spaces. Stormwater BMPs associated with the North Building include five Stormwater infiltration recharge chamber facilities surrounding the building, four deep sump catch basins along the access way, two infiltration basins (west and east basins) and two sediment forebays located southeast of the access way. A six -foot walking trail will be developed surrounding the infiltration basins, connecting Waltham Street to the sidewalk /trail system. Further information of the Stormwater BMPs are available in Attachment F and Attachment H. Proposed work associated with the south side of the North Building will be located within the 25 -foot and 100 -foot buffer zone to BVW. The proposed work within the 25 -foot buffer zone includes the retaining wall and portions of the access road south of the North Building. The proposed work within the 100 -foot buffer zone includes the south -east and east portion of the North building, the adjacent paved access drive and parking area, the east infiltration basin, the southeast infiltration facility, and the main entrance shuttle bus turnaround. 4.2 Expansion of Existing Commons Building The proposed work for the existing Commons Building consists of a multi -story expansion building. The addition will include assisted care units and nursing units. Commons areas and bathrooms will also be provided. A paved access drive (Commons Drive) will run west to east along the north side of the Commons Building expansion. The access drive will connect to the existing main entrance way connecting to Waltham Street, located west of the building. A shuttle bus turnaround will be located northeast of the expansion. Parking areas will be located south of the access ways and will consist of 17 parking spaces. An additional parking area will be located east of the expansion building and consist of 20 parking spaces. A sidewalk will run parallel to the access drive to the parking areas and along the west towards the wellness courtyard and east towards the garden courtyard. A retaining wall with wood guardrail will run along the north side of the paved access drive. Storm water BMPs associated with the Commons Building expansion include two storm water infiltration recharge chambers; one located east and the other located west of the building, modification and expansion of an existing storm water detention basin located northwest of the building, , five SiltPrisonT"^ catch basins along the northern access way, and two deep -sump catch basins in the wellness courtyard. Further information of the Stormwater BMPs is available in Attachment F and Attachment H. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent Proposed work associated with the northwest corner of the Commons Building expansion, the northern access drive, and parking areas are located within the 100 -foot buffer zone to the BVW. Proposed work associated with the northern retaining wall and portions of the sidewalks along the paved access drive are located within the 25 -foot buffer zone to the BVW. These activities will not alter the adjacent BVW located north of the Commons Building expansion. Minor work is proposed within the buffer zone to a NHESP- certified vernal pool located on adjacent property owned by the Town of Lexington. The limit of work is within areas previously developed by Brookhaven and consists of minor relocation of the sidewalk. 4.3 Connecting Access Drive The proposed project includes an access drive connecting the North Building to the Commons Building. The access drive will run north to south over an existing intermittent stream, Chester Brook. A 31 -foot 6 -inch aluminum arch culvert will span the intermittent stream. The purpose of the culvert is to maintain the current hydrologic conditions controlled by an existing culvert, and to minimize BVW impact. A five -foot sidewalk will run parallel to the access drive, over the culvert. Retaining walls with guardrails will line the east and west sides of the access drive. Two pavilions will be located north and south of the access way to aid residents using the sidewalks. The proposed work associated with the access drive will be located within the 25 -foot zone to BVW and will alter approximately 513 square feet of BVW. Brookhaven proposes on -Site replication totaling 1,132 square feet resulting in greater than 2:1 ratio of replication to the impacted area upon completion of the work. The proposed access drive will cross the BVW in an area that has undergone prior alteration primarily associated with the historical greenhouse use; therefore, the proposed access drive will minimize impact to the BVW to the greatest extent possible. For an alternatives analysis refer to Section 4.4 below. 4.3.1 Access Alternatives Analysis Alternative methods for access to the north building were analyzed to ensure that the proposed access drive has minimal environmental impacts. A description of the alternatives analyzed is provided below. Alternative #1 - Access via Waltham Street Waltham Street runs north to south along the western border of the Property. The existing entrance /exit to the current Brookhaven facility is located in the northwest corner of the 1010 Waltham Street lot (Parcel 5- 16A). Under this alternative, access to the proposed North Building would be in the northwest corner of the 960 Waltham Street lot (Parcel 5 -21A). The proposed access would be utilized as an emergency access entrance and would lead to a fire truck turnaround area. The proposed access drive would not involve work within the BVW or within the 25 -foot or 100 -foot buffer zone to BVW. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent The alternative includes utilizing Waltham Street as the access between the North Building and Commons Building. Waltham Street is a main arterial roadway as the two - lane road connects the Lexington Town Center with neighboring centers for Waltham, Bedford, and Woburn; Waltham Street can experience significant traffic volumes. The distance between the existing entrance /exit and the proposed access would be approximately 440 -feet along Waltham Street. Alternative #2 - Access via Westerly Access Road Alternative #2 layout for the access drive would run parallel to and approximately 150 feet east of Waltham Street, in the western portion of the BVW. • The proposed Alternative #2 would impact approximately 650 square feet of BVW and 3,800 square feet of area within a relatively undisturbed portion of the 25 -foot buffer zone. Alternative #3 - Access via Easterly Access Road Access drive would run parallel to and approximately 750 feet east of Waltham Street, in the eastern portion of the BVW. The proposed access drive would impact approximately 513 square feet of BVW and 7,685 square feet of area within the 25 -foot buffer zone. 4.3.2 Access Selection Waltham Street serves as an arterial roadway and can experience significant traffic volumes. The likelihood for accidents by drivers utilizing the roadway for access between buildings would increase. While Alternative #1 does not impact the BVW, the alternative is not safe for the staff and residences that require access to both buildings and to the public using Waltham Street. Therefore, Alternative #1 is not viable. The layout of Alternative #2 would result in the disturbance of BVW and Buffer Zone in an area that is presently relatively undisturbed when compared to Alternative #3. The proposed layout of Alternative #3 would cross at an existing footpath and concrete culvert. The land was also previously disturbed during the former greenhouse use of the property. The Alternative #3 layout of the proposed access drive would have the least impact given the previous and current use of the area and would limit the impact to BVW areas while allowing safe use and access between the new North Building and the existing Brookhaven campus. Therefore, Alternative #3 was chosen for access between the new North Building and the existing Brookhaven campus. 4.3.3 Evaluation of Existing Stone Culvert The selected access drive will cross over an existing stone culvert. The crossing will be configured as an aluminum arch culvert. At the request of a member of the Lexington Conservation Commission made during discussions prior the March 2017 Town Meeting, 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent other measures for the crossing were evaluated. The request was predicated on using the proposed crossing work to improve the existing culvert and bank. The existing stone culvert exerts control over the hydrologic regime of Chester Brook both upstream and downstream of the crossing. If the culvert were to be removed and the bank of the intermittent stream modified to reflect conditions downstream of the culvert, it is likely that the upstream wetland would be dewatered with significant disturbance to the resource area. To maintain hydrologic conditions, the existing culvert would need to be replaced by a flow control structure, such as cast -in -place concrete orifice with overflow weir. Design of the structure may mimic hydrologic conditions; however, specifically matching the operating characteristics of the existing culvert would be extremely difficult. Deviation from the characteristics of the existing culvert would likely result in a change in the hydrologic regime with associated impacts to the wetland system. Further, the work to construct such a control structure would require a greater level of disturbance to the resource area when compared to simply spanning the area with an aluminum arch culvert as now proposed. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 5.0 WETLAND REPLICATION PLAN 5.1 Harvesting Leaf litter will be collected from the property from uncontaminated areas outside of the buffer zone and stockpiled for use in the restoration. A sufficient volume of leaf litter will be harvested to provide soil amendments to wetlands soil and to provide leaf litter in the wetland. O, A, and B horizon soils will be harvested from the property outside of or deeper than contaminated areas and outside of the buffer zone and stockpiled for re -use in the buffer zone and wetland restoration. Harvesting local soils will aid in the reconstruction of the wetland and buffer soils, as they are likely to contain indigenous seeds and similar geochemistry as the soils within the excavation areas. The horizons will be stockpiled separately for re -use in proper sequence and will be kept moist. The harvested areas are outside of the buffer zone and will later be backfilled with common borrow. Downed limbs and trees will also be collected from the property outside of the buffer zone and soil excavation area. Downed limbs will be stockpiled for future use. Once during wetland restoration, limbs and downed trees will be placed sporadically throughout the restoration area. Live plants in the upland area, outside of the buffer zone and impacted areas may also be harvested for transplantation in the restoration area. Site plants may be used in conjunction with purchased plants. Transplanting will be limited to plants outlined in the Plant Materials Guide for Lexington, MA 2011 Edition. Harvesting and transplanting will be done on the same day. 5.2 Reconstruction Once the soil removal is complete, restoration will begin. The wetland will be rebuilt first followed by the buffer zone. The O, A, and B horizons will be rebuilt in the restoration areas to approximately match existing grades, thicknesses and compositions of those layers using materials harvested from the property or newly acquired materials, as needed. The top several inches of the C- horizon may be rototilled to loosen the soil or mixed to form a 13-horizon if needed. The horizons will be reconstructed as loosely as possible and will be rototilled if they become too compact. Soil for the O horizon will be made up of a mix of screened loam (60% max) and peat moss (40% minimum). After excavation of impacted soil and replacement is completed, the disturbed area will be hydro- seeded and /or hand sown with Conservation Seed Mix and Wetland Seed Mix (see attached specification sheets — Attachment B). Planting of trees, shrubs and groundcover will begin at the start of the next growing season. Cinnamon fern plugs will be planted randomly throughout the wetland. A jute mat or similar biodegradable erosion control matting may be utilized to ensure the stability of the reconstructed area. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent Buffer zone plants including deciduous canopy trees, deciduous shrubs and groundcovers will be placed through -out the buffer zone restoration at random locations to provide soil stability and to establish vegetative cover. Native species outlined below will be used. These species were selected from the Plant Materials Guide for Lexington, MA 2011 Edition. Several plants indigenous to the property may also be harvested from upland areas outside of the buffer zone for re -use within the reconstruction area. TYPE Number Deciduous Canopy Trees Red Maple 2 -2.5 "cal 6' -7' (Acer Rubrum) 4 Deciduous Shrubs Highbush Blueberry 3 -gal pot (Vaccinium corymbosum) 8 Sweet Pepper Bush 3 -gal pot (Clethra alnifolia) 4 Groundcovers Wintergreen #1 pot (Gaultheria procumbens) 10 Wetland Species 0 " -6" Water Shallow Marsh Cinnamon Fern plug (Osmunda cinnamomea) 10 Grasses /Sedges New England Wet Mix (18 # /ac) New England Conservation Wildlife Mix (25 # /ac) 5.3 Watering and Maintenance Once planted, small amounts of water (less than 500 gallons per event) will be withdrawn from the existing intermittent stream by pump at less than 5 gallons per minute to water the plantings twice per week for the first two weeks and weekly thereafter for five weeks. Watering schedules may be altered based on weather conditions. If precipitation occurs more than twice per week, watering may be discontinued. If severe drought conditions occur, watering frequency may increase and water may be delivered to the site to maintain the larger plantings to the extent feasible. Long -term maintenance and /or mowing of the excavation area is not proposed. 5.4 Inspection During harvesting, impacted soil removal, restoration, and planting, a scientist will be on -site periodically to inspect the completion of work. A scientist will inspect the site one month after planting, at the end of the first growing season, the spring of the second growing season, and the end of the second growing season. At the end of the second growing season, if the vegetation is established and the restoration appears stable, OHI will request an inspection by the ConCom for a Certificate of Compliance (COC). At any point during the first two years that the portions of the plantings appear to be failing additional restoration and planting may occur. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 6.0 STORMWATER MANAGEMENT A proposed Stormwater Management System (SMS) has been designed for the project. The SMS will meet or exceed current MassDEP Stormwater Standards and the requirements of the Lexington Wetland Protection bylaw. The SMS will collect, convey and treat runoff from the project site and will mitigate peak runoff rates and runoff volume, in accordance with the regulations, such that post - development conditions will not exceed pre - development conditions. Detailed calculations for the SMS are provided in Attachment F. 6.1 Project Type Construction of the proposed project will include activities within BVW and buffer zones to the BVW. The project will include activities near an intermittent stream (Chester Brook) and land shown on FEMA Flood Map as Zone X. A SMS has been designed following the current MassDEP Stormwater Standards and the required Lexington Wetland Protection bylaw stating strategies to be implemented during construction so post - development conditions do not exceed pre - development conditions. The MassDEP Stormwater Standards are further explained below. 6.2 Standard 1 — No New Untreated Discharges The project will not result in any new Stormwater conveyances that may discharge untreated Stormwater directly to or cause erosion to the nearby wetlands or waters of the Commonwealth. Stormwater runoff will be conveyed to Stormwater management controls including infiltration basins, infiltration recharge chambers, catch basins, deep sump catch basins, sediment forebays for water quality treatment, and runoff rate attenuation prior to discharge to adjacent wetlands. Therefore, the requirements of Standard 1 are met. 6.3 Standard 2 - Peak Rate Attenuation Peak rate of discharge after development of the project is equal to or less than the pre - development conditions. Furthermore, the project will not result in an increase in the 1 -year 24 -hour design storm volume of Stormwater discharged from the Site after development, in accordance with the Lexington Wetland Protection Code. The SMS will control post - development peak discharge rates for the 2 -, 10 -, and 100 -year, 24 -hour storms to maintain pre - development peak discharge rates. Therefore, the requirements of Standard 2 are met. The standard further explained in 310 CMR 10.04 referring to the discharge to land subject to coastal storm flowage is not applicable; therefore, the standard is not waived. 6.4 Standard 3 - Annual Recharge to Groundwater A proposed SMS has been designed for the proposed project. The SMS is designed to infiltrate the required recharge volume as determined in accordance with the Massachusetts Stormwater Handbook. Infiltration Best Management Practices (BMPs), including the 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent construction of a Stormwater detention system, infiltration basins, sediment forebays, infiltration recharge chambers, catch basins, and deep sump hooded catch basins, will be taken to eliminate and /or minimize the loss of annual recharge to groundwater. The annual recharge post- development shall approximate the annual recharge from pre - development. A copy of the SMS with the applicable calculations is provided in Attachment F. Therefore, the requirements of Standard 3 are met. 6.5 Standard 4 — Water Quality The proposed project will meet the water quality requirements set in Standard 4 by using several on -site treatment controls to remove at least 80% of the average annual post - construction load of Total Suspended Solids (TSS). According to the MassDEP Stormwater Management Standards, Standard 4 is met when: • Suitable practice for source control and pollution prevention are identified in a long- term pollution prevention plan, and thereafter are implemented and maintained; • Structural Stormwater best management practices are sized to capture the required water quality volume determined in accordance with the Massachusetts Stormwater Handbook; and • Pretreatment is provided in accordance with the Massachusetts Stormwater Handbook. All proposed Stormwater BMPs would be operated and maintained to ensure continuous water quality treatment of runoff. A Site Owner's Manual will be available during and post - development to ensure continuous maintenance of the BMPs and the control and pollution prevention measures following development. The manual will comply with the Long -Term Pollution Prevention Plan and the Long- Term Operation and Maintenance Plan required by the MassDEP Stormwater Management Standards. Structural BMPs include catch basins, deep sump hooded catch basins, sediment forebays, water quality treatment systems, and infiltration basins and recharge chambers that have been sized to capture and treat the flow rate associated with the first 1.0 -inch of runoff from the proposed impervious surfaces. Therefore, the requirements of Standard 4 are met. 6.6 Standard 5 — Land Uses with Higher Potential Pollutant Loads The proposed project area does not consist of land with higher potential pollutant loads. No source controls or pollution prevention plans are noted in the SMS pertaining to higher potential pollutant loads. Therefore, the requirements of Standard 5 are not applicable to the proposed project. 6.7 Standard 6 — Critical Areas Stormwater does not discharge to a Zone II, Interim Wellhead Protection Area of a public water supply, Outstanding Resource Waters, Special Resource Waters, or any other critical area 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent requiring specific controls within the proposed project. Therefore, the requirements of Standard 6 are not applicable to the proposed project. 6.8 Standard 7 — Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable. The proposed project is not a redevelopment project; therefore, the requirements of Standard 7 are not applicable. 6.9 Standard 8 — Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan A National Pollutant Discharge Elimination System (NPDES) Construction General Permit will cover the project. A Stormwater Pollution Prevention Plan ( SWPPP) has been prepared and will be submitted to the EPA prior to commencement of any land disturbance activities. A copy of the SWPPP is provided as Attachment G. Therefore, the requirements of Standard 8 are met. 6.10 Standard 9 —Operation and Maintenance Plan The Stormwater operations and maintenance plan is provided as Attachment H. The plan includes procedures for snow management. Therefore, the requirements of Standard 9 are met. 6.11 Standard 10 — Prohibition of Illicit Discharges All illicit discharges to the Stormwater management system are prohibited. No detectable illicit discharge has been taken or will be taken place during the project development; therefore, the requirements of Standard 10 are not applicable to the proposed project. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 7.0 INVASIVE SPECIES MANAGEMENT Brookhaven at Lexington will implement invasive species management. Invasive species located on the site include garlic mustard (Alliaria petiolata), oriental bittersweet (Celastrus orbiculatus), multiflora rose (Rosa multiflora) and Japanese knotweed (Polygonum cuspidatum). 7.1 Garlic Mustard (Alliaria petiolata)' Goal: Preventing seed production and depleting the seed bank over time. All methods of weed control must be repeated annually for three to four years or more for optimal effectiveness. Primary methodologies: Prescribed burning, manual or mechanical techniques, herbicides, and post- treatment management. Prescribed burning: Used in large areas with significant garlic mustard densities where hand pulling or cutting is not efficient. The burn should take place before the majority of plants mature beyond the rosette stage to prevent plants from forming seeds. A mid - intensity, early spring fire, before native plants emerge, is ideal since spring fires destroy the future seed bank. Fall burning during the rosette stage can be very effective when leaf litter provides adequate fuel and native plants are dormant. Supplemental control measures can be applied until snowfall covers the ground. If the fire is not hot enough, the burned area presents the perfect disturbed habitat for garlic mustard invasions and surviving root crowns will send up flowers stalks and form seeds. Since population density will be low, each plant will produce an abundance of seeds and the disturbance will result in a high rate of seedling survival possibly resulting in an infestation greater than was present. • Manual: Used for small areas and includes weeding and cutting. The goal is to remove the seed heads. Ideally, remove the flower stalks just as the flowers begin to develop for maximum effectiveness. Viable seeds may be formed after the flower stalks are cut so completely remove and destroy all flowers, and seeds present. This technique causes significant soil disturbance, encourages seed sprouting from the seed bank and may impact nearby desirable plants through soil compaction or accidental destruction. A variation of this technique is to remove just the flowers and seed heads. The site will need to be scouted multiple times during the growing season for repeat treatments if flowers or seed heads reform. This method is useful if labor or time is short per outing but multiple outings are possible. This method reduces soil and desirable plant damage. Mechanical: Used during the second year of growth at the time the flower stalk is elongating and is more successful where the plants are already in stress such as during droughts or in 1 DNR, WI. Garlic Mustard (Alliaria petiolata). Invasive Plant Species Fact Sheet. 2004. Job Sheet Pest Management (797) . Revised Jan. 2007. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent drier areas. Involves cutting the stem at ground level with a weed eater, scythe, or other cutting tools. • Chemical: Can be effective for controlling large stands. Plants covered by leaf litter must be uncovered for the chemical treatments to work. Missed plants can repopulate and re- infest an area quickly. If applying near desirable plants, use paint brushes or wicks so only the target species is treated. • Post - treatment management: Garlic mustard invades bare soils, disturbed areas and floodplains usually starting at an edge or opening. Preventing seeds from spreading into such opportunistic habitats is the best management technique especially in protecting natural floodplains. Destroying the rosettes, flowers, seed heads, and seeds will have the greatest impact on reducing garlic mustard population growth rates. The size of the seed bank is related to the population age; thus timely treatment is important to stopping the spread of this plant. 7.2 Oriental bittersweet (Celastrus orbiculatUS)2 Primary methodologies: Manual /mechanical techniques, chemical, combination treatments, post- treatment management. • Manual /Mechanical: For light infestations, vines can be pulled or dug out by the roots and removed from the area. Fruiting vines should be bagged and landfilled. Cutting the vines without removing the roots or chemically treating the stems will stimulate regrowth. This method can be used in any season but preferably before the vines have fruited. • Chemical: Spray the foliage with an appropriate herbicide. Apply after the first hard frost in the fall or in early spring while most native plants are dormant but bittersweet is actively photosynthesizing. Sites should be monitored after treatment for regrowth. • Combination: Cut the vines low to the ground and apply an appropriate herbicide to the cut stumps. Treat in winter, early spring or fall, preferably when native plants are dormant and will be unaffected. Vines can also be cut and a foliar spray used later on the re- sprouts. • Post treatment management: Regular surveys of affected areas and re- treatment where necessary. 2 Forest Invasive Plants Resource Center. https: / /www.na.fs. fed. us/ spfo /invasiveplants /factsheets /pdf /oriental- bittersweet.pdf. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 7.3 Multiflora Rose (Rosa multiflora)3 Primary methodologies: Manual /mechanical techniques, chemical and combination treatments, post- treatment management. Manual /Mechanical: Mechanical and chemical methods are currently the most widely used methods for managing multiflora rose. In high quality natural communities, cutting of individual plants is preferred to site mowing to minimize habitat disturbance. Pulling or removing individual plants by hand is effective when plants are small. Special care should be taken to ensure that all roots are removed to prevent re- sprouting. If plants develop from severed roots these should be removed as well. Cutting is appropriate for small initial populations and for environmentally sensitive areas where herbicides cannot be used. Repeated cutting will control the spread, but will not eradicate it. Stems should be cut at least once per growing season as close to ground level as possible. For disturbed areas containing large populations of multiflora rose, mowing can provide partial control, by restricting top growth and spread. Mowing three to six times a year can be effective. The objective of a mowing program is to clear the existing vegetation and reduce the reproductive capacity of the below ground portions of the plant. • Chemical & Combination Treatments: Cut the stems low to the ground and apply an appropriate herbicide to the cut stumps. Treat in late spring /early summer and again in early fall. Control programs must be monitored and followed up if necessary by repeated herbicide application or used in conjunction with other control methods such as mowing or hand cutting with individual stem treatments. • Post treatment management: Regular surveys of affected areas and re- treatment where necessary. 7.4 Japanese Knotweed (Polygonum cuspidatum)4 Primary methodologies: Manual /mechanical techniques, chemical and combination treatments, post- treatment management. • Manual /Mechanical: Mechanical controls are effective for small initial populations or in environmentally sensitive areas where herbicides cannot be used and include grubbing or pulling seedlings, rhizomes, mature plants, and repeated clipping. Manual control takes special precautions because any live plant part (1/2 inch or larger) may sprout. Plant parts must be disposed of properly and must not be allowed to enter waterways. Stems and 3 Natural Resources Conservation Service. Pest Management — Invasive Plant Control, Multiflora Rose. Conservation Practice Job Sheet NH -314. https:// www. nres. usda. gov/ Internet /FSE _DOCUMENTS /nres144p2_014999.pdf. 4 Natural Resources Conservation service. Pest Management — Invasive Plant Control, Japanese Knotweed. Conservation Practice Job Sheet MN -797. https: / /efotg.sc.egov.usda.gov/ references / public /MN /797JapaneseKnotweed.pdf. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent roots must be contained or dried with little or no soil contact or they may sprout. Do not compost plant parts. Digging or pulling (uprooting) will eliminate a portion of the root system but not all. Pull the root crown and as much root as possible. Each time new sprouts are seen (look after a week and at least 20 feet from the plant) uproot them and get as much root as possible. This method is only feasible on very small patches. Because disturbed, open soil can support rapid invasion by other invasives, managers must monitor their efforts at least once per year and repeat control measures as needed. Limit soil disturbance whenever possible. Hand cutting, mowing or other methods must be applied every 2 -3 weeks from April through August. Cutting should continue after August but less frequently. Prevent plants from exceeding 6 inches in height. Again, dispose of plant parts properly or they will sprout. Covering with heavy plastics and geotextile fabrics has had some success but is costly and requires pulling, cutting or herbicide treatment near the edges. Cut stems to the ground surface and then cover the stand being sure to extend coverage at least 10 feet beyond the farthest stems. Weigh down the edges and monitor for sprouts. Leave the cover in place for at least two growing seasons. The treatments will need to continue for at least three years but probably much longer depending on the size of the patch. Manual control of knotweed is best suited to ecologically sensitive areas and isolated small patches where there is a commitment to avoid herbicide use. Chemical & Combination Treatments: Herbicide applications to knotweed must be carefully planned and implemented as the stands are typically near surface waters. Methods include spraying, wicking, injecting, and pouring. Integrating control techniques, such as cutting in the spring and applying herbicide in late summer may be a good alternative for the site. 1. Foliar Treatment: The best time to foliar spray is when the plants are 3 -6 feet tall. Follow up treatments will be required later in the growing season. Foliar applications appear to be a reasonably efficient approach (1 to 4 treatments over two seasons) to obtain control over small and medium size knotweed patches. Larger patches will often require treatment over several years and combinations of manual and chemical control methods. Do not cut down treated plants for at least a full growing season. 2. Cut Stem Treatment: Use this method in areas where plants are established within or around non - target plants or where vines have grown into the canopy. Cut the live stem about 2 inches above ground level (between the lowest nodes). Immediately apply an appropriate herbicide to the cross - section of the stem. A subsequent foliar application of glyphosate may be require for controlling new seedlings and re- sprouts. • Disposal: Stem and root fragments as small as 1/2 inch can sprout so special care must be taken to contain the plant parts when using manual control. Do not allow plant parts to 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent enter waterways during control. Limit soil contact when drying the plant parts. Small plants may be hung in trees to prevent re- rooting. Cut stems may be piled on a raised platform, brush pile or tarp for drying. Do not compost plant materials as they may sprout and then spread. Piles may be burned. Do not remove soil or plant material from the site unless being disposed of in a landfill. • Post treatment management: Regular surveys of affected areas and re- treatment where necessary. 7.5 Japanese Barberry (Berberis thunbergii)l Primary methodologies: Manual /mechanical techniques, chemical and combination treatments, post- treatment management. • Manual /Mechanical: Mechanical controls include grubbing or pulling seedlings and mature shrubs, and repeated clipping of shrubs. Repeated mowing or cutting will control the spread of Japanese barberry but will not eradicate it. Stems should be cut at least once per growing season as close to ground level as possible. Hand cutting of established clumps is difficult and time consuming due to the long arching stems and prolific thorns. Grubbing or pulling by hand is appropriate for small populations or where herbicides cannot be used. Barberry has shallow roots so small plants may be pulled relatively easily when the soil is moist. Because barberry can re- sprout from root fragments remaining in soil, thorough removal of root portions is important. Manual control works well but may need to be combined with chemical in large or persistent infestations. Because disturbed, open soil can support rapid re- invasion, affected areas should be monitored at least once per year and control measures repeated as needed. Limit soil disturbance whenever possible. Winter clipping should be avoided as it encourages vigorous re- sprouting. • Chemical & Combination Treatments: Chemical control methods are best done during the fall when most native plants are dormant yet invasive plants are still actively growing. This lessens the risk of affecting non - target plants. The barberry's green leaves will provide easy recognition and allow for a thorough treatment at this time. Winter application of chemicals has proven to be successful as well, and further lessens the risk of damaging non - target species. 1. Cut Stump Treatments: For 'cut stump' treatments, horizontally cut the stem near the ground. Leaving some stem will allow another cut and application if there is sprouting. This treatment is best applied late in the growing season when the plant is transporting nutrients to its root system (August- October). 5 Natural Resource Conservation Service (NRCS). Brush Management — Invasive Plant Control Barberries — Berberis sp. Conservation Practice Job Sheet NH -314. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 2. Foliar Treatments: The treatment should be applied to the foliage late in the growing season but can be applied early in the season to minimize non - target impacts. Do not cut down treated plants for at least a full growing season. • Post treatment management: Regular surveys of affected areas and re- treatment where necessary. Disposal: Small, pulled shrubs should be hung in trees to prevent re- rooting. Larger, pulled shrubs may be piled or piled and burned, roots up, to prevent re- establishment. Cut stems may be piled or piled and burned. If chipping, do not remove material from the site as barberry will spread by seeds. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 8.0 COMPLIANCE WITH REGULATIONS The proposed project is designed to meet all requirements set forth under the Massachusetts Wetlands Protection Act (M.G.L. c. 131, § 40), the implementing Regulations (310 CMR 10.00), the Code of the Town of Lexington for Wetland Protection, Chapter 130, and the Town of Lexington Rules. 8.1 General Performance Standards for Bordering Vegetated Wetland 310 CMR 10.55(4)(a) — Where the presumption set forth in 310 CMR 10.55(3) is not overcome, any proposed work in a Bordering Vegetated Wetland shall not destroy or otherwise impair any portion of said area. Construction of the proposed project will include activities within BVW, and buffer zones to the BVW. See 310 CMR 10.55(4)(b) below for further information. 310 CMR 10.55(4)(b) - Notwithstanding the provisions of 310 CMR 10.55(4)(a), the issuing authority may issue an Order of Conditions permitting work that results in the loss of up to 5,000 square feet of Bordering Vegetated Wetland when said area is replaced in accordance with the following general conditions and any additional, specific conditions the issuing authority deems necessary to ensure that the replacement area will function in a manner similar to the area that will be lost: 1. The surface of the replacement area to be created ( "the replacement area ") shall be equal to that of the area that will be lost ( "the lost area "); Activities during development propose the alteration of approximately 100 square feet of BVW. Brookhaven proposes on -Site replication with greater than 2:1 ratio of replication to the impacted area upon completion of the work. 2. The ground water and surface elevation of the replacement area shall be approximately equal to that of the lost area; The proposed replication area has been designed so that groundwater and surface elevations are approximately equal to those of the lost area. Elevations within the BVW that will be impacted range from elevations 219 feet to 223 feet Above Mean Sea Level (AMSL). 3. The overall horizontal configuration and location of the replacement area with respect to the bank shall be similar to that of the lost area; The replication area is located within the same wetland complex and hydrologic system as the impacted wetland resource. The site was selected to provide on -site wetland 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent mitigation. The replication area will be greater than 2:1 ratio of replication to the impacted area. 4. The replacement area shall have an unrestricted hydraulic connection to the same waterbody or waterway associated with the lost area; The proposed replication area will have an unrestricted hydraulic connection to the same, wetland area and intermittent stream associated with the BVW lost area. The unrestricted hydraulic connection will be similar to the existing groundwater and precipitation sources currently in place that contribute to the BVW area and the wetlands. 5. The replacement area shall be located within the same general area of the water body or reach of the waterway as the lost area; The proposed replication area will be located within the area of the BVW impact area. 6. At least 75% of the surface of the replacement area shall be re- established with indigenous wetland plant species within two growing seasons, and prior to said vegetative re- establishment any exposed soil in the replacement area shall be temporarily stabilized to prevent erosion in accordance with standard U.S. Soil Conservation Service methods; and the replacement area shall be provided in a manner which is consistent with all other General Performance Standards for each resource area in Part III of 310 CMR 10.00. A wetlands replication plan is provided in Section 5.0. The plan proposes that O, A, and B Horizon soils and leaf litter will be harvested from the property outside of buffer zone and stockpiled outside of the buffer zone for use in the restoration areas. Harvesting local soils will aid in the reconstruction of the wetland and buffer soils, as they are likely to contain indigenous seeds and similar geochemistry as the soils within the excavation areas. Live plants in the upland area, outside of the buffer zone and impacted areas may also be harvested for transplantation in the restoration area. Site plants may be used in conjunction with purchased plants. Transplanting will be limited to plants outlined in the Plant Materials Guide for Lexington, MA 2011 Edition. Buffer zone plants including deciduous canopy trees, deciduous shrubs and groundcovers will be placed through -out the buffer zone restoration at random locations to provide soil stability and to establish vegetative cover. Native species outlined below will be used. These species were selected from the Plant Materials Guide for Lexington, MA 2011 Edition. Several plants indigenous to the property may also be harvested from upland areas outside of the buffer zone for re -use within the reconstruction area. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 7. The replacement area shall be provided in a manner which is consistent with all other General Performance Standards for each resource area in Part III of 310 CMR 10.00. Construction of the replication area will occur in the buffer zones of the BVW. The replication areas will be provided in a manner that is consistent with all other General Performance Standards, and the Town of Lexington By -Laws and Rules. 310 CMR 10.55(4)(c) - Notwithstanding the provisions of 310 CMR 10.55(4)(a), the issuing authority may issue an Order of Conditions permitting work which results in the loss of a portion of Bordering Vegetated Wetland when; 1. Said portion has a surface area less than 500 square feet; 2. said portion extends in a distinct linear configuration ( "finger- like ") into adjacent uplands; and 3. in the judgment of the issuing authority it is not reasonable to scale down, redesign, or otherwise change the proposed work so that it could be completed without loss of said wetland. The impacted BVW area will be replicated in accordance with general conditions listed in the 310 CMR 10.55(4)(b). 310 CMR 10.55(4)(d) - Notwithstanding the provisions of 310 CMR 10.55(4)(a),(b) and (c), no project may be permitted which will have any adverse effect on specified habitat sites of rare vertebrate or invertebrate species, as identified by procedures established under 310 CMR 10.59. According to the 2008 edition of the Massachusetts Natural Heritage Atlas, the Site is not located within an Estimated Rare Wetland Wildlife Habitat as stated under 310 CMR 10.59. Therefore, the standard is not applicable. 310 CMR 10.55(4)(e) - Any proposed work shall not destroy or otherwise impair any portion of a Bordering Vegetated Wetland that is within an Area of Critical Environmental Concern designated by the Secretary of Energy and Environmental Affairs under M.G.L. c. 21A, § 2(7) and 301 CMR 12.00: Areas of Critical Environmental Concern. 310 CMR 10.55(4)(e): 1. supersedes the provisions of 310 CMR 10.55(4)(b) and (c); 2. shall not apply if the presumption set forth at 310 CMR 10.55(3) is overcome; 3. shall not apply to work proposed under 310 CMR 10.53(3)(1); and 4. shall not apply to maintenance of stormwater detention, retention, or sedimentation ponds, or to maintenance of stormwater energy dissipating structures, that have been constructed in accordance with a valid order of conditions. The proposed project does not destroy or impair any portion of a BVW that is located within an Area of Critical Environmental Concern. Therefore, the standard is not applicable. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 8.2 Town of Lexington Rules The Town of Lexington Conservation Commission adopted rules pursuant to the Code of the Town of Lexington For Wetland Protection, Chapter 130. The rules were provided in Section 5: Performance Standards and are further explained in comparison to the proposed project below. 1. Incorporation of State Standards The state standards and 310 CMR 10.53 -10.60 standards are met as further explained in Section 7.1. Therefore, the project meets the requirement. 2. Increase in Runoff The SMS will collect, convey and treat runoff from the project site and will mitigate peak runoff rates and runoff volume such that post - development conditions will not exceed pre - development conditions for the 2 -year, 10 -year and 100 -year storm events. No increase in the volume of runoff will occur for the 1 -year event. The SMS is provided in Appendix F. Therefore, the project meets the requirement. 3. Structures in Floodplain No building or parking lot shall be located below the 10 -year flood level. Therefore, the project meets the requirement. 4. Wildlife Habitat Impact and Mitigation In general, the Site does not provide significant habitat opportunities. Nonetheless, Brookhaven will utilize existing fieldstone walls for construction of a wall along the northerly side of the trail east of the access drive. Brookhaven will develop and implement an invasive species control program to be implemented after construction of the Project. Based on the limited habitat opportunities, the reconstruction of fieldstone walls, and implementation of an Invasive Species Management Plan, the Project will have no significant deleterious effects on wildlife habitat. Therefore, the project meets the requirement. 5. Buffer Zone The proposed project will include construction and development within the 25 -foot zone and meets the 50% requirement for the 100 -foot zone. Proposed work inside the 25 -foot zone is related to the access drives and construction of the wetland replication areas. An alternative analysis for the access drives is provided in Section 4.4. Therefore, the project meets the requirement. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent 6. Pre - Development Conditions The proposed project is not a redevelopment project; therefore, the requirements are not applicable to the proposed project. 7. Replication of Bordering Wetlands BVW will be replicated in within the same wetland complex and hydrologic system as the impacted wetland resource. The replication area will be greater than 2:1 ratio of replication to the impacted area as well. Further information on the replication area is provided in Section 5. Therefore, the project meets the requirement. 8. Vernal Pool A NHESP Certified vernal pool is located east - southeast of the proposed project area. The proposed project will not: • Discharge contaminated runoff or runoff that would cause erosion or sedimentation or other impacts to the vernal pool; • Impair the capacity of the vernal pool, as well as within 100 feet of the outer edge of the pool, to provide wildlife habitat.; • Have any adverse effect upon species listed by the Massachusetts Natural Heritage and Endangered Species Program or by Massachusetts Division of Fisheries & Wildlife under 312 CMR 8.00; and • Alteration of topography, soil structure, plant community composition and structure, and hydrologic regime, insofar as such alteration substantially reduces the vernal pool habitat's capacity to provide the following important wildlife habitat functions. Therefore, the project meets the requirement. 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent win, wwr 0 W,9 f.'atgestee��1. {�'�sai/rarxt °� v�'�%e�a1d.2 #.t 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent Massaehusetts Department of Environmental Protectio>q Provided by MassDEP: 4 Bureau of Resource Protection - Wetlands MassDEP File #: ., WPA Form 3 - Notice of Wetland FeeTransmittal eDEP Transaction #:931321 Form City/fown:LEXINGTON - Massachusetts Wetlands Protection Act M.G.L. c. 131, §40 A. Applicant Information 1. Applicant: a. First Name JAMES blast Name FREEHLING c. Organization SYMMES LIFECARE DBA BROOKHAVEN AT LEXINGTON, INC. d. Mailing Address 960- 10 10 WALTHAM STREET e. City/Town LEXINGTON f State MA g. Zip Code 02421 h. Phone Number 7818639660 i. Fax 7818639944 j. Email brookhavenatlexington.org jfreehling@brookhavenatlexington.org 2. Property Owner:(if different) a. First Name JAMES b. Last Name FREEHLING c. Organization SYMMES LIEECARE DBA BROOKHAVEN AT LEXINGTON, INC. d. Mailing Address 960- 10 10 WALTHAM STREET e. City/Town LEXINGTON (State MA g. Zip Code 02421 h. Phone Number 7818639660 i. Fax 7818639944 j.Email jfreehlinggbrookhavenatlexington .org 3. Project Location: a. Street Address 960 -1010 WALTHAM STREET b. City/Town LEXINGTON Are you exempted from Fee? r- (YOU HAVE SELECTED'NO') Note: Fee will be exempted if you are one of the following: • City/Town/County/District • Municipal Housing Authority • Indian Tribe Housing Authority • MBTA State agencies are only exempt if the fee is less than $100 B. Fees Activity Type Activity Number Activity Fee RF Multiplier Sub Total B.) EACH BUILDING (FOR DEVELOPMENT) 1 1050.00 1050.00 INCLUDING SITE; A.) EACH CROSSING FOR DEVELOPMENT OR 1 1450.00 1450.00 COMMERCIAL ROAD; City(fown share of filling fee State share of filing fee Total Project Fee $1,262.50 $1,237.50 $2,500.00 Page 1 of 1 * ELECTRONIC COPY APPENDIX B -3 NOTICE OF INTENT fi 1Nr FEES, TRAIL MlT "'1 "AL FC, Rules: L These fees are in addition to the fees paid pursuant to The Wetlands Protection Act, M.G.L. c. 131, s. 40. 2., All Requests and Notices filed pursuant to Lexington Wetland Protection Code, c. 130 shall be accompanied by a filing fee, the amount to be determined by fees adopted by the Lexington Conservation Commission, and a brief description indicating how the applicant calculated the fee. 3. Whenever the Conservation Commission determines that an inadequate fee has been paid, the time period for the Conservation Commission to act shall be stayed until the balance of the fee is paid. 4. If any of the activities are in a Riverfront Area in addition to another Resource Area or Buffer Zone, the fee per activity should be multiplied by 1.5 and then added to the subtotal amount (or add 50% to total fee). 5,, Town. Projects are exempt from Wetland Protection Code Fees. Fee Schedule: NO. /Area Cates Minor Project/Accessory Use <500 s.f. - $200, plus $30 microfilm and scanning fee(house addition, tennis court, swimming pool, utility work, etc.) Minor Project/Accessory Use >500 s.f. - $400, plus $60 microfilm and scanning fee(house addition, tennis court, swimming pool, utility work, etc.) Drain connection to existing storm drain system - $750, plus $100 microfilm and scanning fee Single Family Dwelling - $800, plus $125 microfilm and scanning fees, plus all applicable fees listed below ( *) Subdivisions road and utilities only - $800, plus $125 microfilm and scanning fees, plus all applicable fees listed below ( *) Multiple dwelling structures- $800, plus $125 microfilm and scanning fees, plus $100 per unit located within any Resource Area or Buffer Zone, plus all applicable fees listed below ( *) Each subdivision roadway, other roadway or non single - family dwel ling drivewa aQA all a s cittt d�airra urea unlit' ,grading. curbing, landscaping, and of er associated work exclusive 12/96; rev 7/04; rev. 1/05; rev.5 /05; rev. 8/09 Appendix B - (7) of dwellinas or buildings - $800, plus $125 micro film and scanning fee, plus all applicable fees listed below ( *) Commercial industrial, and institutional ro qt : . ... , - . ,m, . , . L R�,,,� a. Mayor (site work or construction = to or > 500 s.f.) $1,500, plus $250 microfilm and scanning fees, plus all applicable fees listed below ( *) _ b. Minor (site work or construction < 500 s.f.) $500, plus $75 microfilm and scanning fee, plus all applicable fees listed below ( *) 3("c 31.,0 1•17 *Bounda delineations for an resource area $1.00 per linear foot of Resource Area boundary, not to exceed $200 for activities associated with single- family house or $1,500 for all other activities. *gym mporary_or permanent) within the Buffer Zone of a Wor te-,.. Resource Area - $.25 per square foot of Buffer Zone within 25 feet of a Resource Area temporarily or permanently altered and /or within 50 feet of a Resource Area permanently altered with a structure *Work ( temporary or permanent) within Land Subiect to Floodin �Borderina or Isolated) - $.25 per square foot of Land Subject to Flooding temporarily or permanently altered *Work (temporary or permanent) in following Resource Areas: Freshwater Wetland, Wet Meadow, Bog, SwgM Marsh, Creek, River Stream, Pond Lake, Land Under Water, or Bank - $.50 per square foot of Resource Area temporarily or permanently altered *Work (temporary or permanent) in Vernal Pool or it's Buffer Zone a. $.50 per square foot of Vernal Pool temporarily or permanently altered b. $.25 per square foot of Vernal Pool Buffer Zone temporarily or permanently altered Order of Conditions Extensions or Amendments a. Residential Projects — 25% of original filing fee: not less than $100. b. Commercial, Industrial, Institutional, Non- Residential —25% of original filing fee: not less than $300. Emergency Certificate -$100 U fa l 1 to '4� _ TOTAL Fees Adopted 7/21/09 Note: These fees are in addition to the fees paid under M.G.L. Ch. 131, s.40 (ACT). 12/96; rev 7/04; rev. 1105; rev.5 /05; rev. 8/09 Appendix B - (8) '�. wry, ww� C C s 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent Select "File" \ "Save As" to save Form to the following location, Do not save changes in the original L:A1Abutters\Abutters Requests Completed\ new folder name Example: Massachusetts Ave 1625 VU 0 ��il Town of Lexington g- gn W Near Form, Request For Certified Abutters List Request Date R.eq Uest:. .)ir°' F, I Ue II ate 06/02/2017 To Whom It May Concern: I would like to request a Certified Abutters List for the following property: Property Addresses: 1 010 Waltham Street Tax Map #: 5 Other Related Map/Lot#: 5 -19C, 5 -20, 5 -21 A Current Owner(s): For the purpose of contacting abutters for: • Board of Appeals (within 300) • Planning (within 300) • Conservation Commission (Within 100) • Historical Commission (Within 100) Other criteria as follows: Lot #: 16A Unit # • Historical District Commission (within 100) • Selectmen (within ) • Out of Town (Within ) • Town Engineer (Within ) (Example: All condo association owners Or All properties on Elm St between Sugar St and Maple St. ) The Certified Abutters List should be Delivered as follows: Picked up Please call when ready # Phone Number Ext • Emailed to Jborrebach@OHI Engineering.com Printed Name Date Mailing Address Phone Ext Che source data and the process employed to establish this Abutters List has been certified by the Town of Lexington: Dept Use: Date Processed : Fee Collected: Abutters Request Form v 9/16/2015 L: \\ Abutters\ ABUTTERREQUESTFORM \ABUTTERREQESTFORM52014 distributed.pdf I VVVII VI LCJUIIyLVII, lvim May J1, LV1/ "C71l Im Tlarll Ike - COncarc[Tur p iVW iVplpw,,,u 'Pi er RAP - .. - �s�/p�,� /�, , - _� wo Y!Iu 'IK ir�l7la %Winah ! � a NN ' e I "i�'v2;li � fiYb"v VVV NOW 40o ,� ,. r a � _ f'o VV01! mu I i uw " lop , id � u ft' ,�- �dY 4b 0 AW v kti r p. r err ��i„ UN r.�f ; .a� MMMMM �I p '1%4* ft lipf"" y / n 00 IN ti a u IN NIMINs h' All s a- 7 p. �rtp , IIffl Rat — rr�l "n , VI dY N,n � l u w { OF- p ��ry�� 1" = 775 ft Property Information a r�6 Property 5 -16A ID Location 1010 WALTHAM ST x Owner SYMMES LIFE CARE INC MAP FOR REFERENCE ONLY NOT A LEGAL DOCUMENT Town of Lexington, MA makes no claims and no warranties, expressed or implied, concerning the validity or accuracy of the GIS data presented on this map. 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Wetlands Protection Act (MGL Ch. 131, s. 40, as amended) and the Lexington Wetland Protection Code (Ch. 130; as Amended), for a Notice of Intent filed by Choate - Symmes Lifecare, LLC dba Brookhaven at Lexington, for construction of the new "North Building" comprising 49 Independent Living units, the expansion of the existing Commons Building, and the construction of associated access drives, parking, utilities, landscaping, and sidewalks at 960 -1010 Waltham Street, within a bordering vegetated wetlands (BVW) and associated Buffer Zone, on Assessors Property Map #5, Parcels 16A, 19C, 20, and 21A. Plans are available for inspection in Room G -8, Town Office Building weekdays from 8:30 am to 4:30 pm and at Brookhaven at Lexington, 1010 Waltham Street, Lexington, MA. If this hearing is not closed, it will be continued to a date requested by the applicant without further abutter notification. For more information call James R. Borrebach of OHI Engineering, Inc. at 508 - 339 -3929 or the Lexington Conservation Commission at 781 - 0862 -0500 x226, or the DEP Northeast Regional Office at 617 -654- 6500. Note: Notice of Public Hearing will be published at least five (5) days in advance in the Lexington Minuteman (or The Globe, if necessary) and will be posted not less than 48 -hours in advance of the public hearing in the Lexington Town Hall. AFFIDAVIT OF SERVICE Under the Massachusetts Wetlands Protection Act and Lexington Wetland Protection Code, I, James R. Borrebach of OHI Engineering, Inc., hereby certify under the pains and penalties of perjury that on July 18, 2017, 1 mailed a "Notification to Abutters: in compliance with the second paragraph of the Massachusetts General Laws, Chapter 131, s.40, the DEP Guide to Abutter Notification dated April 8, 1994, and Section 130 -3 of the Code of the Town of Lexington, in connection with the following matter: A Notice of Intent filed under the Massachusetts Wetlands Protection Act and the Lexington Wetland Protection Code by Symmes Lifecare, Inc. dba Brookhaven at Lexington with the Lexington Conservation Commission on July 18, 2017 for property located at 960 -1010 Waltham Street in Lexington, MA. This form of the notification, and a list of the abutters and their addresses to whom it was given, are attached to the Affidavit of Service. 4Na Date '�. wry, ww� C C s 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent TOPO! map printed on 12/08/15 from "Unti:tle'.d.tp..o 71'°15.000' W 71114X00' W WGS84 71113.000' W �iM1P ✓(� � YI ✓ M { � S � � x f J" � y"Y ,� lti LP" [� 0 ID y G tx+ � 1 A Y N � # 1. 0 �, , • r `l � ~~ � �� � /raj �� � t t �, � �, f( G l.w a k Site LOCUS P "V!� c - 0 '"^.. �.,. F' �"�... �� ��,.✓ 50� i � Ln Crl a,� ,� /' I ''�"'"�y !� h °t'W� �. +.�,� yp EN yw. , � 1 aYl � ✓ Y� � f .d�' �F Jl' rrc' C'i �' I 4'�� �} fm 12 Mile Radius US ! a N , �' n1�� w 0 ,y r✓f I tw,+, � � Jf ,. ham. .. 71115X00' W 71°14.000' W WGS84 71 °13.000' W TN 5 1 MIRE YSiz' }V� m 14]m GFlT V1 :,m, WOO hb'ETTNS SwEa. craabetl +with TOPOIVC2003N.tlxxualC •a hTm(ww.u�nahonal ,a hicc'otrn'trn Figure 1 _ �. I N E Site LOCUS �'. - s 960 -1010 Waltham Street 44 Wood Avenue Mansfield, MA Lexington, MA �r CL 0 CL CL 9 cm J � O Nw �O .2)0 LL a))J OTHER FLOOD AREAS ZONE X Areas of 0.2% annual chance flood; areas of 1% annual chance flood with average depths of less than I foot or with drainage areas less than I square mite; and areas protected by levees from 1% annual chance flood, OTHER AREAS ZONE X Areas determined to be outside the 0.2% annual chance floodplain. Figure 3 Flood Map 960-1010 Waltham Street Lexington, MA MAP NUMBER 25017CO411E EFFECTIVE DATE JUNE 4, 2010 Federal Emergency Management Agency a MR/104, Ncl illfrow IMF"' 0 0 A k"/ k- F Affr" AfF R/M Im" h 71, 'Ul A Add t � Malf"Id/f/l/l/F/ o do fff o OR Z"1 , f d"11A At A A' Ink , 011, & li OR off, '10 few", Oil % L Ifflow, j CL co m 111 ` 71— - 1 2 gf d �yl/ T 1, 1/1 livol IN "2:2 , ifil ovoo FIFF, mr," Olb CC /r lr„v % 0" 0 CC dell 0 LL LLJ a) _j Ia El ca E In Z+ TIC, > - F E M i U VY A Add t � Malf"Id/f/l/l/F/ o do fff o OR Z"1 , f d"11A At A A' Ink , 011, & li OR off, '10 few", Oil % L Ifflow, j CL co m 111 ` 71— - 1 2 gf d �yl/ T 1, 1/1 livol IN "2:2 , ifil ovoo FIFF, mr," Olb CC /r lr„v % 0" 0 CC dell 0 LL LLJ a) _j Ia '�. wry, ww� C C s 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent '�. wry, ww� C C s 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent Stormwate Management Repoi 5Mr 960-1010 Waltham Street Lexington, Submitted Conservation • • Lexington, r -• • • � dl Prel2ared Goldsmith F Ringwall, Inc. 39 Main Street, Suite 301 MA ML # - •, Ms. .w Table of Contents Section Title 1 Introduction and Methodology 2 Hydrology Summary for 24 -hour Storm 3 Mass DEP Stormwater Management Report Checklist 4 Soil Suitability Assessment Report 5 Appendix Mapped Soil Survey Overlay Flood Insurance Rate Map Map No. 25017CO411 E Pre - Development Pre - Development Impervious Cover Plan (11" x 17 ") Pre - Development North Drainage Map (11" x 17 ") Pre - Development South Drainage Map (11" x 17 ") Existing Stone Culvert Watershed Map (Subcatchment EX. SC -D) (11" x 17 ") Existing Stone Culvert Watershed Map w/ Lexington GIS (Subcatchment EX. SC -D) (11" x 17 ") Watershed Computations Post - Development Post - Development North Drainage Map (11" x 17 ") Post - Development South Drainage Map (11" x 17 ") Watershed Computations Stormwater Quality Computations Groundwater Recharge Water Quality Retention Volume TSS Removal MASTEP Technology Review 72 -Hour Infiltration Draw Down Directly Connected Impervious Area (DCIA) Calculations Impervious Area Summary Pre - Development Conditions Post - Development Conditions Stormwater Management Facilities Summary Attachments "Residential Development North Building & Commons Expansion, Brookhaven at Lexington, 960 -1010 Waltham Street, Lexington, MA," Plan Set (24 "x36 "), by GPR, dated July 2017 "Stormwater Opertations and Maintence Plan," by OHI Engineering, Inc., dated July 18, 2017 Section 1 Introduction and Methodology Introduction and Methodology Regulatory Requirements and Design Intent This narrative is intended to accompany the stormwater management report for the Brookhaven at Lexington North Building and Commons Expansion project. Included in this report are calculations that support engineering design as required by the MassDEP Stormwater Management Handbook and applicable Town of Lexington Design Standards. Site specific information is presented under two scenarios, "pre- development" and "post - development" conditions, so that potential impacts due to the project can be identified, quantified and, as necessary, mitigated. The final design intent seeks to meet the following interrelated goals: 1. Limit peak stormwater runoff rates for the 2 -, 10 -, and 100 -year storm events to existing ( *pre- development) levels; 2. Limit stormwater volumetric runoff for the 1 -year storm event to the existing ( *pre- development) level; 3. Evaluate potential on- and off -site flooding during the 25 -, and 100 - year storm events due to proposed development; 4. Maintain or increase the volume of stormwater recharged per storm event to those of existing ( *pre- development) levels; 5. Prevent appreciable sediment and other suspended solids and contaminants transport by trapping them on site via Best Management Practices; 6. Provide adequate drainage for new surfaces; 7. Maintain existing drainage patterns while providing a cost - effective engineering solution that addresses regulatory as well as real -world constraints. *= "Pre- Development" is defined in the Town of Lexington regulations such that existing impervious areas being disturbed by the proposed project shall be hydrologically calculated as grass, in good condition, for the existing surface runoff conditions. Goldsmith, Prest & Ringwall, Inc. 1 of 6 Brookhaven at Lexington 150167 North Building and Commons Expansion Existing Site Description The subject property consists of approximately 26 acres of developed land for the Brookhaven at Lexington facility, plus an adjacent 6.1 ± acres of formerly developed, currently vacant property located on Property Map 5, Parcels 16A, 19C, 20 & 21A. The proposed Project affects approximately 5.3 acres within the 32.1± acre subject property. The existing Brookhaven property was last expanded in 2003. Drainage design for this expansion was approved in accordance with the Massachusetts Department of Environmental Protection (DEP) Stormwater Management Policy Guidelines (Policy), that formed the foundation of the Massachusetts Stormwater Handbook and Stormwater Management Standards (SWM Handbook). The new lands to be developed are located north of the existing Brookhaven development. These new lands are wooded, with steep slopes, upwards of 50% in places, with ledge rock outcroppings to the north, flattening towards wetlands at the southern and eastern lot boundaries at 1 -5 %. Along the west edge, grade transitions smoothly to meet the existing asphalt sidewalk along Waltham Street. Chester Brook is an intermittent stream with bordering vegetated wetlands (BVW), and the stream flows from east to west across the southern fringe of these vacant northern lands. Chester Brook is an intermittent stream channel that passes through the subject property and through the middle of the Project development area. The headwaters of this stream are composed of a very broad, flat wetland area and a periphery of developed upland areas in a 53.3 acre basin, all leading to an existing stone culvert in the Project area. Upstream of the stone culvert in Chester Brook is a Certified Vernal Pool on adjacent property owned by the Town of Lexington, but the 100 foot Vernal Pool Buffer extends onto the Brookhaven Campus property. Soil mapping by the Natural Resources Conservation Service shown on MASS GIS for this site indicate soils are predominantly Narragansett - Hollis -rock outcrop complex on slopes from 3 to 25 %, Freetown muck on 0 to 1 % slopes and Narragansett silt loam on slopes varying from 8% to 15 %. Soils are characterized as hydraulic group B or D soils. Onsite soils investigations conducted on the northern lands indicate estimated seasonal high groundwater ranges from 28 to 48 inches below grade. Near the existing Brookhaven development, south of Chester Brook, seasonal high groundwater was observed to be between 90 and 92 inches below existing grade during onsite deep test hole investigations. Goldsmith, Prest & Ringwall, Inc. 2 of 6 Brookhaven at Lexington 150167 North Building and Commons Expansion Project Description The proposed project is to construct a new independent living facility on the lands north of Chester Brook, making a single vehicular and pedestrian connection to the existing Brookhaven facility, as well as expanding the existing Commons facilities at Brookhaven. The North Building (for independent living) includes an integral underground parking garage that is partially exposed above grade at the northwest and northeast corners. Some surface parking will also be provided near the North Building. An emergency fire access lane will be installed north of the North Building, with a hammerhead -type turnaround for fire trucks and emergency vehicles. A new "Entrance Only" emergency /fire access entrance from Waltham Street will be provided near the northwest corner of the property, and a former residential driveway entrance onto Waltham Street will be removed. The North Building will be connected to the existing Brookhaven facility via an elevated roadway ( "North Road ") bounded by gravity retaining walls. An aluminum arch span culvert is proposed to support the roadway crossing. The new arch span culvert will span over an existing, degraded, but functioning, stone culvert in Chester Brook, without disturbing the existing culvert, or changing its hydraulic characteristics. Preservation of this existing stone culvert minimizes hydrologic impacts to the large upstream wetland areas. The large 31 foot, 6 inch span, of the culvert was selected specifically to avoid changing flow characteristics of Chester Brook, and to minimize direct wetland impacts. New utility service connections for water, sewer, natural gas, electricity and telecommunications will be extended to the west end of the North Building from Waltham Street. Concrete encased duct banks for telecommunications and electrical services will be installed. Potable water service to the North Building will be tapped into the 10" water main in Waltham Street at the northwest corner of the property and will be connected to the water main being relocated with the Commons Expansion to provide a looped water system into the property. The sanitary sewer line out of the North Building will have an inline grinder, and will connect to the Waltham Street sewer trunkline with an inside drop connection. Adjustments to the Waltham Street drainage system will be installed to provide adequate cover and clearances for the sanitary sewer connection. The Brookhaven Commons Expansion requires the realignment of the "Commons Road" access aisle adjacent to the Commons Expansion, and reconfiguration of existing parking areas. Utility relocations will be installed for water, sewer, natural gas, electrical and telecommunications services. New electrical transformers, and emergency generators will be set at both the North Building and the Commons Expansion. Proposed drainage improvements will be extensive. Goldsmith, Prest & Ringwall, Inc. 3 of 6 Brookhaven at Lexington 150167 North Building and Commons Expansion Drainage Design The proposed improvements all drain to the existing culvert under the main entrance to Brookhaven, that conveys the flow of Chester Brook. The new North Building drains southwards towards Chester Brook and the Commons Expansion generally drains northwards to Chester Brook. The North Building roof and North Garage "green roof' are conveyed directly into underground recharge chambers, and surface waters are conveyed through BMP treatment trains that include deep sump hooded catch basins, Silt Prison Catch Basin inserts, sediment forebays, retention basins, and supplemental underground infiltration chambers. The new Commons Expansion rooftop and portions of the new plaza are directed to underground recharge chambers, and then into an underground detention chamber. A second underground recharge chamber will receive collected roof water from approximately 34,000 square feet of existing roof area, east of the Commons Expansion. An existing shallow detention basin north of the realigned Commons Road will be modified, and will continue to provide detention for discharges from the new Commons Expansion. Hydrologic and Hydraulic Computation Methodology Runoff rates and volumes were computed using the Soil Conservation Service TR -55 Method entitled "Urban Hydrology for Small Watersheds ". The following 24 -hour rainfall events were analyzed: Peak Flow Discharge: Frequency (years): 1, 2, 10, and 100 Volumetric Discharge: Frequency (years): 1 Pre - development topography for the North Building lands are naturally broken into three sub - watershed drainage divides. The existing closed drainage system on the Brookhaven campus is modeled according to field surveyed and available construction record data. Impervious areas being disturbed total 40,894 square feet, and are considered as pervious grass cover in good condition for the pre - developed condition. Three analysis points have been established to evaluate the pre- versus post - developed peak flows and volumetric discharge: Analysis Point #1 (AP1) is located at the existing box culvert under the main entrance driveway into Brookhaven. AP1 provides a point of analysis downstream of all proposed work that encompasses all flow leaving the Project. AP1 is the first analysis point that is approximately 175 feet downstream from the improvements on the northern lands. Due to the configuration of the development, and the existing drainage divides, there is no other practical location to analyze the discharges from the northern lands than at AP1. Goldsmith, Prest & Ringwall, Inc. 4 of 6 Brookhaven at Lexington 150167 North Building and Commons Expansion Analysis Point #2 (AP2) is at the point of discharge from the existing detention basin from the developed Brookhaven Campus. AP2 provides an ideal point of comparison between the existing, and proposed drainage systems from the developed Brookhaven Campus into Chester Brook. Analysis Point #3 (AP3) is placed at the existing stone culvert in Chester Brook. Due to a small amount of flow discharging from the Project to this culvert, and because of its position in the watershed, this point of analysis ensures the existing hydrology for the eastern wetlands is maintained. The Commons Expansion, as computed by the previously approved 2003 BSC Group Drainage Report, has two sub - watersheds. The North Building analysis points are split into areas discharging downstream of the existing Chester Brook culvert (AP1), and areas discharging upstream of the existing Chester Brook culvert (AP2). The 2003 BSC Group Drainage Report split the drainage divides into one for treated rooftops (P1 A) and another aggregated for the remaining areas discharging northwards towards Chester Brook (P1). For continuity in pre- to post- development comparisons, all discharges from the P1 + P1 A areas are evaluated as Analysis Point #3 (AP -3). Town of Lexington stormwater drainage standards are incorporated into the design, including maintaining the ratio of pre- to post - development runoff to infiltration, 50 -year event culvert design, and 25 -year event catch basin designs. Since the three analysis points ultimately reach the same end point, they are summed in the tabulation of peak flow discharge rates. Both pre - developed and post - developed peak discharge rates for the design storm frequencies are computed using Hydro -CAD version 10.00 -14. The hydraulic and hydrologic model accounted for proposed changes to land cover, time of concentration and the proposed stormwater improvements. Conclusion Peak flow discharges are reduced by the project for all storms. Volumetric discharges increase during the 2, 10, and 100 -year storm events due to reduced time of concentration for areas cut off from direct flow into the wetlands. The ratio of runoff to infiltration is improved in the post - developed condition with underground recharge chambers and the net effects from additional volume will be negligible. The deep sump catch basins, Silt Prison deep sump catch basins, sediment forebays, grass channels, infiltration basins and dry wells work together to provide an expected site wide Total Suspended Solids (TSS) removal of 80.76 %. The infiltration chambers and basins retain and infiltrate 14,210 cubic feet of runoff prior to discharging, well in excess of the minimum required 2,388 cubic feet, in accordance with MADEP Stomwater Management Standard 3, and the minimum required 5,013 cubic feet required by Standard 4. Goldsmith, Prest & Ringwall, Inc. 5 of 6 Brookhaven at Lexington 150167 North Building and Commons Expansion The proposed development meets the Town of Lexington and MADEP Stormwater Management Standards through the use of Best Management Practices that address groundwater recharge, water quality (first flush) retention, and suspended solids removal within sustainable BMP's. See Appendix for computed solids quantities/ removal process trains, and water quality runoff volumes. Goldsmith, Prest & Ringwall, Inc. 6 of 6 Brookhaven at Lexington 150167 North Building and Commons Expansion Section 2 Hydrology Summary for 24 -hour Storm HYDROLOGY SUMMARY FOR 24 -HOUR STORM Brookhaven at Lexington 960 -1010 Waltham St, Lexington, MA Project No. 151067 PEAK DISCHARGE RATE Pre - Development (cfs) Analysis Point 1 -YR 2 -YR 10 -YR 100 -YR AP -1 7.47 9.87 25.42 60.31 AP -2 7.37 9.35 24.47 45.51 AP -3 0.27 0.35 0.97 2.24 Development (cfs) Analysis Point 1 -YR 2 -YR 10 -YR 100 -YR AP -1 4.86 7.35 17.92 50.64 AP -2 3.87 6.38 15.66 36.94 AP -3 0.27 0.35 0.97 2.23 Pre - Development vs. Developed (cfs) Analysis Point 1 -YR 2 -YR 10 -YR 100 -YR AP -1 -2.61 -2.52 -7.50 -9.67 AP -2 -3.50 -2.97 -8.81 -8.57 AP -3 0.00 0.00 0.00 -0.01 SITE TOTALS -6.11 -5.49 -16.31 -18.25 TOTAL DISCHARGE VOLUME Pre - Development (Cubic feet) Analysis Point 1 -YR 2 -YR 10 -YR 100 -YR AP -1 72,201 90,667 209,509 555,947 AP -2 29,571 35,940 70,682 153,341 AP -3 38,119 48,433 120,695 350,809 Development (Cubic feet) Analysis Point 1 -YR 2 -YR 10 -YR 100 -YR AP -1 72,127 96,746 221,670 572,878 AP -2 29,035 40,040 77,681 164,096 AP -3 36,192 47,563 120,614 350,759 Pre - Development vs. Developed (Cubic feet) Analysis Point 1 -YR 2 -YR 10 -YR 100 -YR AP -1 -74 6,079 12,161 16,931 AP -2 -536 4,100 6,999 10,755 AP -3 -1,927 -870 -81 -50 SITE TOTALS -2,537 9,309 19,079 27,636 Goldsmith, Prest and Ringwall, Inc. 151067 - Brookhaven at Lexington Section 3 Mass DEP Stormwater Management Report Checklist Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program l Checklist for Stormwater Report A. Introduction Important: When A Stormwater Report must be submitted with the Notice of Intent permit application to document filling out forms compliance with the Stormwater Management Standards. The following checklist is NOT a substitute for on the computer, (which h h hi Report R t St e Stormwater e wc sou provide more substantive and detailed information use only the tab th p p ) but is offered key to move your here as a tool to help the applicant organize their Stormwater Management documentation for their cursor - do not Report and for the reviewer to assess this information in a consistent format. As noted in the Checklist, use the return the Stormwater Report must contain the engineering computations and supporting information set forth in key. Volume 3 of the Massachusetts Stormwater Handbook. The Stormwater Report must be prepared and certified by a Registered Professional Engineer (RPE) licensed in the Commonwealth. The Stormwater Report must include: • The Stormwater Checklist completed and stamped by a Registered Professional Engineer (see page 2) that certifies that the Stormwater Report contains all required submittals.' This Checklist is to be used as the cover for the completed Stormwater Report. • Applicant /Project Name • Project Address • Name of Firm and Registered Professional Engineer that prepared the Report • Long -Term Pollution Prevention Plan required by Standards 4 -6 • Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan required by Standard 82 • Operation and Maintenance Plan required by Standard 9 In addition to all plans and supporting information, the Stormwater Report must include a brief narrative describing stormwater management practices, including environmentally sensitive site design and LID techniques, along with a diagram depicting runoff through the proposed BMP treatment train. Plans are required to show existing and proposed conditions, identify all wetland resource areas, NRCS soil types, critical areas, Land Uses with Higher Potential Pollutant Loads (LUHPPL), and any areas on the site where infiltration rate is greater than 2.4 inches per hour. The Plans shall identify the drainage areas for both existing and proposed conditions at a scale that enables verification of supporting calculations. As noted in the Checklist, the Stormwater Management Report shall document compliance with each of the Stormwater Management Standards as provided in the Massachusetts Stormwater Handbook. The soils evaluation and calculations shall be done using the methodologies set forth in Volume 3 of the Massachusetts Stormwater Handbook. To ensure that the Stormwater Report is complete, applicants are required to fill in the Stormwater Report Checklist by checking the box to indicate that the specified information has been included in the Stormwater Report. If any of the information specified in the checklist has not been submitted, the applicant must provide an explanation. The completed Stormwater Report Checklist and Certification must be submitted with the Stormwater Report. The Stormwater Report may also include the Illicit Discharge Compliance Statement required by Standard 10. If not included in the Stormwater Report, the Illicit Discharge Compliance Statement must be submitted prior to the discharge of stormwater runoff to the post- construction best management practices. 2 For some complex projects, it may not be possible to include the Construction Period Erosion and Sedimentation Control Plan in the Stormwater Report. In that event, the issuing authority has the discretion to issue an Order of Conditions that approves the project and includes a condition requiring the proponent to submit the Construction Period Erosion and Sedimentation Control Plan before commencing any land disturbance activity on the site. swcheck.docx • 04/01/08 Stormwater Report Checklist • Page 1 of 8 Massachusetts Department • Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Sitormwater Report wr The following checklist is intended to serve as a guide for applicants as to the elements that ordinarily need to be addressed in a complete Stormwater Report. The checklist is also intended to provide conservation commissions and other reviewing authorities with a summary of the components necessary for a comprehensive Stormwater Report that addresses the ten Stormwater Standards. Note: Because stormwater requirements vary from project to project, it is possible that a complete Stormwater Report may not include information on some of the subjects specified in the Checklist. If it is determined that a specific item does not apply to the project under review, please note that the item is not applicable (N.A.) and provide the reasons for that determination. A complete checklist must include the Certification set forth below signed by the Registered Professional Engineer who prepared the Stormwater Report. I have reviewed the Stormwater Report, including the soil evaluation, computations, Long-term Pollution Prevention Plan, the Construction Period Erosion and Sedimentation Control Plan (if included), the Long- term Post-Construction Operation and Maintenance Plan, the Illicit Discharge Compliance Statement (if included) and the plans showing the stormwater management system, and have determined that they have been prepared iin accordance with the requirements of the Stormwater Management Standards as further elaborated by the Massachusetts Stormwater Handbook. I have also determined that the information presented in the Stormwater Checklist is accurate and that the information presented in the Stormwater Report accurately reflects conditions at the site as of the date of this permit application. Registered Professional Engineer Block and Signature m3m Project Type: Is the application for new development, redevelopment, or a mix of new and redevelopment? F New development El Mix of New Development and Redevelopment swcheck.docx • 04101108 Stormwater Report Checklist - Page 2 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program l Checklist for Stormwater Report Checklist (continued) LID Measures: Stormwater Standards require LID measures to be considered. Document what environmentally sensitive design and LID Techniques were considered during the planning and design of the project: ❑ No disturbance to any Wetland Resource Areas ❑ Site Design Practices (e.g. clustered development, reduced frontage setbacks) ❑ Reduced Impervious Area (Redevelopment Only) ❑ Minimizing disturbance to existing trees and shrubs ❑ LID Site Design Credit Requested: ❑ Credit 1 ❑ Credit 2 ❑ Credit 3 ❑ Use of "country drainage" versus curb and gutter conveyance and pipe ❑ Bioretention Cells (includes Rain Gardens) ❑ Constructed Stormwater Wetlands (includes Gravel Wetlands designs) ❑ Treebox Filter ❑ Water Quality Swale ® Grass Channel ❑ Green Roof ® Other (describe): Subsurface Infiltration, Sediment Forebays, Infiltration Basins, Porous Pavement. Deep Sump Catch Basins Standard 1: No New Untreated Discharges ® No new untreated discharges ® Outlets have been designed so there is no erosion or scour to wetlands and waters of the Commonwealth ® Supporting calculations specified in Volume 3 of the Massachusetts Stormwater Handbook included. swcheck.docx • 04/01/08 Stormwater Report Checklist • Page 3 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program l Checklist for Stormwater Report Checklist (continued) Standard 2: Peak Rate Attenuation ❑ Standard 2 waiver requested because the project is located in land subject to coastal storm flowage and stormwater discharge is to a wetland subject to coastal flooding. ❑ Evaluation provided to determine whether off -site flooding increases during the 100 -year 24 -hour storm. ® Calculations provided to show that post - development peak discharge rates do not exceed pre - development rates for the 2 -year and 10 -year 24 -hour storms. If evaluation shows that off -site flooding increases during the 100 -year 24 -hour storm, calculations are also provided to show that post - development peak discharge rates do not exceed pre - development rates for the 100 -year 24- hour storm. Standard 3: Recharge ® Soil Analysis provided. ® Required Recharge Volume calculation provided. ❑ Required Recharge volume reduced through use of the LID site Design Credits. ® Sizing the infiltration, BMPs is based on the following method: Check the method used. ® Static ❑ Simple Dynamic ❑ Dynamic Field' ❑ Runoff from all impervious areas at the site discharging to the infiltration BMP. ® Runoff from all impervious areas at the site is not discharging to the infiltration BMP and calculations are provided showing that the drainage area contributing runoff to the infiltration BMPs is sufficient to generate the required recharge volume. ® Recharge BMPs have been sized to infiltrate the Required Recharge Volume. ❑ Recharge BMPs have been sized to infiltrate the Required Recharge Volume only to the maximum extent practicable for the following reason: ❑ Site is comprised solely of C and D soils and /or bedrock at the land surface ❑ M.G.L. c. 21E sites pursuant to 310 CMR 40.0000 ❑ Solid Waste Landfill pursuant to 310 CMR 19.000 ❑ Project is otherwise subject to Stormwater Management Standards only to the maximum extent practicable. ® Calculations showing that the infiltration BMPs will drain in 72 hours are provided. ❑ Property includes a M.G.L. c. 21 E site or a solid waste landfill and a mounding analysis is included. 80% TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used. swcheck.docx • 04/01/08 Stormwater Report Checklist • Page 4 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program l Checklist for Stormwater Report Checklist (continued) Standard 3: Recharge (continued) ❑ The infiltration BMP is used to attenuate peak flows during storms greater than or equal to the 10- year 24 -hour storm and separation to seasonal high groundwater is less than 4 feet and a mounding analysis is provided. ❑ Documentation is provided showing that infiltration BMPs do not adversely impact nearby wetland resource areas. Standard 4: Water Quality The Long -Term Pollution Prevention Plan typically includes the following: • Good housekeeping practices; • Provisions for storing materials and waste products inside or under cover; • Vehicle washing controls; • Requirements for routine inspections and maintenance of stormwater BMPs; • Spill prevention and response plans; • Provisions for maintenance of lawns, gardens, and other landscaped areas; • Requirements for storage and use of fertilizers, herbicides, and pesticides; • Pet waste management provisions; • Provisions for operation and management of septic systems; • Provisions for solid waste management; • Snow disposal and plowing plans relative to Wetland Resource Areas; • Winter Road Salt and /or Sand Use and Storage restrictions; • Street sweeping schedules; • Provisions for prevention of illicit discharges to the stormwater management system; • Documentation that Stormwater BMPs are designed to provide for shutdown and containment in the event of a spill or discharges to or near critical areas or from LUHPPL; • Training for staff or personnel involved with implementing Long -Term Pollution Prevention Plan; • List of Emergency contacts for implementing Long -Term Pollution Prevention Plan. ® A Long -Term Pollution Prevention Plan is attached to Stormwater Report and is included as an attachment to the Wetlands Notice of Intent. ❑ Treatment BMPs subject to the 44% TSS removal pretreatment requirement and the one inch rule for calculating the water quality volume are included, and discharge: ❑ is within the Zone II or Interim Wellhead Protection Area ❑ is near or to other critical areas ❑ is within soils with a rapid infiltration rate (greater than 2.4 inches per hour) ❑ involves runoff from land uses with higher potential pollutant loads. ❑ The Required Water Quality Volume is reduced through use of the LID site Design Credits. ® Calculations documenting that the treatment train meets the 80% TSS removal requirement and, if applicable, the 44% TSS removal pretreatment requirement, are provided. swcheck.docx • 04/01/08 Stormwater Report Checklist • Page 5 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program l Checklist for Stormwater Report Checklist (continued) Standard 4: Water Quality (continued) ® The BMP is sized (and calculations provided) based on: ® The 1/2" or 1" Water Quality Volume or ❑ The equivalent flow rate associated with the Water Quality Volume and documentation is provided showing that the BMP treats the required water quality volume. ® The applicant proposes to use proprietary BMPs, and documentation supporting use of proprietary BMP and proposed TSS removal rate is provided. This documentation may be in the form of the propriety BMP checklist found in Volume 2, Chapter 4 of the Massachusetts Stormwater Handbook and submitting copies of the TARP Report, STEP Report, and /or other third party studies verifying performance of the proprietary BMPs. ❑ A TMDL exists that indicates a need to reduce pollutants other than TSS and documentation showing that the BMPs selected are consistent with the TMDL is provided. Standard 5: Land Uses With Higher Potential Pollutant Loads (LUHPPLs) ❑ The NPDES Multi- Sector General Permit covers the land use and the Stormwater Pollution Prevention Plan ( SWPPP) has been included with the Stormwater Report. ❑ The NPDES Multi- Sector General Permit covers the land use and the SWPPP will be submitted prior to the discharge of stormwater to the post- construction stormwater BMPs. ❑ The NPDES Multi- Sector General Permit does not cover the land use. ❑ LUHPPLs are located at the site and industry specific source control and pollution prevention measures have been proposed to reduce or eliminate the exposure of LUHPPLs to rain, snow, snow melt and runoff, and been included in the long term Pollution Prevention Plan. ❑ All exposure has been eliminated. ❑ All exposure has not been eliminated and all BMPs selected are on MassDEP LUHPPL list. ❑ The LUHPPL has the potential to generate runoff with moderate to higher concentrations of oil and grease (e.g. all parking lots with >1000 vehicle trips per day) and the treatment train includes an oil grit separator, a filtering bioretention area, a sand filter or equivalent. Standard 6: Critical Areas ❑ The discharge is near or to a critical area and the treatment train includes only BMPs that MassDEP has approved for stormwater discharges to or near that particular class of critical area. ® Critical areas and BMPs are identified in the Stormwater Report. swcheck.docx • 04/01/08 Stormwater Report Checklist • Page 6 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program l Checklist for Stormwater Report Checklist (continued) Standard 7: Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable ❑ The project is subject to the Stormwater Management Standards only to the maximum Extent Practicable as a: ❑ Limited Project ❑ Small Residential Projects: 5 -9 single family houses or 5 -9 units in a multi - family development provided there is no discharge that may potentially affect a critical area. ❑ Small Residential Projects: 2 -4 single family houses or 2 -4 units in a multi - family development with a discharge to a critical area ❑ Marina and /or boatyard provided the hull painting, service and maintenance areas are protected from exposure to rain, snow, snow melt and runoff ❑ Bike Path and /or Foot Path ❑ Redevelopment Project ❑ Redevelopment portion of mix of new and redevelopment. ❑ Certain standards are not fully met (Standard No. 1, 8, 9, and 10 must always be fully met) and an explanation of why these standards are not met is contained in the Stormwater Report. ❑ The project involves redevelopment and a description of all measures that have been taken to improve existing conditions is provided in the Stormwater Report. The redevelopment checklist found in Volume 2 Chapter 3 of the Massachusetts Stormwater Handbook may be used to document that the proposed stormwater management system (a) complies with Standards 2, 3 and the pretreatment and structural BMP requirements of Standards 4 -6 to the maximum extent practicable and (b) improves existing conditions. Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan must include the following information: • Narrative; • Construction Period Operation and Maintenance Plan; • Names of Persons or Entity Responsible for Plan Compliance; • Construction Period Pollution Prevention Measures; • Erosion and Sedimentation Control Plan Drawings; • Detail drawings and specifications for erosion control BMPs, including sizing calculations; • Vegetation Planning; • Site Development Plan; • Construction Sequencing Plan; • Sequencing of Erosion and Sedimentation Controls; • Operation and Maintenance of Erosion and Sedimentation Controls; • Inspection Schedule; • Maintenance Schedule; • Inspection and Maintenance Log Form. ® A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan containing the information set forth above has been included in the Stormwater Report. swcheck.docx • 04/01/08 Stormwater Report Checklist • Page 7 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program l Checklist for Stormwater Report Checklist (continued) Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control (continued) ❑ The project is highly complex and information is included in the Stormwater Report that explains why it is not possible to submit the Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan with the application. A Construction Period Pollution Prevention and Erosion and Sedimentation Control has not been included in the Stormwater Report but will be submitted before land disturbance begins. ❑ The project is not covered by a NPDES Construction General Permit. ❑ The project is covered by a NPDES Construction General Permit and a copy of the SWPPP is in the Stormwater Report. ® The project is covered by a NPDES Construction General Permit but no SWPPP been submitted. The SWPPP will be submitted BEFORE land disturbance begins. Standard 9: Operation and Maintenance Plan ® The Post Construction Operation and Maintenance Plan is included in the Stormwater Report and includes the following information: ® Name of the stormwater management system owners; ® Party responsible for operation and maintenance; ® Schedule for implementation of routine and non - routine maintenance tasks; ® Plan showing the location of all stormwater BMPs maintenance access areas; ® Description and delineation of public safety features; ® Estimated operation and maintenance budget; and ® Operation and Maintenance Log Form. ❑ The responsible party is notthe owner of the parcel where the BMP is located and the Stormwater Report includes the following submissions: ❑ A copy of the legal instrument (deed, homeowner's association, utility trust or other legal entity) that establishes the terms of and legal responsibility for the operation and maintenance of the project site stormwater BMPs; ❑ A plan and easement deed that allows site access for the legal entity to operate and maintain BMP functions. Standard 10: Prohibition of Illicit Discharges ❑ The Long -Term Pollution Prevention Plan includes measures to prevent illicit discharges; ❑ An Illicit Discharge Compliance Statement is attached; ® NO Illicit Discharge Compliance Statement is attached but will be submitted prior to the discharge of any stormwater to post- construction BMPs. swcheck.docx • 04/01/08 Stormwater Report Checklist • Page 8 of 8 Section 4 Soil Suitability Assessment Report FORM 11 - SOIL EVALUATOR FORM No. 151067 Date: 5/11/17 Commonwealth of Massachusetts Lexington, Massachusetts Soil Suitability Assessment for Stormwater Management Performed by: Kyle Burchard, GPR, Inc. Date: 5/10/17 Witnessed by: - Unwitnessed - cation Address: Lot No. 960 -1010 Waltham Street Lexington, MA Owner's Name: Brookhaven Address: 1010 Waltham Street Lexington, MA Telephone No. N/A New Construction 0 Upgrade Repair El Office Review Published Soil Survey Available: No D Yes Year Published Internet Publication Scale ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, Soil Name Freetown Muck Soil Limitations , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Soil Name Narragansett- Hollis , , , , , , , , , Soil Limitations , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Soil Name Narragansett- Hollis , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Soil Limitations Surficial Geologic Report Available: No R1 Yes Year Published Publication Scale Geologic Material(Map Unit) Glacial Till Landform Ground Morraine na Soil Map Unit 52A, 106C, 106D Poorly Drained /Saturated Depth to Bedrock Depth to Bedrock Flood Insurance Rate Map: 250308 0005 B . . . . . . . . . . . . . . . . . . . . . . . . . . . . Above 500 Year Flood Boundary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . No El Yes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Within 500 Year Flood Boundary No °✓ Yes Within 100 Year Flood Boundary No R1 Yes Within Velocity Zone No R1 Yes Wetland Area: National Wetlands Inventory Map (map unit) N/A Wetlands Conservancy Program Map (map unit) N/A Current Water Resource Conditions (USGS): Month May Range: Above Normal D Normal R1 Below Normal Other Reference Reviewed USGS FORM 11- SOIL EVALUATOR FORM Location Address or Lot 4: 960 -1010 Waltham Street Lexington, MA On -Site Review Deep Hole #: TP17S -1 Date: 05/10/17 Time: 8:30 AM Location (identify on site plan) See Attached Sketch Land Use Developed Lawn Slope ( %) 2 -5% (eg woodland, agricultural field, vacant lot etc ... ) Vegatation Manicured Lawn Landform Ground Morraine Position on landscape See attached Sketch Distances from: Open Water Body >100 feet Drainage Way >100 feet Possible Wet Area 100± feet Property Line 153± feet Drinking Water Well >100 feet Other: feet Weather: Clear, 50° Surfaces Stones None Deep Observation Hole Log Hole 4 TP 17S -1 NB KB 1 Suface El. 231± Depth from Soil Soil Texture Soil Color Soil Other Surface Horizon (USDA) (MUNSELL) Mottling (Stucture, Stones, Boulders, (inches) Consistence, % Gravel) 0-12 A SL l OYR 4/6 - -- gr, mvfr, many roots 12-48 B SL 5Y 2/2 - -- sbk, mfr, small roots, 5% cob 48 -90 C SL 2.5Y 4/4 - -- sbk, mfr, boney, 15% cob, 5% g Parent Material (geologic) Abalation Till Depth to Bedrock: > 90 inches ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,........................... Depth to Groundwater: Standing Water in the Hole None Weeping from Pit Face: None Estimated Seasonal High Groundwater in the Hole >90 inches Additional Note - large fractured rock at bottom of hole, perhaps rippable, but beyond ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,:....,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,........................... capacity of excavator equipment. Mottling not encountered. Consistently ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, indicating imported fill. ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, FORM 11- SOIL EVALUATOR FORM Location Address or Lot 4: 960 -1010 Waltham Street Lexington, MA On -Site Review Deep Hole #: TP17S -2F Date: 05/10/17 Time: 9:10 AM Location (identify on site plan) See Attached Sketch Land Use Developed Lawn Slope ( %) 0 -3% (eg woodland, agricultural field, vacant lot etc ... ) Vegatation grass Landform Ground Morraine Position on landscape See attached Sketch Distances from: Open Water Body >100 feet Drainage Way >100 feet Possible Wet Area 131± feet Property Line 80± feet Drinking Water Well >100 feet Other: feet Weather: Clear, 50° Surfaces Stones none Deep Observation Hole Log Hole 4 TP 17S -2F NB KB 1 Suface El. 232± Depth from Soil Soil Texture Soil Color Soil Other Surface Horizon (USDA) (MUNSELL) Mottling (Stucture, Stones, Boulders, (inches) Consistence, % Gravel) 0 -12 A LS l OYR 2/2 - -- gr, mvfr, many roots 12 -20 B SL 10YR 3/6 - -- sbk, mvfr 20 -43 C 1 VFSL 10YR 3/4 - -- ma, mvfr, honey, 5% cob, 5% g 43 -92 C2 VFSL IOYR 4/1 (a,90" ma, mvfr, boney, 25% cob, 5 %g 10% f -m 2.5YR 4/8 Parent Material (geologic) Abalation Till Depth to Bedrock: > 92 inches ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,........................... Depth to Groundwater: Standing Water in the Hole None Weeping from Pit Face: None Estimated Seasonal High Groundwater in the Hole 90 inches Aditional Notes - large fractured rock at bottom of hole, perhaps rippable, but beyond ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,:....,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,........................... capacity of excavator equipment. Cobbles generally large stones, 6 " -18” dia. ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,,,,,,,,,,,,,,,,,,,,,,,,,,,, Substantially consisting of placed fill. C2 layer had significantly larger ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,,,,,,,,,,,,,,,,,,,,,,,,,,,, boulders, 12 " -18” dia. FORM 11- SOIL EVALUATOR FORM Location Address or Lot 4: 960 -1010 Waltham Street Lexington, MA On -Site Review Deep Hole #: TP17N -3 Date: 05/10/17 Time: 10:10 AM Location (identify on site plan) See Attached Sketch Land Use Woodland Slope ( %) 5 -15% (eg woodland, agricultural field, vacant lot etc ... ) Vegatation mixed hardwoods and pines Landform Ground Morraine Position on landscape See attached Sketch Distances from: Open Water Body >115 feet Drainage Way >115 feet Possible Wet Area 115± feet Property Line >60 feet Drinking Water Well >150 feet Other: feet Weather: Clear, 50° Surfaces Stones many Deep Observation Hole Log Hole 4 TP 17N -3 NB KB 1 Suface El. 236± Depth from Soil Soil Texture Soil Color Soil Other Surface Horizon (USDA) (MUNSELL) Mottling (Stucture, Stones, Boulders, (inches) Consistency, % Gravel) 0 -1 O - -- - -- - -- 1-10 A SL 10YR 3/3 - -- bk, mfr, many roots 10 -34 Bw VFSL 10YR 5/6 - -- sbk, mfr 34 -72 C GLS 2.5Y 3/2 � 48" gr, ml, boney, 20% cob, 15% g 5 -10% f -m 5YR 5/6 Parent Material (geologic) Abalation Till Depth to Bedrock: > 72 inches ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,........................... Depth to Groundwater: Standing Water in the Hole None Weeping from Pit Face: None Estimated Seasonal High Groundwater in the Hole 48 inches Aditional Notes - large fractured rock at bottom of hole, perhaps rippable, but beyond ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,:....,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,........................... capacity of excavator equipment. Cobbles generally 8 " -12” dia. ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, FORM 11- SOIL EVALUATOR FORM Location Address or Lot 4: 960 -1010 Waltham Street Lexington, MA On -Site Review Deep Hole #: TP17N -1 Date: 05/10/17 Time: 10:40 AM Location (identify on site plan) See Attached Sketch Land Use Woodland Slope ( %) 3 -10% (eg woodland, agricultural field, vacant lot etc ... ) Vegatation mixed hardwoods and pines Landform Ground Morraine Position on landscape See attached Sketch Distances from: Open Water Body >100 feet Drainage Way >100 feet Possible Wet Area >I 00 feet Property Line >60 feet Drinking Water Well >150 feet Other: feet Weather: Clear, 50° Surfaces Stones many Deep Observation Hole Log Hole 4 TP 17N -1 NB KB 1 Suface El. 232± Depth from Soil Soil Texture Soil Color Soil Other Surface Horizon (USDA) (MUNSELL) Mottling (Stucture, Stones, Boulders, (inches) Consistency, % Gravel) 0 -1 O - -- - -- - -- 1-12 A SL IOYR 2/4 - -- bk, mfr, many roots 12 -20 Bw GLS l OYR 4/6 - -- sbk, mfr 20 -56 C VGLS 2.5Y 4/1 � 45" gr, ml, boney, 20% cob, 10% g 5 -10% f -m 5YR 5/8 Parent Material (geologic) Abalation Till Depth to Bedrock: > 56 inches ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,........................... Depth to Groundwater: Standing Water in the Hole None Weeping from Pit Face: None Estimated Seasonal High Groundwater in the Hole 45 inches Aditional Notes - large fractured rock at bottom of hole, perhaps rippable, but beyond ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,:....,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,........................... capacity of excavator equipment. Cobbles generally 2 " -3” dia. ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, FORM 11- SOIL EVALUATOR FORM Location Address or Lot 4: 960 -1010 Waltham Street Lexington, MA On -Site Review Deep Hole #: TP17N -2 Date: 05/10/17 Time: 11:10 AM Location (identify on site plan) See Attached Sketch Land Use Woodland Slope ( %) 0 -3% (eg woodland, agricultural field, vacant lot etc ... ) Vegatation mixed hardwoods and pines Landform Ground Morraine Position on landscape See attached Sketch Distances from: Open Water Body >100 feet Drainage Way >100 feet Possible Wet Area >I 00 feet Property Line >44 feet Drinking Water Well >150 feet Other: feet Weather: Clear, 50° Surfaces Stones many Deep Observation Hole Log Hole 4 TP 17N -2 NB KB 1 Suface El. 236+/ - Depth from Soil Soil Texture Soil Color Soil Other Surface Horizon (USDA) (MUNSELL) Mottling (Stucture, Stones, Boulders, (inches) Consistency, % Gravel) 0 -1 O - -- - -- - -- 1-11 A SL 10YR 3/3 - -- bk, mfr, many roots 11 -26 Bw GLS IOYR 6/6 - -- sbk, mfr 26 -60 C VGLS 2.5YR 4/1 � 48" gr, ml, boney, 30% cob, 10% g 5 -10% f -m 5Y 6/6 Parent Material (geologic) Abalation Till Depth to Bedrock: >60 inches ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,........................... Depth to Groundwater: Standing Water in the Hole None Weeping from Pit Face: None Estimated Seasonal High Groundwater in the Hole 48 inches Aditional Notes large fractured rock at bottom of hole, perhaps rippable, but beyond ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,:....,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, „,,........................... capacity of excavator equipment. Cobbles generally 3 " -6” dia. ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, FORM 11 - SOIL EVALUATOR FORM Location Address or Lot#: 960 -1010 Waltham Street Lexington, MA Determination for Seasonal High Water Table Method Used: Depth observed standing in observation hole inches Depth weeping from side of observation hole inches Depth to soil mottles * inches See individual Reports Ground water adjustment feet Index Well Number Reading Date Index Well Level Adjustment Factor Adjusted Ground Water Level Depth of Naturally Occuring Pervious Material Does at least four feet of naturally occuring pervious material exist in all areas observed throughout the area proposed for the soil absorption system? Yes If not, what is the depth of naturally occuring pervious material? Feet Certification I certify that I am currently approved by the Department of Environmental Protection pursuant to 310 CMR 15.017 to conduct soil evaluations and that the above analysis has been performed by me consistent with the training, expertise and experience described in 310 CMR 15.017. I further certify that the results of my soil evaluation, as indicated, on the attached soil evaluation form, are accurate and in accordance with 310 CMR 15.100 through 15.107. Signature Notes: Date FORM 11 - SOIL EVALUATOR FORM No. 151067 Date: 11/13/15 Commonwealth of Massachusetts Lexington, Massachusetts Soil Suitability Assessment for Stormwater Management Performed by: Nicholas Pauling, PE, GPR, Inc. Date: 11/13/15 ........................................................................................ ............................... ...... ............................... Witnessed by: - Unwitnessed - Location Address: or Lot No. 960 Waltham Street Lexington, MA Owner's Name: Brookhaven Address: 1010 Waltham Street Lexington, MA Telephone No. N/A New Construction El Upgrade ❑ Repair ❑ Office Review Published Soil Survey Available: No ❑ Yes 0 Year Published Internet Publication Scale na Soil Map Unit 52A, 106C , 106D ........................ ............................... Soil Name Freetown Muck ----------------------------------------------------------- - - - Soil Limitations - -- ........ ............................... ------------------------------------------------------------------------------------------------------------------------ ............ ............................... Poorly Drained /Saturated Soil Name Narragansett- Hollis ................................... ............................... Soil Limitations ......................................................................................... Depth to Bedrock ............................... Soil Name Narragansett- Hollis Soil Limitations Depth to Bedrock ................................... ............................... Surficial Geologic Report Available: No 0 Yes ......................................................................................... ❑ ............................... Year Published Publication Scale . ............................... Geologic Material(Map Unit) ......................................................... ...... ............................... Glacial Till ............................... Landform Ground Morraine .................................................................................................. ............................... . Flood Insurance Rate Map: 250308 0005 B ...................................... Above 500 Year Flood Boundary ............................... No ❑ Yes � .............. ❑ Within 500 Year Flood Boundary No ❑ Yes ❑ Within 100 Year Flood Boundary No 0 Yes ❑ Within Velocity Zone No 0 Yes ❑ Wetland Area: National Wetlands Inventory Map (map unit) N/A ........... Wetlands Conservancy Program Map (map unit) N/A Current Water Resource Conditions (USGS): Month November .......................... Range: Above Normal ❑ Normal [3 Below Normal ❑,r Other Reference Reviewed USGS FORM 11 - SOIL EVALUATOR FORM Location Address or Lot #: 960 Waltham Street Lexington, MA On -Site Review Deep Hole #: SWM -1 Date: 11/13/15 Time: 7:45 AM Weather: Clear, 48° ----------------------- - - - - -- ------------------- - - - - -. -------------------------- - - - -.. ---------------------------------- Location (identify on site plan) See Attached Sketch ............................................................................................. ............................... Land Use Woodland Slope ( %) 7-10% Surfaces Stones Many ....................... ............................... ...... ............................... .... ............................... (eg woodland, agricultural field, vacant lot etc...) Vegatation mixed hardwoods and pines .................................................................. ............................... Landform Ground Morraine ................................................................... ............................... Position on landscape See attached Sketch ........................... ............................... Distances from: Open Water Body >100 feet Drainage Way >100 feet .............. ............... Possible Wet Area 100± feet Property Line 87± feet -------- - - - - -- --------- - - -... Drinking Water Well >100 feet Other: .............. feet Deep Observation Hole Log Hole # SWM -1 NB 27/11 Suface El. 225.5± Depth from Soil Soil Texture Soil Color Soil Other Surface Horizon (USDA) (MUNSELL) Mottling (Stucture, Stones, Boulders, (inches) Consistency, % Gravel) 0 - 11 A SL IOYR 2/2 - -- gr, mvfr, many roots 11 - 17 B SL 10YR 3/6 - -- sbk, mvfr 17-51 C SL 2.5Y 4/4 @ 42" ma, mvfr, boney, 15% cob, 5% g 5 -10% f -m 5YR 6/8 Parent Material (geologic) Abalation Till Depth to Bedrock: > 51 inches ............................................. ............................... ....... ............................... Depth to Groundwater: Standing Water in the Hole None Weeping from Pit Face: None . ............................... .................... Estimated Seasonal High Groundwater in the Hole 42 inches Aditional Notes - large boulder at bottom of hole ........................................................................................................................................................ ............................... . FORM 11 - SOIL EVALUATOR FORM Location Address or Lot #: 960 Waltham Street Lexington, MA On -Site Review Deep Hole #: SWM -2 Date: 11/13/15 Time: 8:18 AM ----------------------- - - - - -- ------------------- - - - - -. -------------------------- - - - -.. Location (identify on site plan) See Attached Sketch ....................................................... ............................... Land Use Woodland Slope ( %) 10-12% ....................... ............................... ...... ............................... (eg woodland, agricultural field, vacant lot etc...) Vegatation mixed hardwoods and pines .................................................................. ............................... Landform Ground Morraine ................................................................... ............................... Position on landscape See attached Sketch ........................... ............................... Distances from: Open Water Body >100 feet Drainage Way >100 feet .............. ............... Possible Wet Area 113± feet Property Line 165± feet -------- - - - - -- --------- - - -... Drinking Water Well >100 feet Other: feet Weather: Clear, 48° ................................... Surfaces Stones many Deep Observation Hole Log Hole # SWM -2 NB 27/11 Suface El. 229.6± Depth from Soil Soil Texture Soil Color Soil Other Surface Horizon (USDA) (MUNSELL) Mottling (Stucture, Stones, Boulders, (inches) Consistency, % Gravel) 0 - 9 A SL IOYR 2/2 - -- gr, mvfr, many roots 9-16 B SL 10YR 3/6 - -- sbk, mvfr 16-62 C SL 2.5Y 4/4 @ 38" ma, mvfr, boney, 20% cob, 5% g 5 -10% f -m 5YR 6/8 Parent Material (geologic) Abalation Till Depth to Bedrock: > 62 inches ............................................. ............................... ....... ............................... Depth to Groundwater: Standing Water in the Hole None Weeping from Pit Face: None . ............................... .................... Estimated Seasonal High Groundwater in the Hole 38 inches Aditional Notes FORM 11 - SOIL EVALUATOR FORM Location Address or Lot #: 960 Waltham Street Lexington, MA On -Site Review Deep Hole #: SWM -3 Date: 11/13/15 Time: 8:10 AM ----------------------- - - - - -- ------------------- - - - - -. -------------------------- - - - -.. Location (identify on site plan) See Attached Sketch ....................................................... ............................... Land Use Woodland Slope ( %) 5-7% ....................... ............................... ...... ............................... (eg woodland, agricultural field, vacant lot etc...) Vegatation mixed hardwoods and pines .................................................................. ............................... Landform Ground Morraine ................................................................... ............................... Position on landscape See attached Sketch ........................... ............................... Distances from: Open Water Body >150 feet Drainage Way >150 feet .............. ............... feet Property Line Possible Wet Area 69± >150 feet -------- - - - --- --------- - - -... Drinking Water Well >150 feet Other: .............. feet Weather: Clear, 48° ................................... Surfaces Stones many Deep Observation Hole Log Hole # SWM -3 NB 27/11 Suface El. 223.8± Depth from Soil Soil Texture Soil Color Soil Other Surface Horizon (USDA) (MUNSELL) Mottling (Stucture, Stones, Boulders, (inches) Consistency, % Gravel) 0 - 9 A SL IOYR 2/2 - -- gr, mvfr, many roots 9-14 B SL 10YR 3/6 - -- sbk, mvfr 14-41 C SL 2.5Y 4/4 @ 28" ma, mvfr, boney, 15% cob, 5% g 5 -10% f -m 5YR 6/8 Parent Material (geologic) Abalation Till Depth to Bedrock: > 41 inches ............................................. ............................... ....... ............................... Depth to Groundwater: Standing Water in the Hole None Weeping from Pit Face: None . ............................... .................... Estimated Seasonal High Groundwater in the Hole 28 inches Aditional Notes FORM 11 - SOIL EVALUATOR FORM Location Address or Lot #: 960 Waltham Street Lexington, MA Determination for Seasonal Hiah Water Table Method Used: ❑ Depth observed standing in observation hole inches 13 Depth weeping from side of observation hole inches 10 Depth to soil mottles * inches See individual Reports ❑ Ground water adjustment feet Index Well Number Reading Date ............................ I........ Adjustment Factor Adjusted Ground Water Level Depth of Naturally Occuring Pervious Material Index Well Level Does at least four feet of naturally occuring pervious material exist in all areas observed throughout the area proposed for the soil absorption system? Yes If not, what is the depth of naturally occuring pervious material? Feet Certification I certify that I am currently approved by the Department of Environmental Protection pursuant to 310 CMR 15.017 to conduct soil evaluations and that the above analysis has been performed by me consistent with the training, expertise and experience described in 310 CMR 15.017. I further certify that the results of my soil evaluation, as indicated, on the attached soil evaluation form, are accurate and in accordance with 310 CMR 15.100 through 15.107. Signature Date Notes: Section 5 Appendix Hydrologic Soil Group — Middlesex County, Massachusetts o v 316200 316300 316400 316500 316600 316700 316800 42° 25' 13" N 316900 316800 316900 42° 24'36" N 317000 o 6/13/2017 Page 1 of 5 Z O Q O LL Z Ca G 0 Z W W J CL Q m N Q CL m m E N N O Q 7 O T N y Q E O U (6 t y T N 7 N O O 00 N � N H O O � 7 U O p 6 U O O 6) 'E E U m m Q m —_ Q O N U (6 C E C tl) E m y Zi n O O O m m O- p U m = N = y E in > O O N C > cu Q O N p Q 6 > Q (U U m y E E m m E c -: O C m N tl) c/) a� N E rn C p) E E N 7 Q N (� y m o 0 2 W E U vpi m 0) M UU) UN ) -0 Q (0 m 3 O E 9 � E O 6 3 p C U E O N 7 U 7 E f0A u O N O m U) 6" (n t p 0 0 N � Q y U (') (C) Q .j C t o m m a) O N tl) N CJ U Q N Z y 0 tl) y (n � N m m N 2i '6 O > m CL d N y 7 m Q O N � N O LL N C O U O V 1) � `~ m N t tl) Q m Q m Q C tl) O C p U N O w a m U C O N 3 (n m O Q'— (�j N N p U O N O Q �O (o Q E 30 >, N U O U (O tl) O E >, m tl) O N E S N m O-0 N Q N m E N N � 7 y U O N w '6 y 0 N m- m m U N N �� O O O C y o� UoN �_� '3- J (n (n Q C N— i Q y C O m Q Q (Oj C N Utl) m N O N p C y Q N 2 '6 m Q 0 70 C (6 n E >' E (n - E m 6 U 7 fA 7 0 N C O U p C 0 O N N O O O Q O_ O m V > m O N (OA N (i(n U) U O-N (n N EO yO 0-QN N m p > tl� O O O U N a E n > U 2 Q'6 Q m U) (n (n — — N (4 y N C N L m °- o U L ° o a N 0 N L m o m a y w m `o m U U o Z in O Q R R C N 7 ® ® ® ® " O OL OI d y Y F m o � a o y `o OC O w 0) y a o a w c H a. o 0 0 0 Q rn Q a m o Z rn Q v R y 1119 El 11 p O p 0 y y Q co .j 0 0 a y m � 0 0 0 o a. o 0 a m m U U o z 0) Q a m m S 0 y I- U) O O N N (2 N � 6) IL T N 7 � O 7 N m O N (n Q Q O U m 0 m Z U L v d 7 Cl) O y . O > L L 7 N w 0 (0 O Z U O m N (4 y N C N L m °- o U L ° o a N 0 N L m o m a y w m `o m U U o Z in O Q R R C N 7 ® ® ® ® " O OL OI d y Y F m o � a o y `o OC O w 0) y a o a w c H a. o 0 0 0 Q rn Q a m o Z rn Q v R y 1119 El 11 p O p 0 y y Q co .j 0 0 a y m � 0 0 0 o a. o 0 a m m U U o z 0) Q a m m S 0 y I- U) O O N N (2 N � 6) IL T N 7 � O 7 N m O N (n Q Q O U m 0 m Z U L v d 7 Cl) O y . O > L L 7 N w 0 (0 O Z U .j 0 0 a y m � 0 0 0 o a. o 0 a m m U U o z 0) Q a m m S 0 y I- U) O O N N (2 N � 6) IL T N 7 � O 7 N m O N (n Q Q O U m 0 m Z U L v d 7 Cl) O y . O > L L 7 N w 0 (0 O Z U Hydrologic Soil Group - Middlesex County, Massachusetts Hydrologic Soil Group Hydrologic Soil Group- Summary by Map Unit - Middlesex County, Massachusetts (MA017) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 1 Water 2.0 1.5% 30B Raynham silt loam, 0 to C/D 6.4 4.7% 5 percent slopes 51A Swansea muck, 0 to 1 B/D 1.1 0.8% percent slopes 52A Freetown muck, 0 to 1 B/D 26.8 19.9% percent slopes 73B Whitman fine sandy D 1.1 0.8% loam, 0 to 3 percent slopes, extremely sto ny 104C Hollis -Rock outcrop- D 0.6 0.4% Charlton complex, 0 to 15 percent slopes 104D Hollis -Rock outcrop- A 4.8 3.6% Charlton complex, 15 to 25 percent slopes 106C Narragansett - Hollis- A 33.7 25.0% Rock outcrop complex, 3 to 15 percent slopes 106D Narragansett - Hollis- A 9.4 7.0% Rock outcrop complex, 15 to 25 percent slopes 251 B Haven silt loam, 3 to 8 A 1.9 1.4% percent slopes 261 A Tisbury silt loam, 0 to 3 C 0.9 0.6% percent slopes 262B Quonset sandy loam, 3 A 1.7 1.3% to 8 percent slopes 415C Narragansett silt loam, 8 A 9.1 6.7% to 15 percent slopes 416B Narragansett silt loam, 3 A 3.4 2.5% to 8 percent slopes, very stony 416C Narragansett silt loam, 8 A 3.8 2.8% to 15 percent slopes, very stony 424D Canton fine sandy loam, A 8.0 5.9% 15 to 25 percent slopes, extremely bouldery 602 Urban land 3.8 2.8% USIA Natural Resources Web Soil Survey 6/13/2017 :ice Conservation Service National Cooperative Soil Survey Page 3 of 5 Hydrologic Soil Group — Middlesex County, Massachusetts Hydrologic Soil Group— Summary by Map Unit — Middlesex County, Massachusetts (MA017) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 631 C Charlton -Urban land- A 5.5 4.1% Hollis complex, 3 to 15 percent slopes, rocky 652 Udorthents, refuse 2.4 1.8% substratum 654 Udorthents, loamy 2.4 1.8% 656 Udorthents -Urban land 6.2 4.6% complex Totals for Area of Interest 134.9 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long- duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A /D, B /D, and C /D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A /D, B /D, or C /D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. 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S--- -_ \......-C - - - -_ \....S.c..� �xs }GCB DB Cxs} Cs° ZM X. DET.B I CB19 ca CB1 X� MH CB$ CB16 \ \ MH12 q p ca cB�T a ST ce�e ca Q Q Q ce I I I CB3 B4 � Ex sra Ex. sce �S °} M�,o �S °} cea zo � az, CS °)21__'' C °} .22 Subcat Reach on Link Brookhaven, Lexington, MA 151067 2017 PRE Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq -ft) (s u bcatch me nt -n u m be rs) 90,679 61 >75% Grass cover, Good, HSG B (EX. SC -16, EX. SC -17, EX. SC -18, EX. SC -20, EX. SC -21, EX. SC -22, EX. SC -3, EX. SC -4, EX. SC -6, EX. SC -8, EX. SC -A, EX. SC -B, EX. SC -D) 112,690 80 >75% Grass cover, Good, HSG D (EX. SC -1, EX. SC -15, EX. SC -16, EX. SC -18, EX. SC -2, EX. SC -3, EX. SC -4, EX. SC -5, EX. SC -6, EX. SC -8, EX. SC -9, EX. SC -A, EX. SC -B, EX. SC -C, EX. SC -D) 495 96 Gravel surface, HSG B (EX. SC -D) 3,133 96 Gravel surface, HSG D (EX. SC -A, EX. SC -B, EX. SC -D) 4,600 98 Ledge, HSG B (EX. SC -A, EX. SC -D) 55,279 98 Paved parking, HSG A (EX. SC -D) 221,472 98 Paved parking, HSG B (EX. SC -16, EX. SC -17, EX. SC -18, EX. SC -19, EX. SC -20, EX. SC -21, EX. SC -22, EX. SC -3, EX. SC -4, EX. SC -A, EX. SC -D) 129,049 98 Paved parking, HSG D (EX. SC -1, EX. SC -16, EX. SC -18, EX. SC -19, EX. SC -2, EX. SC -3, EX. SC -4, EX. SC -A, EX. SC -C, EX. SC -D) 63,578 98 Roofs, HSG B (EX. SC -16, EX. SC -17, EX. SC -18, EX. SC -20, EX. SC -21, EX. SC -22, EX. SC -4, EX. SC -6, EX. SC -8, EX. SC -R, EX. SC -ST) 8,258 98 Roofs, HSG D (EX. SC -16, EX. SC -18, EX. SC -8, EX. SC -C, EX. SC -D) 347,789 30 Woods, Good, HSG A (EX. SC -D) 715,199 55 Woods, Good, HSG B (EX. SC -A, EX. SC -B, EX. SC -D) 1,088,315 77 Woods, Good, HSG D (EX. SC -A, EX. SC -B, EX. SC -C, EX. SC -D) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment EX. SC -1: Runoff = 0.16 cfs @ 12.08 hrs, Volume= 485 cf, Depth= 1.53" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 1,735 80 >75% Grass cover, Good, HSG D 2,065 98 Paved parking, HSG D 3,800 90 Weighted Average 1,735 45.66% Pervious Area 2,065 54.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -15: Runoff = 0.04 cfs @ 12.09 hrs, Volume= 128 cf, Depth= 0.89" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 1,734 80 >75% Grass cover, Good, HSG D 1,734 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -16: Runoff = 1.71 cfs @ 12.08 hrs, Volume= 5,311 cf, Depth= 1.45" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 4 Area (sf) CN Description 4,653 98 Roofs, HSG B 6,123 98 Roofs, HSG D 2,023 61 >75% Grass cover, Good, HSG B 8,447 80 >75% Grass cover, Good, HSG D 2,473 98 Paved parking, HSG B 10,524 98 Paved parking, HSG D 176 80 >75% Grass cover, Good, HSG D 9,390 80 >75% Grass cover, Good, HSG D 43,809 89 Weighted Average 20,036 45.73% Pervious Area 23,773 54.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -17: Runoff = 0.27 cfs @ 12.08 hrs, Volume= 853 cf, Depth= 1.18" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 1,325 98 Roofs, HSG B 2,993 61 >75% Grass cover, Good, HSG B 4,366 98 Paved parking, HSG B 8,684 85 Weighted Average 2,993 34.47% Pervious Area 5,691 65.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -18: Runoff = 1.49 cfs @ 12.08 hrs, Volume= 4,600 cf, Depth= 1.38" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 5 Area (so CN Description 13,935 98 Roofs, HSG B 803 98 Roofs, HSG D 9,943 61 >75% Grass cover, Good, HSG B 2,229 80 >75% Grass cover, Good, HSG D 8,923 98 Paved parking, HSG B 4.124 98 Paved oarkina. HSG D 39,957 88 Weighted Average 12,172 30.46% Pervious Area 27,785 69.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -19: Runoff = 0.58 cfs @ 12.07 hrs, Volume= 1,983 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 5,245 98 Paved parking, HSG B 5,234 98 Paved parking, HSG D 10,479 98 Weighted Average 10,479 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -2: Runoff = 0.17 cfs @ 12.07 hrs, Volume= 574 cf, Depth= 2.16" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 3,071 98 Paved parking, HSG D 110 80 >75% Grass cover. Good. HSG D 3,181 97 Weighted Average 110 3.46% Pervious Area 3,071 96.54% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 6 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -20: Runoff = 0.40 cfs @ 12.09 hrs, Volume= 1,357 cf, Depth= 0.69" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 7,685 98 Roofs, HSG B 13,660 61 >75% Grass cover, Good, HSG B 2,108 98 Paved parking, HSG B 23,453 76 Weighted Average 13,660 58.24% Pervious Area 9,793 41.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -21: Runoff = 0.65 cfs @ 12.08 hrs, Volume= 2,024 cf, Depth= 1.31" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 5,373 98 Roofs, HSG B 5,318 61 >75% Grass cover, Good, HSG B 7.833 98 Paved oarkina. HSG B 18,524 87 Weighted Average 5,318 28.71 % Pervious Area 13,206 71.29% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -22: Runoff = 0.43 cfs @ 12.09 hrs, Volume= 1,418 cf, Depth= 0.79" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 7 Area (so CN Description 1,599 98 Roofs, HSG B 11,736 61 >75% Grass cover, Good, HSG B 8,266 98 Paved parking, HSG B 21,601 78 Weighted Average 11,736 79 54.33% Pervious Area 9,865 82 45.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment EX. SC -3: Runoff = 0.29 cfs @ 12.09 hrs, Volume= 929 cf, Depth= 0.84" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 6,580 61 >75% Grass cover, Good, HSG B 263 80 >75% Grass cover, Good, HSG D 6,168 98 Paved parking, HSG B 302 98 Paved parking, HSG D 13,313 79 Weighted Average 6,843 82 51.40% Pervious Area 6,470 48.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -4: Runoff = 0.54 cfs @ 12.08 hrs, Volume= 1,707 cf, Depth= 1.00" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 4,903 98 Roofs, HSG B 8,496 61 >75% Grass cover, Good, HSG B 1,023 80 >75% Grass cover, Good, HSG D 5,266 98 Paved parking, HSG B 688 98 Paved parking, HSG D 143 80 >75% Grass cover, Good, HSG D 20,519 82 Weighted Average 9,662 47.09% Pervious Area 10,857 52.91% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 8 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -5: Runoff = 0.10 cfs @ 12.09 hrs, Volume= 320 cf, Depth= 0.89" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 4,324 80 >75% Grass cover, Good, HSG D 4,324 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -6: Runoff = 0.49 cfs @ 12.09 hrs, Volume= 1,678 cf, Depth= 0.65" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 1,621 98 Roofs, HSG B 8,776 61 >75% Grass cover, Good, HSG B 9,312 80 >75% Grass cover, Good, HSG D 528 61 >75% Grass cover, Good, HSG B 10,715 80 >75% Grass cover, Good, HSG D 30,952 75 Weighted Average 29,331 94.76% Pervious Area 1,621 5.24% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -8: Runoff = 0.58 cfs @ 12.09 hrs, Volume= 1,878 cf, Depth= 0.84" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 9 Area (so CN Description 8,924 98 Roofs, HSG B 1,282 98 Roofs, HSG D 2,977 61 >75% Grass cover, Good, HSG B 1,631 80 >75% Grass cover, Good, HSG D 8,459 61 >75% Grass cover, Good, HSG B 3.635 80 >75% Grass cover. Good. HSG D 26,908 79 Weighted Average 16,702 62.07% Pervious Area 10,206 37.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -9: Runoff = 0.04 cfs @ 12.09 hrs, Volume= 124 cf, Depth= 0.89" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 1,680 80 >75% Grass cover, Good, HSG D 1,680 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -A: Runoff = 0.66 cfs @ 12.15 hrs, Volume= 3,362 cf, Depth= 0.36" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 2,268 61 >75% Grass cover, Good, HSG B 16,260 80 >75% Grass cover, Good, HSG D 2,973 98 Paved parking, HSG B 627 98 Paved parking, HSG D 56,294 55 Woods, Good, HSG B 32,414 77 Woods, Good, HSG D 647 98 Ledge, HSG B 1,746 96 Gravel surface, HSG D 113,229 67 Weighted Average 108,982 96.25% Pervious Area 4,247 3.75% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 10 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 2.4 30 0.5000 0.21 Sheet Flow, 77 Woods, Good, HSG D 1,274 Woods: Light underbrush n= 0.400 P2= 2.80" 0.4 85 0.5000 3.54 Shallow Concentrated Flow, 62,991 100.00% Pervious Area Woodland Kv= 5.0 fps 0.9 105 0.1430 1.89 Shallow Concentrated Flow, (ft/ft) (ft /sec) (cfs) 2.4 30 Woodland Kv= 5.0 fps 0.5 45 0.0890 1.49 Shallow Concentrated Flow, 0.5 110 0.5000 3.54 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 1.5 130 0.0846 1.45 Shallow Concentrated Flow, 0.2500 7.50 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.2 50 0.0600 3.67 Shallow Concentrated Flow, Woodland Kv= 5.0 fps Grassed Waterway Kv= 15.0 fps 1.0 56 0.0357 0.94 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 1.2 49 Woodland Kv= 5.0 fps 6.9 501 Total Summary for Subcatchment EX. SC -B: Runoff = 0.21 cfs @ 12.15 hrs, Volume= 1,418 cf, Depth= 0.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 6,337 61 >75% Grass cover, Good, HSG B 13,753 80 >75% Grass cover, Good, HSG D 34,537 55 Woods, Good, HSG B 7,090 77 Woods, Good, HSG D 1,274 96 Gravel surface, HSG D 62,991 64 Weighted Average 62,991 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 2.4 30 0.5000 0.21 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 0.5 110 0.5000 3.54 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.1 42 0.2500 7.50 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.7 136 0.3680 3.03 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.3 85 0.1170 5.13 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 1.2 49 0.0200 0.71 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 5.2 452 Total Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment EX. SC -C: Runoff = 0.86 cfs @ 12.20 hrs, Volume= 3,591 cf, Depth= 0.79" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 18 98 Roofs, HSG D 15,388 80 >75% Grass cover, Good, HSG D 28 98 Paved parking, HSG D 39,256 77 Woods, Good, HSG D 54,690 78 Weighted Average 54,644 99.92% Pervious Area 46 0.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 6.1 30 0.0070 0.08 Sheet Flow, 102,386 98 Paved parking, HSG D 347,789 Grass: Short n=0.150 P2=2.80" 7.0 488 0.0060 1.16 Shallow Concentrated Flow, 77 Woods, Good, HSG D 3,953 98 Grassed Waterwav Kv= 15.0 fps 13.1 518 Total Summary for Subcatchment EX. SC -D: Runoff = 13.53 cfs @ 12.14 hrs, Volume= 68,988 cf, Depth= 0.36" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 32 98 Roofs, HSG D 585 61 >75% Grass cover, Good, HSG B 10,742 80 >75% Grass cover, Good, HSG D 55,279 98 Paved parking, HSG A 167,851 98 Paved parking, HSG B 102,386 98 Paved parking, HSG D 347,789 30 Woods, Good, HSG A 624,368 55 Woods, Good, HSG B 1,009,555 77 Woods, Good, HSG D 3,953 98 Ledge, HSG B 495 96 Gravel surface, HSG B 113 96 Gravel surface, HSG D 2,323,148 67 Weighted Average 1,993,647 85.82% Pervious Area 329,501 14.18% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 12 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 3.3 30 0.0330 0.15 Sheet Flow, Grass: Short n=0.150 P2=2.80" 0.3 118 0.2550 7.57 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.3 57 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.0 705 0.0850 5.92 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 165 0.0480 3.29 Shallow Concentrated Flow, Grassed Waterwav Kv= 15.0 fps 6.7 1,075 Total Summary for Subcatchment EX. SC -R: Runoff = 0.28 cfs @ 12.07 hrs, Volume= 963 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 5,090 98 Roofs, HSG B 5,090 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -ST: Runoff = 0.47 cfs @ 12.07 hrs, Volume= 1,603 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 8,470 98 Roofs, HSG B 8,470 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 13 Summary for Reach R1: Inflow Area = 2,727,307 sf, 17.53% Impervious, Inflow Depth > 0.30" for 1 -Year event Inflow = 7.59 cfs @ 12.14 hrs, Volume= 69,006 cf Outflow = 6.85 cfs @ 12.20 hrs, Volume= 68,888 cf, Atten= 10 %, Lag= 3.4 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 1.22 fps, Min. Travel Time= 4.4 min Avg. Velocity = 0.32 fps, Avg. Travel Time= 17.0 min Peak Storage= 1,820 cf @ 12.20 hrs Average Depth at Peak Storage= 0.44' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 56.94 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 324.0' Slope= 0.00287' Inlet Invert= 218.80', Outlet Invert= 217.90' H Inflow Area = Inflow = Outflow = Summary for Reach R2: 2,323,148 sf, 14.18% Impervious, Inflow Depth > 0.20" for 1 -Year event 0.27 cfs @ 24.00 hrs, Volume= 38,119 cf 0.27 cfs @ 24.03 hrs, Volume= 38,017 cf, Atten= 0 %, Lag= 1.7 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 0.26 fps, Min. Travel Time= 13.4 min Avg. Velocity = 0.21 fps, Avg. Travel Time= 16.1 min Peak Storage= 216 cf @ 24.03 hrs Average Depth at Peak Storage= 0.09' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 33.66 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 206.0' Slope= 0.0010 '/' Inlet Invert= 219.00', Outlet Invert= 218.80' Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 14 Summary for Pond C1131: Inflow Area = 3,800 sf, 54.34% Impervious, Inflow Depth = 1.53" for 1 -Year event Inflow = 0.16 cfs @ 12.08 hrs, Volume= 485 cf Outflow = 0.16 cfs @ 12.08 hrs, Volume= 485 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.16 cfs @ 12.08 hrs, Volume= 485 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.27' @ 12.08 hrs Flood Elev= 221.25' Device Routing Invert Outlet Devices #1 Primary 224.92' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.15 cfs @ 12.08 hrs HW= 226.20' (Free Discharge) L1= Orifice /Grate (Orifice Controls 0.15 cfs @ 5.45 fps) Summary for Pond CB15: Inflow Area = 1,734 sf, 0.00% Impervious, Inflow Depth = 0.89" for 1 -Year event Inflow = 0.04 cfs @ 12.09 hrs, Volume= 128 cf Outflow = 0.04 cfs @ 12.09 hrs, Volume= 128 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.04 cfs @ 12.09 hrs, Volume= 128 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.19' @ 12.08 hrs Flood Elev= 229.32' Device Routing Invert Outlet Devices #1 Primary 225.10' 12.0" Round Culvert L= 19.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.10'/222.83' S=0.1195'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.04 cfs @ 12.09 hrs HW= 225.19' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.04 cfs @ 1.04 fps) Summary for Pond CB16: Inflow Area = 43,809 sf, 54.27% Impervious, Inflow Depth = 1.45" for 1 -Year event Inflow = 1.71 cfs @ 12.08 hrs, Volume= 5,311 cf Outflow = 1.71 cfs @ 12.08 hrs, Volume= 5,311 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.71 cfs @ 12.08 hrs, Volume= 5,311 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.42' @ 12.08 hrs Flood Elev= 229.50' Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 15 Device Routing Invert Outlet Devices #1 Primary 225.71' 12.0" Round Culvert L= 9.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.71'/222.83' S=0.3200'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.66 cfs @ 12.08 hrs HW= 226.41' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.66 cfs @ 2.84 fps) Summary for Pond CB17: Inflow Area = 8,684 sf, 65.53% Impervious, Inflow Depth = 1.18" for 1 -Year event Inflow = 0.27 cfs @ 12.08 hrs, Volume= 853 cf Outflow = 0.27 cfs @ 12.08 hrs, Volume= 853 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.27 cfs @ 12.08 hrs, Volume= 853 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.52' @ 12.08 hrs Flood Elev= 228.31' Device Routing Invert Outlet Devices #1 Primary 225.13' 12.0" Round Culvert L= 80.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.13'/225.07' S=0.0008'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.27 cfs @ 12.08 hrs HW= 225.52' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.27 cfs @ 1.40 fps) Summary for Pond CB18: Inflow Area = 39,957 sf, 69.54% Impervious, Inflow Depth = 1.38" for 1 -Year event Inflow = 1.49 cfs @ 12.08 hrs, Volume= 4,600 cf Outflow = 1.49 cfs @ 12.08 hrs, Volume= 4,600 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.49 cfs @ 12.08 hrs, Volume= 4,600 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.98' @ 12.08 hrs Flood Elev= 234.91' Device Routing Invert Outlet Devices #1 Primary 230.25' 12.0" Round Culvert L= 14.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.25'/230.10' S=0.0103'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.44 cfs @ 12.08 hrs HW= 230.96' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.44 cfs @ 3.37 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 16 Summary for Pond CB19: Inflow Area = 10,479 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.58 cfs @ 12.07 hrs, Volume= 1,983 cf Outflow = 0.58 cfs @ 12.07 hrs, Volume= 1,983 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.58 cfs @ 12.07 hrs, Volume= 1,983 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.61' @ 12.07 hrs Flood Elev= 235.05' Device Routing Invert Outlet Devices #1 Primary 230.16' 12.0" Round Culvert L= 6.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.16'/230.10' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.56 cfs @ 12.07 hrs HW= 230.60' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.56 cfs @ 2.50 fps) Summary for Pond C1132: Inflow Area = 6,981 sf, 73.57% Impervious, Inflow Depth = 1.82" for 1 -Year event Inflow = 0.33 cfs @ 12.07 hrs, Volume= 1,058 cf Outflow = 0.33 cfs @ 12.07 hrs, Volume= 1,058 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.33 cfs @ 12.07 hrs, Volume= 1,058 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 218.55' @ 12.07 hrs Flood Elev= 225.01' Device Ro Invert Outlet Devices #1 Primary 218.16' 12.0" Round Culvert L= 135.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.16'/ 217.88' S= 0.0021 T Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.32 cfs @ 12.07 hrs HW= 218.54' (Free Discharge) L1= Culvert (Barrel Controls 0.32 cfs @ 1.72 fps) Summary for Pond CB20: Inflow Area = 23,453 sf, 41.76% Impervious, Inflow Depth = 0.69" for 1 -Year event Inflow = 0.40 cfs @ 12.09 hrs, Volume= 1,357 cf Outflow = 0.40 cfs @ 12.09 hrs, Volume= 1,357 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.40 cfs @ 12.09 hrs, Volume= 1,357 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 17 Peak Elev= 236.24' @ 12.09 hrs Flood Elev= 239.00' Device Routing Invert Outlet Devices #1 Primary 235.70' 6.0" Round Culvert L= 143.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 235.70'/228.93' S=0.0472'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 0.20 sf Primary OutFlow Max =0.40 cfs @ 12.09 hrs HW= 236.23' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.40 cfs @ 2.01 fps) Summary for Pond CB21: Inflow Area = 18,524 sf, 71.29% Impervious, Inflow Depth = 1.31" for 1 -Year event Inflow = 0.65 cfs @ 12.08 hrs, Volume= 2,024 cf Outflow = 0.65 cfs @ 12.08 hrs, Volume= 2,024 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.65 cfs @ 12.08 hrs, Volume= 2,024 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.30' @ 12.08 hrs Flood Elev= 247.80' Device Routing Invert Outlet Devices #1 Primary 243.80' 12.0" Round Culvert L= 25.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.80'/243.70' S=0.0039'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.63 cfs @ 12.08 hrs HW= 244.29' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.63 cfs @ 2.43 fps) Summary for Pond CB22: Inflow Area = 21,601 sf, 45.67% Impervious, Inflow Depth = 0.79" for 1 -Year event Inflow = 0.43 cfs @ 12.09 hrs, Volume= 1,418 cf Outflow = 0.43 cfs @ 12.09 hrs, Volume= 1,418 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.43 cfs @ 12.09 hrs, Volume= 1,418 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.08' @ 12.09 hrs Flood Elev= 247.90' Device Routing Invert Outlet Devices #1 Primary 243.70' 12.0" Round Culvert L= 16.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.70'/243.60' S=0.0062'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 18 Primary OutFlow Max =0.42 cfs @ 12.09 hrs HW= 244.07' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.42 cfs @ 2.34 fps) Summary for Pond C1133: Inflow Area = 36,766 sf, 44.23% Impervious, Inflow Depth = 0.75" for 1 -Year event Inflow = 0.69 cfs @ 12.09 hrs, Volume= 2,286 cf Outflow = 0.69 cfs @ 12.09 hrs, Volume= 2,286 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.69 cfs @ 12.09 hrs, Volume= 2,286 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.35' @ 12.09 hrs Flood Elev= 231.88' Device Routing Invert Outlet Devices #1 Primary 228.93' 12.0" Round Culvert L= 16.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.93'/227.98' S=0.0576'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.67 cfs @ 12.09 hrs HW= 229.34' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.67 cfs @ 2.19 fps) Summary for Pond C1134: Inflow Area = 20,519 sf, 52.91% Impervious, Inflow Depth = 1.00" for 1 -Year event Inflow = 0.54 cfs @ 12.08 hrs, Volume= 1,707 cf Outflow = 0.54 cfs @ 12.08 hrs, Volume= 1,707 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.54 cfs @ 12.08 hrs, Volume= 1,707 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.01' @ 12.08 hrs Flood Elev= 232.11' Device Routing Invert Outlet Devices #1 Primary 229.64' 12.0" Round Culvert L= 31.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.64'/227.96' S=0.0542'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.53 cfs @ 12.08 hrs HW= 230.00' (Free Discharge) t--1 =Culvert (Inlet Controls 0.53 cfs @ 2.05 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 19 Summary for Pond CBS: Inflow Area = 35,276 sf, 4.60% Impervious, Inflow = 0.59 cfs @ 12.09 hrs, Volume= Outflow = 0.59 cfs @ 12.09 hrs, Volume= Primary = 0.59 cfs @ 12.09 hrs, Volume= Inflow Depth = 0.68" 1,998 cf 1,998 cf, 1,998 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.29' @ 12.09 hrs Flood Elev= 227.10' for 1 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 222.90' 12.0" Round Culvert L= 34.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.90'/218.20' S=0.1382'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.58 cfs @ 12.09 hrs HW= 223.28' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.58 cfs @ 2.10 fps) Summary for Pond C1136: Inflow Area = 30,952 sf, 5.24% Impervious, Inflow = 0.49 cfs @ 12.09 hrs, Volume= Outflow = 0.49 cfs @ 12.09 hrs, Volume= Primary = 0.49 cfs @ 12.09 hrs, Volume= Inflow Depth = 0.65" 1,678 cf 1,678 cf, 1,678 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.02' @ 12.09 hrs Flood Elev= 227.46' Device Ro Invert Outlet Devices for 1 -Year event Atten= 0 %, Lag= 0.0 min #1 Primary 223.66' 12.0" Round Culvert L= 22.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 223.66'/223.42' S=0.0107'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.48 cfs @ 12.09 hrs HW= 224.02' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.48 cfs @ 2.84 fps) Summary for Pond CBB: Inflow Area = 26,908 sf, 37.93% Impervious, Inflow = 0.58 cfs @ 12.09 hrs, Volume= Outflow = 0.58 cfs @ 12.09 hrs, Volume= Primary = 0.58 cfs @ 12.09 hrs, Volume= Inflow Depth = 0.84" 1,878 cf 1,878 cf, 1,878 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs for 1 -Year event Atten= 0 %, Lag= 0.0 min Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 20 Peak Elev= 226.13' @ 12.09 hrs Flood Elev= 229.38' Device Routing Invert Outlet Devices #1 Primary 225.75' 12.0" Round Culvert L= 20.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.75'/225.15' S=0.0293'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.56 cfs @ 12.09 hrs HW= 226.13' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.56 cfs @ 2.09 fps) Summary for Pond C1139: Inflow Area = 1,680 sf, 0.00% Impervious, Inflow Depth = 0.89" for 1 -Year event Inflow = 0.04 cfs @ 12.09 hrs, Volume= 124 cf Outflow = 0.04 cfs @ 12.09 hrs, Volume= 124 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.04 cfs @ 12.09 hrs, Volume= 124 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.81' @ 12.09 hrs Flood Elev= 229.72' Device Routing Invert Outlet Devices #1 Primary 225.72' 12.0" Round Culvert L= 22.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.72'/225.15' S=0.0253'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.04 cfs @ 12.09 hrs HW= 225.81' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.04 cfs @ 1.03 fps) Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.79' @ 12.14 hrs Surf.Area= 4,415 sf Storage= 2,272 cf Plug -Flow detention time= 5.4 min calculated for 29,550 cf (100% of inflow) Center -of -Mass det. time= 5.1 min ( 844.1 - 838.9 ) Volume Invert Avail.Storage Storage Description #1 217.90' 3,340 cf Custom Stage Data (Irregular)Listed below (Recalc) Summary for Pond DB: MOD.EX. DET.BASIN Inflow Area = 336,078 sf, 42.67% Impervious, Inflow Depth = 1.06" for 1 -Year event Inflow = 8.50 cfs @ 12.09 hrs, Volume= 29,587 cf Outflow = 7.37 cfs @ 12.14 hrs, Volume= 29,571 cf, Atten= 13 %, Lag= 3.5 min Primary = 3.32 cfs @ 12.14 hrs, Volume= 26,242 cf Secondary = 4.05 cfs @ 12.14 hrs, Volume= 3,328 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.79' @ 12.14 hrs Surf.Area= 4,415 sf Storage= 2,272 cf Plug -Flow detention time= 5.4 min calculated for 29,550 cf (100% of inflow) Center -of -Mass det. time= 5.1 min ( 844.1 - 838.9 ) Volume Invert Avail.Storage Storage Description #1 217.90' 3,340 cf Custom Stage Data (Irregular)Listed below (Recalc) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 21 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 217.90 0 0.0 0 0 0 219.00 919 152.0 337 337 1,840 220.00 5,784 605.0 3,003 3,340 29,132 Device Routing Invert Outlet Devices #1 Primary 218.30' 12.0" Round Culvert L= 16.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.30'/ 218.10' S= 0.0121 T Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Secondary 219.50' 174.0 deg x 4.0' long x 1.50' rise Sharp- Crested Vee /Trap Weir Cv= 2.46 (C= 3.08) Primary OutFlow Max =3.32 cfs @ 12.14 hrs HW= 219.79' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.32 cfs @ 4.22 fps) Secondary OutFlow Max =3.97 cfs @ 12.14 hrs HW= 219.79' (Free Discharge) L2= Sharp- Crested Vee /Trap Weir (Weir Controls 3.97 cfs @ 1.46 fps) Summary for Pond DMH1: Inflow Area = 57,285 sf, 47.34% Impervious, Inflow Depth = 0.84" for 1 -Year event Inflow = 1.23 cfs @ 12.09 hrs, Volume= 3,993 cf Outflow = 1.23 cfs @ 12.09 hrs, Volume= 3,993 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.23 cfs @ 12.09 hrs, Volume= 3,993 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 222.94' @ 12.09 hrs Flood Elev= 231.11' Device Routing Invert Outlet Devices #1 Primary 222.31' 12.0" Round Culvert L= 77.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 222.31'/219.41' S=0.0374'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.20 cfs @ 12.09 hrs HW= 222.93' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.20 cfs @ 2.36 fps) Summary for Pond DMH10: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.47 cfs @ 12.07 hrs, Volume= 1,603 cf Outflow = 0.47 cfs @ 12.07 hrs, Volume= 1,603 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.47 cfs @ 12.07 hrs, Volume= 1,603 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 22 Peak Elev= 229.30' @ 12.07 hrs Flood Elev= 232.59' Device Routing Invert Outlet Devices #1 Primary 228.95' 12.0" Round Culvert L= 36.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.95'/228.59' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.45 cfs @ 12.07 hrs HW= 229.29' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.45 cfs @ 2.89 fps) Summary for Pond DMH11: Inflow Area = 90,561 sf, 67.73% Impervious, Inflow Depth = 1.33" for 1 -Year event Inflow = 3.15 cfs @ 12.08 hrs, Volume= 10,025 cf Outflow = 3.15 cfs @ 12.08 hrs, Volume= 10,025 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.15 cfs @ 12.08 hrs, Volume= 10,025 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.19' @ 12.08 hrs Flood Elev= 235.22' Device Routing Invert Outlet Devices #1 Primary 230.00' 12.0" Round Culvert L= 142.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.00'/224.85' S=0.0363'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =3.05 cfs @ 12.08 hrs HW= 231.15' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.05 cfs @ 3.88 fps) Summary for Pond DMH12: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 1.03" for 1 -Year event Inflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Outflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.04' @ 12.08 hrs Flood Elev= 236.45' Device Routing Invert Outlet Devices #1 Primary 232.50' 12.0" Round Culvert L= 68.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 232.50'/230.00' S=0.0368'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 23 Primary OutFlow Max =1.05 cfs @ 12.08 hrs HW= 233.03' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.05 cfs @ 2.48 fps) Summary for Pond DMH13: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 1.03" for 1 -Year event Inflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Outflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.14' @ 12.08 hrs Flood Elev= 239.22' Device Routing Invert Outlet Devices #1 Primary 234.60' 12.0" Round Culvert L= 104.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 234.60'/232.50' S=0.0202'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.05 cfs @ 12.08 hrs HW= 235.13' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.05 cfs @ 2.48 fps) Summary for Pond DMH14: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 1.03" for 1 -Year event Inflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Outflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.34' @ 12.08 hrs Flood Elev= 241.10' Device Routing Invert Outlet Devices #1 Primary 235.80' 12.0" Round Culvert L= 58.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 235.80'/234.60' S=0.0207'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.05 cfs @ 12.08 hrs HW= 236.33' (Free Discharge) t--1 =Culvert (Inlet Controls 1.05 cfs @ 2.48 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 24 Summary for Pond DMH15: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 1.03" for 1 -Year event Inflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Outflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.04' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 243.50' 12.0" Round Culvert L= 228.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.50'/236.30' S=0.0315'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.05 cfs @ 12.08 hrs HW= 244.03' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.05 cfs @ 2.48 fps) Summary for Pond DMH4: Inflow Area = 181,846 sf, 60.20% Impervious, Inflow Depth = 1.25" for 1 -Year event Inflow = 5.80 cfs @ 12.08 hrs, Volume= 18,946 cf Outflow = 5.80 cfs @ 12.08 hrs, Volume= 18,946 cf, Atten= 0 %, Lag= 0.0 min Primary = 5.80 cfs @ 12.08 hrs, Volume= 18,946 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.68' @ 12.08 hrs Flood Elev= 229.65' Device Routing Invert Outlet Devices #1 Primary 220.55' 24.0" Round Culvert L= 89.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 220.55'/219.73' S=0.0092'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =5.61 cfs @ 12.08 hrs HW= 221.65' (Free Discharge) 't--1 =Culvert (Inlet Controls 5.61 cfs @ 3.16 fps) Summary for Pond DMH5: Inflow Area = 153,258 sf, 64.77% Impervious, Inflow Depth = 1.33" for 1 -Year event Inflow = 5.18 cfs @ 12.08 hrs, Volume= 16,944 cf Outflow = 5.18 cfs @ 12.08 hrs, Volume= 16,944 cf, Atten= 0 %, Lag= 0.0 min Primary = 5.18 cfs @ 12.08 hrs, Volume= 16,944 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.96' @ 12.08 hrs Flood Elev= 229.63' Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 25 Device Routing Invert Outlet Devices #1 Primary 222.83' 18.0" Round Culvert L= 282.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.83'/220.70' S=0.0076'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 1.77 sf Primary OutFlow Max =5.02 cfs @ 12.08 hrs HW= 223.94' (Free Discharge) 't--1 =Culvert (Inlet Controls 5.02 cfs @ 3.58 fps) Summary for Pond DMH6: Inflow Area = 107,715 sf, 70.09% Impervious, Inflow Depth = 1.28" for 1 -Year event Inflow = 3.42 cfs @ 12.08 hrs, Volume= 11,505 cf Outflow = 3.42 cfs @ 12.08 hrs, Volume= 11,505 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.42 cfs @ 12.08 hrs, Volume= 11,505 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.03' @ 12.08 hrs Flood Elev= 231.08' Device Routing Invert Outlet Devices #1 Primary 224.14' 24.0" Round Culvert L= 89.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 224.14'/222.83' S=0.0146'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =3.31 cfs @ 12.08 hrs HW= 225.01' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.31 cfs @ 2.51 fps) Summary for Pond EX. C -1: D/W MAIN CULVERT Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 0.31" for 1 -Year event Inflow = 7.44 cfs @ 12.20 hrs, Volume= 72,250 cf Outflow = 7.47 cfs @ 12.20 hrs, Volume= 72,201 cf, Atten= 0 %, Lag= 0.3 min Primary = 7.47 cfs @ 12.20 hrs, Volume= 72,201 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 216.66' @ 12.20 hrs Surf.Area= 0 sf Storage= 212 cf Plug -Flow detention time= 3.2 min calculated for 72,150 cf (100% of inflow) Center -of -Mass det. time= 1.4 min ( 1,592.5 - 1,591.1 ) Volume Invert Avail.Storage Storage Description #1 215.94' 1,029 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 215.94 0 219.44 1,029 Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 26 Device Routing Invert Outlet Devices #1 Primary 216.08' 72.0" W x 42.0" H Box Culvert L= 49.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 216.08'/215.94' S=0.0029'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 21.00 sf Primary OutFlow Max =7.44 cfs @ 12.20 hrs HW= 216.66' (Free Discharge) 't--1 =Culvert (Barrel Controls 7.44 cfs @ 2.85 fps) Summary for Pond EX. P -1: OFF -SITE DEPRESSION Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth = 0.36" for 1 -Year event Inflow = 13.53 cfs @ 12.14 hrs, Volume= 68,988 cf Outflow = 0.48 cfs @ 24.00 hrs, Volume= 62,822 cf, Atten= 96 %, Lag= 711.4 min Discarded = 0.21 cfs @ 24.00 hrs, Volume= 24,703 cf Primary = 0.27 cfs @ 24.00 hrs, Volume= 38,119 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.23' @ 24.00 hrs Surf.Area= 102,166 sf Storage= 51,083 cf Plug -Flow detention time= 1,280.0 min calculated for 62,779 cf (91 % of inflow) Center -of -Mass det. time= 1,238.4 min ( 2,152.1 - 913.6 ) Volume Invert #1 219.00' Avail. e Description 1,815,231 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 219.00 0 0 0 220.00 452,595 226,298 226,298 221.00 508,615 480,605 706,903 222.00 557,476 533,046 1,239,948 223.00 593,089 575,283 1,815,231 Device Routing Invert Outlet Devices #1 Primary 218.80' 18.0" W x 18.0" H Box Culvert X 0.20 L= 16.0' RCP, end - section conforming to fill, Ke= 0.500 Inlet/ Outlet Invert= 218.80'/218.60' S=0.0125'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 2.25 sf #2 Secondary 221.80' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 9.00 11.00 20.00 Height (feet) 1.20 0.00 0.00 1.20 #3 Discarded 219.00' 0.090 in /hr Exfiltration over Surface area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 27 Discarded OutFlow Max =0.21 cfs @ 24.00 hrs HW= 219.23' (Free Discharge) L3= Exfiltration (Exfiltration Controls 0.21 cfs) Primary OutFlow Max =0.27 cfs @ 24.00 hrs HW= 219.23' (Free Discharge) L1= Culvert (Inlet Controls 0.27 cfs @ 0.42 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L2= Asymmetrical Weir ( Controls 0.00 cfs) Summary for Pond EX.INF: ADS U/G INF. Inflow Area = 5,090 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.28 cfs @ 12.07 hrs, Volume= 963 cf Outflow = 0.02 cfs @ 11.00 hrs, Volume= 963 cf, Atten= 93 %, Lag= 0.0 min Discarded = 0.02 cfs @ 11.00 hrs, Volume= 963 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.98' @ 13.42 hrs Surf.Area= 800 sf Storage= 385 cf Plug -Flow detention time= 158.8 min calculated for 963 cf (100% of inflow) Center -of -Mass det. time= 158.7 min ( 919.7 - 761.0 ) Volume Invert Avail.Storage Storage Description #1 224.00' 1,799 cf Custom Stage Data (Prismatic)Listed below (Recalc) x 160 Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq -ft) ( %) (cubic -feet) (cubic -feet) 224.00 5 0.0 0 0 224.01 5 40.0 0 0 224.49 5 40.0 1 1 224.50 5 58.5 0 1 224.99 5 58.5 1 2 225.00 5 73.1 0 2 225.99 5 73.1 4 6 226.00 5 73.1 0 6 226.99 5 73.1 4 10 227.00 5 58.5 0 10 227.50 5 58.5 1 11 Device Routing Invert Outlet Devices #1 Discarded 224.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 226.00' 8.0" Vert. Orifice /Grate C= 0.600 Discarded OutFlow Max =0.02 cfs @ 11.00 hrs HW= 224.01' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 224.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 28 Summary for Pond ST: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.47 cfs @ 12.07 hrs, Volume= 1,603 cf Outflow = 0.12 cfs @ 12.44 hrs, Volume= 627 cf, Atten= 74 %, Lag= 22.4 min Primary = 0.12 cfs @ 12.44 hrs, Volume= 627 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.30' @ 12.44 hrs Surf.Area= 0 sf Storage= 1,004 cf Plug -Flow detention time= 318.9 min calculated for 627 cf (39% of inflow) Center -of -Mass det. time= 172.6 min ( 933.6 - 761.0 ) Volume Invert Avail.Storage Storage Description #1 223.40' 1,360 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 223.40 0 231.40 1,360 Device Routing Invert Outlet Devices #1 Primary 229.14' 12.0" Round Culvert L= 27.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.14'/224.85' S=0.1589'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.11 cfs @ 12.44 hrs HW= 229.30' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.11 cfs @ 1.38 fps) Summary for Link AP1: Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > Inflow = 7.47 cfs @ 12.20 hrs, Volume= 72,201 Primary = 7.47 cfs @ 12.20 hrs, Volume= 72,201 Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Summary for Link AP2: Inflow Area = 341,168 sf, 43.52% Impervious, Inflow Depth = Inflow = 7.37 cfs @ 12.14 hrs, Volume= 29,571 Primary = 7.37 cfs @ 12.14 hrs, Volume= 29,571 Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 0.31" for 1 -Year event cf cf, Atten= 0 %, Lag= 0.0 min 1.04" for 1 -Year event cf cf, Atten= 0 %, Lag= 0.0 min Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 29 Summary for Link AP3: Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth > 0.20" for 1 -Year event Inflow = 0.27 cfs @ 24.00 hrs, Volume= 38,119 cf Primary = 0.27 cfs @ 24.00 hrs, Volume= 38,119 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment EX. SC -1: Runoff = 0.18 cfs @ 12.07 hrs, Volume= 570 cf, Depth= 1.80" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 1,735 80 >75% Grass cover, Good, HSG D 2,065 98 Paved parking, HSG D 3,800 90 Weighted Average 1,735 45.66% Pervious Area 2,065 54.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -15: Runoff = 0.05 cfs @ 12.08 hrs, Volume= 159 cf, Depth= 1.10" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 1,734 80 >75% Grass cover, Good, HSG D 1,734 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -16: Runoff = 2.02 cfs @ 12.08 hrs, Volume= 6,279 cf, Depth= 1.72" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 31 Area (sf) CN Description 4,653 98 Roofs, HSG B 6,123 98 Roofs, HSG D 2,023 61 >75% Grass cover, Good, HSG B 8,447 80 >75% Grass cover, Good, HSG D 2,473 98 Paved parking, HSG B 10,524 98 Paved parking, HSG D 176 80 >75% Grass cover, Good, HSG D 9,390 80 >75% Grass cover, Good, HSG D 43,809 89 Weighted Average 20,036 45.73% Pervious Area 23,773 54.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -17: Runoff = 0.33 cfs @ 12.08 hrs, Volume= 1,029 cf, Depth= 1.42" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 1,325 98 Roofs, HSG B 2,993 61 >75% Grass cover, Good, HSG B 4,366 98 Paved parking, HSG B 8,684 85 Weighted Average 2,993 34.47% Pervious Area 5,691 65.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -18: Runoff = 1.76 cfs @ 12.08 hrs, Volume= 5,466 cf, Depth= 1.64" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 32 Area (so CN Description 13,935 98 Roofs, HSG B 803 98 Roofs, HSG D 9,943 61 >75% Grass cover, Good, HSG B 2,229 80 >75% Grass cover, Good, HSG D 8,923 98 Paved parking, HSG B 4.124 98 Paved oarkina. HSG D 39,957 88 Weighted Average 12,172 30.46% Pervious Area 27,785 69.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -19: Runoff = 0.66 cfs @ 12.07 hrs, Volume= 2,244 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 5,245 98 Paved parking, HSG B 5,234 98 Paved parking, HSG D 10,479 98 Weighted Average 10,479 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -2: Runoff = 0.20 cfs @ 12.07 hrs, Volume= 652 cf, Depth= 2.46" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 3,071 98 Paved parking, HSG D 110 80 >75% Grass cover. Good. HSG D 3,181 97 Weighted Average 110 3.46% Pervious Area 3,071 96.54% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 33 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -20: Runoff = 0.53 cfs @ 12.09 hrs, Volume= 1,725 cf, Depth= 0.88" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 7,685 98 Roofs, HSG B 13,660 61 >75% Grass cover, Good, HSG B 2,108 98 Paved parking, HSG B 23,453 76 Weighted Average 13,660 58.24% Pervious Area 9,793 41.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -21: Runoff = 0.78 cfs @ 12.08 hrs, Volume= 2,417 cf, Depth= 1.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 5,373 98 Roofs, HSG B 5,318 61 >75% Grass cover, Good, HSG B 7.833 98 Paved oarkina. HSG B 18,524 87 Weighted Average 5,318 28.71 % Pervious Area 13,206 71.29% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -22: Runoff = 0.56 cfs @ 12.09 hrs, Volume= 1,780 cf, Depth= 0.99" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 34 Area (so CN Description 1,599 98 Roofs, HSG B 11,736 61 >75% Grass cover, Good, HSG B 8,266 98 Paved parking, HSG B 21,601 78 Weighted Average 11,736 79 54.33% Pervious Area 9,865 82 45.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment EX. SC -3: Runoff = 0.37 cfs @ 12.08 hrs, Volume= 1,159 cf, Depth= 1.04" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 6,580 61 >75% Grass cover, Good, HSG B 263 80 >75% Grass cover, Good, HSG D 6,168 98 Paved parking, HSG B 302 98 Paved parking, HSG D 13,313 79 Weighted Average 6,843 82 51.40% Pervious Area 6,470 48.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -4: Runoff = 0.67 cfs @ 12.08 hrs, Volume= 2,092 cf, Depth= 1.22" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 4,903 98 Roofs, HSG B 8,496 61 >75% Grass cover, Good, HSG B 1,023 80 >75% Grass cover, Good, HSG D 5,266 98 Paved parking, HSG B 688 98 Paved parking, HSG D 143 80 >75% Grass cover, Good, HSG D 20,519 82 Weighted Average 9,662 47.09% Pervious Area 10,857 52.91% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 35 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -5: Runoff = 0.13 cfs @ 12.08 hrs, Volume= 397 cf, Depth= 1.10" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 4,324 80 >75% Grass cover, Good, HSG D 4,324 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -6: Runoff = 0.65 cfs @ 12.09 hrs, Volume= 2,147 cf, Depth= 0.83" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 1,621 98 Roofs, HSG B 8,776 61 >75% Grass cover, Good, HSG B 9,312 80 >75% Grass cover, Good, HSG D 528 61 >75% Grass cover, Good, HSG B 10,715 80 >75% Grass cover, Good, HSG D 30,952 75 Weighted Average 29,331 94.76% Pervious Area 1,621 5.24% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -8: Runoff = 0.74 cfs @ 12.08 hrs, Volume= 2,342 cf, Depth= 1.04" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 36 Area (so CN Description 8,924 98 Roofs, HSG B 1,282 98 Roofs, HSG D 2,977 61 >75% Grass cover, Good, HSG B 1,631 80 >75% Grass cover, Good, HSG D 8,459 61 >75% Grass cover, Good, HSG B 3.635 80 >75% Grass cover. Good. HSG D 26,908 79 Weighted Average 16,702 62.07% Pervious Area 10,206 37.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -9: Runoff = 0.05 cfs @ 12.08 hrs, Volume= 154 cf, Depth= 1.10" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 1,680 80 >75% Grass cover, Good, HSG D 1,680 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -A: Runoff = 1.04 cfs @ 12.13 hrs, Volume= 4,611 cf, Depth= 0.49" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 2,268 61 >75% Grass cover, Good, HSG B 16,260 80 >75% Grass cover, Good, HSG D 2,973 98 Paved parking, HSG B 627 98 Paved parking, HSG D 56,294 55 Woods, Good, HSG B 32,414 77 Woods, Good, HSG D 647 98 Ledge, HSG B 1,746 96 Gravel surface, HSG D 113,229 67 Weighted Average 108,982 96.25% Pervious Area 4,247 3.75% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 37 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 2.4 30 0.5000 0.21 Sheet Flow, 77 Woods, Good, HSG D 1,274 Woods: Light underbrush n= 0.400 P2= 2.80" 0.4 85 0.5000 3.54 Shallow Concentrated Flow, 62,991 100.00% Pervious Area Woodland Kv= 5.0 fps 0.9 105 0.1430 1.89 Shallow Concentrated Flow, (ft/ft) (ft /sec) (cfs) 2.4 30 Woodland Kv= 5.0 fps 0.5 45 0.0890 1.49 Shallow Concentrated Flow, 0.5 110 0.5000 3.54 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 1.5 130 0.0846 1.45 Shallow Concentrated Flow, 0.2500 7.50 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.2 50 0.0600 3.67 Shallow Concentrated Flow, Woodland Kv= 5.0 fps Grassed Waterway Kv= 15.0 fps 1.0 56 0.0357 0.94 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 1.2 49 Woodland Kv= 5.0 fps 6.9 501 Total Summary for Subcatchment EX. SC -B: Runoff = 0.41 cfs @ 12.12 hrs, Volume= 2,017 cf, Depth= 0.38" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 6,337 61 >75% Grass cover, Good, HSG B 13,753 80 >75% Grass cover, Good, HSG D 34,537 55 Woods, Good, HSG B 7,090 77 Woods, Good, HSG D 1,274 96 Gravel surface, HSG D 62,991 64 Weighted Average 62,991 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 2.4 30 0.5000 0.21 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 0.5 110 0.5000 3.54 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.1 42 0.2500 7.50 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.7 136 0.3680 3.03 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.3 85 0.1170 5.13 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 1.2 49 0.0200 0.71 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 5.2 452 Total Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 38 Summary for Subcatchment EX. SC -C: Runoff = 1.10 cfs @ 12.20 hrs, Volume= 4,506 cf, Depth= 0.99" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 18 98 Roofs, HSG D 15,388 80 >75% Grass cover, Good, HSG D 28 98 Paved parking, HSG D 39,256 77 Woods, Good, HSG D 54,690 78 Weighted Average 54,644 99.92% Pervious Area 46 0.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 6.1 30 0.0070 0.08 Sheet Flow, 102,386 98 Paved parking, HSG D 347,789 Grass: Short n=0.150 P2=2.80" 7.0 488 0.0060 1.16 Shallow Concentrated Flow, 77 Woods, Good, HSG D 3,953 98 Grassed Waterwav Kv= 15.0 fps 13.1 518 Total Summary for Subcatchment EX. SC -D: Runoff = 21.97 cfs @ 12.12 hrs, Volume= 94,609 cf, Depth= 0.49" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 32 98 Roofs, HSG D 585 61 >75% Grass cover, Good, HSG B 10,742 80 >75% Grass cover, Good, HSG D 55,279 98 Paved parking, HSG A 167,851 98 Paved parking, HSG B 102,386 98 Paved parking, HSG D 347,789 30 Woods, Good, HSG A 624,368 55 Woods, Good, HSG B 1,009,555 77 Woods, Good, HSG D 3,953 98 Ledge, HSG B 495 96 Gravel surface, HSG B 113 96 Gravel surface, HSG D 2,323,148 67 Weighted Average 1,993,647 85.82% Pervious Area 329,501 14.18% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 39 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 3.3 30 0.0330 0.15 Sheet Flow, Grass: Short n=0.150 P2=2.80" 0.3 118 0.2550 7.57 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.3 57 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.0 705 0.0850 5.92 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 165 0.0480 3.29 Shallow Concentrated Flow, Grassed Waterwav Kv= 15.0 fps 6.7 1,075 Total Summary for Subcatchment EX. SC -R: Runoff = 0.32 cfs @ 12.07 hrs, Volume= 1,090 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 5,090 98 Roofs, HSG B 5,090 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -ST: Runoff = 0.53 cfs @ 12.07 hrs, Volume= 1,813 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 8,470 98 Roofs, HSG B 8,470 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 40 Summary for Reach R1: Inflow Area = 2,727,307 sf, 17.53% Impervious, Inflow Depth > 0.38" for 2 -Year event Inflow = 9.76 cfs @ 12.13 hrs, Volume= 86,259 cf Outflow = 8.92 cfs @ 12.18 hrs, Volume= 86,109 cf, Atten= 9 %, Lag= 3.2 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 1.34 fps, Min. Travel Time= 4.0 min Avg. Velocity = 0.35 fps, Avg. Travel Time= 15.6 min Peak Storage= 2,151 cf @ 12.18 hrs Average Depth at Peak Storage= 0.51' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 56.94 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 324.0' Slope= 0.00287' Inlet Invert= 218.80', Outlet Invert= 217.90' H Inflow Area = Inflow = Outflow = Summary for Reach R2: 2,323,148 sf, 14.18% Impervious, Inflow Depth > 0.25" for 2 -Year event 0.35 cfs @ 23.45 hrs, Volume= 48,433 cf 0.35 cfs @ 23.57 hrs, Volume= 48,301 cf, Atten= 0 %, Lag= 7.5 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 0.28 fps, Min. Travel Time= 12.1 min Avg. Velocity = 0.23 fps, Avg. Travel Time= 14.7 min Peak Storage= 255 cf @ 23.57 hrs Average Depth at Peak Storage= 0.10' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 33.66 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 206.0' Slope= 0.0010 '/' Inlet Invert= 219.00', Outlet Invert= 218.80' Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 41 Summary for Pond C1131: Inflow Area = 3,800 sf, 54.34% Impervious, Inflow Depth = 1.80" for 2 -Year event Inflow = 0.18 cfs @ 12.07 hrs, Volume= 570 cf Outflow = 0.18 cfs @ 12.07 hrs, Volume= 570 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.18 cfs @ 12.07 hrs, Volume= 570 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.79' @ 12.07 hrs Flood Elev= 221.25' Device Routing Invert Outlet Devices #1 Primary 224.92' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.18 cfs @ 12.07 hrs HW= 226.68' (Free Discharge) L1= Orifice /Grate (Orifice Controls 0.18 cfs @ 6.39 fps) Summary for Pond CB15: Inflow Area = 1,734 sf, 0.00% Impervious, Inflow Depth= 1.10" for 2 -Year event Inflow = 0.05 cfs @ 12.08 hrs, Volume= 159 cf Outflow = 0.05 cfs @ 12.08 hrs, Volume= 159 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.05 cfs @ 12.08 hrs, Volume= 159 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.21' @ 12.08 hrs Flood Elev= 229.32' Device Routing Invert Outlet Devices #1 Primary 225.10' 12.0" Round Culvert L= 19.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.10'/222.83' S=0.1195'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.05 cfs @ 12.08 hrs HW= 225.20' (Free Discharge) L1= Culvert (Inlet Controls 0.05 cfs @ 1.10 fps) Summary for Pond CB16: Inflow Area = 43,809 sf, 54.27% Impervious, Inflow Depth = 1.72" for 2 -Year event Inflow = 2.02 cfs @ 12.08 hrs, Volume= 6,279 cf Outflow = 2.02 cfs @ 12.08 hrs, Volume= 6,279 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.02 cfs @ 12.08 hrs, Volume= 6,279 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.50' @ 12.08 hrs Flood Elev= 229.50' Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 42 Device Routing Invert Outlet Devices #1 Primary 225.71' 12.0" Round Culvert L= 9.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.71'/222.83' S=0.3200'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.96 cfs @ 12.08 hrs HW= 226.49' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.96 cfs @ 3.00 fps) Summary for Pond CB17: Inflow Area = 8,684 sf, 65.53% Impervious, Inflow Depth= 1.42" for 2 -Year event Inflow = 0.33 cfs @ 12.08 hrs, Volume= 1,029 cf Outflow = 0.33 cfs @ 12.08 hrs, Volume= 1,029 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.33 cfs @ 12.08 hrs, Volume= 1,029 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.56' @ 12.08 hrs Flood Elev= 228.31' Device Routing Invert Outlet Devices #1 Primary 225.13' 12.0" Round Culvert L= 80.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.13'/225.07' S=0.0008'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.32 cfs @ 12.08 hrs HW= 225.56' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.32 cfs @ 1.49 fps) Summary for Pond CB18: Inflow Area = 39,957 sf, 69.54% Impervious, Inflow Depth= 1.64" for 2 -Year event Inflow = 1.76 cfs @ 12.08 hrs, Volume= 5,466 cf Outflow = 1.76 cfs @ 12.08 hrs, Volume= 5,466 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.76 cfs @ 12.08 hrs, Volume= 5,466 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.06' @ 12.08 hrs Flood Elev= 234.91' Device Routing Invert Outlet Devices #1 Primary 230.25' 12.0" Round Culvert L= 14.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.25'/230.10' S=0.0103'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.71 cfs @ 12.08 hrs HW= 231.05' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.71 cfs @ 3.50 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 43 Summary for Pond CB19: Inflow Area = 10,479 sf,100.00% Impervious, Inflow Depth= 2.57" for 2 -Year event Inflow = 0.66 cfs @ 12.07 hrs, Volume= 2,244 cf Outflow = 0.66 cfs @ 12.07 hrs, Volume= 2,244 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.66 cfs @ 12.07 hrs, Volume= 2,244 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.64' @ 12.07 hrs Flood Elev= 235.05' Device Routing Invert Outlet Devices #1 Primary 230.16' 12.0" Round Culvert L= 6.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.16'/230.10' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.63 cfs @ 12.07 hrs HW= 230.63' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.63 cfs @ 2.57 fps) Summary for Pond C1132: Inflow Area = 6,981 sf, 73.57% Impervious, Inflow Depth = 2.10" for 2 -Year event Inflow = 0.38 cfs @ 12.07 hrs, Volume= 1,223 cf Outflow = 0.38 cfs @ 12.07 hrs, Volume= 1,223 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.38 cfs @ 12.07 hrs, Volume= 1,223 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 218.58' @ 12.07 hrs Flood Elev= 225.01' Device Ro Invert Outlet Devices #1 Primary 218.16' 12.0" Round Culvert L= 135.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.16'/ 217.88' S= 0.0021 T Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.36 cfs @ 12.07 hrs HW= 218.57' (Free Discharge) L1= Culvert (Barrel Controls 0.36 cfs @ 1.80 fps) Summary for Pond CB20: Inflow Area = 23,453 sf, 41.76% Impervious, Inflow Depth = 0.88" for 2 -Year event Inflow = 0.53 cfs @ 12.09 hrs, Volume= 1,725 cf Outflow = 0.53 cfs @ 12.09 hrs, Volume= 1,725 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.53 cfs @ 12.09 hrs, Volume= 1,725 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 44 Peak Elev= 236.45' @ 12.09 hrs Flood Elev= 239.00' Device Routing Invert Outlet Devices #1 Primary 235.70' 6.0" Round Culvert L= 143.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 235.70'/228.93' S=0.0472'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 0.20 sf Primary OutFlow Max =0.51 cfs @ 12.09 hrs HW= 236.43' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.51 cfs @ 2.62 fps) Summary for Pond CB21: Inflow Area = 18,524 sf, 71.29% Impervious, Inflow Depth= 1.57" for 2 -Year event Inflow = 0.78 cfs @ 12.08 hrs, Volume= 2,417 cf Outflow = 0.78 cfs @ 12.08 hrs, Volume= 2,417 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.78 cfs @ 12.08 hrs, Volume= 2,417 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.35' @ 12.08 hrs Flood Elev= 247.80' Device Routing Invert Outlet Devices #1 Primary 243.80' 12.0" Round Culvert L= 25.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.80'/243.70' S=0.0039'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.76 cfs @ 12.08 hrs HW= 244.34' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.76 cfs @ 2.55 fps) Summary for Pond CB22: Inflow Area = 21,601 sf, 45.67% Impervious, Inflow Depth = 0.99" for 2 -Year event Inflow = 0.56 cfs @ 12.09 hrs, Volume= 1,780 cf Outflow = 0.56 cfs @ 12.09 hrs, Volume= 1,780 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.56 cfs @ 12.09 hrs, Volume= 1,780 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.13' @ 12.08 hrs Flood Elev= 247.90' Device Routing Invert Outlet Devices #1 Primary 243.70' 12.0" Round Culvert L= 16.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.70'/243.60' S=0.0062'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 45 Primary OutFlow Max =0.54 cfs @ 12.09 hrs HW= 244.13' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.54 cfs @ 2.48 fps) Summary for Pond C1133: Inflow Area = 36,766 sf, 44.23% Impervious, Inflow Depth = 0.94" for 2 -Year event Inflow = 0.89 cfs @ 12.09 hrs, Volume= 2,884 cf Outflow = 0.89 cfs @ 12.09 hrs, Volume= 2,884 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.89 cfs @ 12.09 hrs, Volume= 2,884 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.41' @ 12.09 hrs Flood Elev= 231.88' Device Routing Invert Outlet Devices #1 Primary 228.93' 12.0" Round Culvert L= 16.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.93'/227.98' S=0.0576'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.87 cfs @ 12.09 hrs HW= 229.41' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.87 cfs @ 2.35 fps) Summary for Pond C1134: Inflow Area = 20,519 sf, 52.91 % Impervious, Inflow Depth = 1.22" for 2 -Year event Inflow = 0.67 cfs @ 12.08 hrs, Volume= 2,092 cf Outflow = 0.67 cfs @ 12.08 hrs, Volume= 2,092 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.67 cfs @ 12.08 hrs, Volume= 2,092 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.05' @ 12.08 hrs Flood Elev= 232.11' Device Routing Invert Outlet Devices #1 Primary 229.64' 12.0" Round Culvert L= 31.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.64'/227.96' S=0.0542'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.65 cfs @ 12.08 hrs HW= 230.05' (Free Discharge) t--1 =Culvert (Inlet Controls 0.65 cfs @ 2.17 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 46 Summary for Pond CBS: Inflow Area = 35,276 sf, 4.60% Impervious, Inflow Depth = 0.87" for 2 -Year event Inflow = 0.78 cfs @ 12.09 hrs, Volume= 2,544 cf Outflow = 0.78 cfs @ 12.09 hrs, Volume= 2,544 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.78 cfs @ 12.09 hrs, Volume= 2,544 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.35' @ 12.09 hrs Flood Elev= 227.10' Device Routing Invert Outlet Devices #1 Primary 222.90' 12.0" Round Culvert L= 34.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.90'/218.20' S=0.1382'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.75 cfs @ 12.09 hrs HW= 223.34' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.75 cfs @ 2.26 fps) Summary for Pond C1136: Inflow Area = 30,952 sf, 5.24% Impervious, Inflow Depth = 0.83" for 2 -Year event Inflow = 0.65 cfs @ 12.09 hrs, Volume= 2,147 cf Outflow = 0.65 cfs @ 12.09 hrs, Volume= 2,147 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.65 cfs @ 12.09 hrs, Volume= 2,147 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.08' @ 12.09 hrs Flood Elev= 227.46' Device Ro Invert Outlet Devices #1 Primary 223.66' 12.0" Round Culvert L= 22.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 223.66'/223.42' S=0.0107'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.63 cfs @ 12.09 hrs HW= 224.08' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.63 cfs @ 3.01 fps) Summary for Pond CBB: Inflow Area = 26,908 sf, 37.93% Impervious, Inflow Depth = 1.04" for 2 -Year event Inflow = 0.74 cfs @ 12.08 hrs, Volume= 2,342 cf Outflow = 0.74 cfs @ 12.08 hrs, Volume= 2,342 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.74 cfs @ 12.08 hrs, Volume= 2,342 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 47 Peak Elev= 226.19' @ 12.08 hrs Flood Elev= 229.38' Device Routing Invert Outlet Devices #1 Primary 225.75' 12.0" Round Culvert L= 20.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.75'/225.15' S=0.0293'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.72 cfs @ 12.08 hrs HW= 226.18' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.72 cfs @ 2.23 fps) Summary for Pond C1139: Inflow Area = 1,680 sf, 0.00% Impervious, Inflow Depth = 1.10" for 2 -Year event Inflow = 0.05 cfs @ 12.08 hrs, Volume= 154 cf Outflow = 0.05 cfs @ 12.08 hrs, Volume= 154 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.05 cfs @ 12.08 hrs, Volume= 154 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.82' @ 12.08 hrs Flood Elev= 229.72' Device Routing Invert Outlet Devices #1 Primary 225.72' 12.0" Round Culvert L= 22.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.72'/225.15' S=0.0253'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.05 cfs @ 12.08 hrs HW= 225.82' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.05 cfs @ 1.09 fps) Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.85' @ 12.13 hrs Surf.Area= 4,786 sf Storage= 2,547 cf Plug -Flow detention time= 5.2 min calculated for 35,916 cf (100% of inflow) Center -of -Mass det. time= 5.0 min ( 838.8 - 833.8 ) Volume Invert Avail.Storage Storage Description #1 217.90' 3,340 cf Custom Stage Data (Irregular)Listed below (Recalc) Summary for Pond DB: MOD.EX. DET.BASIN Inflow Area = 336,078 sf, 42.67% Impervious, Inflow Depth = 1.28" for 2 -Year event Inflow = 10.38 cfs @ 12.08 hrs, Volume= 35,957 cf Outflow = 9.35 cfs @ 12.13 hrs, Volume= 35,940 cf, Atten= 10 %, Lag= 2.6 min Primary = 3.42 cfs @ 12.13 hrs, Volume= 30,334 cf Secondary = 5.94 cfs @ 12.13 hrs, Volume= 5,606 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.85' @ 12.13 hrs Surf.Area= 4,786 sf Storage= 2,547 cf Plug -Flow detention time= 5.2 min calculated for 35,916 cf (100% of inflow) Center -of -Mass det. time= 5.0 min ( 838.8 - 833.8 ) Volume Invert Avail.Storage Storage Description #1 217.90' 3,340 cf Custom Stage Data (Irregular)Listed below (Recalc) Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 48 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 217.90 0 0.0 0 0 0 219.00 919 152.0 337 337 1,840 220.00 5,784 605.0 3,003 3,340 29,132 Device Routing Invert Outlet Devices #1 Primary 218.30' 12.0" Round Culvert L= 16.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.30'/ 218.10' S= 0.0121 T Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Secondary 219.50' 174.0 deg x 4.0' long x 1.50' rise Sharp- Crested Vee /Trap Weir Cv= 2.46 (C= 3.08) Primary OutFlow Max =3.41 cfs @ 12.13 hrs HW= 219.84' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.41 cfs @ 4.34 fps) Secondary OutFlow Max =5.75 cfs @ 12.13 hrs HW= 219.84' (Free Discharge) L2= Sharp- Crested Vee /Trap Weir (Weir Controls 5.75 cfs @ 1.58 fps) Summary for Pond DMH1: Inflow Area = 57,285 sf, 47.34% Impervious, Inflow Depth = 1.04" for 2 -Year event Inflow = 1.56 cfs @ 12.08 hrs, Volume= 4,976 cf Outflow = 1.56 cfs @ 12.08 hrs, Volume= 4,976 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.56 cfs @ 12.08 hrs, Volume= 4,976 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.04' @ 12.08 hrs Flood Elev= 231.11' Device Routing Invert Outlet Devices #1 Primary 222.31' 12.0" Round Culvert L= 77.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 222.31'/219.41' S=0.0374'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.52 cfs @ 12.08 hrs HW= 223.02' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.52 cfs @ 2.54 fps) Summary for Pond DMH10: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.53 cfs @ 12.07 hrs, Volume= 1,813 cf Outflow = 0.53 cfs @ 12.07 hrs, Volume= 1,813 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.53 cfs @ 12.07 hrs, Volume= 1,813 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 49 Peak Elev= 229.32' @ 12.07 hrs Flood Elev= 232.59' Device Routing Invert Outlet Devices #1 Primary 228.95' 12.0" Round Culvert L= 36.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.95'/228.59' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.51 cfs @ 12.07 hrs HW= 229.31' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.51 cfs @ 2.97 fps) Summary for Pond DMH11: Inflow Area = 90,561 sf, 67.73% Impervious, Inflow Depth = 1.58" for 2 -Year event Inflow = 3.75 cfs @ 12.08 hrs, Volume= 11,906 cf Outflow = 3.75 cfs @ 12.08 hrs, Volume= 11,906 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.75 cfs @ 12.08 hrs, Volume= 11,906 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.47' @ 12.08 hrs Flood Elev= 235.22' Device Routing Invert Outlet Devices #1 Primary 230.00' 12.0" Round Culvert L= 142.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.00'/224.85' S=0.0363'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =3.63 cfs @ 12.08 hrs HW= 231.42' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.63 cfs @ 4.62 fps) Summary for Pond DMH12: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth= 1.26" for 2 -Year event Inflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Outflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.11' @ 12.08 hrs Flood Elev= 236.45' Device Routing Invert Outlet Devices #1 Primary 232.50' 12.0" Round Culvert L= 68.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 232.50'/230.00' S=0.0368'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 50 Primary OutFlow Max =1.29 cfs @ 12.08 hrs HW= 233.10' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.29 cfs @ 2.64 fps) Summary for Pond DMH13: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth= 1.26" for 2 -Year event Inflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Outflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.21' @ 12.08 hrs Flood Elev= 239.22' Device Routing Invert Outlet Devices #1 Primary 234.60' 12.0" Round Culvert L= 104.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 234.60'/232.50' S=0.0202'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.29 cfs @ 12.08 hrs HW= 235.20' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.29 cfs @ 2.64 fps) Summary for Pond DMH14: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth= 1.26" for 2 -Year event Inflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Outflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.41' @ 12.08 hrs Flood Elev= 241.10' Device Routing Invert Outlet Devices #1 Primary 235.80' 12.0" Round Culvert L= 58.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 235.80'/234.60' S=0.0207'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.29 cfs @ 12.08 hrs HW= 236.40' (Free Discharge) t--1 =Culvert (Inlet Controls 1.29 cfs @ 2.64 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 51 Summary for Pond DMH15: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth= 1.26" for 2 -Year event Inflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Outflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.11' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 243.50' 12.0" Round Culvert L= 228.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.50'/236.30' S=0.0315'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.29 cfs @ 12.08 hrs HW= 244.10' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.29 cfs @ 2.64 fps) Summary for Pond DMH4: Inflow Area = 181,846 sf, 60.20% Impervious, Inflow Depth = 1.50" for 2 -Year event Inflow = 6.94 cfs @ 12.08 hrs, Volume= 22,708 cf Outflow = 6.94 cfs @ 12.08 hrs, Volume= 22,708 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.94 cfs @ 12.08 hrs, Volume= 22,708 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.80' @ 12.08 hrs Flood Elev= 229.65' Device Routing Invert Outlet Devices #1 Primary 220.55' 24.0" Round Culvert L= 89.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 220.55'/219.73' S=0.0092'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =6.72 cfs @ 12.08 hrs HW= 221.78' (Free Discharge) 't--1 =Culvert (Inlet Controls 6.72 cfs @ 3.33 fps) Summary for Pond DMH5: Inflow Area = 153,258 sf, 64.77% Impervious, Inflow Depth = 1.58" for 2 -Year event Inflow = 6.15 cfs @ 12.08 hrs, Volume= 20,211 cf Outflow = 6.15 cfs @ 12.08 hrs, Volume= 20,211 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.15 cfs @ 12.08 hrs, Volume= 20,211 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.10' @ 12.08 hrs Flood Elev= 229.63' Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 52 Device Routing Invert Outlet Devices #1 Primary 222.83' 18.0" Round Culvert L= 282.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.83'/220.70' S=0.0076'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 1.77 sf Primary OutFlow Max =5.96 cfs @ 12.08 hrs HW= 224.08' (Free Discharge) 't--1 =Culvert (Inlet Controls 5.96 cfs @ 3.80 fps) Summary for Pond DMH6: Inflow Area = 107,715 sf, 70.09% Impervious, Inflow Depth = 1.53" for 2 -Year event Inflow = 4.08 cfs @ 12.08 hrs, Volume= 13,773 cf Outflow = 4.08 cfs @ 12.08 hrs, Volume= 13,773 cf, Atten= 0 %, Lag= 0.0 min Primary = 4.08 cfs @ 12.08 hrs, Volume= 13,773 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.12' @ 12.08 hrs Flood Elev= 231.08' Device Routing Invert Outlet Devices #1 Primary 224.14' 24.0" Round Culvert L= 89.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 224.14'/222.83' S=0.0146'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =3.95 cfs @ 12.08 hrs HW= 225.10' (Free Discharge) L1 = Culvert (Inlet Controls 3.95 cfs @ 2.64 fps) Summary for Pond EX. C -1: D/W MAIN CULVERT Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 0.38" for 2 -Year event Inflow = 10.01 cfs @ 12.17 hrs, Volume= 90,720 cf Outflow = 9.87 cfs @ 12.18 hrs, Volume= 90,667 cf, Atten= 1 %, Lag= 0.4 min Primary = 9.87 cfs @ 12.18 hrs, Volume= 90,667 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 216.78' @ 12.18 hrs Surf.Area= 0 sf Storage= 248 cf Plug -Flow detention time= 2.7 min calculated for 90,667 cf (100% of inflow) Center -of -Mass det. time= 1.1 min ( 1,583.2 - 1,582.1 ) Volume Invert Avail.Storage Storage Description #1 215.94' 1,029 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 215.94 0 219.44 1,029 Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 53 Device Routing Invert Outlet Devices #1 Primary 216.08' 72.0" W x 42.0" H Box Culvert L= 49.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 216.08'/215.94' S=0.0029'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 21.00 sf Primary OutFlow Max =9.74 cfs @ 12.18 hrs HW= 216.78' (Free Discharge) 't--1 =Culvert (Barrel Controls 9.74 cfs @ 3.10 fps) Summary for Pond EX. P -1: OFF -SITE DEPRESSION Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth = 0.49" for 2 -Year event Inflow = 21.97 cfs @ 12.12 hrs, Volume= 94,609 cf Outflow = 0.64 cfs @ 23.45 hrs, Volume= 83,764 cf, Atten= 97 %, Lag= 679.3 min Discarded = 0.29 cfs @ 23.45 hrs, Volume= 35,331 cf Primary = 0.35 cfs @ 23.45 hrs, Volume= 48,433 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.31' @ 23.45 hrs Surf.Area= 140,667 sf Storage= 70,333 cf Plug -Flow detention time= 1,296.8 min calculated for 83,706 cf (88% of inflow) Center -of -Mass det. time= 1,244.2 min ( 2,144.8 - 900.6 ) Volume Invert #1 219.00' Avail. e Description 1,815,231 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 219.00 0 0 0 220.00 452,595 226,298 226,298 221.00 508,615 480,605 706,903 222.00 557,476 533,046 1,239,948 223.00 593,089 575,283 1,815,231 Device Routing Invert Outlet Devices #1 Primary 218.80' 18.0" W x 18.0" H Box Culvert X 0.20 L= 16.0' RCP, end - section conforming to fill, Ke= 0.500 Inlet/ Outlet Invert= 218.80'/218.60' S=0.0125'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 2.25 sf #2 Secondary 221.80' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 9.00 11.00 20.00 Height (feet) 1.20 0.00 0.00 1.20 #3 Discarded 219.00' 0.090 in /hr Exfiltration over Surface area Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 54 Discarded OutFlow Max =0.29 cfs @ 23.45 hrs HW= 219.31' (Free Discharge) L3= Exfiltration (Exfiltration Controls 0.29 cfs) Primary OutFlow Max =0.35 cfs @ 23.45 hrs HW= 219.31' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.35 cfs @ 0.46 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L2= Asymmetrical Weir ( Controls 0.00 cfs) Summary for Pond EX.INF: ADS U/G INF. Inflow Area = 5,090 sf,100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.32 cfs @ 12.07 hrs, Volume= 1,090 cf Outflow = 0.02 cfs @ 10.65 hrs, Volume= 1,090 cf, Atten= 94 %, Lag= 0.0 min Discarded = 0.02 cfs @ 10.65 hrs, Volume= 1,090 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.10' @ 13.72 hrs Surf.Area= 800 sf Storage= 457 cf Plug -Flow detention time= 193.6 min calculated for 1,089 cf (100% of inflow) Center -of -Mass det. time= 193.5 min ( 951.9 - 758.4 ) Volume Invert Avail.Storage Storage Description #1 224.00' 1,799 cf Custom Stage Data (Prismatic)Listed below (Recalc) x 160 Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq -ft) ( %) (cubic -feet) (cubic -feet) 224.00 5 0.0 0 0 224.01 5 40.0 0 0 224.49 5 40.0 1 1 224.50 5 58.5 0 1 224.99 5 58.5 1 2 225.00 5 73.1 0 2 225.99 5 73.1 4 6 226.00 5 73.1 0 6 226.99 5 73.1 4 10 227.00 5 58.5 0 10 227.50 5 58.5 1 11 Device Routing Invert Outlet Devices #1 Discarded 224.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 226.00' 8.0" Vert. Orifice /Grate C= 0.600 Discarded OutFlow Max =0.02 cfs @ 10.65 hrs HW= 224.01' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 224.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 55 Summary for Pond ST: Inflow Area = 8,470 sf, 100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.53 cfs @ 12.07 hrs, Volume= 1,813 cf Outflow = 0.25 cfs @ 12.27 hrs, Volume= 838 cf, Atten= 54 %, Lag= 11.8 min Primary = 0.25 cfs @ 12.27 hrs, Volume= 838 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.38' @ 12.27 hrs Surf.Area= 0 sf Storage= 1,017 cf Plug -Flow detention time= 274.9 min calculated for 838 cf (46% of inflow) Center -of -Mass det. time= 143.3 min ( 901.7 - 758.4 ) Volume Invert Avail.Storage Storage Description #1 223.40' 1,360 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 223.40 0 231.40 1,360 Device Routing Invert Outlet Devices #1 Primary 229.14' 12.0" Round Culvert L= 27.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.14'/224.85' S=0.1589'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.22 cfs @ 12.27 hrs HW= 229.37' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.22 cfs @ 1.64 fps) Summary for Link AP1: Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 0.38" for 2 -Year event Inflow = 9.87 cfs @ 12.18 hrs, Volume= 90,667 cf Primary = 9.87 cfs @ 12.18 hrs, Volume= 90,667 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Summary for Link AP2: Inflow Area = 341,168 sf, 43.52% Impervious, Inflow Depth = 1.26" for 2 -Year event Inflow = 9.35 cfs @ 12.13 hrs, Volume= 35,940 cf Primary = 9.35 cfs @ 12.13 hrs, Volume= 35,940 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 56 Summary for Link AP3: Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth > 0.25" for 2 -Year event Inflow = 0.35 cfs @ 23.45 hrs, Volume= 48,433 cf Primary = 0.35 cfs @ 23.45 hrs, Volume= 48,433 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 57 Summary for Subcatchment EX. SC -1: Runoff = 0.32 cfs @ 12.07 hrs, Volume= 1,015 cf, Depth= 3.20" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 1,735 80 >75% Grass cover, Good, HSG D 2,065 98 Paved parking, HSG D 3,800 90 Weighted Average 1,735 45.66% Pervious Area 2,065 54.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -15: Runoff = 0.11 cfs @ 12.08 hrs, Volume= 331 cf, Depth= 2.29" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 1,734 80 >75% Grass cover, Good, HSG D 1,734 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -16: Runoff = 3.61 cfs @ 12.07 hrs, Volume= 11,338 cf, Depth= 3.11" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 58 Area (sf) CN Description 4,653 98 Roofs, HSG B 6,123 98 Roofs, HSG D 2,023 61 >75% Grass cover, Good, HSG B 8,447 80 >75% Grass cover, Good, HSG D 2,473 98 Paved parking, HSG B 10,524 98 Paved parking, HSG D 176 80 >75% Grass cover, Good, HSG D 9,390 80 >75% Grass cover, Good, HSG D 43,809 89 Weighted Average 20,036 45.73% Pervious Area 23,773 54.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -17: Runoff = 0.63 cfs @ 12.08 hrs, Volume= 1,974 cf, Depth= 2.73" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 1,325 98 Roofs, HSG B 2,993 61 >75% Grass cover, Good, HSG B 4,366 98 Paved parking, HSG B 8,684 85 Weighted Average 2,993 34.47% Pervious Area 5,691 65.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -18: Runoff = 3.20 cfs @ 12.07 hrs, Volume= 10,018 cf, Depth= 3.01" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 59 Area (so CN Description 13,935 98 Roofs, HSG B 803 98 Roofs, HSG D 9,943 61 >75% Grass cover, Good, HSG B 2,229 80 >75% Grass cover, Good, HSG D 8,923 98 Paved parking, HSG B 4.124 98 Paved oarkina. HSG D 39,957 88 Weighted Average 12,172 30.46% Pervious Area 27,785 69.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -19: Runoff = 1.02 cfs @ 12.07 hrs, Volume= 3,549 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 5,245 98 Paved parking, HSG B 5,234 98 Paved parking, HSG D 10,479 98 Weighted Average 10,479 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -2: Runoff = 0.31 cfs @ 12.07 hrs, Volume= 1,047 cf, Depth= 3.95" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 3,071 98 Paved parking, HSG D 110 80 >75% Grass cover. Good. HSG D 3,181 97 Weighted Average 110 3.46% Pervious Area 3,071 96.54% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 60 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -20: Runoff = 1.24 cfs @ 12.08 hrs, Volume= 3,853 cf, Depth= 1.97" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 7,685 98 Roofs, HSG B 13,660 61 >75% Grass cover, Good, HSG B 2,108 98 Paved parking, HSG B 23,453 76 Weighted Average 13,660 58.24% Pervious Area 9,793 41.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -21: Runoff = 1.44 cfs @ 12.07 hrs, Volume= 4,497 cf, Depth= 2.91" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 5,373 98 Roofs, HSG B 5,318 61 >75% Grass cover, Good, HSG B 7.833 98 Paved oarkina. HSG B 18,524 87 Weighted Average 5,318 28.71 % Pervious Area 13,206 71.29% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -22: Runoff = 1.24 cfs @ 12.08 hrs, Volume= 3,832 cf, Depth= 2.13" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 61 Area (so CN Description 1,599 98 Roofs, HSG B 11,736 61 >75% Grass cover, Good, HSG B 8,266 98 Paved parking, HSG B 21,601 78 Weighted Average 11,736 79 54.33% Pervious Area 9,865 82 45.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment EX. SC -3: Runoff = 0.79 cfs @ 12.08 hrs, Volume= 2,451 cf, Depth= 2.21" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 6,580 61 >75% Grass cover, Good, HSG B 263 80 >75% Grass cover, Good, HSG D 6,168 98 Paved parking, HSG B 302 98 Paved parking, HSG D 13,313 79 Weighted Average 6,843 82 51.40% Pervious Area 6,470 48.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -4: Runoff = 1.36 cfs @ 12.08 hrs, Volume= 4,209 cf, Depth= 2.46" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 4,903 98 Roofs, HSG B 8,496 61 >75% Grass cover, Good, HSG B 1,023 80 >75% Grass cover, Good, HSG D 5,266 98 Paved parking, HSG B 688 98 Paved parking, HSG D 143 80 >75% Grass cover, Good, HSG D 20,519 82 Weighted Average 9,662 47.09% Pervious Area 10,857 52.91% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 62 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -5: Runoff = 0.27 cfs @ 12.08 hrs, Volume= 826 cf, Depth= 2.29" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 4,324 80 >75% Grass cover, Good, HSG D 4,324 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -6: Runoff = 1.57 cfs @ 12.08 hrs, Volume= 4,888 cf, Depth= 1.89" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 1,621 98 Roofs, HSG B 8,776 61 >75% Grass cover, Good, HSG B 9,312 80 >75% Grass cover, Good, HSG D 528 61 >75% Grass cover, Good, HSG B 10,715 80 >75% Grass cover, Good, HSG D 30,952 75 Weighted Average 29,331 94.76% Pervious Area 1,621 5.24% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -8: Runoff = 1.60 cfs @ 12.08 hrs, Volume= 4,955 cf, Depth= 2.21" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 63 Area (so CN Description 8,924 98 Roofs, HSG B 1,282 98 Roofs, HSG D 2,977 61 >75% Grass cover, Good, HSG B 1,631 80 >75% Grass cover, Good, HSG D 8,459 61 >75% Grass cover, Good, HSG B 3.635 80 >75% Grass cover. Good. HSG D 26,908 79 Weighted Average 16,702 62.07% Pervious Area 10,206 37.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -9: Runoff = 0.10 cfs @ 12.08 hrs, Volume= 321 cf, Depth= 2.29" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 1,680 80 >75% Grass cover, Good, HSG D 1,680 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -A: Runoff = 3.65 cfs @ 12.11 hrs, Volume= 12,583 cf, Depth= 1.33" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 2,268 61 >75% Grass cover, Good, HSG B 16,260 80 >75% Grass cover, Good, HSG D 2,973 98 Paved parking, HSG B 627 98 Paved parking, HSG D 56,294 55 Woods, Good, HSG B 32,414 77 Woods, Good, HSG D 647 98 Ledge, HSG B 1,746 96 Gravel surface, HSG D 113,229 67 Weighted Average 108,982 96.25% Pervious Area 4,247 3.75% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 64 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 2.4 30 0.5000 0.21 Sheet Flow, 77 Woods, Good, HSG D 1,274 Woods: Light underbrush n= 0.400 P2= 2.80" 0.4 85 0.5000 3.54 Shallow Concentrated Flow, 62,991 100.00% Pervious Area Woodland Kv= 5.0 fps 0.9 105 0.1430 1.89 Shallow Concentrated Flow, (ft/ft) (ft /sec) (cfs) 2.4 30 Woodland Kv= 5.0 fps 0.5 45 0.0890 1.49 Shallow Concentrated Flow, 0.5 110 0.5000 3.54 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 1.5 130 0.0846 1.45 Shallow Concentrated Flow, 0.2500 7.50 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.2 50 0.0600 3.67 Shallow Concentrated Flow, Woodland Kv= 5.0 fps Grassed Waterway Kv= 15.0 fps 1.0 56 0.0357 0.94 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 1.2 49 Woodland Kv= 5.0 fps 6.9 501 Total Summary for Subcatchment EX. SC -B: Runoff = 1.76 cfs @ 12.09 hrs, Volume= 6,013 cf, Depth= 1.15" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 6,337 61 >75% Grass cover, Good, HSG B 13,753 80 >75% Grass cover, Good, HSG D 34,537 55 Woods, Good, HSG B 7,090 77 Woods, Good, HSG D 1,274 96 Gravel surface, HSG D 62,991 64 Weighted Average 62,991 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 2.4 30 0.5000 0.21 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 0.5 110 0.5000 3.54 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.1 42 0.2500 7.50 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.7 136 0.3680 3.03 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.3 85 0.1170 5.13 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 1.2 49 0.0200 0.71 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 5.2 452 Total Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 65 Summary for Subcatchment EX. SC -C: Runoff = 2.46 cfs @ 12.19 hrs, Volume= 9,702 cf, Depth= 2.13" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 18 98 Roofs, HSG D 15,388 80 >75% Grass cover, Good, HSG D 28 98 Paved parking, HSG D 39,256 77 Woods, Good, HSG D 54,690 78 Weighted Average 54,644 99.92% Pervious Area 46 0.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 6.1 30 0.0070 0.08 Sheet Flow, 102,386 98 Paved parking, HSG D 347,789 Grass: Short n=0.150 P2=2.80" 7.0 488 0.0060 1.16 Shallow Concentrated Flow, 77 Woods, Good, HSG D 3,953 98 Grassed Waterwav Kv= 15.0 fps 13.1 518 Total Summary for Subcatchment EX. SC -D: Runoff = 75.39 cfs @ 12.11 hrs, Volume= 258,167 cf, Depth= 1.33" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 32 98 Roofs, HSG D 585 61 >75% Grass cover, Good, HSG B 10,742 80 >75% Grass cover, Good, HSG D 55,279 98 Paved parking, HSG A 167,851 98 Paved parking, HSG B 102,386 98 Paved parking, HSG D 347,789 30 Woods, Good, HSG A 624,368 55 Woods, Good, HSG B 1,009,555 77 Woods, Good, HSG D 3,953 98 Ledge, HSG B 495 96 Gravel surface, HSG B 113 96 Gravel surface, HSG D 2,323,148 67 Weighted Average 1,993,647 85.82% Pervious Area 329,501 14.18% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 66 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 3.3 30 0.0330 0.15 Sheet Flow, Grass: Short n=0.150 P2=2.80" 0.3 118 0.2550 7.57 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.3 57 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.0 705 0.0850 5.92 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 165 0.0480 3.29 Shallow Concentrated Flow, Grassed Waterwav Kv= 15.0 fps 6.7 1,075 Total Summary for Subcatchment EX. SC -R: Runoff = 0.49 cfs @ 12.07 hrs, Volume= 1,724 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 5,090 98 Roofs, HSG B 5,090 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -ST: Runoff = 0.82 cfs @ 12.07 hrs, Volume= 2,869 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 8,470 98 Roofs, HSG B 8,470 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 67 Summary for Reach R1: Inflow Area = 2,727,307 sf, 17.53% Impervious, Inflow Depth > 0.87" for 10 -Year event Inflow = 26.36 cfs @ 12.10 hrs, Volume= 197,200 cf Outflow = 21.76 cfs @ 12.13 hrs, Volume= 196,984 cf, Atten= 17 %, Lag= 1.9 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 1.83 fps, Min. Travel Time= 3.0 min Avg. Velocity = 0.47 fps, Avg. Travel Time= 11.5 min Peak Storage= 3,833 cf @ 12.13 hrs Average Depth at Peak Storage= 0.86' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 56.94 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 324.0' Slope= 0.00287' Inlet Invert= 218.80', Outlet Invert= 217.90' H Inflow Area = Inflow = Outflow = Summary for Reach R2: 2,323,148 sf, 14.18% Impervious, Inflow Depth > 0.62" for 10 -Year event 0.97 cfs @ 20.89 hrs, Volume= 120,695 cf 0.97 cfs @ 20.98 hrs, Volume= 120,505 cf, Atten= 0 %, Lag= 5.0 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 0.42 fps, Min. Travel Time= 8.2 min Avg. Velocity = 0.33 fps, Avg. Travel Time= 10.5 min Peak Storage= 474 cf @ 20.98 hrs Average Depth at Peak Storage= 0.19' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 33.66 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 206.0' Slope= 0.0010 '/' Inlet Invert= 219.00', Outlet Invert= 218.80' Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 68 Summary for Pond C1131: Inflow Area = 3,800 sf, 54.34% Impervious, Inflow Depth= 3.20" for 10 -Year event Inflow = 0.32 cfs @ 12.07 hrs, Volume= 1,015 cf Outflow = 0.32 cfs @ 12.07 hrs, Volume= 1,015 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.32 cfs @ 12.07 hrs, Volume= 1,015 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.62' @ 12.07 hrs Flood Elev= 221.25' Device Routing Invert Outlet Devices #1 Primary 224.92' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.31 cfs @ 12.07 hrs HW= 230.26' (Free Discharge) L1= Orifice /Grate (Orifice Controls 0.31 cfs @ 11.13 fps) Summary for Pond CB15: Inflow Area = 1,734 sf, 0.00% Impervious, Inflow Depth = 2.29" for 10 -Year event Inflow = 0.11 cfs @ 12.08 hrs, Volume= 331 cf Outflow = 0.11 cfs @ 12.08 hrs, Volume= 331 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.11 cfs @ 12.08 hrs, Volume= 331 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.26' @ 12.08 hrs Flood Elev= 229.32' Device Routing Invert Outlet Devices #1 Primary 225.10' 12.0" Round Culvert L= 19.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.10'/222.83' S=0.1195'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.10 cfs @ 12.08 hrs HW= 225.25' (Free Discharge) L1= Culvert (Inlet Controls 0.10 cfs @ 1.33 fps) Summary for Pond CB16: Inflow Area = 43,809 sf, 54.27% Impervious, Inflow Depth = 3.11" for 10 -Year event Inflow = 3.61 cfs @ 12.07 hrs, Volume= 11,338 cf Outflow = 3.61 cfs @ 12.07 hrs, Volume= 11,338 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.61 cfs @ 12.07 hrs, Volume= 11,338 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.11' @ 12.07 hrs Flood Elev= 229.50' Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 69 Device Routing Invert Outlet Devices #1 Primary 225.71' 12.0" Round Culvert L= 9.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.71'/222.83' S=0.3200'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =3.47 cfs @ 12.07 hrs HW= 227.05' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.47 cfs @ 4.42 fps) Summary for Pond CB17: Inflow Area = 8,684 sf, 65.53% Impervious, Inflow Depth = 2.73" for 10 -Year event Inflow = 0.63 cfs @ 12.08 hrs, Volume= 1,974 cf Outflow = 0.63 cfs @ 12.08 hrs, Volume= 1,974 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.63 cfs @ 12.08 hrs, Volume= 1,974 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.73' @ 12.08 hrs Flood Elev= 228.31' Device Routing Invert Outlet Devices #1 Primary 225.13' 12.0" Round Culvert L= 80.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.13'/225.07' S=0.0008'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.61 cfs @ 12.08 hrs HW= 225.72' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.61 cfs @ 1.85 fps) Summary for Pond CB18: Inflow Area = 39,957 sf, 69.54% Impervious, Inflow Depth = 3.01" for 10 -Year event Inflow = 3.20 cfs @ 12.07 hrs, Volume= 10,018 cf Outflow = 3.20 cfs @ 12.07 hrs, Volume= 10,018 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.20 cfs @ 12.07 hrs, Volume= 10,018 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.54' @ 12.07 hrs Flood Elev= 234.91' Device Routing Invert Outlet Devices #1 Primary 230.25' 12.0" Round Culvert L= 14.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.25'/230.10' S=0.0103'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =3.09 cfs @ 12.07 hrs HW= 231.50' (Free Discharge) 't--1 =Culvert (Barrel Controls 3.09 cfs @ 4.04 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 70 Summary for Pond CB19: Inflow Area = 10,479 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 1.02 cfs @ 12.07 hrs, Volume= 3,549 cf Outflow = 1.02 cfs @ 12.07 hrs, Volume= 3,549 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.02 cfs @ 12.07 hrs, Volume= 3,549 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.78' @ 12.07 hrs Flood Elev= 235.05' Device Routing Invert Outlet Devices #1 Primary 230.16' 12.0" Round Culvert L= 6.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.16'/230.10' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.98 cfs @ 12.07 hrs HW= 230.76' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.98 cfs @ 2.84 fps) Summary for Pond C1132: Inflow Area = 6,981 sf, 73.57% Impervious, Inflow Depth = 3.54" for 10 -Year event Inflow = 0.63 cfs @ 12.07 hrs, Volume= 2,062 cf Outflow = 0.63 cfs @ 12.07 hrs, Volume= 2,062 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.63 cfs @ 12.07 hrs, Volume= 2,062 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 218.70' @ 12.07 hrs Flood Elev= 225.01' Device Ro Invert Outlet Devices #1 Primary 218.16' 12.0" Round Culvert L= 135.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.16'/ 217.88' S= 0.0021 T Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.60 cfs @ 12.07 hrs HW= 218.69' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.60 cfs @ 2.07 fps) Summary for Pond CB20: Inflow Area = 23,453 sf, 41.76% Impervious, Inflow Depth = 1.97" for 10 -Year event Inflow = 1.24 cfs @ 12.08 hrs, Volume= 3,853 cf Outflow = 1.24 cfs @ 12.08 hrs, Volume= 3,853 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.24 cfs @ 12.08 hrs, Volume= 3,853 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 71 Peak Elev= 238.69' @ 12.08 hrs Flood Elev= 239.00' Device Routing Invert Outlet Devices #1 Primary 235.70' 6.0" Round Culvert L= 143.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 235.70'/228.93' S=0.0472'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 0.20 sf Primary OutFlow Max =1.20 cfs @ 12.08 hrs HW= 238.54' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.20 cfs @ 6.11 fps) Summary for Pond CB21: Inflow Area = 18,524 sf, 71.29% Impervious, Inflow Depth = 2.91" for 10 -Year event Inflow = 1.44 cfs @ 12.07 hrs, Volume= 4,497 cf Outflow = 1.44 cfs @ 12.07 hrs, Volume= 4,497 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.44 cfs @ 12.07 hrs, Volume= 4,497 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.58' @ 12.07 hrs Flood Elev= 247.80' Device Routing Invert Outlet Devices #1 Primary 243.80' 12.0" Round Culvert L= 25.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.80'/243.70' S=0.0039'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.39 cfs @ 12.07 hrs HW= 244.57' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.39 cfs @ 2.98 fps) Summary for Pond CB22: Inflow Area = 21,601 sf, 45.67% Impervious, Inflow Depth = 2.13" for 10 -Year event Inflow = 1.24 cfs @ 12.08 hrs, Volume= 3,832 cf Outflow = 1.24 cfs @ 12.08 hrs, Volume= 3,832 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.24 cfs @ 12.08 hrs, Volume= 3,832 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.39' @ 12.08 hrs Flood Elev= 247.90' Device Routing Invert Outlet Devices #1 Primary 243.70' 12.0" Round Culvert L= 16.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.70'/243.60' S=0.0062'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 72 Primary OutFlow Max =1.20 cfs @ 12.08 hrs HW= 244.38' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.20 cfs @ 3.00 fps) Summary for Pond C1133: Inflow Area = 36,766 sf, 44.23% Impervious, Inflow = 2.03 cfs @ 12.08 hrs, Volume= Outflow = 2.03 cfs @ 12.08 hrs, Volume= Primary = 2.03 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.06" 6,304 cf 6,304 cf, 6,304 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.72' @ 12.08 hrs Flood Elev= 231.88' for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 228.93' 12.0" Round Culvert L= 16.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.93'/227.98' S=0.0576'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.97 cfs @ 12.08 hrs HW= 229.71' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.97 cfs @ 3.00 fps) Summary for Pond C1134: Inflow Area = 20,519 sf, 52.91 % Impervious, Inflow = 1.36 cfs @ 12.08 hrs, Volume= Outflow = 1.36 cfs @ 12.08 hrs, Volume= Primary = 1.36 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.46" 4,209 cf 4,209 cf, 4,209 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.26' @ 12.08 hrs Flood Elev= 232.11' for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 229.64' 12.0" Round Culvert L= 31.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.64'/227.96' S=0.0542'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.32 cfs @ 12.08 hrs HW= 230.25' (Free Discharge) t--1 =Culvert (Inlet Controls 1.32 cfs @ 2.65 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 73 Summary for Pond CBS: Inflow Area = 35,276 sf, 4.60% Impervious, Inflow Depth = 1.94" for 10 -Year event Inflow = 1.83 cfs @ 12.08 hrs, Volume= 5,713 cf Outflow = 1.83 cfs @ 12.08 hrs, Volume= 5,713 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.83 cfs @ 12.08 hrs, Volume= 5,713 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.64' @ 12.08 hrs Flood Elev= 227.10' Device Routing Invert Outlet Devices #1 Primary 222.90' 12.0" Round Culvert L= 34.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.90'/218.20' S=0.1382'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.78 cfs @ 12.08 hrs HW= 223.63' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.78 cfs @ 2.90 fps) Summary for Pond C1136: Inflow Area = 30,952 sf, 5.24% Impervious, Inflow Depth = 1.89" for 10 -Year event Inflow = 1.57 cfs @ 12.08 hrs, Volume= 4,888 cf Outflow = 1.57 cfs @ 12.08 hrs, Volume= 4,888 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.57 cfs @ 12.08 hrs, Volume= 4,888 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.38' @ 12.08 hrs Flood Elev= 227.46' Device Ro Invert Outlet Devices #1 Primary 223.66' 12.0" Round Culvert L= 22.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 223.66'/223.42' S=0.0107'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.52 cfs @ 12.08 hrs HW= 224.37' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.52 cfs @ 3.60 fps) Summary for Pond CBB: Inflow Area = 26,908 sf, 37.93% Impervious, Inflow Depth = 2.21" for 10 -Year event Inflow = 1.60 cfs @ 12.08 hrs, Volume= 4,955 cf Outflow = 1.60 cfs @ 12.08 hrs, Volume= 4,955 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.60 cfs @ 12.08 hrs, Volume= 4,955 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 74 Peak Elev= 226.43' @ 12.08 hrs Flood Elev= 229.38' Device Routing Invert Outlet Devices #1 Primary 225.75' 12.0" Round Culvert L= 20.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.75'/225.15' S=0.0293'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.55 cfs @ 12.08 hrs HW= 226.42' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.55 cfs @ 2.78 fps) Summary for Pond C1139: Inflow Area = 1,680 sf, 0.00% Impervious, Inflow Depth = 2.29" for 10 -Year event Inflow = 0.10 cfs @ 12.08 hrs, Volume= 321 cf Outflow = 0.10 cfs @ 12.08 hrs, Volume= 321 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.10 cfs @ 12.08 hrs, Volume= 321 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.87' @ 12.08 hrs Flood Elev= 229.72' Device Routing Invert Outlet Devices #1 Primary 225.72' 12.0" Round Culvert L= 22.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.72'/225.15' S=0.0253'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.10 cfs @ 12.08 hrs HW= 225.87' (Free Discharge) L1= Culvert (Inlet Controls 0.10 cfs @ 1.33 fps) Summary for Pond DB: MOD.EX. DET.BASIN Inflow Area = 336,078 sf, 42.67% Impervious, Inflow Depth= 2.52" for 10 -Year event Inflow = 21.26 cfs @ 12.08 hrs, Volume= 70,698 cf Outflow = 24.47 cfs @ 12.10 hrs, Volume= 70,682 cf, Atten= 0 %, Lag= 0.9 min Primary = 3.84 cfs @ 12.10 hrs, Volume= 50,299 cf Secondary = 20.63 cfs @ 12.10 hrs, Volume= 20,383 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 220.13' @ 12.10 hrs Surf.Area= 5,784 sf Storage= 3,340 cf Plug -Flow detention time= 5.5 min calculated for 70,682 cf (100% of inflow) Center -of -Mass det. time= 4.4 min ( 820.7 - 816.3 ) Volume Invert Avail.Storage Storage Description #1 217.90' 3,340 cf Custom Stage Data (Irregular)Listed below (Recalc) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 75 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 217.90 0 0.0 0 0 0 219.00 919 152.0 337 337 1,840 220.00 5,784 605.0 3,003 3,340 29,132 Device Routing Invert Outlet Devices #1 Primary 218.30' 12.0" Round Culvert L= 16.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.30'/ 218.10' S= 0.0121 T Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Secondary 219.50' 174.0 deg x 4.0' long x 1.50' rise Sharp- Crested Vee /Trap Weir Cv= 2.46 (C= 3.08) Primary OutFlow Max =3.83 cfs @ 12.10 hrs HW= 220.12' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.83 cfs @ 4.88 fps) Secondary OutFlow Max =20.12 cfs @ 12.10 hrs HW= 220.12' (Free Discharge) L2= Sharp- Crested Vee /Trap Weir (Weir Controls 20.12 cfs @ 2.06 fps) Summary for Pond DMH1: Inflow Area = 57,285 sf, 47.34% Impervious, Inflow Depth= 2.20" for 10 -Year event Inflow = 3.39 cfs @ 12.08 hrs, Volume= 10,513 cf Outflow = 3.39 cfs @ 12.08 hrs, Volume= 10,513 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.39 cfs @ 12.08 hrs, Volume= 10,513 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.83' @ 12.08 hrs Flood Elev= 231.11' Device Routing Invert Outlet Devices #1 Primary 222.31' 12.0" Round Culvert L= 77.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 222.31'/219.41' S=0.0374'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =3.28 cfs @ 12.08 hrs HW= 223.78' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.28 cfs @ 4.18 fps) Summary for Pond DMH10: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.82 cfs @ 12.07 hrs, Volume= 2,869 cf Outflow = 0.82 cfs @ 12.07 hrs, Volume= 2,869 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.82 cfs @ 12.07 hrs, Volume= 2,869 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 76 Peak Elev= 229.42' @ 12.07 hrs Flood Elev= 232.59' Device Routing Invert Outlet Devices #1 Primary 228.95' 12.0" Round Culvert L= 36.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.95'/228.59' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.79 cfs @ 12.07 hrs HW= 229.41' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.79 cfs @ 3.27 fps) Summary for Pond DMH11: Inflow Area = 90,561 sf, 67.73% Impervious, Inflow Depth = 2.90" for 10 -Year event Inflow = 6.90 cfs @ 12.07 hrs, Volume= 21,896 cf Outflow = 6.90 cfs @ 12.07 hrs, Volume= 21,896 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.90 cfs @ 12.07 hrs, Volume= 21,896 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.79' @ 12.07 hrs Flood Elev= 235.22' Device Routing Invert Outlet Devices #1 Primary 230.00' 12.0" Round Culvert L= 142.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.00'/224.85' S=0.0363'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =6.65 cfs @ 12.07 hrs HW= 233.59' (Free Discharge) 't--1 =Culvert (Inlet Controls 6.65 cfs @ 8.46 fps) Summary for Pond DMH12: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth= 2.49" for 10 -Year event Inflow = 2.67 cfs @ 12.08 hrs, Volume= 8,329 cf Outflow = 2.67 cfs @ 12.08 hrs, Volume= 8,329 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.67 cfs @ 12.08 hrs, Volume= 8,329 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.49' @ 12.08 hrs Flood Elev= 236.45' Device Routing Invert Outlet Devices #1 Primary 232.50' 12.0" Round Culvert L= 68.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 232.50'/230.00' S=0.0368'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 77 Primary OutFlow Max =2.59 cfs @ 12.08 hrs HW= 233.46' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.59 cfs @ 3.34 fps) Summary for Pond DMH13: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 2.67 cfs @ 12.08 hrs, Volume= Outflow = 2.67 cfs @ 12.08 hrs, Volume= Primary = 2.67 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.49" 8,329 cf 8,329 cf, 8,329 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.59' @ 12.08 hrs Flood Elev= 239.22' for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 234.60' 12.0" Round Culvert L= 104.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 234.60'/232.50' S=0.0202'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =2.59 cfs @ 12.08 hrs HW= 235.56' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.59 cfs @ 3.34 fps) Summary for Pond DMH14: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 2.67 cfs @ 12.08 hrs, Volume= Outflow = 2.67 cfs @ 12.08 hrs, Volume= Primary = 2.67 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.49" 8,329 cf 8,329 cf, 8,329 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.79' @ 12.08 hrs Flood Elev= 241.10' for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 235.80' 12.0" Round Culvert L= 58.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 235.80'/234.60' S=0.0207'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =2.59 cfs @ 12.08 hrs HW= 236.76' (Free Discharge) t--1 =Culvert (Inlet Controls 2.59 cfs @ 3.34 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 78 Summary for Pond DMH15: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 2.67 cfs @ 12.08 hrs, Volume= Outflow = 2.67 cfs @ 12.08 hrs, Volume= Primary = 2.67 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.49" 8,329 cf 8,329 cf, 8,329 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.49' @ 12.08 hrs for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 243.50' 12.0" Round Culvert L= 228.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.50'/236.30' S=0.0315'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =2.59 cfs @ 12.08 hrs HW= 244.46' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.59 cfs @ 3.34 fps) Summary for Pond DMH4: Inflow Area = 181,846 sf, 60.20% Impervious, Inflow = 13.68 cfs @ 12.08 hrs, Volume= Outflow = 13.68 cfs @ 12.08 hrs, Volume= Primary = 13.68 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.82" 42,708 cf 42,708 cf, 42,708 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 222.59' @ 12.08 hrs Flood Elev= 229.65' for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 220.55' 24.0" Round Culvert L= 89.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 220.55'/219.73' S=0.0092'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =13.27 cfs @ 12.08 hrs HW= 222.53' (Free Discharge) 't--1 =Culvert (Inlet Controls 13.27 cfs @ 4.23 fps) Summary for Pond DMH5: Inflow Area = 153,258 sf, 64.77% Impervious, Inflow = 11.98 cfs @ 12.08 hrs, Volume= Outflow = 11.98 cfs @ 12.08 hrs, Volume= Primary = 11.98 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.93" 37,432 cf 37,432 cf, 37,432 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.34' @ 12.08 hrs Flood Elev= 229.63' for 10 -Year event Atten= 0 %, Lag= 0.0 min Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 79 Device Routing Invert Outlet Devices #1 Primary 222.83' 18.0" Round Culvert L= 282.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.83'/220.70' S=0.0076'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 1.77 sf Primary OutFlow Max =11.60 cfs @ 12.08 hrs HW= 226.15' (Free Discharge) 't--1 =Culvert (Barrel Controls 11.60 cfs @ 6.57 fps) Summary for Pond DMH6: Inflow Area = 107,715 sf, 70.09% Impervious, Inflow Depth = 2.87" for 10 -Year event Inflow = 8.29 cfs @ 12.08 hrs, Volume= 25,763 cf Outflow = 8.29 cfs @ 12.08 hrs, Volume= 25,763 cf, Atten= 0 %, Lag= 0.0 min Primary = 8.29 cfs @ 12.08 hrs, Volume= 25,763 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.64' @ 12.08 hrs Flood Elev= 231.08' Device Routing Invert Outlet Devices #1 Primary 224.14' 24.0" Round Culvert L= 89.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 224.14'/222.83' S=0.0146'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =8.03 cfs @ 12.08 hrs HW= 225.61' (Free Discharge) L1 = Culvert (Inlet Controls 8.03 cfs @ 3.25 fps) Summary for Pond EX. C -1: D/W MAIN CULVERT Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 0.89" for 10 -Year event Inflow = 25.27 cfs @ 12.13 hrs, Volume= 209,567 cf Outflow = 25.42 cfs @ 12.13 hrs, Volume= 209,509 cf, Atten= 0 %, Lag= 0.5 min Primary = 25.42 cfs @ 12.13 hrs, Volume= 209,509 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 217.44' @ 12.13 hrs Surf.Area= 0 sf Storage= 442 cf Plug -Flow detention time= 1.5 min calculated for 209,363 cf (100% of inflow) Center -of -Mass det. time= 0.7 min ( 1,556.2 - 1,555.4 ) Volume Invert Avail.Storage Storage Description #1 215.94' 1,029 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 215.94 0 219.44 1,029 Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 80 Device Routing Invert Outlet Devices #1 Primary 216.08' 72.0" W x 42.0" H Box Culvert L= 49.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 216.08'/215.94' S=0.0029'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 21.00 sf Primary OutFlow Max =24.73 cfs @ 12.13 hrs HW= 217.42' (Free Discharge) 't--1 =Culvert (Barrel Controls 24.73 cfs @ 4.11 fps) Summary for Pond EX. P -1: OFF -SITE DEPRESSION Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth = 1.33" for 10 -Year event Inflow = 75.39 cfs @ 12.11 hrs, Volume= 258,167 cf Outflow = 1.76 cfs @ 20.89 hrs, Volume= 220,095 cf, Atten= 98 %, Lag= 527.0 min Discarded = 0.80 cfs @ 20.89 hrs, Volume= 99,400 cf Primary = 0.97 cfs @ 20.89 hrs, Volume= 120,695 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.84' @ 20.89 hrs Surf.Area= 381,825 sf Storage= 190,913 cf Plug -Flow detention time= 1,274.7 min calculated for 220,095 cf (85% of inflow) Center -of -Mass det. time= 1,208.7 min ( 2,074.1 - 865.4 ) Volume Invert #1 219.00' Avail. e Description 1,815,231 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 219.00 0 0 0 220.00 452,595 226,298 226,298 221.00 508,615 480,605 706,903 222.00 557,476 533,046 1,239,948 223.00 593,089 575,283 1,815,231 Device Routing Invert Outlet Devices #1 Primary 218.80' 18.0" W x 18.0" H Box Culvert X 0.20 L= 16.0' RCP, end - section conforming to fill, Ke= 0.500 Inlet/ Outlet Invert= 218.80'/218.60' S=0.0125'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 2.25 sf #2 Secondary 221.80' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 9.00 11.00 20.00 Height (feet) 1.20 0.00 0.00 1.20 #3 Discarded 219.00' 0.090 in /hr Exfiltration over Surface area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 81 Discarded OutFlow Max =0.80 cfs @ 20.89 hrs HW= 219.84' (Free Discharge) L3= Exfiltration (Exfiltration Controls 0.80 cfs) Primary OutFlow Max =0.97 cfs @ 20.89 hrs HW= 219.84' (Free Discharge) L1= Culvert (Barrel Controls 0.97 cfs @ 0.83 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L2= Asymmetrical Weir ( Controls 0.00 cfs) Summary for Pond EX.INF: ADS U/G INF. Inflow Area = 5,090 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.49 cfs @ 12.07 hrs, Volume= 1,724 cf Outflow = 0.02 cfs @ 9.35 hrs, Volume= 1,724 cf, Atten= 96 %, Lag= 0.0 min Discarded = 0.02 cfs @ 9.35 hrs, Volume= 1,724 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.81' @ 15.09 hrs Surf.Area= 800 sf Storage= 870 cf Plug -Flow detention time= 388.6 min calculated for 1,723 cf (100% of inflow) Center -of -Mass det. time= 388.7 min ( 1,138.4 - 749.7 ) Volume Invert Avail.Storage Storage Description #1 224.00' 1,799 cf Custom Stage Data (Prismatic)Listed below (Recalc) x 160 Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq -ft) ( %) (cubic -feet) (cubic -feet) 224.00 5 0.0 0 0 224.01 5 40.0 0 0 224.49 5 40.0 1 1 224.50 5 58.5 0 1 224.99 5 58.5 1 2 225.00 5 73.1 0 2 225.99 5 73.1 4 6 226.00 5 73.1 0 6 226.99 5 73.1 4 10 227.00 5 58.5 0 10 227.50 5 58.5 1 11 Device Routing Invert Outlet Devices #1 Discarded 224.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 226.00' 8.0" Vert. Orifice /Grate C= 0.600 Discarded OutFlow Max =0.02 cfs @ 9.35 hrs HW= 224.01' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 224.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 82 Summary for Pond ST: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.82 cfs @ 12.07 hrs, Volume= 2,869 cf Outflow = 0.81 cfs @ 12.09 hrs, Volume= 1,893 cf, Atten= 1 %, Lag= 1.3 min Primary = 0.81 cfs @ 12.09 hrs, Volume= 1,893 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.60' @ 12.09 hrs Surf.Area= 0 sf Storage= 1,054 cf Plug -Flow detention time= 195.5 min calculated for 1,893 cf (66% of inflow) Center -of -Mass det. time= 94.7 min ( 844.4 - 749.7 ) Volume Invert Avail.Storage Storage Description #1 223.40' 1,360 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 223.40 0 231.40 1,360 Device Routing Invert Outlet Devices #1 Primary 229.14' 12.0" Round Culvert L= 27.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.14'/224.85' S=0.1589'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.79 cfs @ 12.09 hrs HW= 229.59' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.79 cfs @ 2.29 fps) Summary for Link AP1: Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 0.89" for 10 -Year event Inflow = 25.42 cfs @ 12.13 hrs, Volume= 209,509 cf Primary = 25.42 cfs @ 12.13 hrs, Volume= 209,509 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Summary for Link AP2: Inflow Area = 341,168 sf, 43.52% Impervious, Inflow Depth = 2.49" for 10 -Year event Inflow = 24.47 cfs @ 12.10 hrs, Volume= 70,682 cf Primary = 24.47 cfs @ 12.10 hrs, Volume= 70,682 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 83 Summary for Link AP3: Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth > 0.62" for 10 -Year event Inflow = 0.97 cfs @ 20.89 hrs, Volume= 120,695 cf Primary = 0.97 cfs @ 20.89 hrs, Volume= 120,695 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 84 Summary for Subcatchment EX. SC -1: Runoff = 0.61 cfs @ 12.07 hrs, Volume= 1,999 cf, Depth= 6.31" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 1,735 80 >75% Grass cover, Good, HSG D 2,065 98 Paved parking, HSG D 3,800 90 Weighted Average 1,735 45.66% Pervious Area 2,065 54.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -15: Runoff = 0.24 cfs @ 12.07 hrs, Volume= 745 cf, Depth= 5.16" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 1,734 80 >75% Grass cover, Good, HSG D 1,734 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -16: Runoff = 6.95 cfs @ 12.07 hrs, Volume= 22,623 cf, Depth= 6.20" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 85 Area (sf) CN Description 4,653 98 Roofs, HSG B 6,123 98 Roofs, HSG D 2,023 61 >75% Grass cover, Good, HSG B 8,447 80 >75% Grass cover, Good, HSG D 2,473 98 Paved parking, HSG B 10,524 98 Paved parking, HSG D 176 80 >75% Grass cover, Good, HSG D 9,390 80 >75% Grass cover, Good, HSG D 43,809 89 Weighted Average 20,036 45.73% Pervious Area 23,773 54.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -17: Runoff = 1.30 cfs @ 12.07 hrs, Volume= 4,148 cf, Depth= 5.73" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 1,325 98 Roofs, HSG B 2,993 61 >75% Grass cover, Good, HSG B 4,366 98 Paved parking, HSG B 8,684 85 Weighted Average 2,993 34.47% Pervious Area 5,691 65.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -18: Runoff = 6.26 cfs @ 12.07 hrs, Volume= 20,245 cf, Depth= 6.08" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 86 Area (so CN Description 13,935 98 Roofs, HSG B 803 98 Roofs, HSG D 9,943 61 >75% Grass cover, Good, HSG B 2,229 80 >75% Grass cover, Good, HSG D 8,923 98 Paved parking, HSG B 4.124 98 Paved oarkina. HSG D 39,957 88 Weighted Average 12,172 30.46% Pervious Area 27,785 69.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -19: Runoff = 1.78 cfs @ 12.07 hrs, Volume= 6,340 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 5,245 98 Paved parking, HSG B 5,234 98 Paved parking, HSG D 10,479 98 Weighted Average 10,479 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -2: Runoff = 0.54 cfs @ 12.07 hrs, Volume= 1,893 cf, Depth= 7.14" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 3,071 98 Paved parking, HSG D 110 80 >75% Grass cover. Good. HSG D 3,181 97 Weighted Average 110 3.46% Pervious Area 3,071 96.54% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 87 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -20: Runoff = 2.96 cfs @ 12.08 hrs, Volume= 9,196 cf, Depth= 4.71" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 7,685 98 Roofs, HSG B 13,660 61 >75% Grass cover, Good, HSG B 2,108 98 Paved parking, HSG B 23,453 76 Weighted Average 13,660 58.24% Pervious Area 9,793 41.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -21: Runoff = 2.86 cfs @ 12.07 hrs, Volume= 9,206 cf, Depth= 5.96" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 5,373 98 Roofs, HSG B 5,318 61 >75% Grass cover, Good, HSG B 7.833 98 Paved oarkina. HSG B 18,524 87 Weighted Average 5,318 28.71 % Pervious Area 13,206 71.29% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -22: Runoff = 2.86 cfs @ 12.07 hrs, Volume= 8,876 cf, Depth= 4.93" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 88 Area (so CN Description 1,599 98 Roofs, HSG B 11,736 61 >75% Grass cover, Good, HSG B 8,266 98 Paved parking, HSG B 21,601 78 Weighted Average 11,736 79 54.33% Pervious Area 9,865 82 45.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment EX. SC -3: Runoff = 1.80 cfs @ 12.07 hrs, Volume= 5,596 cf, Depth= 5.04" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 6,580 61 >75% Grass cover, Good, HSG B 263 80 >75% Grass cover, Good, HSG D 6,168 98 Paved parking, HSG B 302 98 Paved parking, HSG D 13,313 79 Weighted Average 6,843 82 51.40% Pervious Area 6,470 48.60% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -4: Runoff = 2.93 cfs @ 12.07 hrs, Volume= 9,210 cf, Depth= 5.39" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 4,903 98 Roofs, HSG B 8,496 61 >75% Grass cover, Good, HSG B 1,023 80 >75% Grass cover, Good, HSG D 5,266 98 Paved parking, HSG B 688 98 Paved parking, HSG D 143 80 >75% Grass cover, Good, HSG D 20,519 82 Weighted Average 9,662 47.09% Pervious Area 10,857 52.91% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 89 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -5: Runoff = 0.60 cfs @ 12.07 hrs, Volume= 1,859 cf, Depth= 5.16" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 4,324 80 >75% Grass cover, Good, HSG D 4,324 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -6: Runoff = 3.82 cfs @ 12.08 hrs, Volume= 11,847 cf, Depth= 4.59" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 1,621 98 Roofs, HSG B 8,776 61 >75% Grass cover, Good, HSG B 9,312 80 >75% Grass cover, Good, HSG D 528 61 >75% Grass cover, Good, HSG B 10,715 80 >75% Grass cover, Good, HSG D 30,952 75 Weighted Average 29,331 94.76% Pervious Area 1,621 5.24% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -8: Runoff = 3.64 cfs @ 12.07 hrs, Volume= 11,311 cf, Depth= 5.04" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 90 Area (so CN Description 8,924 98 Roofs, HSG B 1,282 98 Roofs, HSG D 2,977 61 >75% Grass cover, Good, HSG B 1,631 80 >75% Grass cover, Good, HSG D 8,459 61 >75% Grass cover, Good, HSG B 3.635 80 >75% Grass cover. Good. HSG D 26,908 79 Weighted Average 16,702 62.07% Pervious Area 10,206 37.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -9: Runoff = 0.23 cfs @ 12.07 hrs, Volume= 722 cf, Depth= 5.16" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 1,680 80 >75% Grass cover, Good, HSG D 1,680 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -A: Runoff = 10.79 cfs @ 12.10 hrs, Volume= 35,007 cf, Depth= 3.71" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 2,268 61 >75% Grass cover, Good, HSG B 16,260 80 >75% Grass cover, Good, HSG D 2,973 98 Paved parking, HSG B 627 98 Paved parking, HSG D 56,294 55 Woods, Good, HSG B 32,414 77 Woods, Good, HSG D 647 98 Ledge, HSG B 1,746 96 Gravel surface, HSG D 113,229 67 Weighted Average 108,982 96.25% Pervious Area 4,247 3.75% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 91 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 2.4 30 0.5000 0.21 Sheet Flow, 77 Woods, Good, HSG D 1,274 Woods: Light underbrush n= 0.400 P2= 2.80" 0.4 85 0.5000 3.54 Shallow Concentrated Flow, 62,991 100.00% Pervious Area Woodland Kv= 5.0 fps 0.9 105 0.1430 1.89 Shallow Concentrated Flow, (ft/ft) (ft /sec) (cfs) 2.4 30 Woodland Kv= 5.0 fps 0.5 45 0.0890 1.49 Shallow Concentrated Flow, 0.5 110 0.5000 3.54 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 1.5 130 0.0846 1.45 Shallow Concentrated Flow, 0.2500 7.50 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.2 50 0.0600 3.67 Shallow Concentrated Flow, Woodland Kv= 5.0 fps Grassed Waterway Kv= 15.0 fps 1.0 56 0.0357 0.94 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 1.2 49 Woodland Kv= 5.0 fps 6.9 501 Total Summary for Subcatchment EX. SC -B: Runoff = 5.69 cfs @ 12.08 hrs, Volume= 17,778 cf, Depth= 3.39" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 6,337 61 >75% Grass cover, Good, HSG B 13,753 80 >75% Grass cover, Good, HSG D 34,537 55 Woods, Good, HSG B 7,090 77 Woods, Good, HSG D 1,274 96 Gravel surface, HSG D 62,991 64 Weighted Average 62,991 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 2.4 30 0.5000 0.21 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 2.80" 0.5 110 0.5000 3.54 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.1 42 0.2500 7.50 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.7 136 0.3680 3.03 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 0.3 85 0.1170 5.13 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 1.2 49 0.0200 0.71 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 5.2 452 Total Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 92 Summary for Subcatchment EX. SC -C: Runoff = 5.69 cfs @ 12.18 hrs, Volume= 22,472 cf, Depth= 4.93" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 18 98 Roofs, HSG D 15,388 80 >75% Grass cover, Good, HSG D 28 98 Paved parking, HSG D 39,256 77 Woods, Good, HSG D 54,690 78 Weighted Average 54,644 99.92% Pervious Area 46 0.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 6.1 30 0.0070 0.08 Sheet Flow, 102,386 98 Paved parking, HSG D 347,789 Grass: Short n=0.150 P2=2.80" 7.0 488 0.0060 1.16 Shallow Concentrated Flow, 77 Woods, Good, HSG D 3,953 98 Grassed Waterwav Kv= 15.0 fps 13.1 518 Total Summary for Subcatchment EX. SC -D: Runoff = 222.80 cfs @ 12.10 hrs, Volume= 718,253 cf, Depth= 3.71" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 32 98 Roofs, HSG D 585 61 >75% Grass cover, Good, HSG B 10,742 80 >75% Grass cover, Good, HSG D 55,279 98 Paved parking, HSG A 167,851 98 Paved parking, HSG B 102,386 98 Paved parking, HSG D 347,789 30 Woods, Good, HSG A 624,368 55 Woods, Good, HSG B 1,009,555 77 Woods, Good, HSG D 3,953 98 Ledge, HSG B 495 96 Gravel surface, HSG B 113 96 Gravel surface, HSG D 2,323,148 67 Weighted Average 1,993,647 85.82% Pervious Area 329,501 14.18% Impervious Area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 93 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 3.3 30 0.0330 0.15 Sheet Flow, Grass: Short n=0.150 P2=2.80" 0.3 118 0.2550 7.57 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.3 57 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.0 705 0.0850 5.92 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 165 0.0480 3.29 Shallow Concentrated Flow, Grassed Waterwav Kv= 15.0 fps 6.7 1,075 Total Summary for Subcatchment EX. SC -R: Runoff = 0.87 cfs @ 12.07 hrs, Volume= 3,080 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 5,090 98 Roofs, HSG B 5,090 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -ST: Runoff = 1.44 cfs @ 12.07 hrs, Volume= 5,125 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 8,470 98 Roofs, HSG B 8,470 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 94 Summary for Reach R1: Inflow Area = 2,727,307 sf, 17.53% Impervious, Inflow Depth > 2.29" for 100 -Year event Inflow = 51.74 cfs @ 12.07 hrs, Volume= 521,504 cf Outflow = 49.47 cfs @ 12.11 hrs, Volume= 521,020 cf, Atten= 4 %, Lag= 2.2 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 2.42 fps, Min. Travel Time= 2.2 min Avg. Velocity = 0.70 fps, Avg. Travel Time= 7.7 min Peak Storage= 6,627 cf @ 12.11 hrs Average Depth at Peak Storage= 1.38' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 56.94 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 324.0' Slope= 0.00287' Inlet Invert= 218.80', Outlet Invert= 217.90' H Summary for Reach R2: Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth > 1 Inflow = 2.24 cfs @ 22.78 hrs, Volume= 350,809 cf Outflow = 2.24 cfs @ 22.84 hrs, Volume= 350,385 cf, Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 0.58 fps, Min. Travel Time= 5.9 min Avg. Velocity = 0.49 fps, Avg. Travel Time= 7.0 min Peak Storage= 798 cf @ 22.84 hrs Average Depth at Peak Storage= 0.31' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 33.66 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 206.0' Slope= 0.0010 '/' Inlet Invert= 219.00', Outlet Invert= 218.80' 81" for 100 -Year event Atten= 0 %, Lag= 3.7 min Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 95 Summary for Pond C1131: Inflow Area = 3,800 sf, 54.34% Impervious, Inflow Depth = 6.31" for 100 -Year event Inflow = 0.61 cfs @ 12.07 hrs, Volume= 1,999 cf Outflow = 0.61 cfs @ 12.07 hrs, Volume= 1,999 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.61 cfs @ 12.07 hrs, Volume= 1,999 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 245.51' @ 12.07 hrs Flood Elev= 221.25' Device Routing Invert Outlet Devices #1 Primary 224.92' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.59 cfs @ 12.07 hrs HW= 244.22' (Free Discharge) L1= Orifice /Grate (Orifice Controls 0.59 cfs @ 21.15 fps) Summary for Pond CB15: Inflow Area = 1,734 sf, 0.00% Impervious, Inflow Depth = 5.16" for 100 -Year event Inflow = 0.24 cfs @ 12.07 hrs, Volume= 745 cf Outflow = 0.24 cfs @ 12.07 hrs, Volume= 745 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.24 cfs @ 12.07 hrs, Volume= 745 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.34' @ 12.07 hrs Flood Elev= 229.32' Device Routing Invert Outlet Devices #1 Primary 225.10' 12.0" Round Culvert L= 19.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.10'/222.83' S=0.1195'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.23 cfs @ 12.07 hrs HW= 225.33' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.23 cfs @ 1.64 fps) Summary for Pond CB16: Inflow Area = 43,809 sf, 54.27% Impervious, Inflow Depth = 6.20" for 100 -Year event Inflow = 6.95 cfs @ 12.07 hrs, Volume= 22,623 cf Outflow = 6.95 cfs @ 12.07 hrs, Volume= 22,623 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.95 cfs @ 12.07 hrs, Volume= 22,623 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.55' @ 12.07 hrs Flood Elev= 229.50' Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 96 Device Routing Invert Outlet Devices #1 Primary 225.71' 12.0" Round Culvert L= 9.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.71'/222.83' S=0.3200'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =6.69 cfs @ 12.07 hrs HW= 229.34' (Free Discharge) 't--1 =Culvert (Inlet Controls 6.69 cfs @ 8.52 fps) Summary for Pond CB17: Inflow Area = 8,684 sf, 65.53% Impervious, Inflow Depth = 5.73" for 100 -Year event Inflow = 1.30 cfs @ 12.07 hrs, Volume= 4,148 cf Outflow = 1.30 cfs @ 12.07 hrs, Volume= 4,148 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.30 cfs @ 12.07 hrs, Volume= 4,148 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.01' @ 12.07 hrs Flood Elev= 228.31' Device Routing Invert Outlet Devices #1 Primary 225.13' 12.0" Round Culvert L= 80.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.13'/225.07' S=0.0008'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.26 cfs @ 12.07 hrs HW= 225.99' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.26 cfs @ 2.33 fps) Summary for Pond CB18: Inflow Area = 39,957 sf, 69.54% Impervious, Inflow Depth = 6.08" for 100 -Year event Inflow = 6.26 cfs @ 12.07 hrs, Volume= 20,245 cf Outflow = 6.26 cfs @ 12.07 hrs, Volume= 20,245 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.26 cfs @ 12.07 hrs, Volume= 20,245 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.46' @ 12.07 hrs Flood Elev= 234.91' Device Routing Invert Outlet Devices #1 Primary 230.25' 12.0" Round Culvert L= 14.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.25'/230.10' S=0.0103'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =6.03 cfs @ 12.07 hrs HW= 233.29' (Free Discharge) 't--1 =Culvert (Inlet Controls 6.03 cfs @ 7.68 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 97 Summary for Pond CB19: Inflow Area = 10,479 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.78 cfs @ 12.07 hrs, Volume= 6,340 cf Outflow = 1.78 cfs @ 12.07 hrs, Volume= 6,340 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.78 cfs @ 12.07 hrs, Volume= 6,340 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.03' @ 12.07 hrs Flood Elev= 235.05' Device Routing Invert Outlet Devices #1 Primary 230.16' 12.0" Round Culvert L= 6.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.16'/230.10' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.72 cfs @ 12.07 hrs HW= 231.01' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.72 cfs @ 3.27 fps) Summary for Pond C1132: Inflow Area = 6,981 sf, 73.57% Impervious, Inflow Depth = 6.69" for 100 -Year event Inflow = 1.15 cfs @ 12.07 hrs, Volume= 3,892 cf Outflow = 1.15 cfs @ 12.07 hrs, Volume= 3,892 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.15 cfs @ 12.07 hrs, Volume= 3,892 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 218.92' @ 12.07 hrs Flood Elev= 225.01' Device Ro Invert Outlet Devices #1 Primary 218.16' 12.0" Round Culvert L= 135.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.16'/ 217.88' S= 0.0021 T Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.11 cfs @ 12.07 hrs HW= 218.91' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.11 cfs @ 2.45 fps) Summary for Pond CB20: Inflow Area = 23,453 sf, 41.76% Impervious, Inflow Depth = 4.71" for 100 -Year event Inflow = 2.96 cfs @ 12.08 hrs, Volume= 9,196 cf Outflow = 2.96 cfs @ 12.08 hrs, Volume= 9,196 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.96 cfs @ 12.08 hrs, Volume= 9,196 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 98 Peak Elev= 259.52' @ 12.08 hrs Flood Elev= 239.00' Device Routing Invert Outlet Devices #1 Primary 235.70' 6.0" Round Culvert L= 143.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 235.70'/228.93' S=0.0472'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 0.20 sf Primary OutFlow Max =2.86 cfs @ 12.08 hrs HW= 257.91' (Free Discharge) 't--1 =Culvert (Barrel Controls 2.86 cfs @ 14.59 fps) Summary for Pond CB21: Inflow Area = 18,524 sf, 71.29% Impervious, Inflow Depth = 5.96" for 100 -Year event Inflow = 2.86 cfs @ 12.07 hrs, Volume= 9,206 cf Outflow = 2.86 cfs @ 12.07 hrs, Volume= 9,206 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.86 cfs @ 12.07 hrs, Volume= 9,206 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 245.10' @ 12.07 hrs Flood Elev= 247.80' Device Routing Invert Outlet Devices #1 Primary 243.80' 12.0" Round Culvert L= 25.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.80'/243.70' S=0.0039'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =2.76 cfs @ 12.07 hrs HW= 245.06' (Free Discharge) 't--1 =Culvert (Barrel Controls 2.76 cfs @ 3.60 fps) Summary for Pond CB22: Inflow Area = 21,601 sf, 45.67% Impervious, Inflow Depth = 4.93" for 100 -Year event Inflow = 2.86 cfs @ 12.07 hrs, Volume= 8,876 cf Outflow = 2.86 cfs @ 12.07 hrs, Volume= 8,876 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.86 cfs @ 12.07 hrs, Volume= 8,876 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.92' @ 12.07 hrs Flood Elev= 247.90' Device Routing Invert Outlet Devices #1 Primary 243.70' 12.0" Round Culvert L= 16.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.70'/243.60' S=0.0062'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 99 Primary OutFlow Max =2.76 cfs @ 12.07 hrs HW= 244.89' (Free Discharge) 't--1 =Culvert (Barrel Controls 2.76 cfs @ 3.73 fps) Summary for Pond C1133: Inflow Area = 36,766 sf, 44.23% Impervious, Inflow Depth= 4.83" for 100 -Year event Inflow = 4.77 cfs @ 12.07 hrs, Volume= 14,792 cf Outflow = 4.77 cfs @ 12.07 hrs, Volume= 14,792 cf, Atten= 0 %, Lag= 0.0 min Primary = 4.77 cfs @ 12.07 hrs, Volume= 14,792 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.00' @ 12.07 hrs Flood Elev= 231.88' Device Routing Invert Outlet Devices #1 Primary 228.93' 12.0" Round Culvert L= 16.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.93'/227.98' S=0.0576'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =4.60 cfs @ 12.07 hrs HW= 230.91' (Free Discharge) 't--1 =Culvert (Inlet Controls 4.60 cfs @ 5.85 fps) Summary for Pond C1134: Inflow Area = 20,519 sf, 52.91% Impervious, Inflow Depth = 5.39" for 100 -Year event Inflow = 2.93 cfs @ 12.07 hrs, Volume= 9,210 cf Outflow = 2.93 cfs @ 12.07 hrs, Volume= 9,210 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.93 cfs @ 12.07 hrs, Volume= 9,210 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.73' @ 12.07 hrs Flood Elev= 232.11' Device Routing Invert Outlet Devices #1 Primary 229.64' 12.0" Round Culvert L= 31.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.64'/227.96' S=0.0542'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =2.82 cfs @ 12.07 hrs HW= 230.70' (Free Discharge) t--1 =Culvert (Inlet Controls 2.82 cfs @ 3.60 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 100 Summary for Pond CBS: Inflow Area = 35,276 sf, 4.60% Impervious, Inflow Depth= 4.66" for 100 -Year event Inflow = 4.41 cfs @ 12.08 hrs, Volume= 13,705 cf Outflow = 4.41 cfs @ 12.08 hrs, Volume= 13,705 cf, Atten= 0 %, Lag= 0.0 min Primary = 4.41 cfs @ 12.08 hrs, Volume= 13,705 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.75' @ 12.08 hrs Flood Elev= 227.10' Device Routing Invert Outlet Devices #1 Primary 222.90' 12.0" Round Culvert L= 34.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.90'/218.20' S=0.1382'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =4.27 cfs @ 12.08 hrs HW= 224.67' (Free Discharge) 't--1 =Culvert (Inlet Controls 4.27 cfs @ 5.44 fps) Summary for Pond C1136: Inflow Area = 30,952 sf, 5.24% Impervious, Inflow Depth= 4.59" for 100 -Year event Inflow = 3.82 cfs @ 12.08 hrs, Volume= 11,847 cf Outflow = 3.82 cfs @ 12.08 hrs, Volume= 11,847 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.82 cfs @ 12.08 hrs, Volume= 11,847 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.20' @ 12.08 hrs Flood Elev= 227.46' Device Ro Invert Outlet Devices #1 Primary 223.66' 12.0" Round Culvert L= 22.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 223.66'/223.42' S=0.0107'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =3.70 cfs @ 12.08 hrs HW= 225.14' (Free Discharge) 't--1 =Culvert (Barrel Controls 3.70 cfs @ 4.71 fps) Summary for Pond CBB: Inflow Area = 26,908 sf, 37.93% Impervious, Inflow Depth= 5.04" for 100 -Year event Inflow = 3.64 cfs @ 12.07 hrs, Volume= 11,311 cf Outflow = 3.64 cfs @ 12.07 hrs, Volume= 11,311 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.64 cfs @ 12.07 hrs, Volume= 11,311 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 101 Peak Elev= 227.16' @ 12.07 hrs Flood Elev= 229.38' Device Routing Invert Outlet Devices #1 Primary 225.75' 12.0" Round Culvert L= 20.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.75'/225.15' S=0.0293'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =3.50 cfs @ 12.07 hrs HW= 227.11' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.50 cfs @ 4.46 fps) Summary for Pond C1139: Inflow Area = 1,680 sf, 0.00% Impervious, Inflow Depth = 5.16" for 100 -Year event Inflow = 0.23 cfs @ 12.07 hrs, Volume= 722 cf Outflow = 0.23 cfs @ 12.07 hrs, Volume= 722 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.23 cfs @ 12.07 hrs, Volume= 722 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.95' @ 12.07 hrs Flood Elev= 229.72' Device Routing Invert Outlet Devices #1 Primary 225.72' 12.0" Round Culvert L= 22.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.72'/225.15' S=0.0253'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.22 cfs @ 12.07 hrs HW= 225.95' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.22 cfs @ 1.63 fps) Summary for Pond DB: MOD.EX. DET.BASIN Inflow Area = 336,078 sf, 42.67% Impervious, Inflow Depth= 5.44" for 100 -Year event Inflow = 44.67 cfs @ 12.08 hrs, Volume= 152,437 cf Outflow = 45.51 cfs @ 12.07 hrs, Volume= 152,421 cf, Atten= 0 %, Lag= 0.0 min Primary = 4.16 cfs @ 12.07 hrs, Volume= 89,432 cf Secondary = 41.34 cfs @ 12.07 hrs, Volume= 62,989 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 220.36' @ 12.07 hrs Surf.Area= 5,784 sf Storage= 3,340 cf Plug -Flow detention time= 5.1 min calculated for 152,421 cf (100% of inflow) Center -of -Mass det. time= 4.0 min ( 800.5 - 796.5 ) Volume Invert Avail.Storage Storage Description #1 217.90' 3,340 cf Custom Stage Data (Irregular)Listed below (Recalc) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 102 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 217.90 0 0.0 0 0 0 219.00 919 152.0 337 337 1,840 220.00 5,784 605.0 3,003 3,340 29,132 Device Routing Invert Outlet Devices #1 Primary 218.30' 12.0" Round Culvert L= 16.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.30'/ 218.10' S= 0.0121 T Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Secondary 219.50' 174.0 deg x 4.0' long x 1.50' rise Sharp- Crested Vee /Trap Weir Cv= 2.46 (C= 3.08) Primary OutFlow Max =4.13 cfs @ 12.07 hrs HW= 220.34' (Free Discharge) 't--1 =Culvert (Inlet Controls 4.13 cfs @ 5.26 fps) Secondary OutFlow Max =39.36 cfs @ 12.07 hrs HW= 220.34' (Free Discharge) L2= Sharp- Crested Vee /Trap Weir (Weir Controls 39.36 cfs @ 2.36 fps) Summary for Pond DMH1: Inflow Area = 57,285 sf, 47.34% Impervious, Inflow Depth= 5.03" for 100 -Year event Inflow = 7.71 cfs @ 12.07 hrs, Volume= 24,002 cf Outflow = 7.71 cfs @ 12.07 hrs, Volume= 24,002 cf, Atten= 0 %, Lag= 0.0 min Primary = 7.71 cfs @ 12.07 hrs, Volume= 24,002 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.08' @ 12.07 hrs Flood Elev= 231.11' Device Routing Invert Outlet Devices #1 Primary 222.31' 12.0" Round Culvert L= 77.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 222.31'/219.41' S=0.0374'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =7.42 cfs @ 12.07 hrs HW= 227.76' (Free Discharge) 't--1 =Culvert (Inlet Controls 7.42 cfs @ 9.45 fps) Summary for Pond DMH10: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.44 cfs @ 12.07 hrs, Volume= 5,125 cf Outflow = 1.44 cfs @ 12.07 hrs, Volume= 5,125 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.44 cfs @ 12.07 hrs, Volume= 5,125 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 103 Peak Elev= 229.61' @ 12.07 hrs Flood Elev= 232.59' Device Routing Invert Outlet Devices #1 Primary 228.95' 12.0" Round Culvert L= 36.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.95'/228.59' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.39 cfs @ 12.07 hrs HW= 229.60' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.39 cfs @ 3.67 fps) Summary for Pond DMH11: Inflow Area = 90,561 sf, 67.73% Impervious, Inflow Depth = 5.92" for 100 -Year event Inflow = 13.77 cfs @ 12.07 hrs, Volume= 44,667 cf Outflow = 13.77 cfs @ 12.07 hrs, Volume= 44,667 cf, Atten= 0 %, Lag= 0.0 min Primary = 13.77 cfs @ 12.07 hrs, Volume= 44,667 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 250.86' @ 12.07 hrs Flood Elev= 235.22' Device Routing Invert Outlet Devices #1 Primary 230.00' 12.0" Round Culvert L= 142.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.00'/224.85' S=0.0363'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =13.26 cfs @ 12.07 hrs HW= 249.30' (Free Discharge) 't--1 =Culvert (Barrel Controls 13.26 cfs @ 16.88 fps) Summary for Pond DMH12: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 5.41" for 100 -Year event Inflow = 5.72 cfs @ 12.07 hrs, Volume= 18,082 cf Outflow = 5.72 cfs @ 12.07 hrs, Volume= 18,082 cf, Atten= 0 %, Lag= 0.0 min Primary = 5.72 cfs @ 12.07 hrs, Volume= 18,082 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.27' @ 12.07 hrs Flood Elev= 236.45' Device Routing Invert Outlet Devices #1 Primary 232.50' 12.0" Round Culvert L= 68.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 232.50'/230.00' S=0.0368'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 104 Primary OutFlow Max =5.51 cfs @ 12.07 hrs HW= 235.12' (Free Discharge) L1= Culvert (Inlet Controls 5.51 cfs @ 7.02 fps) Summary for Pond DMH13: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 5.72 cfs @ 12.07 hrs, Volume= Outflow = 5.72 cfs @ 12.07 hrs, Volume= Primary = 5.72 cfs @ 12.07 hrs, Volume= Inflow Depth = 5.41" 18,082 cf 18,082 cf, 18,082 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 237.37' @ 12.07 hrs Flood Elev= 239.22' for 100 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 234.60' 12.0" Round Culvert L= 104.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 234.60'/232.50' S=0.0202'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =5.51 cfs @ 12.07 hrs HW= 237.22' (Free Discharge) L1= Culvert (Inlet Controls 5.51 cfs @ 7.02 fps) Summary for Pond DMH14: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 5.72 cfs @ 12.07 hrs, Volume= Outflow = 5.72 cfs @ 12.07 hrs, Volume= Primary = 5.72 cfs @ 12.07 hrs, Volume= Inflow Depth = 5.41" 18,082 cf 18,082 cf, 18,082 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 238.57' @ 12.07 hrs Flood Elev= 241.10' for 100 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 235.80' 12.0" Round Culvert L= 58.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 235.80'/234.60' S=0.0207'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =5.51 cfs @ 12.07 hrs HW= 238.42' (Free Discharge) L1= Culvert (Inlet Controls 5.51 cfs @ 7.02 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 105 Summary for Pond DMH15: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 5.72 cfs @ 12.07 hrs, Volume= Outflow = 5.72 cfs @ 12.07 hrs, Volume= Primary = 5.72 cfs @ 12.07 hrs, Volume= Inflow Depth = 5.41" 18,082 cf 18,082 cf, 18,082 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 246.27' @ 12.07 hrs for 100 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 243.50' 12.0" Round Culvert L= 228.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.50'/236.30' S=0.0315'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =5.51 cfs @ 12.07 hrs HW= 246.12' (Free Discharge) L1= Culvert (Inlet Controls 5.51 cfs @ 7.02 fps) Summary for Pond DMH4: Inflow Area = 181,846 sf, 60.20% Impervious, Inflow = 27.52 cfs @ 12.07 hrs, Volume= Outflow = 27.52 cfs @ 12.07 hrs, Volume= Primary = 27.52 cfs @ 12.07 hrs, Volume= Inflow Depth = 5.83" 88,365 cf 88,365 cf, 88,365 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.75' @ 12.07 hrs Flood Elev= 229.65' for 100 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 220.55' 24.0" Round Culvert L= 89.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 220.55'/219.73' S=0.0092'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =26.51 cfs @ 12.07 hrs HW= 225.49' (Free Discharge) 't--1 =Culvert (Inlet Controls 26.51 cfs @ 8.44 fps) Summary for Pond DMH5: Inflow Area = 153,258 sf, 64.77% Impervious, Inflow = 23.65 cfs @ 12.07 hrs, Volume= Outflow = 23.65 cfs @ 12.07 hrs, Volume= Primary = 23.65 cfs @ 12.07 hrs, Volume= Inflow Depth = 5.98" 76,332 cf 76,332 cf, 76,332 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 238.41' @ 12.07 hrs Flood Elev= 229.63' for 100 -Year event Atten= 0 %, Lag= 0.0 min Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 106 Device Routing Invert Outlet Devices #1 Primary 222.83' 18.0" Round Culvert L= 282.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.83'/220.70' S=0.0076'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 1.77 sf Primary OutFlow Max =22.78 cfs @ 12.07 hrs HW= 237.41' (Free Discharge) 't--1 =Culvert (Barrel Controls 22.78 cfs @ 12.89 fps) Summary for Pond DMH6: Inflow Area = 107,715 sf, 70.09% Impervious, Inflow Depth = 5.90" for 100 -Year event Inflow = 16.46 cfs @ 12.07 hrs, Volume= 52,964 cf Outflow = 16.46 cfs @ 12.07 hrs, Volume= 52,964 cf, Atten= 0 %, Lag= 0.0 min Primary = 16.46 cfs @ 12.07 hrs, Volume= 52,964 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.02' @ 12.07 hrs Flood Elev= 231.08' Device Routing Invert Outlet Devices #1 Primary 224.14' 24.0" Round Culvert L= 89.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 224.14'/222.83' S=0.0146'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =15.86 cfs @ 12.07 hrs HW= 226.90' (Free Discharge) 't--1 =Culvert (Inlet Controls 15.86 cfs @ 5.05 fps) Summary for Pond EX. C -1: D/W MAIN CULVERT Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 2.35" for 100 -Year event Inflow = 60.26 cfs @ 12.11 hrs, Volume= 556,027 cf Outflow = 60.31 cfs @ 12.11 hrs, Volume= 555,947 cf, Atten= 0 %, Lag= 0.1 min Primary = 60.31 cfs @ 12.11 hrs, Volume= 555,947 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 218.56' @ 12.11 hrs Surf.Area= 0 sf Storage= 770 cf Plug -Flow detention time= 0.8 min calculated for 555,947 cf (100% of inflow) Center -of -Mass det. time= 0.4 min ( 1,725.8 - 1,725.3 ) Volume Invert Avail.Storage Storage Description #1 215.94' 1,029 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 215.94 0 219.44 1,029 Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 107 Device Routing Invert Outlet Devices #1 Primary 216.08' 72.0" W x 42.0" H Box Culvert L= 49.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 216.08'/215.94' S=0.0029'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 21.00 sf Primary OutFlow Max =59.03 cfs @ 12.11 hrs HW= 218.52' (Free Discharge) 't--1 =Culvert (Barrel Controls 59.03 cfs @ 5.37 fps) Summary for Pond EX. P -1: OFF -SITE DEPRESSION Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth = 3.71" for 100 -Year event Inflow = 222.80 cfs @ 12.10 hrs, Volume= 718,253 cf Outflow = 3.27 cfs @ 22.78 hrs, Volume= 558,510 cf, Atten= 99 %, Lag= 640.4 min Discarded = 1.03 cfs @ 22.78 hrs, Volume= 207,701 cf Primary = 2.24 cfs @ 22.78 hrs, Volume= 350,809 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 220.74' @ 22.78 hrs Surf.Area= 494,058 sf Storage= 582,012 cf Plug -Flow detention time= 1,572.0 min calculated for 558,510 cf (78% of inflow) Center -of -Mass det. time= 1,488.3 min ( 2,323.1 - 834.8 ) Volume Invert #1 219.00' Avail. e Description 1,815,231 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 219.00 0 0 0 220.00 452,595 226,298 226,298 221.00 508,615 480,605 706,903 222.00 557,476 533,046 1,239,948 223.00 593,089 575,283 1,815,231 Device Routing Invert Outlet Devices #1 Primary 218.80' 18.0" W x 18.0" H Box Culvert X 0.20 L= 16.0' RCP, end - section conforming to fill, Ke= 0.500 Inlet/ Outlet Invert= 218.80'/218.60' S=0.0125'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 2.25 sf #2 Secondary 221.80' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 9.00 11.00 20.00 Height (feet) 1.20 0.00 0.00 1.20 #3 Discarded 219.00' 0.090 in /hr Exfiltration over Surface area Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 108 Discarded OutFlow Max =1.03 cfs @ 22.78 hrs HW= 220.74' (Free Discharge) L3= Exfiltration (Exfiltration Controls 1.03 cfs) Primary OutFlow Max =2.24 cfs @ 22.78 hrs HW= 220.74' (Free Discharge) 't--1 =Culvert (Barrel Controls 2.24 cfs @ 1.03 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L2= Asymmetrical Weir ( Controls 0.00 cfs) Summary for Pond EX.INF: ADS U/G INF. Inflow Area = 5,090 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 0.87 cfs @ 12.07 hrs, Volume= 3,080 cf Outflow = 0.37 cfs @ 12.26 hrs, Volume= 3,080 cf, Atten= 58 %, Lag= 11.6 min Discarded = 0.02 cfs @ 7.45 hrs, Volume= 2,160 cf Primary = 0.35 cfs @ 12.26 hrs, Volume= 920 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.34' @ 12.26 hrs Surf.Area= 800 sf Storage= 1,178 cf Plug -Flow detention time= 331.6 min calculated for 3,080 cf (100% of inflow) Center -of -Mass det. time= 331.6 min ( 1,072.7 - 741.1 ) Volume Invert Avail.Storage Storage Description #1 224.00' 1,799 cf Custom Stage Data (Prismatic)Listed below (Recalc) x 160 Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq -ft) ( %) (cubic -feet) (cubic -feet) 224.00 5 0.0 0 0 224.01 5 40.0 0 0 224.49 5 40.0 1 1 224.50 5 58.5 0 1 224.99 5 58.5 1 2 225.00 5 73.1 0 2 225.99 5 73.1 4 6 226.00 5 73.1 0 6 226.99 5 73.1 4 10 227.00 5 58.5 0 10 227.50 5 58.5 1 11 Device Routing Invert Outlet Devices #1 Discarded 224.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 226.00' 8.0" Vert. Orifice /Grate C= 0.600 Discarded OutFlow Max =0.02 cfs @ 7.45 hrs HW= 224.01' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =0.34 cfs @ 12.26 hrs HW= 226.33' (Free Discharge) L2= Orifice /Grate (Orifice Controls 0.34 cfs @ 1.97 fps) Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 109 Summary for Pond ST: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.44 cfs @ 12.07 hrs, Volume= 5,125 cf Outflow = 1.42 cfs @ 12.09 hrs, Volume= 4,149 cf, Atten= 1 %, Lag= 1.1 min Primary = 1.42 cfs @ 12.09 hrs, Volume= 4,149 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.77' @ 12.09 hrs Surf.Area= 0 sf Storage= 1,084 cf Plug -Flow detention time= 146.6 min calculated for 4,149 cf (81 % of inflow) Center -of -Mass det. time= 70.8 min ( 811.9 - 741.1 ) Volume Invert Avail.Storage Storage Description #1 223.40' 1,360 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 223.40 0 231.40 1,360 Device Routing Invert Outlet Devices #1 Primary 229.14' 12.0" Round Culvert L= 27.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.14'/224.85' S=0.1589'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.38 cfs @ 12.09 hrs HW= 229.76' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.38 cfs @ 2.69 fps) Summary for Link AP1: Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 2.35" for 100 -Year event Inflow = 60.31 cfs @ 12.11 hrs, Volume= 555,947 cf Primary = 60.31 cfs @ 12.11 hrs, Volume= 555,947 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Summary for Link AP2: Inflow Area = 341,168 sf, 43.52% Impervious, Inflow Depth = 5.39" for 100 -Year event Inflow = 45.51 cfs @ 12.07 hrs, Volume= 153,341 cf Primary = 45.51 cfs @ 12.07 hrs, Volume= 153,341 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 PRE Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 110 Summary for Link AP3: Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth > 1.81" for 100 -Year event Inflow = 2.24 cfs @ 22.78 hrs, Volume= 350,809 cf Primary = 2.24 cfs @ 22.78 hrs, Volume= 350,809 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs - - woo•aur,a6•x,MM� - -- N- 1SOd -WMS d` h 30VNIV80 Hi8ON 'v 11 NIV. 11 LIOZ 3Nn 31V4 iN3WdM3A3a -1SOd '3NI9llVM9NILg1S38d'HllWSOlO9 slinjonils g puel Jo} 1�j cl !E) 9JA :AHO Wd1i 18 S113snHOVSSVV4 'NOlONIX3l suoilnlos6ui.issulou3 L901,91, :eor NOlONIX3l ONV N3nVHNOOae 0 0 zJ y z � m W 0 ¢ z W z O Z m � r w 0 Q w m° a m o U w w = w r U) o 0 z Q z w w _ U w ¢ Z a ?_ m d o D 3 3 Q v? Of o U Ln Ad se c� I A� Lu dc� NIX r W 0 ¢7 i/ Lu f �S� `�; •� � � �' ,� r�,� ,�h, a �ta — 1 �� a I ; �m ti r= m mm � t I mtt; I� a n I � I 00 .. ... .. ... ... ... . . .. ... . '10 Ye 4 a s r mi N w I �I t 8 � IBiA� a 1 h �a 1�HH1S / 3 iss �b7 s1ron°� 9rs! � W H17b rF•., h f:. 17�f a �H �.oy _ - - w °o•aur,a6•x,MM� - -- S- 1SOd -WMS d` V4 30VNIV2Kl Hinos "' °SZ "a 301OJ' 'v 11 NIV. 11 LIOZ 3Nn 31V4 iN3WdM3A3a -1SOd '3NI9llVM9NILg1SB8d'H111NSOlO9 slinjonils g puel Jo} 1�j cl !E) 9JA :AHO Wd1i J 8 S113snHOVSSVV4 'NOlONIX3l suol)nlos 6ui.issulou3 L901,91, :eor NOlONIX3l ONV N3nVHNOOae oN .. r z OE z LU OE O J o w / Z m D N Q w r m o am0 w 0 cr w z w z w `n.. ¢ a z o I z n r n < 3 m 3 w o O� O w Q Z jnW w 0 ID 1 r ��� fll III II a r. e A l J I IY] I a Illw k} e o f Y flH "} L l4 w I° x- L \ \ \ gg � w ... z u I } z OZ u � 000e ep Pre AP1 Pre AP2 Pre AP3 o-1 Cs��} NW CULVERT DM = �s °.. Cs R} NF R3 NF1 U/G 1 F. WEST WALE U/G INF P SGRB RSGRe............. � DM� P sGRC �NF L C:.:.::.:.::. }� U/ INF. c a P. 1C -2 P. scFa1 -umro 0� C�)p C °} �� d FB ST , ca �.,..... A �� Lea U/G F. P.SGi � -cei PscFaw JJ �B � B � -CB3 ............. ............. IN F. W INF.BASIN E FB EAST -- --- Cs° °} P. SC -D NF / ............. ...",�....11 ...",�...... Qom/ U/G INF. AP1( x c-, R1 R2 � AP'3 CI P -1 DNV MAIN CULVERT 4 OFF -SITE DEPRESSION AP2 FROM "POST AP2' Subcat Reach on Link Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq -ft) (s u bcatch me nt -n u m be rs) 33,879 61 >75% Grass cover, Good, HSG B (P. SC -1, P. SC -2, P. SC -3, P. SC -4, P. SC -D, P. SC -FBE, P. SC -FBW, P. SC -NWC, P. SC -P) 46,016 80 >75% Grass cover, Good, HSG D (P. SC -4, P. SC -C3, P. SC -D, P. SC -FBE, P. SC -FBW, P. SC -P) 4,600 98 Ledge, HSG B (P. SC -D, P. SC -NWC) 55,279 98 Paved parking, HSG A (P. SC -D) 192,825 98 Paved parking, HSG B (P. SC -1, P. SC -2, P. SC -3, P. SC -4, P. SC -D, P. SC -FBW, P. SC -NWC, P. SC -P) 110,991 98 Paved parking, HSG D (P. SC -3, P. SC -4, P. SC -D, P. SC -FBE, P. SC -FBW, P. SC -NWC, P. SC -P) 34,037 98 Roofs, HSG B (P. SC -R4, P. SC -R5, P. SC -R6, P. SC -R7, P. SC -R8) 347,789 30 Woods, Good, HSG A (P. SC -D) 637,867 55 Woods, Good, HSG B (P. SC -D, P. SC -NWC) 1,029,613 77 Woods, Good, HSG D (P. SC -C3, P. SC -D, P. SC -NWC) Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment P. SC -1: Runoff = 0.35 cfs @ 12.08 hrs, Volume= 1,098 cf, Depth= 1.31" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 2,938 61 >75% Grass cover, Good, HSG B 7,111 98 Paved parking, HSG B 10,049 87 Weighted Average 2,938 29.24% Pervious Area 7,111 70.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -2: Runoff = 0.01 cfs @ 12.12 hrs, Volume= 61 cf, Depth= 0.33" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 1,947 61 >75% Grass cover, Good, HSG B 305 98 Paved parking, HSG B 2,252 66 Weighted Average 1,947 86.46% Pervious Area 305 13.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -3: Runoff = 0.54 cfs @ 12.08 hrs, Volume= 1,670 cf, Depth= 1.24" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 4 Area (so CN Description 5,364 61 >75% Grass cover, Good, HSG B 992 98 Paved parking, HSG D 9,758 98 Paved parking, HSG B 16,114 86 Weighted Average 5,364 88 33.29% Pervious Area 10,750 66.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment P. SC -4: Runoff = 0.43 cfs @ 12.08 hrs, Volume= 1,315 cf, Depth= 1.38" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 841 61 >75% Grass cover, Good, HSG B 4,445 80 >75% Grass cover, Good, HSG D 1,472 98 Paved parking, HSG B 4,668 98 Paved parking, HSG D 11,426 88 Weighted Average 5,286 46.26% Pervious Area 6,140 53.74% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C3: Runoff = 1.06 cfs @ 12.09 hrs, Volume= 3,410 cf, Depth= 0.84" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 26,830 80 >75% Grass cover, Good, HSG D 22.040 77 Woods. Good. HSG D 48,870 79 Weighted Average 48,870 100.00% Pervious Area Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 5 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -D: Runoff = 13.57 cfs @ 12.14 hrs, Volume= 68,926 cf, Depth= 0.36" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 10,561 61 >75% Grass cover, Good, HSG B 3,835 80 >75% Grass cover, Good, HSG D 167,851 98 Paved parking, HSG B 102,329 98 Paved parking, HSG D 55,279 98 Paved parking, HSG A 624,368 55 Woods, Good, HSG B 1,005,091 77 Woods, Good, HSG D 347,789 30 Woods, Good, HSG A 3,953 98 Ledge, HSG B 2,321,056 67 Weighted Average 1,991,644 57 85.81 % Pervious Area 329,412 Shallow Concentrated Flow, 14.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 3.1 30 0.0330 0.16 Sheet Flow, Grass: Short n= 0.150 P2= 3.16" 0.3 118 0.2550 7.57 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.3 57 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.0 705 0.0850 5.92 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 165 0.0480 3.29 Shallow Concentrated Flow, Grassed Waterwav Kv= 15.0 fps 6.5 1,075 Total Summary for Subcatchment P. SC -FBE: Runoff = 0.07 cfs @ 12.08 hrs, Volume= 225 cf, Depth= 1.12" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 6 Area (so CN Description 362 61 >75% Grass cover, Good, HSG B 1,176 80 >75% Grass cover, Good, HSG D 881 98 Paved parking, HSG D 2,419 84 Weighted Average 1,538 72 63.58% Pervious Area 881 68 36.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment P. SC -FBW: Runoff = 0.07 cfs @ 12.10 hrs, Volume= 261 cf, Depth= 0.53" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 3,310 61 >75% Grass cover, Good, HSG B 1,761 80 >75% Grass cover, Good, HSG D 569 98 Paved parking, HSG B 286 98 Paved parking, HSG D 5,926 72 Weighted Average 5,071 68 85.57% Pervious Area 855 14.43% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -NWC: Runoff = 0.21 cfs @ 12.11 hrs, Volume= 924 cf, Depth= 0.39" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 6,262 61 >75% Grass cover, Good, HSG B 5,092 98 Paved parking, HSG B 609 98 Paved parking, HSG D 13,499 55 Woods, Good, HSG B 2,482 77 Woods, Good, HSG D 647 98 Ledge, HSG B 28,591 68 Weighted Average 22,243 77.80% Pervious Area 6,348 22.20% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 7 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -P: Runoff = 0.26 cfs @ 12.09 hrs, Volume= 848 cf, Depth= 0.84" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 2,294 61 >75% Grass cover, Good, HSG B 7,969 80 >75% Grass cover, Good, HSG D 667 98 Paved parking, HSG B 1,226 98 Paved parking, HSG D 12,156 79 Weighted Average 10,263 84.43% Pervious Area 1,893 15.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R4: Runoff = 0.76 cfs @ 12.07 hrs, Volume= 2,602 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 13,748 98 Roofs, HSG B 13,748 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R5: Runoff = 0.42 cfs @ 12.07 hrs, Volume= 1,434 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 8 Area (so CN Description 7,577 98 Roofs, HSG B 7,577 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R6: Runoff = 0.27 cfs @ 12.07 hrs, Volume= 931 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 4,922 98 Roofs, HSG B 4,922 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R7: Runoff = 0.18 cfs @ 12.07 hrs, Volume= 617 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 3,261 98 Roofs, HSG B 3,261 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R8: Runoff = 0.25 cfs @ 12.07 hrs, Volume= 857 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 9 Area (so CN Description 4,529 98 Roofs, HSG B 4,529 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Reach R1: Inflow Area = 2,840,536 sf, 20.65% Impervious, Inflow Depth > 0.31" for 1 -Year event Inflow = 5.12 cfs @ 12.12 hrs, Volume= 72,271 cf Outflow = 4.86 cfs @ 12.21 hrs, Volume= 72,175 cf, Atten= 5 %, Lag= 5.6 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 1.07 fps, Min. Travel Time= 5.0 min Avg. Velocity = 0.32 fps, Avg. Travel Time= 16.8 min Peak Storage= 1,464 cf @ 12.21 hrs Average Depth at Peak Storage= 0.36' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 56.94 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 324.0' Slope= 0.00287' Inlet Invert= 218.80', Outlet Invert= 217.90' Summary for Reach R2: Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow Depth > 0.19" for 1 -Year event Inflow = 0.27 cfs @ 23.97 hrs, Volume= 36,192 cf Outflow = 0.27 cfs @ 24.03 hrs, Volume= 36,108 cf, Atten= 0 %, Lag= 3.3 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 0.26 fps, Min. Travel Time= 13.4 min Avg. Velocity = 0.21 fps, Avg. Travel Time= 16.5 min Peak Storage= 216 cf @ 24.03 hrs Average Depth at Peak Storage= 0.09' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 33.66 cfs Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 10 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 206.0' Slope= 0.0010 '/' Inlet Invert= 219.00', Outlet Invert= 218.80' Summary for Reach R3: WEST SWALE Inflow Area = 36,168 sf, 38.50% Impervious, Inflow Depth = 0.31" for 1 -Year event Inflow = 0.21 cfs @ 12.11 hrs, Volume= 924 cf Outflow = 0.21 cfs @ 12.12 hrs, Volume= 924 cf, Atten= 0 %, Lag= 0.5 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 1.69 fps, Min. Travel Time= 0.6 min Avg. Velocity = 0.87 fps, Avg. Travel Time= 1.3 min Peak Storage= 8 cf @ 12.12 hrs Average Depth at Peak Storage= 0.20' Bank -Full Depth= 1.00' Flow Area= 3.0 sf, Capacity= 14.77 cfs 0.00' x 1.00' deep channel, n= 0.035 Side Slope Z- value= 3.07' Top Width= 6.00' Length= 66.0' Slope= 0.03647' Inlet Invert= 234.40', Outlet Invert= 232.00' Summary for Pond EX. C -1: D/W MAIN CULVERT Inflow Area = 2,840,536 sf, 20.65% Impervious, Inflow Depth > 0.30" for 1 -Year event Inflow = 4.86 cfs @ 12.21 hrs, Volume= 72,175 cf Outflow = 4.86 cfs @ 12.21 hrs, Volume= 72,127 cf, Atten= 0 %, Lag= 0.2 min Primary = 4.86 cfs @ 12.21 hrs, Volume= 72,127 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 216.51' @ 12.21 hrs Surf.Area= 0 sf Storage= 168 cf Plug -Flow detention time= 3.2 min calculated for 72,077 cf (100% of inflow) Center -of -Mass det. time= 1.3 min ( 1,520.4 - 1,519.0 ) Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 11 Volume Invert Avail.Storage Storage Description #1 215.94' 1,029 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 215.94 0 219.44 1,029 Device Routing Invert Outlet Devices #1 Primary 216.08' 72.0" W x 42.0" H Box Culvert L= 49.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 216.08'/215.94' S=0.0029'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 21.00 sf Primary OutFlow Max =4.84 cfs @ 12.21 hrs HW= 216.51' (Free Discharge) 't--1 =Culvert (Barrel Controls 4.84 cfs @ 2.49 fps) Summary for Pond FBE: FB EAST Inflow Area = 45,959 sf, 69.24% Impervious, Inflow Depth = 0.85" for 1 -Year event Inflow = 1.05 cfs @ 12.08 hrs, Volume= 3,271 cf Outflow = 1.03 cfs @ 12.10 hrs, Volume= 3,123 cf, Atten= 2 %, Lag= 1.3 min Discarded = 0.00 cfs @ 12.10 hrs, Volume= 104 cf Primary = 1.03 cfs @ 12.10 hrs, Volume= 3,019 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.84' @ 12.10 hrs Surf.Area= 319 sf Storage= 323 cf Flood Elev= 227.00' Surf.Area= 350 sf Storage= 375 cf Plug -Flow detention time= 88.1 min calculated for 3,121 cf (95% of inflow) Center -of -Mass det. time= 65.1 min ( 896.8 - 831.7 ) Volume Invert Avail.Storage Storage Description #1 224.00' 375 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 224.00 0 0 0 225.00 50 25 25 226.00 150 100 125 227.00 350 250 375 Device Routing Invert Outlet Devices #1 Primary 226.50' 2.0' long x 10.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Discarded 224.00' 0.090 in /hr Exfiltration over Surface area Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 12 Discarded OutFlow Max =0.00 cfs @ 12.10 hrs HW= 226.84' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =1.02 cfs @ 12.10 hrs HW= 226.84' (Free Discharge) L1 =Broad -Crested Rectangular Weir (Weir Controls 1.02 cfs @ 1.49 fps) Summary for Pond FBW: FB WEST Inflow Area = 52,143 sf, 41.98% Impervious, Inflow Depth = 0.53" for 1 -Year event Inflow = 0.62 cfs @ 12.10 hrs, Volume= 2,283 cf Outflow = 0.59 cfs @ 12.12 hrs, Volume= 2,283 cf, Atten= 6 %, Lag= 1.7 min Discarded = 0.00 cfs @ 12.12 hrs, Volume= 25 cf Primary = 0.59 cfs @ 12.12 hrs, Volume= 2,258 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.39' @ 12.12 hrs Surf.Area= 282 sf Storage= 92 cf Flood Elev= 231.50' Surf.Area= 732 sf Storage= 896 cf Plug -Flow detention time= 7.1 min calculated for 2,283 cf (100% of inflow) Center -of -Mass det. time= 6.9 min ( 874.3 - 867.4 ) Volume Invert Avail.Storage Storage Description #1 229.00' 896 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 229.00 199 54.0 0 0 199 230.00 445 84.0 314 314 536 231.00 732 108.0 583 896 915 Device Routing Invert Outlet Devices #1 Primary 229.00' 12.0" Round Culvert L= 31.0' CMP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 229.00'/227.00' S=0.0645'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Secondary 230.00' 3.0' long x 13.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.60 2.64 2.70 2.66 2.65 2.66 2.65 2.63 #3 Discarded 229.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 12.12 hrs HW= 229.38' (Free Discharge) L3= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.57 cfs @ 12.12 hrs HW= 229.38' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.57 cfs @ 2.09 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 229.00' (Free Discharge) L2= Broad -Crested Rectangular Weir( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 13 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.84' @ 12.43 hrs Surf.Area= 1,287 sf Storage= 797 cf Plug -Flow detention time= 31.9 min calculated for 3,799 cf (100% of inflow Center -of -Mass det. time= 32.1 min ( 893.3 - 861.1 ) Volume Invert Summary for Pond IBE: INF.BASIN E Inflow Area = 110,258 sf, 50.43% Impervious, Inflow Depth = 0.41" for 1 -Year event Inflow = 1.03 cfs @ 12.10 hrs, Volume= 3,801 cf Outflow = 0.35 cfs @ 12.43 hrs, Volume= 3,801 cf, Atten= 66 %, Lag= 19.5 min Discarded = 0.00 cfs @ 12.43 hrs, Volume= 83 cf Primary = 0.34 cfs @ 12.43 hrs, Volume= 3,718 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.84' @ 12.43 hrs Surf.Area= 1,287 sf Storage= 797 cf Plug -Flow detention time= 31.9 min calculated for 3,799 cf (100% of inflow Center -of -Mass det. time= 32.1 min ( 893.3 - 861.1 ) Volume Invert Avail.Storage Storage Description #1 223.00' 8,617 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 223.00 620 0 0 224.00 1,418 1,019 1,019 225.00 2,097 1,758 2,777 226.00 2,621 2,359 5,136 227.00 4,341 3,481 8,617 Device Routing Invert Outlet Devices #1 Primary 223.00' 15.0" Round Culvert L= 30.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 223.00'/222.60' S=0.0133'/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf #2 Device 1 223.00' 4.0" Vert. LOW FLOW ORIFICE C= 0.600 #3 Device 1 225.25' 12.0" W x 12.0" H Vert. WEIR NOTCH C= 0.600 #4 Device 1 226.25' 48.0" Horiz. SPILLWAY C= 0.600 Limited to weir flow at low heads #5 Discarded 223.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 12.43 hrs HW= 223.83' (Free Discharge) T 5= Exfiltration ( Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.34 cfs @ 12.43 hrs HW= 223.83' (Free Discharge) L1= Culvert (Passes 0.34 cfs of 2.60 cfs potential flow) 12 =LOW FLOW ORIFICE (Orifice Controls 0.34 cfs @ 3.94 fps) 3 =WEIR NOTCH ( Controls 0.00 cfs) 4=SPILLWAY ( Controls 0.00 cfs) Summary for Pond IBW: INF. BASIN W Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 14 Inflow Area = 64,299 sf, 36.99% Impervious, Inflow Depth = 0.58" for 1 -Year event Inflow = 0.84 cfs @ 12.11 hrs, Volume= 3,106 cf Outflow = 0.44 cfs @ 12.35 hrs, Volume= 3,106 cf, Atten= 48 %, Lag= 14.0 min Discarded = 0.00 cfs @ 12.35 hrs, Volume= 670 cf Primary = 0.43 cfs @ 12.35 hrs, Volume= 2,436 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.44' @ 12.35 hrs Surf.Area= 1,876 sf Storage= 763 cf Plug -Flow detention time= 305.6 min calculated for 3,106 cf (100% of inflow) Center -of -Mass det. time= 305.5 min ( 1,174.5 - 869.0 ) Volume Invert Avail.Storage Storage Description #1 227.00' 4,452 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 227.00 1,607 0 0 228.00 2,221 1,914 1,914 229.00 2,854 2,538 4,452 Device Ro Invert Outlet Devices #1 Secondary 228.00' 2.0' long x 20.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 #2 Discarded 227.00' 0.090 in /hr Exfiltration over Surface area #3 Primary 225.00' 8.0" Round Culvert L= 62.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0081 T Cc= 0.900 n=0.013, Flow Area= 0.35 sf #4 Device 3 227.28' 8.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.00 cfs @ 12.35 hrs HW= 227.44' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.43 cfs @ 12.35 hrs HW= 227.44' (Free Discharge) L3= Culvert (Passes 0.43 cfs of 1.92 cfs potential flow) L4= Orifice /Grate (Weir Controls 0.43 cfs @ 1.30 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 227.00' (Free Discharge) 't--1 =Broad-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond INF1: U/G INF. Inflow Area = 7,577 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.42 cfs @ 12.07 hrs, Volume= 1,434 cf Outflow = 0.04 cfs @ 12.35 hrs, Volume= 1,434 cf, Atten= 92 %, Lag= 16.8 min Discarded = 0.04 cfs @ 12.35 hrs, Volume= 1,434 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 15 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.08' @ 12.98 hrs Surf.Area= 1,509 sf Storage= 599 cf Flood Elev= 239.50' Surf.Area= 2,085 sf Storage= 3,269 cf Plug -Flow detention time= 186.0 min calculated for 1,433 cf (100% of inflow) Center -of -Mass det. time= 185.9 min ( 946.9 - 761.0 ) Volume Invert Avail.Storage Storage Description #1A 234.00' 279 cf 21.50'W x 17.44'L x 2.33'H Field A 875 cf Overall - 177 cf Embedded = 698 cf x 40.0% Voids #2A 234.50' 177 cf ADS_StormTech SC -310 +Cap x 12 Inside #1 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.121 = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 6 Rows of 2 Chambers #313 234.00' 102 cf 11.34'W x 18.00'L x 3.17'H Field B 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #413 234.50' 267 cf Concrete Dry Well 500gal x 4 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 2 Chambers #5C 234.00' 176 cf 11.34'W x 34.00'L x 3.17'H Field C 1,222 cf Overall - 783 cf Embedded = 439 cf x 40.0% Voids #6C 234.50' 534 cf Concrete Dry Well 500gal x 8 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 4 Chambers #7D 235.00' 220 cf 16.01'W x 34.00'L x 3.17'H Field D 1,726 cf Overall - 1,175 cf Embedded = 551 cf x 40.0% Voids #8D 235.50' 800 cf Concrete Dry Well 500gal x 12 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 4 Chambers #9E 236.00' 419 cf 18.17'W x 31.68'L x 2.33'H Field E 1,343 cf Overall - 295 cf Embedded = 1,048 cf x 40.0% Voids #10E 236.50' 295 cf ADS _StormTech SC -310 +Cap x 20 Inside #9 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.121 = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 5 Rows of 4 Chambers 3,269 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Storage Group E created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 234.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 239.50' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 16 Discarded OutFlow Max =0.04 cfs @ 12.35 hrs HW= 235.01' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 234.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond INF2: U/G INF. Inflow Area = 64,299 sf, 36.99% Impervious, Inflow Depth = 0.45" for 1 -Year event Inflow = 0.43 cfs @ 12.35 hrs, Volume= 2,436 cf Outflow = 0.16 cfs @ 13.30 hrs, Volume= 2,436 cf, Atten= 62 %, Lag= 57.3 min Discarded = 0.02 cfs @ 12.65 hrs, Volume= 1,654 cf Primary = 0.15 cfs @ 13.30 hrs, Volume= 782 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.05' @ 13.30 hrs Surf.Area= 681 sf Storage= 964 cf Plug -Flow detention time= 508.5 min calculated for 2,435 cf (100% of inflow) Center -of -Mass det. time= 509.2 min ( 1,412.4 - 903.2 ) Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 17 Volume Invert Avail.Storage Storage Description #113 227.50' 109 cf 8.17'W x 17.44'L x 2.33'H Field B 332 cf Overall - 59 cf Embedded = 273 cf x 40.0% Voids #213 228.00' 59 cf ADS_StormTech SC -310 +Cap x 4 Inside #1 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 2 Rows of 2 Chambers #3C 226.50' 45 cf 6.67'W x 10.00'L x 3.17'H Field C 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #4C 227.00' 67 cf Concrete Dry Well 500gal Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #5D 226.00' 45 cf 6.67'W x 10.00'L x 3.17'H Field D 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #6D 226.50' 67 cf Concrete Dry Well 500gal Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #7E 225.00' 78 cf 6.67'W x 18.00'L x 3.25'H Field E 391 cf Overall - 196 cf Embedded = 195 cf x 40.0% Voids #8E 225.50' 133 cf Concrete Dry Well 500gal x 2 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #9F 225.00' 67 cf 4.83'W x 17.44'L x 2.33'H Field F 197 cf Overall - 29 cf Embedded = 167 cf x 40.0% Voids #10F 225.50' 29 cf ADS _StormTech SC -310 +Cap x 2 Inside #9 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #11G 224.50' 67 cf 4.83'W x 17.44'L x 2.33'H Field G 197 cf Overall - 29 cf Embedded = 167 cf x 40.0% Voids #12G 225.00' 29 cf ADS _StormTech SC -310 +Cap x 2 Inside #11 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #13H 224.00' 41 cf 4.83'W x 10.32'L x 2.33'H Field H 116 cf Overall - 15 cf Embedded = 102 cf x 40.0% Voids #14H 224.50' 15 cf ADS _StormTech RC -310 +Cap Inside #13 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #151 224.00' 45 cf 6.67'W x 10.00'L x 3.17'H Field 1 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #161 224.50' 67 cf Concrete Dry Well 500gal Inside #15 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 964 cf Total Available Storage Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Storage Group E created with Chamber Wizard Storage Group F created with Chamber Wizard Storage Group G created with Chamber Wizard Storage Group H created with Chamber Wizard Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 18 Storage Group I created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 233.00' 12.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.02 cfs @ 12.65 hrs HW= 227.59' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =0.11 cfs @ 13.30 hrs HW= 233.05' (Free Discharge) L2= Orifice /Grate (Weir Controls 0.11 cfs @ 0.72 fps) Summary for Pond INF3: U/G INF. Inflow Area = 13,748 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.76 cfs @ 12.07 hrs, Volume= 2,602 cf Outflow = 0.02 cfs @ 11.90 hrs, Volume= 2,602 cf, Atten= 97 %, Lag= 0.0 min Discarded = 0.02 cfs @ 11.90 hrs, Volume= 2,602 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 234.26' @ 15.72 hrs Surf.Area= 1,006 sf Storage= 1,595 cf Plug -Flow detention time= 640.3 min calculated for 2,600 cf (100% of inflow) Center -of -Mass det. time= 640.6 min ( 1,401.6 - 761.0 ) Volume Invert Avail.Storage Storage Description #1A 232.50' 139 cf 11.34'W x 26.00'L x 3.17'H Field A 935 cf Overall - 588 cf Embedded = 347 cf x 40.0% Voids #2A 233.00' 400 cf Concrete Dry Well 500gal x 6 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 3 Chambers #313 231.50' 175 cf 16.01'W x 26.00'L x 3.17'H Field B 1,320 cf Overall - 881 cf Embedded = 438 cf x 40.0% Voids #413 232.00' 600 cf Concrete Dry Well 500gal x 9 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 3 Chambers #5C 231.00' 139 cf 11.34'W x 26.00'L x 3.17'H Field C 935 cf Overall - 588 cf Embedded = 347 cf x 40.0% Voids #6C 231.50' 400 cf Concrete Dry Well 500gal x 6 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 3 Chambers 1,854 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 19 Device Routing Invert Outlet Devices #1 Discarded 231.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 237.50' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.02 cfs @ 11.90 hrs HW= 232.57' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 231.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond INF4: U/G INF. Inflow Area = 3,261 sf, 100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.18 cfs @ 12.07 hrs, Volume= 617 cf Outflow = 0.00 cfs @ 12.30 hrs, Volume= 376 cf, Atten= 99 %, Lag= 13.8 min Discarded = 0.00 cfs @ 12.30 hrs, Volume= 376 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.82' @ 22.32 hrs Surf.Area= 943 sf Storage= 512 cf Plug -Flow detention time= 1,548.3 min calculated for 376 cf (61 % of inflow) Center -of -Mass det. time= 1,444.2 min ( 2,205.2 - 761.0 ) Volume Invert Avail.Storage Storage Description #1A 225.50' 106 cf 20.68'W x 10.00'L x 3.17'H Field A 656 cf Overall - 392 cf Embedded = 264 cf x 40.0% Voids #2A 226.00' 267 cf Concrete Dry Well 500gal x 4 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 4 Rows of 1 Chambers #313 225.50' 102 cf 11.34'W x 18.00'L x 3.17'H Field B 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #413 226.00' 267 cf Concrete Dry Well 500gal x 4 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 2 Chambers #5C 224.50' 159 cf 20.68'W x 18.00'L x 3.17'H Field C 1,180 cf Overall - 783 cf Embedded = 397 cf x 40.0% Voids #6C 225.00' 534 cf Concrete Dry Well 500gal x 8 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 4 Rows of 2 Chambers #7D 224.00' 86 cf 16.01'W x 10.00'L x 3.17'H Field D 508 cf Overall - 294 cf Embedded = 214 cf x 40.0% Voids #8D 224.50' 200 cf Concrete Dry Well 500gal x 3 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 1 Chambers Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 20 1,719 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.00' 0.090 in /hr Exfiltration over Surface area #2 Primary 230.00' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.00 cfs @ 12.30 hrs HW= 225.51' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 224.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond INF5: U/G INF. Inflow Area = 9,451 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.53 cfs @ 12.07 hrs, Volume= 1,788 cf Outflow = 0.03 cfs @ 10.70 hrs, Volume= 1,788 cf, Atten= 94 %, Lag= 0.0 min Discarded = 0.03 cfs @ 10.70 hrs, Volume= 1,788 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.07' @ 13.89 hrs Surf.Area= 1,230 sf Storage= 798 cf Plug -Flow detention time= 230.6 min calculated for 1,787 cf (100% of inflow) Center -of -Mass det. time= 230.5 min ( 991.5 - 761.0 ) Volume Invert Avail.Storage Storage Description #1A 234.00' 756 cf 98.39'W x 12.50'L x 3.83'H Field A 4,710 cf Overall - 2,821 cf Embedded = 1,889 cf x 40.0% Voids #2A 234.50' 2,187 cf Concrete Dry Well 1000gal x 17 Inside #1 Inside= 62.0 "W x 30.0 "H => 12.86 sf x 10.001 = 128.6 cf Outside= 68.0 "W x 34.0 "H => 15.81 sf x 10.501 = 166.0 cf 17 Rows of 1 Chambers 2,943 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 234.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 239.00' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 21 Discarded OutFlow Max =0.03 cfs @ 10.70 hrs HW= 234.05' (Free Discharge) L1= Exfiltration ( Exfiltration Controls 0.03 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 234.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond P -CB1 *: Inflow Area = 10,049 sf, 70.76% Impervious, Inflow Depth = 1.31" for 1 -Year event Inflow = 0.35 cfs @ 12.08 hrs, Volume= 1,098 cf Outflow = 0.35 cfs @ 12.08 hrs, Volume= 1,098 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.35 cfs @ 12.08 hrs, Volume= 1,098 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.29' @ 12.08 hrs Flood Elev= 236.77' Device Routing Invert Outlet Devices #1 Primary 231.00' 12.0" Round Culvert L= 33.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 231.00'/230.00' S=0.0303'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.34 cfs @ 12.08 hrs HW= 231.29' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.34 cfs @ 1.83 fps) Summary for Pond P -C1132: Inflow Area = 2,252 sf, 13.54% Impervious, Inflow Depth = 0.33" for 1 -Year event Inflow = 0.01 cfs @ 12.12 hrs, Volume= 61 cf Outflow = 0.01 cfs @ 12.12 hrs, Volume= 61 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.01 cfs @ 12.12 hrs, Volume= 61 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.06' @ 12.12 hrs Flood Elev= 229.50' Device Routing Invert Outlet Devices #1 Primary 225.00' 12.0" Round Culvert L= 82.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0061 T Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.01 cfs @ 12.12 hrs HW= 225.06' (Free Discharge) L1= Culvert (Barrel Controls 0.01 cfs @ 0.83 fps) Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 22 Summary for Pond P -C1133: Inflow Area = 41,288 sf, 74.21% Impervious, Inflow Depth = 0.87" for 1 -Year event Inflow = 0.96 cfs @ 12.08 hrs, Volume= 2,985 cf Outflow = 0.96 cfs @ 12.08 hrs, Volume= 2,985 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.96 cfs @ 12.08 hrs, Volume= 2,985 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.52' @ 12.08 hrs Flood Elev= 229.10' Device Routing Invert Outlet Devices #1 Primary 225.00' 15.0" Round Culvert L= 81.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 225.00'/224.50' S=0.0062'/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =0.93 cfs @ 12.08 hrs HW= 225.51' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.93 cfs @ 2.92 fps) Summary for Pond P -C1134: Inflow Area = 11,426 sf, 53.74% Impervious, Inflow Depth = 1.38" for 1 -Year event Inflow = 0.43 cfs @ 12.08 hrs, Volume= 1,315 cf Outflow = 0.43 cfs @ 12.08 hrs, Volume= 1,315 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.43 cfs @ 12.08 hrs, Volume= 1,315 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.05' @ 12.08 hrs Flood Elev= 229.23' Device Ro Invert Outlet Devices #1 Primary 225.70' 12.0" Round Culvert L= 96.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.70'/225.00' S=0.0073'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.41 cfs @ 12.08 hrs HW= 226.04' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.41 cfs @ 2.60 fps) Summary for Pond P -DMH2: Inflow Area = 7,577 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.42 cfs @ 12.07 hrs, Volume= 1,434 cf Outflow = 0.42 cfs @ 12.07 hrs, Volume= 1,434 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.42 cfs @ 12.07 hrs, Volume= 1,434 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 23 Peak Elev= 237.82' @ 12.07 hrs Flood Elev= 242.00' Device Routing Invert Outlet Devices #1 Primary 237.50' 12.0" Round Culvert L= 36.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 237.50'/237.00' S=0.0139'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.41 cfs @ 12.07 hrs HW= 237.82' (Free Discharge) L1= Culvert (Inlet Controls 0.41 cfs @ 1.91 fps) Summary for Pond P -DMH3: Inflow Area = 3,261 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.18 cfs @ 12.07 hrs, Volume= 617 cf Outflow = 0.18 cfs @ 12.07 hrs, Volume= 617 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.18 cfs @ 12.07 hrs, Volume= 617 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.72' @ 12.07 hrs Flood Elev= 230.50' Device Routing Invert Outlet Devices #1 Primary 227.50' 12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.50'/227.40' S=0.0125'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.17 cfs @ 12.07 hrs HW= 227.72' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.17 cfs @ 2.06 fps) Summary for Pond P -DMH4: Inflow Area = 13,748 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.76 cfs @ 12.07 hrs, Volume= 2,602 cf Outflow = 0.76 cfs @ 12.07 hrs, Volume= 2,602 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.76 cfs @ 12.07 hrs, Volume= 2,602 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 234.84' @ 12.07 hrs Flood Elev= 239.00' Device Routing Invert Outlet Devices #1 Primary 234.40' 12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 234.40'/234.00' S=0.0500'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 24 Primary OutFlow Max =0.74 cfs @ 12.07 hrs HW= 234.83' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.74 cfs @ 2.24 fps) Summary for Pond P -DMH5: Inflow Area = 9,451 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.53 cfs @ 12.07 hrs, Volume= 1,788 cf Outflow = 0.53 cfs @ 12.07 hrs, Volume= 1,788 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.53 cfs @ 12.07 hrs, Volume= 1,788 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 238.36' @ 12.07 hrs Flood Elev= 243.80' Device Routing Invert Outlet Devices #1 Primary 238.00' 12.0" Round Culvert L= 26.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 238.00'/236.00' S=0.0769'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.51 cfs @ 12.07 hrs HW= 238.35' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.51 cfs @ 2.03 fps) Summary for Pond P. C -1: NW CULVERT Inflow Area = 28,591 sf, 22.20% Impervious, Inflow Depth = 0.39" for 1 -Year event Inflow = 0.21 cfs @ 12.11 hrs, Volume= 924 cf Outflow = 0.21 cfs @ 12.11 hrs, Volume= 924 cf, Atten= 0 %, Lag= 0.0 min Discarded = 0.00 cfs @ 12.11 hrs, Volume= 0 cf Primary = 0.21 cfs @ 12.11 hrs, Volume= 924 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.00' @ 12.11 hrs Surf.Area= 51 sf Storage= 0 cf Plug -Flow detention time= 0.0 min calculated for 924 cf (100% of inflow) Center -of -Mass det. time= 0.0 min ( 906.5 - 906.5 ) Volume Invert Avail.Storage Storage Description #1 236.00' 777 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 236.00 51 31.0 0 0 51 237.00 145 57.0 94 94 238 238.00 334 86.0 233 327 576 239.00 576 117.0 450 777 1,087 Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 25 Device Routing Invert Outlet Devices #1 Primary 235.40' 12.0" Round Culvert L= 100.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 235.40'/234.40' S=0.0100'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Discarded 236.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 12.11 hrs HW= 236.00' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =1.31 cfs @ 12.11 hrs HW= 236.00' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.31 cfs @ 2.65 fps) Summary for Pond P. P -1: OFF -SITE DEPRESSION Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow = 13.57 cfs @ 12.14 hrs, Volume= Outflow = 0.48 cfs @ 23.97 hrs, Volume= Discarded = 0.21 cfs @ 23.97 hrs, Volume= Primary = 0.27 cfs @ 23.97 hrs, Volume= Secondary = 0.00 cfs @ 0.00 hrs, Volume= Tertiary = 0.00 cfs @ 0.00 hrs, Volume= Inflow Depth= 0.35" for 1 -Year event 68,926 cf 61,107 cf, 24,915 cf 36,192 cf 0 cf 0 cf Atten= 96 %, Lag= 710.0 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.23' @ 23.97 hrs Surf.Area= 102,082 sf Storage= 51,041 cf Plug -Flow detention time= 1,246.5 min calculated for 61,065 cf (89% of inflow) Center -of -Mass det. time= 1,194.9 min ( 2,108.3 - 913.4 ) Volume Invert #1 219.00' MV01 e Description 1,815,231 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 219.00 0 0 0 220.00 452,595 226,298 226,298 221.00 508,615 480,605 706,903 222.00 557,476 533,046 1,239,948 223.00 593,089 575,283 1,815,231 Device Routing Invert Outlet Devices #1 Primary 218.80' 18.0" W x 18.0" H Box Exist. Culvert X 0.20 L= 16.0' RCP, end - section conforming to fill, Ke= 0.500 Inlet/ Outlet Invert= 218.80'/218.60' S=0.0125'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 2.25 sf #2 Secondary 221.80' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 9.00 11.00 20.00 Height (feet) 1.20 0.00 0.00 1.20 #3 Discarded 219.00' 0.090 in /hr Exfiltration over Surface area #4 Tertiary 222.00' 384.0" W x 72.0" H, R= 384.0" Arch Prop. Culvert L= 55.0' Box, headwall w/3 square edges, Ke= 0.500 Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 26 Inlet/ Outlet Invert= 222.00'/222.00' S=0.0000'/' Cc= 0.900 n=0.025 Corrugated metal, Flow Area= 147.57 sf Discarded OutFlow Max =0.21 cfs @ 23.97 hrs HW= 219.23' (Free Discharge) L3= Exfiltration (Exfiltration Controls 0.21 cfs) Primary OutFlow Max =0.27 cfs @ 23.97 hrs HW= 219.23' (Free Discharge) L1= Exist. Culvert (Inlet Controls 0.27 cfs @ 0.42 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L2= Asymmetrical Weir ( Controls 0.00 cfs) Tertiary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L4 =Prop. Culvert ( Controls 0.00 cfs) Summary for Link 1 L: Pre AP1 Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 0.31" for 1 -Year event Inflow = 7.47 cfs @ 12.20 hrs, Volume= 72,201 cf Primary = 7.47 cfs @ 12.20 hrs, Volume= 72,201 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 1 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP1.hce Summary for Link 2L: Pre AP2 Inflow Area = 341,168 sf, 43.52% Impervious, Inflow Depth = 1.04" for 1 -Year event Inflow = 7.37 cfs @ 12.14 hrs, Volume= 29,571 cf Primary = 7.37 cfs @ 12.14 hrs, Volume= 29,571 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 1 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP2.hce Summary for Link 3L: Pre AP3 Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth > 0.20" for 1 -Year event Inflow = 0.27 cfs @ 24.00 hrs, Volume= 38,119 cf Primary = 0.27 cfs @ 24.00 hrs, Volume= 38,119 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 1 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP3.hce Brookhaven, Lexington, MA 151067 2017 POST 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 27 Summary for Link AP1: Inflow Area = 2,840,536 sf, 20.65% Impervious, Inflow Depth > 0.30" for 1 -Year event Inflow = 4.86 cfs @ 12.21 hrs, Volume= 72,127 cf Primary = 4.86 cfs @ 12.21 hrs, Volume= 72,127 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Summary for Link AP2: FROM "POST AP2" Inflow Area = 347,640 sf, 54.32% Impervious, Inflow Depth = 1.00" for 1 -Year event Inflow = 3.87 cfs @ 12.25 hrs, Volume= 29,035 cf Primary = 3.87 cfs @ 12.25 hrs, Volume= 29,035 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 1 -Year Primary Outflow Imported from 151067 2017 POST AP2 porous pavement-Link AP2.hce Summary for Link AP3: Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow Depth > 0.19" for 1 -Year event Inflow = 0.27 cfs @ 23.97 hrs, Volume= 36,192 cf Primary = 0.27 cfs @ 23.97 hrs, Volume= 36,192 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs _____ Subcat Reach on Link MHi Q MOD.EX. �T BASIN 1 uxi A ce1 81 ST ce1 ce Z4, (/- -- 0 \_s- /sc,) \ R\ / \ B3 B4 ec Ea / \ xscn 1, / ca xeca 't3L x112 UIG'IET � � =e -oMx NF6 Q �—/sF� - U /tF. \ exsc- AB, scl (I sc -I 11 2� Q \ __ \ 11 2) _____ Subcat Reach on Link Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq -ft) (s u bcatch me nt -n u m be rs) 70,683 61 >75% Grass cover, Good, HSG B (EX. SC -17, EX. SC -18, EX. SC -20, EX. SC -21, EX. SC -22, EX. SC -3, P. SC -11, P. SC -12, P. SC -13, P. SC -5, P. SC -6, P. SC -7, P. SC -E4) 43,334 80 >75% Grass cover, Good, HSG D (EX. SC -1, EX. SC -18, EX. SC -3, P. SC -10, P. SC -12, P. SC -5, P. SC -6, P. SC -8, P. SC -9, P. SC -C1, P. SC -C2, P. SC -E4) 45,897 98 Paved parking, HSG B (EX. SC -17, EX. SC -18, EX. SC -19, EX. SC -20, EX. SC -21, EX. SC -22, EX. SC -3, P. SC -11, P. SC -12, P. SC -13, P. SC -5, P. SC -E4) 56,711 98 Paved parking, HSG D (EX. SC -1, EX. SC -18, EX. SC -19, EX. SC -2, EX. SC -3, P. SC -10, P. SC -12, P. SC -5, P. SC -8, P. SC -9, P. SC -E4) 11,745 1 Porous Pavement (P. SC -10, P. SC -11, P. SC -12, P. SC -5, P. SC -6, P. SC -7, P. SC -8, P. SC -9, P. SC -E4) 76,636 98 Roofs, HSG B (EX. SC -17, EX. SC -18, EX. SC -20, EX. SC -21, EX. SC -22, EX. SC -R, EX. SC -ST, P. SC -E4, P. SC -R1, P. SC -R3, P. SC -R9) 9,589 98 Roofs, HSG D (EX. SC -18, P. SC -12, P. SC -R2) 33,045 77 Woods, Good, HSG D (P. SC -C1, P. SC -C2) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment EX. SC -1: Runoff = 0.16 cfs @ 12.08 hrs, Volume= 485 cf, Depth= 1.53" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 1,735 80 >75% Grass cover, Good, HSG D 2,065 98 Paved parking, HSG D 3,800 90 Weighted Average 1,735 45.66% Pervious Area 2,065 54.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -17: Runoff = 0.27 cfs @ 12.08 hrs, Volume= 853 cf, Depth= 1.18" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 1,325 98 Roofs, HSG B 2,993 61 >75% Grass cover, Good, HSG B 4.366 98 Paved oarkina. HSG B 8,684 85 Weighted Average 2,993 34.47% Pervious Area 5,691 65.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -18: Runoff = 1.49 cfs @ 12.08 hrs, Volume= 4,600 cf, Depth= 1.38" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 4 Area (so CN Description 13,935 98 Roofs, HSG B 803 98 Roofs, HSG D 9,943 61 >75% Grass cover, Good, HSG B 2,229 80 >75% Grass cover, Good, HSG D 8,923 98 Paved parking, HSG B 4.124 98 Paved oarkina. HSG D 39,957 88 Weighted Average 12,172 30.46% Pervious Area 27,785 69.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -19: Runoff = 0.58 cfs @ 12.07 hrs, Volume= 1,983 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 5,245 98 Paved parking, HSG B 5,234 98 Paved parking, HSG D 10,479 98 Weighted Average 10,479 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -2: Runoff = 0.18 cfs @ 12.07 hrs, Volume= 602 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 3,181 98 Paved parking, HSG D 3,181 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment EX. SC -20: Runoff = 0.40 cfs @ 12.09 hrs, Volume= 1,357 cf, Depth= 0.69" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 7,685 98 Roofs, HSG B 13,660 61 >75% Grass cover, Good, HSG B 2,108 98 Paved parking, HSG B 23,453 76 Weighted Average 13,660 58.24% Pervious Area 9,793 41.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -21: Runoff = 0.65 cfs @ 12.08 hrs, Volume= 2,024 cf, Depth= 1.31" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 5,373 98 Roofs, HSG B 5,318 61 >75% Grass cover, Good, HSG B 7,833 98 Paved parking, HSG B 18,524 87 Weighted Average 5,318 28.71 % Pervious Area 13,206 71.29% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -22: Runoff = 0.43 cfs @ 12.09 hrs, Volume= 1,418 cf, Depth= 0.79" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 6 Area (so CN Description 1,599 98 Roofs, HSG B 11,736 61 >75% Grass cover, Good, HSG B 8,266 98 Paved parking, HSG B 21,601 78 Weighted Average 11,736 71 54.33% Pervious Area 9,865 45.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment EX. SC -3: Runoff = 0.14 cfs @ 12.10 hrs, Volume= 545 cf, Depth= 0.49" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 6,580 61 >75% Grass cover, Good, HSG B 6,168 80 >75% Grass cover, Good, HSG D 263 98 Paved parking, HSG B 302 98 Paved parking, HSG D 13,313 71 Weighted Average 12,748 95.76% Pervious Area 565 4.24% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -R: Runoff = 0.28 cfs @ 12.07 hrs, Volume= 963 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 5,090 98 Roofs, HSG B 5,090 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment EX. SC -ST: Runoff = 0.47 cfs @ 12.07 hrs, Volume= 1,603 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 8,470 98 Roofs, HSG B 8,470 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -10: Runoff = 0.01 cfs @ 12.32 hrs, Volume= 44 cf, Depth= 0.20" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 1,023 80 >75% Grass cover, Good, HSG D 833 98 Paved parking, HSG D 859 1 Porous Pavement 2,715 61 Weighted Average 1,882 69.32% Pervious Area 833 30.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -11: Runoff = 0.00 cfs @ 12.37 hrs, Volume= 20 cf, Depth= 0.15" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 1,072 61 >75% Grass cover, Good, HSG B 264 98 Paved parking, HSG B 203 1 Porous Pavement 1,539 59 Weighted Average 1,275 82.85% Pervious Area 264 17.15% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 8 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -12: Runoff = 1.07 cfs @ 12.08 hrs, Volume= 3,393 cf, Depth= 0.94" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 1,039 98 Roofs, HSG D 4,014 61 >75% Grass cover, Good, HSG B 7,822 80 >75% Grass cover, Good, HSG D 2,473 98 Paved parking, HSG B 23,442 98 Paved parking, HSG D 4,415 1 Porous Pavement 43,205 81 Weighted Average 16,251 37.61 % Pervious Area 26,954 62.39% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -13: Runoff = 0.03 cfs @ 12.09 hrs, Volume= 91 cf, Depth= 0.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 1,280 61 >75% Grass cover, Good, HSG B 643 98 Paved parking, HSG B 1,923 73 Weighted Average 1,280 66.56% Pervious Area 643 33.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment P. SC -5: Runoff = 0.41 cfs @ 12.09 hrs, Volume= 1,368 cf, Depth= 0.69" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 2,793 61 >75% Grass cover, Good, HSG B 8,051 80 >75% Grass cover, Good, HSG D 249 98 Paved parking, HSG B 9,862 98 Paved parking, HSG D 2,687 1 Porous Pavement 23,642 76 Weighted Average 13,531 57.23% Pervious Area 10,111 42.77% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -6: Runoff = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Depth= 0.00" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 1,176 61 >75% Grass cover, Good, HSG B 163 80 >75% Grass cover, Good, HSG D 1,710 1 Porous Pavement 3,049 28 Weighted Average 3,049 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -7: Runoff = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Depth= 0.00" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 10 Area (so CN Description 2,315 61 >75% Grass cover, Good, HSG B 907 1 Porous Pavement 3,222 44 Weighted Average 3,222 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -8: Runoff = 0.26 cfs @ 12.08 hrs, Volume= 796 cf, Depth= 1.31" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 2,049 80 >75% Grass cover, Good, HSG D 4,757 98 Paved parking, HSG D 478 1 Porous Pavement 7,284 87 Weighted Average 2,527 34.69% Pervious Area 4,757 65.31% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -9: Runoff = 0.10 cfs @ 12.08 hrs, Volume= 305 cf, Depth= 1.12" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 347 80 >75% Grass cover, Good, HSG D 2,512 98 Paved parking, HSG D 417 1 Porous Pavement 3,276 84 Weighted Average 764 23.32% Pervious Area 2,512 76.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment P. SC -C1: Runoff = 0.41 cfs @ 12.09 hrs, Volume= 1,307 cf, Depth= 0.84" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 11,805 80 >75% Grass cover, Good, HSG D 6,928 77 Woods, Good, HSG D 18,733 79 Weighted Average 18,733 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C2: Runoff = 0.52 cfs @ 12.09 hrs, Volume= 1,710 cf, Depth= 0.74" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (sf) CN Description 1,605 80 >75% Grass cover, Good, HSG D 26,117 77 Woods, Good, HSG D 27,722 77 Weighted Average 27,722 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -E4: Runoff = 0.38 cfs @ 12.09 hrs, Volume= 1,218 cf, Depth= 0.89" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 12 Area (so CN Description 2,571 98 Roofs, HSG B 7,803 61 >75% Grass cover, Good, HSG B 337 80 >75% Grass cover, Good, HSG D 5,264 98 Paved parking, HSG B 399 98 Paved parking, HSG D 69 1 Porous Pavement 16,443 80 Weighted Average 8,209 49.92% Pervious Area 8,234 50.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R1: Runoff = 0.21 cfs @ 12.07 hrs, Volume= 725 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 3,833 98 Roofs, HSG B 3,833 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R2: Runoff = 0.43 cfs @ 12.07 hrs, Volume= 1,466 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 7,747 98 Roofs, HSG D 7,747 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 13 Summary for Subcatchment P. SC -R3: Runoff = 1.20 cfs @ 12.07 hrs, Volume= 4,087 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 21,598 98 Roofs, HSG B 21,598 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R9: Runoff = 0.29 cfs @ 12.07 hrs, Volume= 976 cf, Depth= 2.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 1 -Year Rainfall= 2.50" Area (so CN Description 5,157 98 Roofs, HSG B 5,157 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Pond C1131: Inflow Area = 3,800 sf, 54.34% Impervious, Inflow Depth = 1.53" for 1 -Year event Inflow = 0.16 cfs @ 12.08 hrs, Volume= 485 cf Outflow = 0.16 cfs @ 12.08 hrs, Volume= 485 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.16 cfs @ 12.08 hrs, Volume= 485 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.44' @ 12.08 hrs Flood Elev= 224.92' Device Routing Invert Outlet Devices #1 Primary 224.92' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads #2 Primary 221.25' 12.0" Round Culvert L= 15.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 221.25'/218.16' S=0.1994'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 14 Primary OutFlow Max =0.15 cfs @ 12.08 hrs HW= 221.44' (Free Discharge) �__2=Culvert 1= Orifice /Grate ( Controls 0.00 cfs) (Inlet Controls 0.15 cfs @ 1.48 fps) Summary for Pond CB16: Inflow Area = 43,205 sf, 62.39% Impervious, Inflow Depth = 0.94" for 1 -Year event Inflow = 1.07 cfs @ 12.08 hrs, Volume= 3,393 cf Outflow = 1.07 cfs @ 12.08 hrs, Volume= 3,393 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.07 cfs @ 12.08 hrs, Volume= 3,393 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.25' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 225.71' 12.0" Round Culvert L= 9.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.71'/222.83' S=0.3200'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 229.50' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =1.04 cfs @ 12.08 hrs HW= 226.24' (Free Discharge) �__2=Orifi 1= Culve rt (Inlet Controls 1.04 cfs @ 2.47 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB17: Inflow Area = 8,684 sf, 65.53% Impervious, Inflow Depth = 1.18" for 1 -Year event Inflow = 0.27 cfs @ 12.08 hrs, Volume= 853 cf Outflow = 0.27 cfs @ 12.08 hrs, Volume= 853 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.27 cfs @ 12.08 hrs, Volume= 853 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.52' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 225.13' 12.0" Round Culvert L= 80.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.13'/225.07' S=0.0008'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 228.31' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.27 cfs @ 12.08 hrs HW= 225.52' (Free Discharge) t1= Culvert (Barrel Controls 0.27 cfs @ 1.40 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 15 Summary for Pond CB18: Inflow Area = 39,957 sf, 69.54% Impervious, Inflow Depth = 1.38" for 1 -Year event Inflow = 1.49 cfs @ 12.08 hrs, Volume= 4,600 cf Outflow = 1.49 cfs @ 12.08 hrs, Volume= 4,600 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.49 cfs @ 12.08 hrs, Volume= 4,600 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.98' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 230.25' 12.0" Round Culvert L= 14.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.25'/230.10' S=0.0103'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 234.91' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =1.44 cfs @ 12.08 hrs HW= 230.96' (Free Discharge) �--2=Orifi 1= Culve rt (Barrel Controls 1.44 cfs @ 3.37 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB19: Inflow Area = 10,479 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.58 cfs @ 12.07 hrs, Volume= 1,983 cf Outflow = 0.58 cfs @ 12.07 hrs, Volume= 1,983 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.58 cfs @ 12.07 hrs, Volume= 1,983 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.61' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 230.16' 12.0" Round Culvert L= 6.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.16'/230.10' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 235.05' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.56 cfs @ 12.07 hrs HW= 230.60' (Free Discharge) t1= Culvert (Barrel Controls 0.56 cfs @ 2.50 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond C1132: Inflow Area = 6,981 sf, 75.15% Impervious, Inflow Depth= 1.87" for 1 -Year event Inflow = 0.33 cfs @ 12.07 hrs, Volume= 1,087 cf Outflow = 0.33 cfs @ 12.07 hrs, Volume= 1,087 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.33 cfs @ 12.07 hrs, Volume= 1,087 cf Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 16 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 218.55' @ 12.07 hrs Flood Elev= 225.01' Device Routing Invert Outlet Devices #1 Primary 218.16' 12.0" Round Culvert L= 135.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.16'/ 217.88' S= 0.0021 T Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 225.01' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.32 cfs @ 12.07 hrs HW= 218.54' (Free Discharge) �I!=Culvert (Barrel Controls 0.32 cfs @ 1.73 fps) 2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond CB20: Inflow Area = 23,453 sf, 41.76% Impervious, Inflow Depth = 0.69" for 1 -Year event Inflow = 0.40 cfs @ 12.09 hrs, Volume= 1,357 cf Outflow = 0.40 cfs @ 12.09 hrs, Volume= 1,357 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.40 cfs @ 12.09 hrs, Volume= 1,357 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.24' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 235.70' 6.0" Round Culvert L= 143.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 235.70'/228.93' S=0.0472'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 0.20 sf #2 Primary 239.00' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.40 cfs @ 12.09 hrs HW= 236.23' (Free Discharge) �--2=Orifi 1= Culve rt (Inlet Controls 0.40 cfs @ 2.01 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB21: Inflow Area = 18,524 sf, 71.29% Impervious, Inflow Depth = 1.31" for 1 -Year event Inflow = 0.65 cfs @ 12.08 hrs, Volume= 2,024 cf Outflow = 0.65 cfs @ 12.08 hrs, Volume= 2,024 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.65 cfs @ 12.08 hrs, Volume= 2,024 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.30' @ 12.08 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 17 Device Routing Invert Outlet Devices #1 Primary 243.80' 12.0" Round Culvert L= 25.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.80'/243.70' S=0.0039'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 247.80' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.63 cfs @ 12.08 hrs HW= 244.29' (Free Discharge) t1= Culvert (Barrel Controls 0.63 cfs @ 2.43 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond CB22: Inflow Area = 21,601 sf, 45.67% Impervious, Inflow Depth = 0.79" for 1 -Year event Inflow = 0.43 cfs @ 12.09 hrs, Volume= 1,418 cf Outflow = 0.43 cfs @ 12.09 hrs, Volume= 1,418 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.43 cfs @ 12.09 hrs, Volume= 1,418 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.08' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 243.70' 12.0" Round Culvert L= 16.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.70'/243.60' S=0.0062'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 247.90' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.42 cfs @ 12.09 hrs HW= 244.07' (Free Discharge) �__2=Orifi 1= Culve rt (Barrel Controls 0.42 cfs @ 2.34 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond C1133: Inflow Area = 36,766 sf, 28.17% Impervious, Inflow Depth = 0.62" for 1 -Year event Inflow = 0.55 cfs @ 12.09 hrs, Volume= 1,902 cf Outflow = 0.55 cfs @ 12.09 hrs, Volume= 1,902 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.55 cfs @ 12.09 hrs, Volume= 1,902 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.30' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 228.93' 12.0" Round Culvert L= 16.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.93'/227.98' S=0.0576'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 231.88' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 18 Limited to weir flow at low heads Primary OutFlow Max =0.54 cfs @ 12.09 hrs HW= 229.30' (Free Discharge) �__2=Orifi 1= Culve rt (Inlet Controls 0.54 cfs @ 2.06 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond C1134: Inflow Area = 16,443 sf, 50.08% Impervious, Inflow = 0.38 cfs @ 12.09 hrs, Volume= Outflow = 0.38 cfs @ 12.09 hrs, Volume= Primary = 0.38 cfs @ 12.09 hrs, Volume= Inflow Depth = 0.89" 1,218 cf 1,218 cf, 1,218 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.95' @ 12.08 hrs for 1 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 229.64' 12.0" Round Culvert L= 31.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.64'/227.96' S=0.0542'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 232.11' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.37 cfs @ 12.09 hrs HW= 229.94' (Free Discharge) �__2=Orifi 1= Culve rt (Inlet Controls 0.37 cfs @ 1.87 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond DB: MOD.EX. DET.BASIN Inflow Area = 319,918 sf, 59.03% Impervious, Inflow = 6.86 cfs @ 12.08 hrs, Volume= Outflow = 3.62 cfs @ 12.35 hrs, Volume= Primary = 3.62 cfs @ 12.35 hrs, Volume= Inflow Depth = 1.03" 27,423 cf 27,325 cf, 27,325 cf for 1 -Year event Atten= 47 %, Lag= 15.9 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.92' @ 12.35 hrs Surf.Area= 4,816 sf Storage= 3,062 cf Plug -Flow detention time= 14.2 min calculated for 27,325 cf (100% of inflow) Center -of -Mass det. time= 11.4 min ( 856.6 - 845.2 ) Volume Invert Avail.Storage Storage Description #1 218.00' 18,957 cf Custom Stage Data (Irregular)Listed below (Recalc) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 19 Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 218.00 331 121.0 0 0 331 219.00 961 165.0 619 619 1,343 220.00 5,260 601.0 2,823 3,442 27,922 221.00 8,303 630.0 6,724 10,166 30,829 222.00 9,288 647.0 8,791 18,957 32,671 Device Routing Invert Outlet Devices #1 Primary 218.25' 12.0" Round Culvert L= 16.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 218.25'/217.81' S=0.0267'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Primary 220.00' 4.0' long x 15.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max =3.62 cfs @ 12.35 hrs HW= 219.92' (Free Discharge) �__2= 1= Culvert (Inlet Controls 3.62 cfs @ 4.60 fps) Broad - Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond DMH1: Inflow Area = 53,209 sf, 34.94% Impervious, Inflow Depth = 0.70" for 1 -Year event Inflow = 0.93 cfs @ 12.09 hrs, Volume= 3,120 cf Outflow = 0.93 cfs @ 12.09 hrs, Volume= 3,120 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.93 cfs @ 12.09 hrs, Volume= 3,120 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 222.84' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 222.31' 12.0" Round Culvert L= 77.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 222.31'/219.41' S=0.0374'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.91 cfs @ 12.09 hrs HW= 222.83' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.91 cfs @ 2.17 fps) Summary for Pond DMH10: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.47 cfs @ 12.07 hrs, Volume= 1,603 cf Outflow = 0.47 cfs @ 12.07 hrs, Volume= 1,603 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.47 cfs @ 12.07 hrs, Volume= 1,603 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 20 Peak Elev= 229.30' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 228.95' 12.0" Round Culvert L= 36.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.95'/228.59' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.45 cfs @ 12.07 hrs HW= 229.29' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.45 cfs @ 2.89 fps) Summary for Pond DMH11: Inflow Area = 90,561 sf, 67.73% Impervious, Inflow Depth = 1.33" for 1 -Year event Inflow = 3.15 cfs @ 12.08 hrs, Volume= 10,025 cf Outflow = 3.15 cfs @ 12.08 hrs, Volume= 10,025 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.15 cfs @ 12.08 hrs, Volume= 10,025 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.19' @ 12.08 hrs Device Routina Invert Outlet Devices #1 Primary 230.00' 12.0" Round Culvert L= 142.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.00'/224.85' S=0.0363'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =3.05 cfs @ 12.08 hrs HW= 231.15' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.05 cfs @ 3.88 fps) Summary for Pond DMH12: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 1.03" for 1 -Year event Inflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Outflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.04' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 232.50' 12.0" Round Culvert L= 68.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 232.50'/230.00' S=0.0368'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.05 cfs @ 12.08 hrs HW= 233.03' (Free Discharge) L1 = Culvert (Inlet Controls 1.05 cfs @ 2.48 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 21 Summary for Pond DMH13: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 1.03" for 1 -Year event Inflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Outflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.14' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 234.60' 12.0" Round Culvert L= 104.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 234.60'/232.50' S=0.0202'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.05 cfs @ 12.08 hrs HW= 235.13' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.05 cfs @ 2.48 fps) Summary for Pond DMH14: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 1.03" for 1 -Year event Inflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Outflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.34' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 235.80' 12.0" Round Culvert L= 58.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 235.80'/234.60' S=0.0207'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.05 cfs @ 12.08 hrs HW= 236.33' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.05 cfs @ 2.48 fps) Summary for Pond DMH15: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 1.03" for 1 -Year event Inflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Outflow = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.09 cfs @ 12.08 hrs, Volume= 3,442 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.04' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 243.50' 12.0" Round Culvert Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 22 L= 228.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.50'/236.30' S=0.0315'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.05 cfs @ 12.08 hrs HW= 244.03' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.05 cfs @ 2.48 fps) Summary for Pond DMH4: Inflow Area = 180,561 sf, 68.88% Impervious, Inflow Depth = 1.19" for 1 -Year event Inflow = 5.21 cfs @ 12.08 hrs, Volume= 17,925 cf Outflow = 5.21 cfs @ 12.08 hrs, Volume= 17,925 cf, Atten= 0 %, Lag= 0.0 min Primary = 5.21 cfs @ 12.08 hrs, Volume= 17,925 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 220.88' @ 12.08 hrs Flood Elev= 229.00' Device Routing Invert Outlet Devices #1 Primary 219.80' 24.0" Round TO EX. 24" FES IN EX. DET.BASIN L= 29.3' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 219.80'/219.44' S=0.0123'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =5.05 cfs @ 12.08 hrs HW= 220.86' (Free Discharge) t--1 =TO EX. 24" FES IN EX. DET.BASIN (Barrel Controls 5.05 cfs @ 4.33 fps) Summary for Pond DMH5: Inflow Area = 150,920 sf, 67.88% Impervious, Inflow Depth = 1.18" for 1 -Year event Inflow = 4.49 cfs @ 12.08 hrs, Volume= 14,898 cf Outflow = 4.49 cfs @ 12.08 hrs, Volume= 14,898 cf, Atten= 0 %, Lag= 0.0 min Primary = 4.49 cfs @ 12.08 hrs, Volume= 14,898 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.86' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 222.83' 18.0" Round Culvert L= 282.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.83'/220.70' S=0.0076'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 1.77 sf Primary OutFlow Max =4.35 cfs @ 12.08 hrs HW= 223.84' (Free Discharge) t--1 =Culvert (Inlet Controls 4.35 cfs @ 3.43 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 23 Summary for Pond DMH6: Inflow Area = 107,715 sf, 70.09% Impervious, Inflow Depth = 1.28" for 1 -Year event Inflow = 3.42 cfs @ 12.08 hrs, Volume= 11,505 cf Outflow = 3.42 cfs @ 12.08 hrs, Volume= 11,505 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.42 cfs @ 12.08 hrs, Volume= 11,505 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.03' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 224.14' 24.0" Round Culvert 0.01 cfs @ L= 89.5' CPP, projecting, no headwall, Ke= 0.900 1,244 cf Inlet/ Outlet Invert= 224.14'/222.83' S=0.0146'/' Cc= 0.900 0.75 cfs @ n=0.010 PVC, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =3.32 cfs @ 12.08 hrs HW= 225.01' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.32 cfs @ 2.51 fps) Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.94' @ 12.35 hrs Surf.Area= 2,670 sf Storage= 3,527 cf Plug -Flow detention time= 560.0 min calculated for 5,228 cf (73% of inflow) Center -of -Mass det. time= 466.7 min ( 1,248.7 - 782.0 ) Summary for Pond INF6: U/G INF. Inflow Area = 60,434 sf, 67.23% Impervious, Inflow Depth = 1.42" for 1 -Year event Inflow = 2.10 cfs @ 12.07 hrs, Volume= 7,144 cf Outflow = 0.75 cfs @ 12.35 hrs, Volume= 5,228 cf, Atten= 64 %, Lag= 16.5 min Discarded = 0.01 cfs @ 11.95 hrs, Volume= 1,244 cf Primary = 0.75 cfs @ 12.35 hrs, Volume= 3,983 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.94' @ 12.35 hrs Surf.Area= 2,670 sf Storage= 3,527 cf Plug -Flow detention time= 560.0 min calculated for 5,228 cf (73% of inflow) Center -of -Mass det. time= 466.7 min ( 1,248.7 - 782.0 ) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 24 Volume Invert Avail.Storage Storage Description #1A 227.00' 310 cf 25.35'W x 34.00'L x 3.17'H Field A 2,732 cf Overall - 1,958 cf Embedded = 774 cf x 40.0% Voids #2A 227.50' 1,334 cf Concrete Dry Well 500gal x 20 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 5 Rows of 4 Chambers #313 226.00' 265 cf 20.68'W x 34.00'L x 3.17'H Field B 2,229 cf Overall - 1,567 cf Embedded = 662 cf x 40.0% Voids #413 226.50' 1,067 cf Concrete Dry Well 500gal x 16 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 4 Rows of 4 Chambers #5C 225.00' 310 cf 16.01'W x 50.00'L x 3.17'H Field C 2,538 cf Overall - 1,763 cf Embedded = 775 cf x 40.0% Voids #6C 225.50' 1,201 cf Concrete Dry Well 500gal x 18 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 3 Rows of 6 Chambers #7D 224.50' 102 cf 11.34'W x 18.00'L x 3.17'H Field D 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #8D 225.00' 267 cf Concrete Dry Well 500gal x 4 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 2 Rows of 2 Chambers #9 224.50' 402 cf 8.00'D x 4.00'H Vertical Cone /Cvlinderx 2 5,258 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.50' 0.090 in /hr Exfiltration over Surface area #2 Primary 227.50' 12.0" Round Culvert L= 23.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 227.50'/ 224.30' S= 0.1391 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max =0.01 cfs @ 11.95 hrs HW= 227.04' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max =0.74 cfs @ 12.35 hrs HW= 227.94' (Free Discharge) L2= Culvert (Inlet Controls 0.74 cfs @ 2.25 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 25 Summary for Pond INF7: U/G INF. Inflow Area = 7,747 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.43 cfs @ 12.07 hrs, Volume= 1,466 cf Outflow = 0.22 cfs @ 12.22 hrs, Volume= 1,002 cf, Atten= 49 %, Lag= 8.7 min Discarded = 0.00 cfs @ 4.95 hrs, Volume= 206 cf Primary = 0.22 cfs @ 12.22 hrs, Volume= 796 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.29' @ 12.22 hrs Surf.Area= 402 sf Storage= 721 cf Plug -Flow detention time= 494.6 min calculated for 1,002 cf (68% of inflow) Center -of -Mass det. time= 399.1 min ( 1,160.1 - 761.0 ) Volume Invert Avail.Storage Storage Description #1 226.50' 1,608 cf 8.00'D x 4.00'H Vertical Cone /Cylinderx 8 Device Routing Invert Outlet Devices #1 Primary 228.00' 6.0" Round Culvert L= 48.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 228.00'/225.00' S=0.0625'/' Cc= 0.900 n=0.013, Flow Area= 0.20 sf #2 Discarded 226.50' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 4.95 hrs HW= 226.54' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.22 cfs @ 12.22 hrs HW= 228.29' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.22 cfs @ 1.83 fps) Summary for Pond P -C11310: Inflow Area = 2,715 sf, 30.68% Impervious, Inflow Depth = 0.20" for 1 -Year event Inflow = 0.01 cfs @ 12.32 hrs, Volume= 44 cf Outflow = 0.01 cfs @ 12.32 hrs, Volume= 44 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.01 cfs @ 12.32 hrs, Volume= 44 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.02' @ 12.32 hrs Flood Elev= 231.40' Device Routing Invert Outlet Devices #1 Primary 224.00' 12.0" Round Culvert L= 20.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 224.00'/222.00' S=0.1000'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.00 cfs @ 12.32 hrs HW= 224.02' (Free Discharge) L1= Culvert (Inlet Controls 0.00 cfs @ 0.42 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 26 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.07' @ 12.10 hrs Flood Elev= 231.30' Device Routing Invert Outlet Devices #1 Primary 226.00' 12.0" Round Culvert L= 44.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 226.00'/225.00' S=0.0227'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.02 cfs @ 12.10 hrs HW= 226.07' (Free Discharge) L1= Culvert (Inlet Controls 0.02 cfs @ 0.91 fps) Summary for Pond P -C11313: Inflow Area = 1,923 sf, 33.44% Impervious, Inflow Depth = 0.57" for 1 -Year event Inflow = 0.03 cfs @ 12.09 hrs, Volume= 91 cf Outflow = 0.03 cfs @ 12.09 hrs, Volume= 91 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.03 cfs @ 12.09 hrs, Volume= 91 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.87' @ 12.09 hrs Flood Elev= 231.76' Device Ro Invert Outlet Devices #1 Primary 227.80' 12.0" Round Culvert L= 65.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.80'/226.00' S=0.0277'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.02 cfs @ 12.09 hrs HW= 227.87' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.02 cfs @ 0.93 fps) Summary for Pond P -C1135: Inflow Area = 23,642 sf, 42.77% Impervious, Inflow Depth = 0.69" for 1 -Year event Inflow = 0.41 cfs @ 12.09 hrs, Volume= 1,368 cf Outflow = 0.41 cfs @ 12.09 hrs, Volume= 1,368 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.41 cfs @ 12.09 hrs, Volume= 1,368 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Summary for Pond P -C11311: Inflow Area = 3,462 sf, 26.20% Impervious, Inflow Depth = 0.38" for 1 -Year event Inflow = 0.03 cfs @ 12.10 hrs, Volume= 111 cf Outflow = 0.03 cfs @ 12.10 hrs, Volume= 111 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.03 cfs @ 12.10 hrs, Volume= 111 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.07' @ 12.10 hrs Flood Elev= 231.30' Device Routing Invert Outlet Devices #1 Primary 226.00' 12.0" Round Culvert L= 44.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 226.00'/225.00' S=0.0227'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.02 cfs @ 12.10 hrs HW= 226.07' (Free Discharge) L1= Culvert (Inlet Controls 0.02 cfs @ 0.91 fps) Summary for Pond P -C11313: Inflow Area = 1,923 sf, 33.44% Impervious, Inflow Depth = 0.57" for 1 -Year event Inflow = 0.03 cfs @ 12.09 hrs, Volume= 91 cf Outflow = 0.03 cfs @ 12.09 hrs, Volume= 91 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.03 cfs @ 12.09 hrs, Volume= 91 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.87' @ 12.09 hrs Flood Elev= 231.76' Device Ro Invert Outlet Devices #1 Primary 227.80' 12.0" Round Culvert L= 65.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.80'/226.00' S=0.0277'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.02 cfs @ 12.09 hrs HW= 227.87' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.02 cfs @ 0.93 fps) Summary for Pond P -C1135: Inflow Area = 23,642 sf, 42.77% Impervious, Inflow Depth = 0.69" for 1 -Year event Inflow = 0.41 cfs @ 12.09 hrs, Volume= 1,368 cf Outflow = 0.41 cfs @ 12.09 hrs, Volume= 1,368 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.41 cfs @ 12.09 hrs, Volume= 1,368 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 27 Peak Elev= 225.32' @ 12.09 hrs Flood Elev= 228.89' Device Routing Invert Outlet Devices #1 Primary 225.00' 15.0" Round Culvert L= 70.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0071 T Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =0.40 cfs @ 12.09 hrs HW= 225.31' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.40 cfs @ 2.47 fps) Summary for Pond P -C1136: Inflow Area = 6,271 sf, 0.00% Impervious, Inflow Depth= 0.00" for 1 -Year event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.00' @ 0.00 hrs Flood Elev= 230.80' Device Routing Invert Outlet Devices #1 Primary 227.00' 12.0" Round Culvert L= 43.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.00'/225.50' S=0.0349'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 227.00' (Free Discharge) 't--1 =Culvert ( Controls 0.00 cfs) Summary for Pond P -C1137: Inflow Area = 3,222 sf, 0.00% Impervious, Inflow Depth = 0.00" for 1 -Year event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.50' @ 0.00 hrs Flood Elev= 231.50' Device Routing Invert Outlet Devices #1 Primary 228.50' 8.0" Round Culvert L= 73.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 228.50'/228.00' S=0.0068'/' Cc= 0.900 n=0.013, Flow Area= 0.35 sf Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 28 Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 228.50' (Free Discharge) 't--1 =Culvert ( Controls 0.00 cfs) Summary for Pond P -C1138: Inflow Area = 7,284 sf, 65.31% Impervious, Inflow Depth = 1.31" for 1 -Year event Inflow = 0.26 cfs @ 12.08 hrs, Volume= 796 cf Outflow = 0.26 cfs @ 12.08 hrs, Volume= 796 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.26 cfs @ 12.08 hrs, Volume= 796 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.48' @ 12.08 hrs Flood Elev= 231.10' Device Routing Invert Outlet Devices #1 Primary 224.20' 12.0" Round Culvert L= 15.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 224.20'/224.00' S=0.0133'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.25 cfs @ 12.08 hrs HW= 224.48' (Free Discharge) L1= Culvert (Inlet Controls 0.25 cfs @ 1.41 fps) Summary for Pond P -C1139: Inflow Area = 3,276 sf, 76.68% Impervious, Inflow Depth = 1.12" for 1 -Year event Inflow = 0.10 cfs @ 12.08 hrs, Volume= 305 cf Outflow = 0.10 cfs @ 12.08 hrs, Volume= 305 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.10 cfs @ 12.08 hrs, Volume= 305 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.65' @ 12.08 hrs Flood Elev= 231.76' Device Routing Invert Outlet Devices #1 Primary 223.50' 12.0" Round Culvert L= 56.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 223.50'/222.00' S=0.0268'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.09 cfs @ 12.08 hrs HW= 223.64' (Free Discharge) t--1 =Culvert (Inlet Controls 0.09 cfs @ 1.29 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 29 Summary for Pond P- DMH12: Inflow Area = 158,667 sf, 69.45% Impervious, Inflow Depth = 1.19" for 1 -Year event Inflow = 4.54 cfs @ 12.08 hrs, Volume= 15,694 cf Outflow = 4.54 cfs @ 12.08 hrs, Volume= 15,694 cf, Atten= 0 %, Lag= 0.0 min Primary = 4.54 cfs @ 12.08 hrs, Volume= 15,694 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 222.94' @ 12.08 hrs Flood Elev= 231.15' Device Routing Invert Outlet Devices #1 Primary 222.00' 24.0" Round Culvert L= 132.5' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 222.00'/221.00' S=0.0075'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =4.41 cfs @ 12.08 hrs HW= 222.93' (Free Discharge) 't--1 =Culvert (Barrel Controls 4.41 cfs @ 4.54 fps) Summary for Pond P- DMH12A: Inflow Area = 7,747 sf,100.00% Impervious, Inflow Depth = 1.23" for 1 -Year event Inflow = 0.22 cfs @ 12.22 hrs, Volume= 796 cf Outflow = 0.22 cfs @ 12.22 hrs, Volume= 796 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.22 cfs @ 12.22 hrs, Volume= 796 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.23' @ 12.22 hrs Flood Elev= 232.20' Device Ro Invert Outlet Devices #1 Primary 225.00' 12.0" Round Culvert L= 31.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.00'/223.00' S=0.0645'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Primary 231.00' 6.0' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =0.21 cfs @ 12.22 hrs HW= 225.22' (Free Discharge) tl=Culvert (Inlet Controls 0.21 cfs @ 1.61 fps) 2= Broad - Crested Rectangular Weir( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 30 Summary for Pond P -DMH6: Inflow Area = 60,434 sf, 67.23% Impervious, Inflow Depth = 0.79" for 1 -Year event Inflow = 0.74 cfs @ 12.39 hrs, Volume= 3,983 cf Outflow = 0.74 cfs @ 12.39 hrs, Volume= 3,983 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.74 cfs @ 12.39 hrs, Volume= 3,983 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 220.92' @ 12.39 hrs Flood Elev= 226.70' Device Routing Invert Outlet Devices #1 Primary 220.55' 24.0" Round Culvert L= 21.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 220.55'/219.50' S=0.0500'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =0.73 cfs @ 12.39 hrs HW= 220.92' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.73 cfs @ 1.83 fps) Summary for Pond P -DMH7: Inflow Area = 60,434 sf, 67.23% Impervious, Inflow Depth = 0.79" for 1 -Year event Inflow = 0.75 cfs @ 12.35 hrs, Volume= 3,983 cf Outflow = 0.75 cfs @ 12.35 hrs, Volume= 3,983 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.75 cfs @ 12.35 hrs, Volume= 3,983 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.68' @ 12.35 hrs Flood Elev= 233.00' Device Routing Invert Outlet Devices #1 Primary 225.00' 24.0" Round Culvert L= 78.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.00'/223.50' S=0.0192'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf #2 Device 1 230.00' 0.5' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =0.75 cfs @ 12.35 hrs HW= 230.68' (Free Discharge) L1= Culvert (Passes 0.75 cfs of 32.71 cfs potential flow) L2= Broad -crested Rectangular Weir (Weir Controls 0.75 cfs @ 2.21 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 31 Summary for Pond P -DMH8: Inflow Area = 21,598 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 1.20 cfs @ 12.07 hrs, Volume= 4,087 cf Outflow = 1.20 cfs @ 12.07 hrs, Volume= 4,087 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.20 cfs @ 12.07 hrs, Volume= 4,087 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.52' @ 12.07 hrs Flood Elev= 232.42' Device Routing Invert Outlet Devices #1 Primary 228.00' 15.0" Round Culvert L= 134.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 228.00'/ 224.50' S= 0.0261 T Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =1.16 cfs @ 12.07 hrs HW= 228.51' (Free Discharge) L1= Culvert (Inlet Controls 1.16 cfs @ 2.44 fps) Summary for Pond P -DMH9: Inflow Area = 170,001 sf, 68.88% Impervious, Inflow Depth = 1.19" for 1 -Year event Inflow = 4.85 cfs @ 12.08 hrs, Volume= 16,824 cf Outflow = 4.85 cfs @ 12.08 hrs, Volume= 16,824 cf, Atten= 0 %, Lag= 0.0 min Primary = 4.85 cfs @ 12.08 hrs, Volume= 16,824 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.95' @ 12.08 hrs Flood Elev= 232.70' Device Ro Invert Outlet Devices #1 Primary 221.00' 24.0" Round DOGHOUSE JUNCTION TO EX. 24" HDPE L= 107.5' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 221.00'/219.90' S=0.0102'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =4.71 cfs @ 12.08 hrs HW= 221.93' (Free Discharge) L1= DOGHOUSE JUNCTION TO EX. 24" HDPE(Inlet Controls 4.71 cfs @ 3.29 fps) Summary for Pond ST: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 2.27" for 1 -Year event Inflow = 0.47 cfs @ 12.07 hrs, Volume= 1,603 cf Outflow = 0.12 cfs @ 12.44 hrs, Volume= 627 cf, Atten= 74 %, Lag= 22.4 min Primary = 0.12 cfs @ 12.44 hrs, Volume= 627 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 32 Peak Elev= 229.30' @ 12.44 hrs Surf.Area= 0 sf Storage= 1,004 cf Plug -Flow detention time= 318.9 min calculated for 627 cf (39% of inflow) Center -of -Mass det. time= 172.6 min ( 933.6 - 761.0 ) Volume Invert Avail.Storage Storage Description #1 223.40' 1,360 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 223.40 0 231.40 1,360 Device Routing Invert Outlet Devices #1 Primary 229.14' 12.0" Round Culvert L= 27.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.14'/224.85' S=0.1589'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.11 cfs @ 12.44 hrs HW= 229.30' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.11 cfs @ 1.38 fps) Summary for Pond SWM1: U/G DET. Inflow Area = 60,434 sf, 67.23% Impervious, Inflow Depth = 0.79" for 1 -Year event Inflow = 0.75 cfs @ 12.35 hrs, Volume= 3,983 cf Outflow = 0.74 cfs @ 12.39 hrs, Volume= 3,983 cf, Atten= 1 %, Lag= 2.3 min Primary = 0.74 cfs @ 12.39 hrs, Volume= 3,983 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.00' @ 12.39 hrs Surf.Area= 560 sf Storage= 108 cf Flood Elev= 226.00' Surf.Area= 560 sf Storage= 1,211 cf Plug -Flow detention time= 5.1 min calculated for 3,981 cf (100% of inflow) Center -of -Mass det. time= 5.1 min ( 904.8 - 899.6 ) Volume Invert Avail.Storage Storage Description #1A 220.50' 359 cf 14.00'W x 40.00'L x 3.50'H Field A 1,960 cf Overall - 1,063 cf Embedded = 897 cf x 40.0% Voids #2A 220.50' 852 cf ADS N -12 36" x 6 Inside #1 Inside= 36.1 "W x 36.1 "H => 7.10 sf x 20.001 = 142.0 cf Outside= 42.0 "W x 42.0 "H => 8.86 sf x 20.001 = 177.1 cf 3 Rows of 2 Chambers 1,211 cf Total Available Storage Storage Group A created with Chamber Wizard Brookhaven, Lexington, MA 151067 2017 POST AP2 1 YEAR Type 111 24 -hr 1 -Year Rainfall= 2.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 33 Device Routing Invert Outlet Devices #1 Primary 220.50' 12.0" Round Culvert L= 21.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 220.50'/219.00' S=0.0714'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Device 1 220.50' 12.0" Vert. LOW FLOW ORIFICE C= 0.600 #3 Primary 224.00' 0.5' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =0.73 cfs @ 12.39 hrs HW= 220.99' (Free Discharge) T_71 =Culvert (Inlet Controls 0.73 cfs @ 1.89 fps) L2 =LOW FLOW ORIFICE (Passes 0.73 cfs of 0.93 cfs potential flow) 3= Broad -Crested Rectangular Weir( Controls 0.00 cfs) Summary for Link AP2: Inflow Area = 347,640 sf, 54.32% Impervious, Inflow Depth = 1.00" for 1 -Year event Inflow = 3.87 cfs @ 12.25 hrs, Volume= 29,035 cf Primary = 3.87 cfs @ 12.25 hrs, Volume= 29,035 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs „ L,.� 2L 3L,c� Pre AP1 Pre AP2 Pre AP3 P scNwc - - - - - -- NW CU LVERT oaHP so-Rs w R3 A, (s 4 Ccc.c} NF3 \..Sc_R) \.S 31 1 / \.Sc.R) WEST WALE U/G INF. --S- U/G U/G INF. b ce ce P. SC -P P. SC -3 P. SC -4 P -oMea P -oMe --------- A _._ _._ _..- BE ce3 cea NF4 NF5 FB ST INF. B SIN W NF.BASIN E FB EAST - - - - - -- U/G IN /G INF. B � SSG} P. SC -1 � -ce1 P.scFew NF2 U/G INF. AP1 x R1 R2 AP3 Cf P -1 P. SC -D Cc 1 ❑ ❑ C:.1 C D/W MAIN CULVERT OFF -SITE 11 DEPRESSION AP2 FROM "POST AP2” Link Routing Diagram for 151067 2017 POST Prepared by Goldsmith, Prest & Ringwall, Inc., Printed 7/14/2017 Subcat Reach on HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Brookhaven, Lexington, MA 151067 2017 POST Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq -ft) (s u bcatch me nt -n u m be rs) 33,879 61 >75% Grass cover, Good, HSG B (P. SC -1, P. SC -2, P. SC -3, P. SC -4, P. SC -D, P. SC -FBE, P. SC -FBW, P. SC -NWC, P. SC -P) 46,016 80 >75% Grass cover, Good, HSG D (P. SC -4, P. SC -C3, P. SC -D, P. SC -FBE, P. SC -FBW, P. SC -P) 4,600 98 Ledge, HSG B (P. SC -D, P. SC -NWC) 55,279 98 Paved parking, HSG A (P. SC -D) 192,825 98 Paved parking, HSG B (P. SC -1, P. SC -2, P. SC -3, P. SC -4, P. SC -D, P. SC -FBW, P. SC -NWC, P. SC -P) 110,991 98 Paved parking, HSG D (P. SC -3, P. SC -4, P. SC -D, P. SC -FBE, P. SC -FBW, P. SC -NWC, P. SC -P) 34,037 98 Roofs, HSG B (P. SC -R4, P. SC -R5, P. SC -R6, P. SC -R7, P. SC -R8) 347,789 30 Woods, Good, HSG A (P. SC -D) 637,867 55 Woods, Good, HSG B (P. SC -D, P. SC -NWC) 1,029,613 77 Woods, Good, HSG D (P. SC -C3, P. SC -D, P. SC -NWC) Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment P. SC -1: Runoff = 0.42 cfs @ 12.08 hrs, Volume= 1,311 cf, Depth= 1.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 2,938 61 >75% Grass cover, Good, HSG B 7,111 98 Paved parking, HSG B 10,049 87 Weighted Average 2,938 29.24% Pervious Area 7,111 70.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -2: Runoff = 0.02 cfs @ 12.11 hrs, Volume= 85 cf, Depth= 0.45" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 1,947 61 >75% Grass cover, Good, HSG B 305 98 Paved parking, HSG B 2,252 66 Weighted Average 1,947 86.46% Pervious Area 305 13.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -3: Runoff = 0.65 cfs @ 12.08 hrs, Volume= 2,004 cf, Depth= 1.49" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 4 Area (so CN Description 5,364 61 >75% Grass cover, Good, HSG B 992 98 Paved parking, HSG D 9,758 98 Paved parking, HSG B 16,114 86 Weighted Average 5,364 88 33.29% Pervious Area 10,750 66.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment P. SC -4: Runoff = 0.50 cfs @ 12.08 hrs, Volume= 1,563 cf, Depth= 1.64" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 841 61 >75% Grass cover, Good, HSG B 4,445 80 >75% Grass cover, Good, HSG D 1,472 98 Paved parking, HSG B 4,668 98 Paved parking, HSG D 11,426 88 Weighted Average 5,286 46.26% Pervious Area 6,140 53.74% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C3: Runoff = 1.34 cfs @ 12.08 hrs, Volume= 4,253 cf, Depth= 1.04" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 26,830 80 >75% Grass cover, Good, HSG D 22.040 77 Woods. Good. HSG D 48,870 79 Weighted Average 48,870 100.00% Pervious Area Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 5 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -D: Runoff = 22.14 cfs @ 12.12 hrs, Volume= 94,524 cf, Depth= 0.49" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 10,561 61 >75% Grass cover, Good, HSG B 3,835 80 >75% Grass cover, Good, HSG D 167,851 98 Paved parking, HSG B 102,329 98 Paved parking, HSG D 55,279 98 Paved parking, HSG A 624,368 55 Woods, Good, HSG B 1,005,091 77 Woods, Good, HSG D 347,789 30 Woods, Good, HSG A 3,953 98 Ledge, HSG B 2,321,056 67 Weighted Average 1,991,644 57 85.81 % Pervious Area 329,412 Shallow Concentrated Flow, 14.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 3.1 30 0.0330 0.16 Sheet Flow, Grass: Short n= 0.150 P2= 3.16" 0.3 118 0.2550 7.57 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.3 57 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.0 705 0.0850 5.92 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 165 0.0480 3.29 Shallow Concentrated Flow, Grassed Waterwav Kv= 15.0 fps 6.5 1,075 Total Summary for Subcatchment P. SC -FBE: Runoff = 0.09 cfs @ 12.08 hrs, Volume= 273 cf, Depth= 1.35" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 6 Area (so CN Description 362 61 >75% Grass cover, Good, HSG B 1,176 80 >75% Grass cover, Good, HSG D 881 98 Paved parking, HSG D 2,419 84 Weighted Average 1,538 72 63.58% Pervious Area 881 68 36.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment P. SC -FBW: Runoff = 0.10 cfs @ 12.09 hrs, Volume= 342 cf, Depth= 0.69" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 3,310 61 >75% Grass cover, Good, HSG B 1,761 80 >75% Grass cover, Good, HSG D 569 98 Paved parking, HSG B 286 98 Paved parking, HSG D 5,926 72 Weighted Average 5,071 68 85.57% Pervious Area 855 14.43% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -NWC: Runoff = 0.32 cfs @ 12.10 hrs, Volume= 1,254 cf, Depth= 0.53" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 6,262 61 >75% Grass cover, Good, HSG B 5,092 98 Paved parking, HSG B 609 98 Paved parking, HSG D 13,499 55 Woods, Good, HSG B 2,482 77 Woods, Good, HSG D 647 98 Ledge, HSG B 28,591 68 Weighted Average 22,243 77.80% Pervious Area 6,348 22.20% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 7 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -P: Runoff = 0.33 cfs @ 12.08 hrs, Volume= 1,058 cf, Depth= 1.04" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 2,294 61 >75% Grass cover, Good, HSG B 7,969 80 >75% Grass cover, Good, HSG D 667 98 Paved parking, HSG B 1,226 98 Paved parking, HSG D 12,156 79 Weighted Average 10,263 84.43% Pervious Area 1,893 15.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R4: Runoff = 0.86 cfs @ 12.07 hrs, Volume= 2,943 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 13,748 98 Roofs, HSG B 13,748 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R5: Runoff = 0.47 cfs @ 12.07 hrs, Volume= 1,622 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 8 Area (so CN Description 7,577 98 Roofs, HSG B 7,577 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R6: Runoff = 0.31 cfs @ 12.07 hrs, Volume= 1,054 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 4,922 98 Roofs, HSG B 4,922 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R7: Runoff = 0.20 cfs @ 12.07 hrs, Volume= 698 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 3,261 98 Roofs, HSG B 3,261 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R8: Runoff = 0.28 cfs @ 12.07 hrs, Volume= 970 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 9 Area (so CN Description 4,529 98 Roofs, HSG B 4,529 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Reach R1: Inflow Area = 2,840,536 sf, 21.06% Impervious, Inflow Depth > 0.41" for 2 -Year event Inflow = 7.45 cfs @ 12.27 hrs, Volume= 96,921 cf Outflow = 7.35 cfs @ 12.32 hrs, Volume= 96,797 cf, Atten= 1 %, Lag= 2.9 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 1.25 fps, Min. Travel Time= 4.3 min Avg. Velocity = 0.36 fps, Avg. Travel Time= 15.0 min Peak Storage= 1,903 cf @ 12.32 hrs Average Depth at Peak Storage= 0.45' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 56.94 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 324.0' Slope= 0.00287' Inlet Invert= 218.80', Outlet Invert= 217.90' Summary for Reach R2: Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow Depth > 0.24" for 2 -Year event Inflow = 0.35 cfs @ 23.43 hrs, Volume= 47,563 cf Outflow = 0.35 cfs @ 23.56 hrs, Volume= 47,454 cf, Atten= 0 %, Lag= 7.6 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 0.28 fps, Min. Travel Time= 12.1 min Avg. Velocity = 0.23 fps, Avg. Travel Time= 14.8 min Peak Storage= 255 cf @ 23.56 hrs Average Depth at Peak Storage= 0.10' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 33.66 cfs Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 10 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 206.0' Slope= 0.0010 '/' Inlet Invert= 219.00', Outlet Invert= 218.80' Summary for Reach R3: WEST SWALE Inflow Area = 36,168 sf, 38.50% Impervious, Inflow Depth= 0.42" for 2 -Year event Inflow = 0.32 cfs @ 12.10 hrs, Volume= 1,254 cf Outflow = 0.32 cfs @ 12.11 hrs, Volume= 1,254 cf, Atten= 0 %, Lag= 0.4 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 1.89 fps, Min. Travel Time= 0.6 min Avg. Velocity = 0.93 fps, Avg. Travel Time= 1.2 min Peak Storage= 11 cf @ 12.11 hrs Average Depth at Peak Storage= 0.24' Bank -Full Depth= 1.00' Flow Area= 3.0 sf, Capacity= 14.77 cfs 0.00' x 1.00' deep channel, n= 0.035 Side Slope Z- value= 3.07' Top Width= 6.00' Length= 66.0' Slope= 0.03647' Inlet Invert= 234.40', Outlet Invert= 232.00' Summary for Pond EX. C -1: D/W MAIN CULVERT Inflow Area = 2,840,536 sf, 21.06% Impervious, Inflow Depth > 0.41" for 2 -Year event Inflow = 7.35 cfs @ 12.32 hrs, Volume= 96,797 cf Outflow = 7.35 cfs @ 12.33 hrs, Volume= 96,746 cf, Atten= 0 %, Lag= 0.3 min Primary = 7.35 cfs @ 12.33 hrs, Volume= 96,746 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 216.65' @ 12.33 hrs Surf.Area= 0 sf Storage= 210 cf Plug -Flow detention time= 2.5 min calculated for 96,746 cf (100% of inflow) Center -of -Mass det. time= 1.1 min ( 1,509.2 - 1,508.1 ) Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 11 Volume Invert Avail.Storage Storage Description #1 215.94' 1,029 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 215.94 0 219.44 1,029 Device Routing Invert Outlet Devices #1 Primary 216.08' 72.0" W x 42.0" H Box Culvert L= 49.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 216.08'/215.94' S=0.0029'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 21.00 sf Primary OutFlow Max =7.32 cfs @ 12.33 hrs HW= 216.65' (Free Discharge) 't--1 =Culvert (Barrel Controls 7.32 cfs @ 2.84 fps) Summary for Pond FBE: FB EAST Inflow Area = 45,959 sf, 69.24% Impervious, Inflow Depth = 1.03" for 2 -Year event Inflow = 1.26 cfs @ 12.08 hrs, Volume= 3,935 cf Outflow = 1.24 cfs @ 12.10 hrs, Volume= 3,786 cf, Atten= 1 %, Lag= 1.3 min Discarded = 0.00 cfs @ 12.10 hrs, Volume= 104 cf Primary = 1.24 cfs @ 12.10 hrs, Volume= 3,682 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.89' @ 12.10 hrs Surf.Area= 328 sf Storage= 337 cf Flood Elev= 227.00' Surf.Area= 350 sf Storage= 375 cf Plug -Flow detention time= 74.5 min calculated for 3,784 cf (96% of inflow) Center -of -Mass det. time= 55.3 min ( 882.2 - 826.9 ) Volume Invert Avail.Storage Storage Description #1 224.00' 375 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 224.00 0 0 0 225.00 50 25 25 226.00 150 100 125 227.00 350 250 375 Device Routing Invert Outlet Devices #1 Primary 226.50' 2.0' long x 10.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Discarded 224.00' 0.090 in /hr Exfiltration over Surface area Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 12 Discarded OutFlow Max =0.00 cfs @ 12.10 hrs HW= 226.89' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =1.24 cfs @ 12.10 hrs HW= 226.89' (Free Discharge) L1 =Broad -Crested Rectangular Weir (Weir Controls 1.24 cfs @ 1.59 fps) Summary for Pond FBW: FB WEST Inflow Area = 52,143 sf, 41.98% Impervious, Inflow Depth= 0.67" for 2 -Year event Inflow = 0.84 cfs @ 12.09 hrs, Volume= 2,907 cf Outflow = 0.80 cfs @ 12.12 hrs, Volume= 2,907 cf, Atten= 5 %, Lag= 1.6 min Discarded = 0.00 cfs @ 12.12 hrs, Volume= 26 cf Primary = 0.80 cfs @ 12.12 hrs, Volume= 2,881 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.45' @ 12.12 hrs Surf.Area= 299 sf Storage= 112 cf Flood Elev= 231.50' Surf.Area= 732 sf Storage= 896 cf Plug -Flow detention time= 6.4 min calculated for 2,907 cf (100% of inflow) Center -of -Mass det. time= 6.2 min ( 867.1 - 860.9 ) Volume Invert Avail.Storage Storage Description #1 229.00' 896 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 229.00 199 54.0 0 0 199 230.00 445 84.0 314 314 536 231.00 732 108.0 583 896 915 Device Routing Invert Outlet Devices #1 Primary 229.00' 12.0" Round Culvert L= 31.0' CMP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 229.00'/227.00' S=0.0645'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Secondary 230.00' 3.0' long x 13.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.60 2.64 2.70 2.66 2.65 2.66 2.65 2.63 #3 Discarded 229.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 12.12 hrs HW= 229.45' (Free Discharge) L3= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.77 cfs @ 12.12 hrs HW= 229.45' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.77 cfs @ 2.27 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 229.00' (Free Discharge) L2= Broad -Crested Rectangular Weir( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 13 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.01' @ 12.78 hrs Surf.Area= 1,427 sf Storage= 1,038 cf Plug -Flow detention time= 35.3 min calculated for 5,262 cf (100% of inflow Center -of -Mass det. time= 35.5 min ( 890.6 - 855.1 ) Volume Invert Summary for Pond IBE: INF.BASIN E Inflow Area = 110,258 sf, 50.43% Impervious, Inflow Depth = 0.57" for 2 -Year event Inflow = 1.24 cfs @ 12.10 hrs, Volume= 5,265 cf Outflow = 0.39 cfs @ 12.78 hrs, Volume= 5,265 cf, Atten= 69 %, Lag= 40.8 min Discarded = 0.00 cfs @ 12.78 hrs, Volume= 91 cf Primary = 0.39 cfs @ 12.78 hrs, Volume= 5,174 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.01' @ 12.78 hrs Surf.Area= 1,427 sf Storage= 1,038 cf Plug -Flow detention time= 35.3 min calculated for 5,262 cf (100% of inflow Center -of -Mass det. time= 35.5 min ( 890.6 - 855.1 ) Volume Invert Avail.Storage Storage Description #1 223.00' 8,617 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 223.00 620 0 0 224.00 1,418 1,019 1,019 225.00 2,097 1,758 2,777 226.00 2,621 2,359 5,136 227.00 4,341 3,481 8,617 Device Routing Invert Outlet Devices #1 Primary 223.00' 15.0" Round BASIN OUTLET CULVERT L= 30.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 223.00'/222.60' S=0.0133'/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf #2 Device 1 223.00' 4.0" Vert. LOW FLOW ORIFICE C= 0.600 #3 Device 1 225.25' 12.0" W x 12.0" H Vert. WEIR NOTCH C= 0.600 #4 Device 1 226.25' 48.0" Horiz. SPILLWAY C= 0.600 Limited to weir flow at low heads #5 Discarded 223.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 12.78 hrs HW= 224.01' (Free Discharge) T 5= Exfiltration ( Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.39 cfs @ 12.78 hrs HW= 224.01' (Free Discharge) L1 =BASIN OUTLET CULVERT (Passes 0.39 cfs of 3.49 cfs potential flow) 12 =LOW FLOW ORIFICE (Orifice Controls 0.39 cfs @ 4.43 fps) 3 =WEIR NOTCH ( Controls 0.00 cfs) 4=SPILLWAY ( Controls 0.00 cfs) Summary for Pond IBW: INF. BASIN W Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 14 Inflow Area = 64,299 sf, 36.99% Impervious, Inflow Depth = 0.74" for 2 -Year event Inflow = 1.11 cfs @ 12.11 hrs, Volume= 3,939 cf Outflow = 0.68 cfs @ 12.26 hrs, Volume= 3,939 cf, Atten= 39 %, Lag= 8.9 min Discarded = 0.00 cfs @ 12.26 hrs, Volume= 676 cf Primary = 0.68 cfs @ 12.26 hrs, Volume= 3,262 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.49' @ 12.26 hrs Surf.Area= 1,910 sf Storage= 868 cf Plug -Flow detention time= 243.4 min calculated for 3,936 cf (100% of inflow) Center -of -Mass det. time= 245.0 min ( 1,107.3 - 862.3 ) Volume Invert Avail.Storage Storage Description #1 227.00' 4,452 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 227.00 1,607 0 0 228.00 2,221 1,914 1,914 229.00 2,854 2,538 4,452 Device Ro Invert Outlet Devices #1 Secondary 228.00' 2.0' long x 20.0' breadth Broad - Crested Rectangular Weir 7,577 sf, 100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.47 cfs @ Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Outflow = 0.04 cfs @ 12.20 hrs, Volume= 1,622 cf, Atten= 92 %, Lag= 7.8 min Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 #2 Discarded 227.00' 0.090 in /hr Exfiltration over Surface area #3 Primary 225.00' 8.0" Round Culvert L= 62.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0081 T Cc= 0.900 n=0.013, Flow Area= 0.35 sf #4 Device 3 227.28' 8.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.00 cfs @ 12.26 hrs HW= 227.49' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.67 cfs @ 12.26 hrs HW= 227.49' (Free Discharge) L3= Culvert (Passes 0.67 cfs of 1.94 cfs potential flow) L4= Orifice /Grate (Weir Controls 0.67 cfs @ 1.51 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 227.00' (Free Discharge) 't--1 =Broad-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond INF1: U/G INF. Inflow Area = 7,577 sf, 100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.47 cfs @ 12.07 hrs, Volume= 1,622 cf Outflow = 0.04 cfs @ 12.20 hrs, Volume= 1,622 cf, Atten= 92 %, Lag= 7.8 min Discarded = 0.04 cfs @ 12.20 hrs, Volume= 1,622 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 15 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.20' @ 13.10 hrs Surf.Area= 1,509 sf Storage= 698 cf Flood Elev= 239.50' Surf.Area= 2,085 sf Storage= 3,269 cf Plug -Flow detention time= 200.6 min calculated for 1,621 cf (100% of inflow) Center -of -Mass det. time= 200.6 min ( 959.0 - 758.4 ) Volume Invert Avail.Storage Storage Description #1A 234.00' 279 cf 21.50'W x 17.44'L x 2.33'H Field A 875 cf Overall - 177 cf Embedded = 698 cf x 40.0% Voids #2A 234.50' 177 cf ADS_StormTech SC -310 +Cap x 12 Inside #1 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.121 = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 6 Rows of 2 Chambers #313 234.00' 102 cf 11.34'W x 18.00'L x 3.17'H Field B 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #413 234.50' 267 cf Concrete Dry Well 500gal x 4 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 2 Chambers #5C 234.00' 176 cf 11.34'W x 34.00'L x 3.17'H Field C 1,222 cf Overall - 783 cf Embedded = 439 cf x 40.0% Voids #6C 234.50' 534 cf Concrete Dry Well 500gal x 8 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 4 Chambers #7D 235.00' 220 cf 16.01'W x 34.00'L x 3.17'H Field D 1,726 cf Overall - 1,175 cf Embedded = 551 cf x 40.0% Voids #8D 235.50' 800 cf Concrete Dry Well 500gal x 12 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 4 Chambers #9E 236.00' 419 cf 18.17'W x 31.68'L x 2.33'H Field E 1,343 cf Overall - 295 cf Embedded = 1,048 cf x 40.0% Voids #10E 236.50' 295 cf ADS _StormTech SC -310 +Cap x 20 Inside #9 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.121 = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 5 Rows of 4 Chambers 3,269 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Storage Group E created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 234.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 239.50' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 16 Discarded OutFlow Max =0.04 cfs @ 12.20 hrs HW= 235.01' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 234.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond INF2: U/G INF. Inflow Area = 64,299 sf, 36.99% Impervious, Inflow Depth = 0.61" for 2 -Year event Inflow = 0.68 cfs @ 12.26 hrs, Volume= 3,262 cf Outflow = 0.46 cfs @ 12.65 hrs, Volume= 3,262 cf, Atten= 33 %, Lag= 23.3 min Discarded = 0.02 cfs @ 12.40 hrs, Volume= 1,678 cf Primary = 0.44 cfs @ 12.65 hrs, Volume= 1,584 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.12' @ 12.65 hrs Surf.Area= 681 sf Storage= 964 cf Plug -Flow detention time= 388.8 min calculated for 3,260 cf (100% of inflow) Center -of -Mass det. time= 389.5 min ( 1,280.4 - 890.9 ) Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 17 Volume Invert Avail.Storage Storage Description #113 227.50' 109 cf 8.17'W x 17.44'L x 2.33'H Field B 332 cf Overall - 59 cf Embedded = 273 cf x 40.0% Voids #213 228.00' 59 cf ADS_StormTech SC -310 +Cap x 4 Inside #1 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 2 Rows of 2 Chambers #3C 226.50' 45 cf 6.67'W x 10.00'L x 3.17'H Field C 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #4C 227.00' 67 cf Concrete Dry Well 500gal Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #5D 226.00' 45 cf 6.67'W x 10.00'L x 3.17'H Field D 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #6D 226.50' 67 cf Concrete Dry Well 500gal Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #7E 225.00' 78 cf 6.67'W x 18.00'L x 3.25'H Field E 391 cf Overall - 196 cf Embedded = 195 cf x 40.0% Voids #8E 225.50' 133 cf Concrete Dry Well 500gal x 2 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #9F 225.00' 67 cf 4.83'W x 17.44'L x 2.33'H Field F 197 cf Overall - 29 cf Embedded = 167 cf x 40.0% Voids #10F 225.50' 29 cf ADS _StormTech SC -310 +Cap x 2 Inside #9 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #11G 224.50' 67 cf 4.83'W x 17.44'L x 2.33'H Field G 197 cf Overall - 29 cf Embedded = 167 cf x 40.0% Voids #12G 225.00' 29 cf ADS _StormTech SC -310 +Cap x 2 Inside #11 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #13H 224.00' 41 cf 4.83'W x 10.32'L x 2.33'H Field H 116 cf Overall - 15 cf Embedded = 102 cf x 40.0% Voids #14H 224.50' 15 cf ADS _StormTech SC -310 +Cap Inside #13 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #151 224.00' 45 cf 6.67'W x 10.00'L x 3.17'H Field 1 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #161 224.50' 67 cf Concrete Dry Well 500gal Inside #15 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 964 cf Total Available Storage Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Storage Group E created with Chamber Wizard Storage Group F created with Chamber Wizard Storage Group G created with Chamber Wizard Storage Group H created with Chamber Wizard Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 18 Storage Group I created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 233.00' 12.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.02 cfs @ 12.40 hrs HW= 227.62' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =0.40 cfs @ 12.65 hrs HW= 233.11' (Free Discharge) L2= Orifice /Grate (Weir Controls 0.40 cfs @ 1.11 fps) Summary for Pond INF3: U/G INF. Inflow Area = 13,748 sf,100.00% Impervious, Inflow Depth= 2.57" for 2 -Year event Inflow = 0.86 cfs @ 12.07 hrs, Volume= 2,943 cf Outflow = 0.03 cfs @ 15.35 hrs, Volume= 2,943 cf, Atten= 96 %, Lag= 196.5 min Discarded = 0.02 cfs @ 11.80 hrs, Volume= 2,934 cf Primary = 0.01 cfs @ 15.35 hrs, Volume= 10 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 237.51' @ 15.35 hrs Surf.Area= 1,006 sf Storage= 1,854 cf Plug -Flow detention time= 734.2 min calculated for 2,941 cf (100% of inflow) Center -of -Mass det. time= 734.7 min ( 1,493.0 - 758.4 ) Volume Invert Avail.Storage Storage Description #1A 232.50' 139 cf 11.34'W x 26.00'L x 3.17'H Field A 935 cf Overall - 588 cf Embedded = 347 cf x 40.0% Voids #2A 233.00' 400 cf Concrete Dry Well 500gal x 6 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 3 Chambers #313 231.50' 175 cf 16.01'W x 26.00'L x 3.17'H Field B 1,320 cf Overall - 881 cf Embedded = 438 cf x 40.0% Voids #413 232.00' 600 cf Concrete Dry Well 500gal x 9 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 3 Chambers #5C 231.00' 139 cf 11.34'W x 26.00'L x 3.17'H Field C 935 cf Overall - 588 cf Embedded = 347 cf x 40.0% Voids #6C 231.50' 400 cf Concrete Dry Well 500gal x 6 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 3 Chambers 1,854 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 19 Device Routing Invert Outlet Devices #1 Discarded 231.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 237.50' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.02 cfs @ 11.80 hrs HW= 232.55' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =0.00 cfs @ 15.35 hrs HW= 237.51' (Free Discharge) L2= Orifice /Grate (Weir Controls 0.00 cfs @ 0.26 fps) Summary for Pond INF4: U/G INF. Inflow Area = 3,261 sf, 100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.20 cfs @ 12.07 hrs, Volume= 698 cf Outflow = 0.00 cfs @ 12.15 hrs, Volume= 412 cf, Atten= 99 %, Lag= 4.8 min Discarded = 0.00 cfs @ 12.15 hrs, Volume= 412 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.96' @ 23.33 hrs Surf.Area= 943 sf Storage= 590 cf Plug -Flow detention time= 1,638.4 min calculated for 412 cf (59% of inflow) Center -of -Mass det. time= 1,529.7 min ( 2,288.0 - 758.4 ) Volume Invert Avail.Storage Storage Description #1A 225.50' 106 cf 20.68'W x 10.00'L x 3.17'H Field A 656 cf Overall - 392 cf Embedded = 264 cf x 40.0% Voids #2A 226.00' 267 cf Concrete Dry Well 500gal x 4 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 4 Rows of 1 Chambers #313 225.50' 102 cf 11.34'W x 18.00'L x 3.17'H Field B 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #413 226.00' 267 cf Concrete Dry Well 500gal x 4 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 2 Chambers #5C 224.50' 159 cf 20.68'W x 18.00'L x 3.17'H Field C 1,180 cf Overall - 783 cf Embedded = 397 cf x 40.0% Voids #6C 225.00' 534 cf Concrete Dry Well 500gal x 8 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 4 Rows of 2 Chambers #7D 224.00' 86 cf 16.01'W x 10.00'L x 3.17'H Field D 508 cf Overall - 294 cf Embedded = 214 cf x 40.0% Voids #8D 224.50' 200 cf Concrete Dry Well 500gal x 3 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 1 Chambers Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 20 1,719 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.00' 0.090 in /hr Exfiltration over Surface area #2 Primary 230.00' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.00 cfs @ 12.15 hrs HW= 225.50' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 224.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.22' @ 14.19 hrs Surf.Area= 1,230 sf Storage= 944 cf Plug -Flow detention time= 276.4 min calculated for 2,022 cf (100% of inflow) Center -of -Mass det. time= 276.4 min ( 1,034.8 - 758.4 ) Volume Invert Avail.Storage Storage Description #1A 234.00' 756 cf 98.39'W x 12.50'L x 3.83'H Field A 4,710 cf Overall - 2,821 cf Embedded = 1,889 cf x 40.0% Voids #2A 234.50' 2,187 cf Concrete Dry Well 1000gal x 17 Inside #1 Inside= 62.0 "W x 30.0 "H => 12.86 sf x 10.001 = 128.6 cf Outside= 68.0 "W x 34.0 "H => 15.81 sf x 10.501 = 166.0 cf 17 Rows of 1 Chambers 2,943 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 234.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 239.00' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Summary for Pond INF5: U/G INF. Inflow Area = 9,451 sf,100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.59 cfs @ 12.07 hrs, Volume= 2,023 cf Outflow = 0.03 cfs @ 10.40 hrs, Volume= 2,023 cf, Atten= 95 %, Lag= 0.0 min Discarded = 0.03 cfs @ 10.40 hrs, Volume= 2,023 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.22' @ 14.19 hrs Surf.Area= 1,230 sf Storage= 944 cf Plug -Flow detention time= 276.4 min calculated for 2,022 cf (100% of inflow) Center -of -Mass det. time= 276.4 min ( 1,034.8 - 758.4 ) Volume Invert Avail.Storage Storage Description #1A 234.00' 756 cf 98.39'W x 12.50'L x 3.83'H Field A 4,710 cf Overall - 2,821 cf Embedded = 1,889 cf x 40.0% Voids #2A 234.50' 2,187 cf Concrete Dry Well 1000gal x 17 Inside #1 Inside= 62.0 "W x 30.0 "H => 12.86 sf x 10.001 = 128.6 cf Outside= 68.0 "W x 34.0 "H => 15.81 sf x 10.501 = 166.0 cf 17 Rows of 1 Chambers 2,943 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 234.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 239.00' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 21 Discarded OutFlow Max =0.03 cfs @ 10.40 hrs HW= 234.05' (Free Discharge) L1= Exfiltration ( Exfiltration Controls 0.03 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 234.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond P -CB1 *: Inflow Area = 10,049 sf, 70.76% Impervious, Inflow Depth = 1.57" for 2 -Year event Inflow = 0.42 cfs @ 12.08 hrs, Volume= 1,311 cf Outflow = 0.42 cfs @ 12.08 hrs, Volume= 1,311 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.42 cfs @ 12.08 hrs, Volume= 1,311 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.32' @ 12.08 hrs Flood Elev= 236.77' Device Routing Invert Outlet Devices #1 Primary 231.00' 12.0" Round Culvert L= 33.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 231.00'/230.00' S=0.0303'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.41 cfs @ 12.08 hrs HW= 231.32' (Free Discharge) L1= Culvert (Inlet Controls 0.41 cfs @ 1.91 fps) Summary for Pond P -C1132: Inflow Area = 2,252 sf, 13.54% Impervious, Inflow Depth= 0.45" for 2 -Year event Inflow = 0.02 cfs @ 12.11 hrs, Volume= 85 cf Outflow = 0.02 cfs @ 12.11 hrs, Volume= 85 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.02 cfs @ 12.11 hrs, Volume= 85 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.08' @ 12.11 hrs Flood Elev= 229.50' Device Routing Invert Outlet Devices #1 Primary 225.00' 12.0" Round Culvert L= 82.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0061 T Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.02 cfs @ 12.11 hrs HW= 225.08' (Free Discharge) L1= Culvert (Barrel Controls 0.02 cfs @ 1.00 fps) Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 22 Summary for Pond P -C1133: Inflow Area = 41,288 sf, 74.21% Impervious, Inflow Depth = 1.04" for 2 -Year event Inflow = 1.15 cfs @ 12.08 hrs, Volume= 3,577 cf Outflow = 1.15 cfs @ 12.08 hrs, Volume= 3,577 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.15 cfs @ 12.08 hrs, Volume= 3,577 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.58' @ 12.08 hrs Flood Elev= 229.10' Device Routing Invert Outlet Devices #1 Primary 225.00' 15.0" Round Culvert L= 81.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 225.00'/224.50' S=0.0062'/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =1.12 cfs @ 12.08 hrs HW= 225.56' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.12 cfs @ 3.05 fps) Summary for Pond P -C1134: Inflow Area = 11,426 sf, 53.74% Impervious, Inflow Depth = 1.64" for 2 -Year event Inflow = 0.50 cfs @ 12.08 hrs, Volume= 1,563 cf Outflow = 0.50 cfs @ 12.08 hrs, Volume= 1,563 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.50 cfs @ 12.08 hrs, Volume= 1,563 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.08' @ 12.08 hrs Flood Elev= 229.23' Device Ro Invert Outlet Devices #1 Primary 225.70' 12.0" Round Culvert L= 96.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.70'/225.00' S=0.0073'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.49 cfs @ 12.08 hrs HW= 226.07' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.49 cfs @ 2.72 fps) Summary for Pond P -DMH2: Inflow Area = 7,577 sf, 100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.47 cfs @ 12.07 hrs, Volume= 1,622 cf Outflow = 0.47 cfs @ 12.07 hrs, Volume= 1,622 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.47 cfs @ 12.07 hrs, Volume= 1,622 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 23 Peak Elev= 237.84' @ 12.07 hrs Flood Elev= 242.00' Device Routing Invert Outlet Devices #1 Primary 237.50' 12.0" Round Culvert L= 36.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 237.50'/237.00' S=0.0139'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.46 cfs @ 12.07 hrs HW= 237.84' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.46 cfs @ 1.97 fps) Summary for Pond P -DMH3: Inflow Area = 3,261 sf,100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.20 cfs @ 12.07 hrs, Volume= 698 cf Outflow = 0.20 cfs @ 12.07 hrs, Volume= 698 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.20 cfs @ 12.07 hrs, Volume= 698 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.74' @ 12.07 hrs Flood Elev= 230.50' Device Routing Invert Outlet Devices #1 Primary 227.50' 12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.50'/227.40' S=0.0125'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.20 cfs @ 12.07 hrs HW= 227.73' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.20 cfs @ 2.12 fps) Summary for Pond P -DMH4: Inflow Area = 13,748 sf,100.00% Impervious, Inflow Depth= 2.57" for 2 -Year event Inflow = 0.86 cfs @ 12.07 hrs, Volume= 2,943 cf Outflow = 0.86 cfs @ 12.07 hrs, Volume= 2,943 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.86 cfs @ 12.07 hrs, Volume= 2,943 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 234.87' @ 12.07 hrs Flood Elev= 239.00' Device Routing Invert Outlet Devices #1 Primary 234.40' 12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 234.40'/234.00' S=0.0500'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 24 Primary OutFlow Max =0.83 cfs @ 12.07 hrs HW= 234.86' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.83 cfs @ 2.32 fps) Summary for Pond P -DMH5: Inflow Area = 9,451 sf,100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.59 cfs @ 12.07 hrs, Volume= 2,023 cf Outflow = 0.59 cfs @ 12.07 hrs, Volume= 2,023 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.59 cfs @ 12.07 hrs, Volume= 2,023 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 238.39' @ 12.07 hrs Flood Elev= 243.80' Device Routing Invert Outlet Devices #1 Primary 238.00' 12.0" Round Culvert L= 26.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 238.00'/236.00' S=0.0769'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.57 cfs @ 12.07 hrs HW= 238.38' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.57 cfs @ 2.09 fps) Summary for Pond P. C -1: NW CULVERT Inflow Area = 28,591 sf, 22.20% Impervious, Inflow Depth = 0.53" for 2 -Year event Inflow = 0.32 cfs @ 12.10 hrs, Volume= 1,254 cf Outflow = 0.32 cfs @ 12.10 hrs, Volume= 1,254 cf, Atten= 0 %, Lag= 0.0 min Discarded = 0.00 cfs @ 12.10 hrs, Volume= 0 cf Primary = 0.32 cfs @ 12.10 hrs, Volume= 1,254 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.01' @ 12.10 hrs Surf.Area= 51 sf Storage= 0 cf Plug -Flow detention time= 0.0 min calculated for 1,253 cf (100% of inflow) Center -of -Mass det. time= 0.0 min ( 894.3 - 894.3 ) Volume Invert Avail.Storage Storage Description #1 236.00' 777 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 236.00 51 31.0 0 0 51 237.00 145 57.0 94 94 238 238.00 334 86.0 233 327 576 239.00 576 117.0 450 777 1,087 Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 25 Device Routing Invert Outlet Devices #1 Primary 235.40' 12.0" Round Culvert L= 100.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 235.40'/234.40' S=0.0100'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Discarded 236.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 12.10 hrs HW= 236.01' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =1.32 cfs @ 12.10 hrs HW= 236.01' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.32 cfs @ 2.65 fps) Summary for Pond P. P -1: OFF -SITE DEPRESSION Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow = 22.14 cfs @ 12.12 hrs, Volume= Outflow = 0.65 cfs @ 23.43 hrs, Volume= Discarded = 0.29 cfs @ 23.43 hrs, Volume= Primary = 0.35 cfs @ 23.43 hrs, Volume= Secondary = 0.00 cfs @ 0.00 hrs, Volume= Tertiary = 0.00 cfs @ 0.00 hrs, Volume= Inflow Depth = 0.49" for 2 -Year event 94,524 cf 82,897 cf, 35,334 cf 47,563 cf 0 cf 0 cf Atten= 97 %, Lag= 678.6 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.31' @ 23.43 hrs Surf.Area= 140,531 sf Storage= 70,266 cf Plug -Flow detention time= 1,282.3 min calculated for 82,897 cf (88% of inflow) Center -of -Mass det. time= 1,225.1 min ( 2,125.5 - 900.4 ) Volume Invert #1 219.00' MV01 e Description 1,815,231 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 219.00 0 0 0 220.00 452,595 226,298 226,298 221.00 508,615 480,605 706,903 222.00 557,476 533,046 1,239,948 223.00 593,089 575,283 1,815,231 Device Routing Invert Outlet Devices #1 Primary 218.80' 18.0" W x 18.0" H Box Exist. Culvert X 0.20 L= 16.0' RCP, end - section conforming to fill, Ke= 0.500 Inlet/ Outlet Invert= 218.80'/218.60' S=0.0125'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 2.25 sf #2 Secondary 221.80' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 9.00 11.00 20.00 Height (feet) 1.20 0.00 0.00 1.20 #3 Discarded 219.00' 0.090 in /hr Exfiltration over Surface area #4 Tertiary 222.00' 384.0" W x 72.0" H, R= 384.0" Arch Prop. Culvert L= 55.0' Box, headwall w/3 square edges, Ke= 0.500 Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 26 Inlet/ Outlet Invert= 222.00'/222.00' S=0.0000'/' Cc= 0.900 n=0.025 Corrugated metal, Flow Area= 147.57 sf Discarded OutFlow Max =0.29 cfs @ 23.43 hrs HW= 219.31' (Free Discharge) L3= Exfiltration ( Exfiltration Controls 0.29 cfs) Primary OutFlow Max =0.35 cfs @ 23.43 hrs HW= 219.31' (Free Discharge) 't--1 =Exist. Culvert (Inlet Controls 0.35 cfs @ 0.46 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L2= Asymmetrical Weir ( Controls 0.00 cfs) Tertiary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L4 =Prop. Culvert ( Controls 0.00 cfs) Summary for Link 1 L: Pre AP1 Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 0.38" for 2 -Year event Inflow = 9.87 cfs @ 12.18 hrs, Volume= 90,667 cf Primary = 9.87 cfs @ 12.18 hrs, Volume= 90,667 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 2 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP1.hce Summary for Link 2L: Pre AP2 Inflow Area = 341,168 sf, 43.52% Impervious, Inflow Depth = 1.26" for 2 -Year event Inflow = 9.35 cfs @ 12.13 hrs, Volume= 35,940 cf Primary = 9.35 cfs @ 12.13 hrs, Volume= 35,940 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 2 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP2.hce Summary for Link 3L: Pre AP3 Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth > 0.25" for 2 -Year event Inflow = 0.35 cfs @ 23.45 hrs, Volume= 48,433 cf Primary = 0.35 cfs @ 23.45 hrs, Volume= 48,433 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 2 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP3.hce Brookhaven, Lexington, MA 151067 2017 POST Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 27 Summary for Link AP1: Inflow Area = 2,840,536 sf, 21.06% Impervious, Inflow Depth > 0.41" for 2 -Year event Inflow = 7.35 cfs @ 12.33 hrs, Volume= 96,746 cf Primary = 7.35 cfs @ 12.33 hrs, Volume= 96,746 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Summary for Link AP2: FROM "POST AP2" Inflow Area = 347,640 sf, 57.70% Impervious, Inflow Depth= 1.38" for 2 -Year event Inflow = 6.38 cfs @ 12.28 hrs, Volume= 40,040 cf Primary = 6.38 cfs @ 12.28 hrs, Volume= 40,040 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 2 -Year Primary Outflow Imported from 151067 2017 POST AP2-Link AP2.hce Summary for Link AP3: Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow Depth > 0.24" for 2 -Year event Inflow = 0.35 cfs @ 23.43 hrs, Volume= 47,563 cf Primary = 0.35 cfs @ 23.43 hrs, Volume= 47,563 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 28 Summary for Subcatchment P. SC -1: Runoff = 0.78 cfs @ 12.07 hrs, Volume= 2,440 cf, Depth= 2.91" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 2,938 61 >75% Grass cover, Good, HSG B 7,111 98 Paved parking, HSG B 10,049 87 Weighted Average 2,938 29.24% Pervious Area 7,111 70.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -2: Runoff = 0.07 cfs @ 12.09 hrs, Volume= 238 cf, Depth= 1.27" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 1,947 61 >75% Grass cover, Good, HSG B 305 98 Paved parking, HSG B 2,252 66 Weighted Average 1,947 86.46% Pervious Area 305 13.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -3: Runoff = 1.22 cfs @ 12.07 hrs, Volume= 3,786 cf, Depth= 2.82" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 29 Area (so CN Description 5,364 61 >75% Grass cover, Good, HSG B 992 98 Paved parking, HSG D 9,758 98 Paved parking, HSG B 16,114 86 Weighted Average 5,364 88 33.29% Pervious Area 10,750 66.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment P. SC -4: Runoff = 0.92 cfs @ 12.07 hrs, Volume= 2,865 cf, Depth= 3.01" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 841 61 >75% Grass cover, Good, HSG B 4,445 80 >75% Grass cover, Good, HSG D 1,472 98 Paved parking, HSG B 4,668 98 Paved parking, HSG D 11,426 88 Weighted Average 5,286 46.26% Pervious Area 6,140 53.74% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C3: Runoff = 2.91 cfs @ 12.08 hrs, Volume= 8,999 cf, Depth= 2.21" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 26,830 80 >75% Grass cover, Good, HSG D 22.040 77 Woods. Good. HSG D 48,870 79 Weighted Average 48,870 100.00% Pervious Area Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 30 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -D: Runoff = 75.83 cfs @ 12.11 hrs, Volume= 257,934 cf, Depth= 1.33" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 10,561 61 >75% Grass cover, Good, HSG B 3,835 80 >75% Grass cover, Good, HSG D 167,851 98 Paved parking, HSG B 102,329 98 Paved parking, HSG D 55,279 98 Paved parking, HSG A 624,368 55 Woods, Good, HSG B 1,005,091 77 Woods, Good, HSG D 347,789 30 Woods, Good, HSG A 3,953 98 Ledge, HSG B 2,321,056 67 Weighted Average 1,991,644 57 85.81 % Pervious Area 329,412 Shallow Concentrated Flow, 14.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 3.1 30 0.0330 0.16 Sheet Flow, Grass: Short n= 0.150 P2= 3.16" 0.3 118 0.2550 7.57 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.3 57 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.0 705 0.0850 5.92 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 165 0.0480 3.29 Shallow Concentrated Flow, Grassed Waterwav Kv= 15.0 fps 6.5 1,075 Total Summary for Subcatchment P. SC -FBE: Runoff = 0.17 cfs @ 12.08 hrs, Volume= 532 cf, Depth= 2.64" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 31 Area (so CN Description 362 61 >75% Grass cover, Good, HSG B 1,176 80 >75% Grass cover, Good, HSG D 881 98 Paved parking, HSG D 2,419 84 Weighted Average 1,538 72 63.58% Pervious Area 881 68 36.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment P. SC -FBW: Runoff = 0.26 cfs @ 12.08 hrs, Volume= 827 cf, Depth= 1.67" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 3,310 61 >75% Grass cover, Good, HSG B 1,761 80 >75% Grass cover, Good, HSG D 569 98 Paved parking, HSG B 286 98 Paved parking, HSG D 5,926 72 Weighted Average 5,071 68 85.57% Pervious Area 855 14.43% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -NWC: Runoff = 1.03 cfs @ 12.09 hrs, Volume= 3,333 cf, Depth= 1.40" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 6,262 61 >75% Grass cover, Good, HSG B 5,092 98 Paved parking, HSG B 609 98 Paved parking, HSG D 13,499 55 Woods, Good, HSG B 2,482 77 Woods, Good, HSG D 647 98 Ledge, HSG B 28,591 68 Weighted Average 22,243 77.80% Pervious Area 6,348 22.20% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 32 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -P: Runoff = 0.72 cfs @ 12.08 hrs, Volume= 2,238 cf, Depth= 2.21" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 2,294 61 >75% Grass cover, Good, HSG B 7,969 80 >75% Grass cover, Good, HSG D 667 98 Paved parking, HSG B 1,226 98 Paved parking, HSG D 12,156 79 Weighted Average 10,263 84.43% Pervious Area 1,893 15.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R4: Runoff = 1.33 cfs @ 12.07 hrs, Volume= 4,656 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 13,748 98 Roofs, HSG B 13,748 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R5: Runoff = 0.74 cfs @ 12.07 hrs, Volume= 2,566 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 33 Area (so CN Description 7,577 98 Roofs, HSG B 7,577 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R6: Runoff = 0.48 cfs @ 12.07 hrs, Volume= 1,667 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 4,922 98 Roofs, HSG B 4,922 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R7: Runoff = 0.32 cfs @ 12.07 hrs, Volume= 1,105 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 3,261 98 Roofs, HSG B 3,261 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R8: Runoff = 0.44 cfs @ 12.07 hrs, Volume= 1,534 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 34 Area (so CN Description 4,529 98 Roofs, HSG B 4,529 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Reach R1: Inflow Area = 2,840,536 sf, 21.06% Impervious, Inflow Depth > 0.94" for 10 -Year event Inflow = 18.29 cfs @ 12.16 hrs, Volume= 221,945 cf Outflow = 17.91 cfs @ 12.20 hrs, Volume= 221,728 cf, Atten= 2 %, Lag= 2.8 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 1.72 fps, Min. Travel Time= 3.1 min Avg. Velocity = 0.49 fps, Avg. Travel Time= 11.0 min Peak Storage= 3,372 cf @ 12.20 hrs Average Depth at Peak Storage= 0.77' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 56.94 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 324.0' Slope= 0.00287' Inlet Invert= 218.80', Outlet Invert= 217.90' Summary for Reach R2: Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow Depth > 0.62" for 10 -Year event Inflow = 0.97 cfs @ 20.89 hrs, Volume= 120,614 cf Outflow = 0.97 cfs @ 20.97 hrs, Volume= 120,425 cf, Atten= 0 %, Lag= 5.0 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 0.42 fps, Min. Travel Time= 8.2 min Avg. Velocity = 0.33 fps, Avg. Travel Time= 10.5 min Peak Storage= 474 cf @ 20.97 hrs Average Depth at Peak Storage= 0.19' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 33.66 cfs Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 35 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 206.0' Slope= 0.0010 '/' Inlet Invert= 219.00', Outlet Invert= 218.80' Summary for Reach R3: WEST SWALE Inflow Area = 36,168 sf, 38.50% Impervious, Inflow Depth = 1.11" for 10 -Year event Inflow = 1.03 cfs @ 12.09 hrs, Volume= 3,333 cf Outflow = 1.03 cfs @ 12.09 hrs, Volume= 3,333 cf, Atten= 0 %, Lag= 0.4 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 2.53 fps, Min. Travel Time= 0.4 min Avg. Velocity = 1.13 fps, Avg. Travel Time= 1.0 min Peak Storage= 27 cf @ 12.09 hrs Average Depth at Peak Storage= 0.37' Bank -Full Depth= 1.00' Flow Area= 3.0 sf, Capacity= 14.77 cfs 0.00' x 1.00' deep channel, n= 0.035 Side Slope Z- value= 3.07' Top Width= 6.00' Length= 66.0' Slope= 0.03647' Inlet Invert= 234.40', Outlet Invert= 232.00' Summary for Pond EX. C -1: D/W MAIN CULVERT Inflow Area = 2,840,536 sf, 21.06% Impervious, Inflow Depth > 0.94" for 10 -Year event Inflow = 17.91 cfs @ 12.20 hrs, Volume= 221,728 cf Outflow = 17.92 cfs @ 12.21 hrs, Volume= 221,670 cf, Atten= 0 %, Lag= 0.2 min Primary = 17.92 cfs @ 12.21 hrs, Volume= 221,670 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 217.15' @ 12.21 hrs Surf.Area= 0 sf Storage= 355 cf Plug -Flow detention time= 1.4 min calculated for 221,670 cf (100% of inflow) Center -of -Mass det. time= 0.7 min ( 1,518.2 - 1,517.6 ) Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 36 Volume Invert Avail.Storage Storage Description #1 215.94' 1,029 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 215.94 0 219.44 1,029 Device Routing Invert Outlet Devices #1 Primary 216.08' 72.0" W x 42.0" H Box Culvert L= 49.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 216.08'/215.94' S=0.0029'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 21.00 sf Primary OutFlow Max =17.85 cfs @ 12.21 hrs HW= 217.14' (Free Discharge) 't--1 =Culvert (Barrel Controls 17.85 cfs @ 3.73 fps) Summary for Pond FBE: FB EAST Inflow Area = 45,959 sf, 69.24% Impervious, Inflow Depth = 2.31" for 10 -Year event Inflow = 3.28 cfs @ 12.14 hrs, Volume= 8,846 cf Outflow = 3.16 cfs @ 12.14 hrs, Volume= 8,698 cf, Atten= 3 %, Lag= 0.0 min Discarded = 0.00 cfs @ 12.05 hrs, Volume= 108 cf Primary = 3.16 cfs @ 12.14 hrs, Volume= 8,589 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.20' @ 12.14 hrs Surf.Area= 350 sf Storage= 375 cf Flood Elev= 227.00' Surf.Area= 350 sf Storage= 375 cf Plug -Flow detention time= 37.3 min calculated for 8,698 cf (98% of inflow) Center -of -Mass det. time= 27.2 min ( 831.7 - 804.4 ) Volume Invert Avail.Storage Storage Description #1 224.00' 375 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 224.00 0 0 0 225.00 50 25 25 226.00 150 100 125 227.00 350 250 375 Device Routing Invert Outlet Devices #1 Primary 226.50' 2.0' long x 10.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Discarded 224.00' 0.090 in /hr Exfiltration over Surface area Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 37 Discarded OutFlow Max =0.00 cfs @ 12.05 hrs HW= 227.05' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =2.99 cfs @ 12.14 hrs HW= 227.18' (Free Discharge) L1 =Broad -Crested Rectangular Weir(Weir Controls 2.99 cfs @ 2.22 fps) Summary for Pond FBW: FB WEST Inflow Area = 52,143 sf, 41.98% Impervious, Inflow Depth = 1.52" for 10 -Year event Inflow = 2.06 cfs @ 12.09 hrs, Volume= 6,599 cf Outflow = 1.98 cfs @ 12.11 hrs, Volume= 6,599 cf, Atten= 4 %, Lag= 1.5 min Discarded = 0.00 cfs @ 12.11 hrs, Volume= 30 cf Primary = 1.97 cfs @ 12.11 hrs, Volume= 6,569 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.78' @ 12.11 hrs Surf.Area= 382 sf Storage= 223 cf Flood Elev= 231.50' Surf.Area= 732 sf Storage= 896 cf Plug -Flow detention time= 4.4 min calculated for 6,594 cf (100% of inflow) Center -of -Mass det. time= 4.4 min ( 844.0 - 839.6 ) Volume Invert Avail.Storage Storage Description #1 229.00' 896 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 229.00 199 54.0 0 0 199 230.00 445 84.0 314 314 536 231.00 732 108.0 583 896 915 Device Routing Invert Outlet Devices #1 Primary 229.00' 12.0" Round Culvert L= 31.0' CMP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 229.00'/227.00' S=0.0645'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Secondary 230.00' 3.0' long x 13.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.60 2.64 2.70 2.66 2.65 2.66 2.65 2.63 #3 Discarded 229.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 12.11 hrs HW= 229.77' (Free Discharge) L3= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =1.93 cfs @ 12.11 hrs HW= 229.77' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.93 cfs @ 2.98 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 229.00' (Free Discharge) L2= Broad -Crested Rectangular Weir( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 38 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.70' @ 12.60 hrs Surf.Area= 2,463 sf Storage= 4,367 cf Plug -Flow detention time= 55.8 min calculated for 14,971 cf (100% of inflow Center -of -Mass det. time= 55.9 min ( 887.6 - 831.7 ) Volume Invert Summary for Pond IBE: INF.BASIN E Inflow Area = 110,258 sf, 50.43% Impervious, Inflow Depth = 1.63" for 10 -Year event Inflow = 3.84 cfs @ 12.17 hrs, Volume= 14,981 cf Outflow = 1.64 cfs @ 12.60 hrs, Volume= 14,981 cf, Atten= 57 %, Lag= 26.0 min Discarded = 0.01 cfs @ 12.60 hrs, Volume= 141 cf Primary = 1.63 cfs @ 12.60 hrs, Volume= 14,840 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.70' @ 12.60 hrs Surf.Area= 2,463 sf Storage= 4,367 cf Plug -Flow detention time= 55.8 min calculated for 14,971 cf (100% of inflow Center -of -Mass det. time= 55.9 min ( 887.6 - 831.7 ) Volume Invert Avail.Storage Storage Description #1 223.00' 8,617 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 223.00 620 0 0 224.00 1,418 1,019 1,019 225.00 2,097 1,758 2,777 226.00 2,621 2,359 5,136 227.00 4,341 3,481 8,617 Device Routing Invert Outlet Devices #1 Primary 223.00' 15.0" Round BASIN OUTLET CULVERT L= 30.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 223.00'/222.60' S=0.0133'/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf #2 Device 1 223.00' 4.0" Vert. LOW FLOW ORIFICE C= 0.600 #3 Device 1 225.25' 12.0" W x 12.0" H Vert. WEIR NOTCH C= 0.600 #4 Device 1 226.25' 48.0" Horiz. SPILLWAY C= 0.600 Limited to weir flow at low heads #5 Discarded 223.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.01 cfs @ 12.60 hrs HW= 225.70' (Free Discharge) T 5= Exfiltration ( Exfiltration Controls 0.01 cfs) Primary OutFlow Max =1.63 cfs @ 12.60 hrs HW= 225.70' (Free Discharge) L1 =BASIN OUTLET CULVERT (Passes 1.63 cfs of 8.51 cfs potential flow) 12 =LOW FLOW ORIFICE (Orifice Controls 0.67 cfs @ 7.66 fps) 3 =WEIR NOTCH (Orifice Controls 0.96 cfs @ 2.15 fps) 4=SPILLWAY ( Controls 0.00 cfs) Summary for Pond IBW: INF. BASIN W Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 39 Inflow Area = 64,299 sf, 36.99% Impervious, Inflow Depth = 1.64" for 10 -Year event Inflow = 2.67 cfs @ 12.10 hrs, Volume= 8,807 cf Outflow = 1.38 cfs @ 12.28 hrs, Volume= 8,807 cf, Atten= 48 %, Lag= 10.4 min Discarded = 0.00 cfs @ 12.28 hrs, Volume= 703 cf Primary = 1.37 cfs @ 12.28 hrs, Volume= 8,104 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.95' @ 12.28 hrs Surf.Area= 2,188 sf Storage= 1,794 cf Plug -Flow detention time= 119.3 min calculated for 8,801 cf (100% of inflow) Center -of -Mass det. time= 121.0 min ( 961.2 - 840.2 ) Volume Invert Avail.Storage Storage Description #1 227.00' 4,452 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 227.00 1,607 0 0 228.00 2,221 1,914 1,914 229.00 2,854 2,538 4,452 Device Ro Invert Outlet Devices #1 Secondary 228.00' 2.0' long x 20.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 #2 Discarded 227.00' 0.090 in /hr Exfiltration over Surface area #3 Primary 225.00' 8.0" Round Culvert L= 62.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0081 T Cc= 0.900 n=0.013, Flow Area= 0.35 sf #4 Device 3 227.28' 8.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.00 cfs @ 12.28 hrs HW= 227.94' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =1.37 cfs @ 12.28 hrs HW= 227.94' (Free Discharge) L3= Culvert (Passes 1.37 cfs of 2.12 cfs potential flow) L4= Orifice /Grate (Orifice Controls 1.37 cfs @ 3.92 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 227.00' (Free Discharge) 't--1 =Broad-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond INF1: U/G INF. Inflow Area = 7,577 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.74 cfs @ 12.07 hrs, Volume= 2,566 cf Outflow = 0.04 cfs @ 12.00 hrs, Volume= 2,566 cf, Atten= 95 %, Lag= 0.0 min Discarded = 0.04 cfs @ 12.00 hrs, Volume= 2,566 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 40 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.85' @ 14.22 hrs Surf.Area= 1,509 sf Storage= 1,296 cf Flood Elev= 239.50' Surf.Area= 2,085 sf Storage= 3,269 cf Plug -Flow detention time= 336.7 min calculated for 2,565 cf (100% of inflow) Center -of -Mass det. time= 336.7 min ( 1,086.4 - 749.7 ) Volume Invert Avail.Storage Storage Description #1A 234.00' 279 cf 21.50'W x 17.44'L x 2.33'H Field A 875 cf Overall - 177 cf Embedded = 698 cf x 40.0% Voids #2A 234.50' 177 cf ADS_StormTech SC -310 +Cap x 12 Inside #1 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.121 = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 6 Rows of 2 Chambers #313 234.00' 102 cf 11.34'W x 18.00'L x 3.17'H Field B 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #413 234.50' 267 cf Concrete Dry Well 500gal x 4 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 2 Chambers #5C 234.00' 176 cf 11.34'W x 34.00'L x 3.17'H Field C 1,222 cf Overall - 783 cf Embedded = 439 cf x 40.0% Voids #6C 234.50' 534 cf Concrete Dry Well 500gal x 8 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 4 Chambers #7D 235.00' 220 cf 16.01'W x 34.00'L x 3.17'H Field D 1,726 cf Overall - 1,175 cf Embedded = 551 cf x 40.0% Voids #8D 235.50' 800 cf Concrete Dry Well 500gal x 12 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 4 Chambers #9E 236.00' 419 cf 18.17'W x 31.68'L x 2.33'H Field E 1,343 cf Overall - 295 cf Embedded = 1,048 cf x 40.0% Voids #10E 236.50' 295 cf ADS _StormTech SC -310 +Cap x 20 Inside #9 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.121 = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 5 Rows of 4 Chambers 3,269 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Storage Group E created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 234.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 239.50' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 41 Discarded OutFlow Max =0.04 cfs @ 12.00 hrs HW= 235.02' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 234.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond INF2: U/G INF. Inflow Area = 64,299 sf, 36.99% Impervious, Inflow Depth = 1.51" for 10 -Year event Inflow = 1.37 cfs @ 12.28 hrs, Volume= 8,104 cf Outflow = 2.04 cfs @ 12.30 hrs, Volume= 8,104 cf, Atten= 0 %, Lag= 1.4 min Discarded = 0.02 cfs @ 12.10 hrs, Volume= 1,712 cf Primary = 2.02 cfs @ 12.30 hrs, Volume= 6,392 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.34' @ 12.30 hrs Surf.Area= 681 sf Storage= 964 cf Plug -Flow detention time= 160.0 min calculated for 8,098 cf (100% of inflow) Center -of -Mass det. time= 160.9 min ( 1,023.1 - 862.1 ) Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 42 Volume Invert Avail.Storage Storage Description #113 227.50' 109 cf 8.17'W x 17.44'L x 2.33'H Field B 332 cf Overall - 59 cf Embedded = 273 cf x 40.0% Voids #213 228.00' 59 cf ADS_StormTech SC -310 +Cap x 4 Inside #1 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 2 Rows of 2 Chambers #3C 226.50' 45 cf 6.67'W x 10.00'L x 3.17'H Field C 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #4C 227.00' 67 cf Concrete Dry Well 500gal Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #5D 226.00' 45 cf 6.67'W x 10.00'L x 3.17'H Field D 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #6D 226.50' 67 cf Concrete Dry Well 500gal Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #7E 225.00' 78 cf 6.67'W x 18.00'L x 3.25'H Field E 391 cf Overall - 196 cf Embedded = 195 cf x 40.0% Voids #8E 225.50' 133 cf Concrete Dry Well 500gal x 2 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #9F 225.00' 67 cf 4.83'W x 17.44'L x 2.33'H Field F 197 cf Overall - 29 cf Embedded = 167 cf x 40.0% Voids #10F 225.50' 29 cf ADS _StormTech SC -310 +Cap x 2 Inside #9 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #11G 224.50' 67 cf 4.83'W x 17.44'L x 2.33'H Field G 197 cf Overall - 29 cf Embedded = 167 cf x 40.0% Voids #12G 225.00' 29 cf ADS _StormTech SC -310 +Cap x 2 Inside #11 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #13H 224.00' 41 cf 4.83'W x 10.32'L x 2.33'H Field H 116 cf Overall - 15 cf Embedded = 102 cf x 40.0% Voids #14H 224.50' 15 cf ADS _StormTech SC -310 +Cap Inside #13 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #151 224.00' 45 cf 6.67'W x 10.00'L x 3.17'H Field 1 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #161 224.50' 67 cf Concrete Dry Well 500gal Inside #15 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 964 cf Total Available Storage Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Storage Group E created with Chamber Wizard Storage Group F created with Chamber Wizard Storage Group G created with Chamber Wizard Storage Group H created with Chamber Wizard Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 43 Storage Group I created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 233.00' 12.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.02 cfs @ 12.10 hrs HW= 228.41' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =2.01 cfs @ 12.30 hrs HW= 233.34' (Free Discharge) L2= Orifice /Grate (Weir Controls 2.01 cfs @ 1.90 fps) Summary for Pond INF3: U/G INF. Inflow Area = 13,748 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 1.33 cfs @ 12.07 hrs, Volume= 4,656 cf Outflow = 1.56 cfs @ 12.15 hrs, Volume= 4,656 cf, Atten= 0 %, Lag= 4.8 min Discarded = 0.02 cfs @ 10.80 hrs, Volume= 3,231 cf Primary = 1.53 cfs @ 12.15 hrs, Volume= 1,426 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 240.23' @ 12.16 hrs Surf.Area= 1,006 sf Storage= 1,854 cf Plug -Flow detention time= 530.9 min calculated for 4,653 cf (100% of inflow) Center -of -Mass det. time= 531.6 min ( 1,281.3 - 749.7 ) Volume Invert Avail.Storage Storage Description #1A 232.50' 139 cf 11.34'W x 26.00'L x 3.17'H Field A 935 cf Overall - 588 cf Embedded = 347 cf x 40.0% Voids #2A 233.00' 400 cf Concrete Dry Well 500gal x 6 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 3 Chambers #313 231.50' 175 cf 16.01'W x 26.00'L x 3.17'H Field B 1,320 cf Overall - 881 cf Embedded = 438 cf x 40.0% Voids #413 232.00' 600 cf Concrete Dry Well 500gal x 9 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 3 Chambers #5C 231.00' 139 cf 11.34'W x 26.00'L x 3.17'H Field C 935 cf Overall - 588 cf Embedded = 347 cf x 40.0% Voids #6C 231.50' 400 cf Concrete Dry Well 500gal x 6 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 3 Chambers 1,854 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 44 Device Routing Invert Outlet Devices #1 Discarded 231.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 237.50' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.02 cfs @ 10.80 hrs HW= 232.51' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =1.53 cfs @ 12.15 hrs HW= 240.13' (Free Discharge) L2= Orifice /Grate (Orifice Controls 1.53 cfs @ 7.81 fps) Summary for Pond INF4: U/G INF. Inflow Area = 3,261 sf, 100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.32 cfs @ 12.07 hrs, Volume= 1,105 cf Outflow = 0.00 cfs @ 11.90 hrs, Volume= 455 cf, Atten= 99 %, Lag= 0.0 min Discarded = 0.00 cfs @ 11.90 hrs, Volume= 455 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.59' @ 24.05 hrs Surf.Area= 943 sf Storage= 989 cf Plug -Flow detention time= 1,786.5 min calculated for 455 cf (41 % of inflow) Center -of -Mass det. time= 1,636.6 min ( 2,386.3 - 749.7 ) Volume Invert Avail.Storage Storage Description #1A 225.50' 106 cf 20.68'W x 10.00'L x 3.17'H Field A 656 cf Overall - 392 cf Embedded = 264 cf x 40.0% Voids #2A 226.00' 267 cf Concrete Dry Well 500gal x 4 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 4 Rows of 1 Chambers #313 225.50' 102 cf 11.34'W x 18.00'L x 3.17'H Field B 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #413 226.00' 267 cf Concrete Dry Well 500gal x 4 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 2 Chambers #5C 224.50' 159 cf 20.68'W x 18.00'L x 3.17'H Field C 1,180 cf Overall - 783 cf Embedded = 397 cf x 40.0% Voids #6C 225.00' 534 cf Concrete Dry Well 500gal x 8 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 4 Rows of 2 Chambers #7D 224.00' 86 cf 16.01'W x 10.00'L x 3.17'H Field D 508 cf Overall - 294 cf Embedded = 214 cf x 40.0% Voids #8D 224.50' 200 cf Concrete Dry Well 500gal x 3 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 1 Chambers Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 45 1,719 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.00' 0.090 in /hr Exfiltration over Surface area #2 Primary 230.00' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.00 cfs @ 11.90 hrs HW= 225.53' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 224.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond INF5: U/G INF. Inflow Area = 9,451 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.92 cfs @ 12.07 hrs, Volume= 3,201 cf Outflow = 0.03 cfs @ 9.00 hrs, Volume= 3,201 cf, Atten= 97 %, Lag= 0.0 min Discarded = 0.03 cfs @ 9.00 hrs, Volume= 3,201 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.07' @ 15.65 hrs Surf.Area= 1,230 sf Storage= 1,771 cf Plug -Flow detention time= 526.3 min calculated for 3,199 cf (100% of inflow) Center -of -Mass det. time= 526.5 min ( 1,276.2 - 749.7 ) Volume Invert Avail.Storage Storage Description #1A 234.00' 756 cf 98.39'W x 12.50'L x 3.83'H Field A 4,710 cf Overall - 2,821 cf Embedded = 1,889 cf x 40.0% Voids #2A 234.50' 2,187 cf Concrete Dry Well 1000gal x 17 Inside #1 Inside= 62.0 "W x 30.0 "H => 12.86 sf x 10.001 = 128.6 cf Outside= 68.0 "W x 34.0 "H => 15.81 sf x 10.501 = 166.0 cf 17 Rows of 1 Chambers 2,943 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 234.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 239.00' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 46 Discarded OutFlow Max =0.03 cfs @ 9.00 hrs HW= 234.05' (Free Discharge) L1= Exfiltration ( Exfiltration Controls 0.03 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 234.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond P -CB1 *: Inflow Area = 10,049 sf, 70.76% Impervious, Inflow = 0.78 cfs @ 12.07 hrs, Volume= Outflow = 0.78 cfs @ 12.07 hrs, Volume= Primary = 0.78 cfs @ 12.07 hrs, Volume= Inflow Depth = 2,440 cf 2,440 cf, 2,440 cf 2.91" for 10 -Year event Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.45' @ 12.07 hrs Flood Elev= 236.77' Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 231.00' 12.0" Round Culvert L= 33.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 231.00'/230.00' S=0.0303'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.75 cfs @ 12.07 hrs HW= 231.44' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.75 cfs @ 2.26 fps) Summary for Pond P -C1132: Inflow Area = 2,252 sf, 13.54% Impervious, Inflow = 0.07 cfs @ 12.09 hrs, Volume= Outflow = 0.07 cfs @ 12.09 hrs, Volume= Primary = 0.07 cfs @ 12.09 hrs, Volume= Inflow Depth = 1.27" 238 cf 238 cf, 238 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.15' @ 12.09 hrs Flood Elev= 229.50' for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 225.00' 12.0" Round Culvert L= 82.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0061 T Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.07 cfs @ 12.09 hrs HW= 225.15' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.07 cfs @ 1.48 fps) Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 47 Summary for Pond P -C1133: Inflow Area = 41,288 sf, 74.21% Impervious, Inflow Depth = 2.35" for 10 -Year event Inflow = 3.09 cfs @ 12.14 hrs, Volume= 8,076 cf Outflow = 3.09 cfs @ 12.14 hrs, Volume= 8,076 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.09 cfs @ 12.14 hrs, Volume= 8,076 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.04' @ 12.14 hrs Flood Elev= 229.10' Device Routing Invert Outlet Devices #1 Primary 225.00' 15.0" Round Culvert L= 81.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 225.00'/224.50' S=0.0062'/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =2.90 cfs @ 12.14 hrs HW= 225.99' (Free Discharge) 't--1 =Culvert (Barrel Controls 2.90 cfs @ 3.79 fps) Summary for Pond P -C1134: Inflow Area = 11,426 sf, 53.74% Impervious, Inflow Depth = 3.01" for 10 -Year event Inflow = 0.92 cfs @ 12.07 hrs, Volume= 2,865 cf Outflow = 0.92 cfs @ 12.07 hrs, Volume= 2,865 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.92 cfs @ 12.07 hrs, Volume= 2,865 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.23' @ 12.07 hrs Flood Elev= 229.23' Device Ro Invert Outlet Devices #1 Primary 225.70' 12.0" Round Culvert L= 96.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.70'/225.00' S=0.0073'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.88 cfs @ 12.07 hrs HW= 226.21' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.88 cfs @ 3.16 fps) Summary for Pond P -DMH2: Inflow Area = 7,577 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.74 cfs @ 12.07 hrs, Volume= 2,566 cf Outflow = 0.74 cfs @ 12.07 hrs, Volume= 2,566 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.74 cfs @ 12.07 hrs, Volume= 2,566 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 48 Peak Elev= 237.93' @ 12.07 hrs Flood Elev= 242.00' Device Routing Invert Outlet Devices #1 Primary 237.50' 12.0" Round Culvert L= 36.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 237.50'/237.00' S=0.0139'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.71 cfs @ 12.07 hrs HW= 237.93' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.71 cfs @ 2.22 fps) Summary for Pond P -DMH3: Inflow Area = 3,261 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.32 cfs @ 12.07 hrs, Volume= 1,105 cf Outflow = 0.32 cfs @ 12.07 hrs, Volume= 1,105 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.32 cfs @ 12.07 hrs, Volume= 1,105 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.80' @ 12.07 hrs Flood Elev= 230.50' Device Routing Invert Outlet Devices #1 Primary 227.50' 12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.50'/227.40' S=0.0125'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.30 cfs @ 12.07 hrs HW= 227.80' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.30 cfs @ 2.32 fps) Summary for Pond P -DMH4: Inflow Area = 13,748 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 1.33 cfs @ 12.07 hrs, Volume= 4,656 cf Outflow = 1.33 cfs @ 12.07 hrs, Volume= 4,656 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.33 cfs @ 12.07 hrs, Volume= 4,656 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.01' @ 12.07 hrs Flood Elev= 239.00' Device Routing Invert Outlet Devices #1 Primary 234.40' 12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 234.40'/234.00' S=0.0500'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 49 Primary OutFlow Max =1.28 cfs @ 12.07 hrs HW= 235.00' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.28 cfs @ 2.63 fps) Summary for Pond P -DMH5: Inflow Area = 9,451 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.92 cfs @ 12.07 hrs, Volume= 3,201 cf Outflow = 0.92 cfs @ 12.07 hrs, Volume= 3,201 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.92 cfs @ 12.07 hrs, Volume= 3,201 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 238.49' @ 12.07 hrs Flood Elev= 243.80' Device Routing Invert Outlet Devices #1 Primary 238.00' 12.0" Round Culvert L= 26.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 238.00'/236.00' S=0.0769'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.88 cfs @ 12.07 hrs HW= 238.48' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.88 cfs @ 2.36 fps) Summary for Pond P. C -1: NW CULVERT Inflow Area = 28,591 sf, 22.20% Impervious, Inflow Depth = 1.40" for 10 -Year event Inflow = 1.03 cfs @ 12.09 hrs, Volume= 3,333 cf Outflow = 1.03 cfs @ 12.09 hrs, Volume= 3,333 cf, Atten= 0 %, Lag= 0.0 min Discarded = 0.00 cfs @ 12.09 hrs, Volume= 0 cf Primary = 1.03 cfs @ 12.09 hrs, Volume= 3,333 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.02' @ 12.09 hrs Surf.Area= 53 sf Storage= 1 cf Plug -Flow detention time= 0.0 min calculated for 3,331 cf (100% of inflow) Center -of -Mass det. time= 0.0 min ( 861.0 - 860.9 ) Volume Invert Avail.Storage Storage Description #1 236.00' 777 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 236.00 51 31.0 0 0 51 237.00 145 57.0 94 94 238 238.00 334 86.0 233 327 576 239.00 576 117.0 450 777 1,087 Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 50 Device Routing Invert Outlet Devices #1 Primary 235.40' 12.0" Round Culvert L= 100.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 235.40'/234.40' S=0.0100'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Discarded 236.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 12.09 hrs HW= 236.02' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =1.38 cfs @ 12.09 hrs HW= 236.02' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.38 cfs @ 2.68 fps) Summary for Pond P. P -1: OFF -SITE DEPRESSION Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow Depth = 1.33" for 10 -Year event Inflow = 75.83 cfs @ 12.11 hrs, Volume= 257,934 cf Outflow = 1.76 cfs @ 20.89 hrs, Volume= 219,933 cf, Atten= 98 %, Lag= 526.7 min Discarded = 0.79 cfs @ 20.89 hrs, Volume= 99,319 cf Primary = 0.97 cfs @ 20.89 hrs, Volume= 120,614 cf Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Tertiary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 219.84' @ 20.89 hrs Surf.Area= 381,547 sf Storage= 190,773 cf Plug -Flow detention time= 1,273.8 min calculated for 219,781 cf (85% of inflow) Center -of -Mass det. time= 1,209.2 min ( 2,074.4 - 865.3 ) Volume Invert #1 219.00' MV01 e Description 1,815,231 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 219.00 0 0 0 220.00 452,595 226,298 226,298 221.00 508,615 480,605 706,903 222.00 557,476 533,046 1,239,948 223.00 593,089 575,283 1,815,231 Device Routing Invert Outlet Devices #1 Primary 218.80' 18.0" W x 18.0" H Box Exist. Culvert X 0.20 L= 16.0' RCP, end - section conforming to fill, Ke= 0.500 Inlet/ Outlet Invert= 218.80'/218.60' S=0.0125'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 2.25 sf #2 Secondary 221.80' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 9.00 11.00 20.00 Height (feet) 1.20 0.00 0.00 1.20 #3 Discarded 219.00' 0.090 in /hr Exfiltration over Surface area #4 Tertiary 222.00' 384.0" W x 72.0" H, R= 384.0" Arch Prop. Culvert L= 55.0' Box, headwall w/3 square edges, Ke= 0.500 Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 51 Inlet/ Outlet Invert= 222.00'/222.00' S=0.0000'/' Cc= 0.900 n=0.025 Corrugated metal, Flow Area= 147.57 sf Discarded OutFlow Max =0.79 cfs @ 20.89 hrs HW= 219.84' (Free Discharge) L3= Exfiltration (Exfiltration Controls 0.79 cfs) Primary OutFlow Max =0.97 cfs @ 20.89 hrs HW= 219.84' (Free Discharge) L1= Exist. Culvert (Barrel Controls 0.97 cfs @ 0.83 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L2= Asymmetrical Weir ( Controls 0.00 cfs) Tertiary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L4 =Prop. Culvert ( Controls 0.00 cfs) Summary for Link 1 L: Pre AP1 Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 0.89" for 10 -Year event Inflow = 25.42 cfs @ 12.13 hrs, Volume= 209,509 cf Primary = 25.42 cfs @ 12.13 hrs, Volume= 209,509 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 10 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP1.hce Summary for Link 2L: Pre AP2 Inflow Area = 341,168 sf, 43.52% Impervious, Inflow Depth = 2.49" for 10 -Year event Inflow = 24.47 cfs @ 12.10 hrs, Volume= 70,682 cf Primary = 24.47 cfs @ 12.10 hrs, Volume= 70,682 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 10 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP2.hce Summary for Link 3L: Pre AP3 Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth > 0.62" for 10 -Year event Inflow = 0.97 cfs @ 20.89 hrs, Volume= 120,695 cf Primary = 0.97 cfs @ 20.89 hrs, Volume= 120,695 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 10 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP3.hce Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 52 Summary for Link AP1: Inflow Area = 2,840,536 sf, 21.06% Impervious, Inflow Depth > 0.94" for 10 -Year event Inflow = 17.92 cfs @ 12.21 hrs, Volume= 221,670 cf Primary = 17.92 cfs @ 12.21 hrs, Volume= 221,670 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Summary for Link AP2: FROM "POST AP2" Inflow Area = 347,640 sf, 57.70% Impervious, Inflow Depth= 2.68" for 10 -Year event Inflow = 15.66 cfs @ 12.17 hrs, Volume= 77,681 cf Primary = 15.66 cfs @ 12.17 hrs, Volume= 77,681 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 10 -Year Primary Outflow Imported from 151067 2017 POST AP2-Link AP2.hce Summary for Link AP3: Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow Depth > 0.62" for 10 -Year event Inflow = 0.97 cfs @ 20.89 hrs, Volume= 120,614 cf Primary = 0.97 cfs @ 20.89 hrs, Volume= 120,614 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 53 Summary for Subcatchment P. SC -1: Runoff = 1.55 cfs @ 12.07 hrs, Volume= 4,994 cf, Depth= 5.96" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 2,938 61 >75% Grass cover, Good, HSG B 7,111 98 Paved parking, HSG B 10,049 87 Weighted Average 2,938 29.24% Pervious Area 7,111 70.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -2: Runoff = 0.22 cfs @ 12.08 hrs, Volume= 676 cf, Depth= 3.60" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 1,947 61 >75% Grass cover, Good, HSG B 305 98 Paved parking, HSG B 2,252 66 Weighted Average 1,947 86.46% Pervious Area 305 13.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -3: Runoff = 2.46 cfs @ 12.07 hrs, Volume= 7,852 cf, Depth= 5.85" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 54 Area (so CN Description 5,364 61 >75% Grass cover, Good, HSG B 992 98 Paved parking, HSG D 9,758 98 Paved parking, HSG B 16,114 86 Weighted Average 5,364 88 33.29% Pervious Area 10,750 66.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment P. SC -4: Runoff = 1.79 cfs @ 12.07 hrs, Volume= 5,789 cf, Depth= 6.08" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 841 61 >75% Grass cover, Good, HSG B 4,445 80 >75% Grass cover, Good, HSG D 1,472 98 Paved parking, HSG B 4,668 98 Paved parking, HSG D 11,426 88 Weighted Average 5,286 46.26% Pervious Area 6,140 53.74% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C3: Runoff = 6.60 cfs @ 12.07 hrs, Volume= 20,542 cf, Depth= 5.04" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 26,830 80 >75% Grass cover, Good, HSG D 22.040 77 Woods. Good. HSG D 48,870 79 Weighted Average 48,870 100.00% Pervious Area Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 55 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -D: Runoff = 223.91 cfs @ 12.10 hrs, Volume= 717,606 cf, Depth= 3.71" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 10,561 61 >75% Grass cover, Good, HSG B 3,835 80 >75% Grass cover, Good, HSG D 167,851 98 Paved parking, HSG B 102,329 98 Paved parking, HSG D 55,279 98 Paved parking, HSG A 624,368 55 Woods, Good, HSG B 1,005,091 77 Woods, Good, HSG D 347,789 30 Woods, Good, HSG A 3,953 98 Ledge, HSG B 2,321,056 67 Weighted Average 1,991,644 57 85.81 % Pervious Area 329,412 Shallow Concentrated Flow, 14.19% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 3.1 30 0.0330 0.16 Sheet Flow, Grass: Short n= 0.150 P2= 3.16" 0.3 118 0.2550 7.57 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 0.3 57 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.0 705 0.0850 5.92 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.8 165 0.0480 3.29 Shallow Concentrated Flow, Grassed Waterwav Kv= 15.0 fps 6.5 1,075 Total Summary for Subcatchment P. SC -FBE: Runoff = 0.36 cfs @ 12.07 hrs, Volume= 1,132 cf, Depth= 5.62" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 56 Area (so CN Description 362 61 >75% Grass cover, Good, HSG B 1,176 80 >75% Grass cover, Good, HSG D 881 98 Paved parking, HSG D 2,419 84 Weighted Average 1,538 72 63.58% Pervious Area 881 68 36.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment P. SC -FBW: Runoff = 0.68 cfs @ 12.08 hrs, Volume= 2,103 cf, Depth= 4.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 3,310 61 >75% Grass cover, Good, HSG B 1,761 80 >75% Grass cover, Good, HSG D 569 98 Paved parking, HSG B 286 98 Paved parking, HSG D 5,926 72 Weighted Average 5,071 68 85.57% Pervious Area 855 14.43% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -NWC: Runoff = 2.94 cfs @ 12.08 hrs, Volume= 9,099 cf, Depth= 3.82" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 6,262 61 >75% Grass cover, Good, HSG B 5,092 98 Paved parking, HSG B 609 98 Paved parking, HSG D 13,499 55 Woods, Good, HSG B 2,482 77 Woods, Good, HSG D 647 98 Ledge, HSG B 28,591 68 Weighted Average 22,243 77.80% Pervious Area 6,348 22.20% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 57 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -P: Runoff = 1.64 cfs @ 12.07 hrs, Volume= 5,110 cf, Depth= 5.04" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 2,294 61 >75% Grass cover, Good, HSG B 7,969 80 >75% Grass cover, Good, HSG D 667 98 Paved parking, HSG B 1,226 98 Paved parking, HSG D 12,156 79 Weighted Average 10,263 84.43% Pervious Area 1,893 15.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R4: Runoff = 2.34 cfs @ 12.07 hrs, Volume= 8,318 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 13,748 98 Roofs, HSG B 13,748 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R5: Runoff = 1.29 cfs @ 12.07 hrs, Volume= 4,584 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 58 Area (so CN Description 7,577 98 Roofs, HSG B 7,577 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R6: Runoff = 0.84 cfs @ 12.07 hrs, Volume= 2,978 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 4,922 98 Roofs, HSG B 4,922 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R7: Runoff = 0.55 cfs @ 12.07 hrs, Volume= 1,973 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 3,261 98 Roofs, HSG B 3,261 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R8: Runoff = 0.77 cfs @ 12.07 hrs, Volume= 2,740 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 59 Area (so CN Description 4,529 98 Roofs, HSG B 4,529 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Reach R1: Inflow Area = 2,840,536 sf, 21.06% Impervious, Inflow Depth > 2.42" for 100 -Year event Inflow = 52.04 cfs @ 12.15 hrs, Volume= 573,443 cf Outflow = 51.06 cfs @ 12.17 hrs, Volume= 572,958 cf, Atten= 2 %, Lag= 1.5 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 2.43 fps, Min. Travel Time= 2.2 min Avg. Velocity = 0.73 fps, Avg. Travel Time= 7.4 min Peak Storage= 6,772 cf @ 12.17 hrs Average Depth at Peak Storage= 1.41' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 56.94 cfs 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 324.0' Slope= 0.00287' Inlet Invert= 218.80', Outlet Invert= 217.90' Summary for Reach R2: Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow Depth > 1.80" for 100 -Year event Inflow = 2.23 cfs @ 22.82 hrs, Volume= 350,759 cf Outflow = 2.23 cfs @ 22.88 hrs, Volume= 350,335 cf, Atten= 0 %, Lag= 3.7 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 0.58 fps, Min. Travel Time= 5.9 min Avg. Velocity = 0.49 fps, Avg. Travel Time= 7.0 min Peak Storage= 794 cf @ 22.88 hrs Average Depth at Peak Storage= 0.31' Bank -Full Depth= 1.50' Flow Area= 22.5 sf, Capacity= 33.66 cfs Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 60 12.00' x 1.50' deep channel, n= 0.035 Earth, dense weeds Side Slope Z- value= 2.07' Top Width= 18.00' Length= 206.0' Slope= 0.0010 '/' Inlet Invert= 219.00', Outlet Invert= 218.80' Summary for Reach R3: WEST SWALE Inflow Area = 36,168 sf, 38.50% Impervious, Inflow Depth= 3.02" for 100 -Year event Inflow = 2.93 cfs @ 12.09 hrs, Volume= 9,098 cf Outflow = 2.94 cfs @ 12.09 hrs, Volume= 9,098 cf, Atten= 0 %, Lag= 0.3 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Max. Velocity= 3.29 fps, Min. Travel Time= 0.3 min Avg. Velocity = 1.36 fps, Avg. Travel Time= 0.8 min Peak Storage= 59 cf @ 12.09 hrs Average Depth at Peak Storage= 0.55' Bank -Full Depth= 1.00' Flow Area= 3.0 sf, Capacity= 14.77 cfs 0.00' x 1.00' deep channel, n= 0.035 Side Slope Z- value= 3.07' Top Width= 6.00' Length= 66.0' Slope= 0.03647' Inlet Invert= 234.40', Outlet Invert= 232.00' Summary for Pond EX. C -1: D/W MAIN CULVERT Inflow Area = 2,840,536 sf, 21.06% Impervious, Inflow Depth > 2.42" for 100 -Year event Inflow = 51.06 cfs @ 12.17 hrs, Volume= 572,958 cf Outflow = 50.64 cfs @ 12.18 hrs, Volume= 572,878 cf, Atten= 1 %, Lag= 0.3 min Primary = 50.64 cfs @ 12.18 hrs, Volume= 572,878 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 218.28' @ 12.18 hrs Surf.Area= 0 sf Storage= 687 cf Plug -Flow detention time= 0.8 min calculated for 572,878 cf (100% of inflow) Center -of -Mass det. time= 0.4 min ( 1,700.8 - 1,700.4 ) Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 61 Volume Invert Avail.Storage Storage Description #1 215.94' 1,029 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 215.94 0 219.44 1,029 Device Routing Invert Outlet Devices #1 Primary 216.08' 72.0" W x 42.0" H Box Culvert L= 49.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 216.08'/215.94' S=0.0029'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 21.00 sf Primary OutFlow Max =50.08 cfs @ 12.18 hrs HW= 218.26' (Free Discharge) 't--1 =Culvert (Barrel Controls 50.08 cfs @ 5.11 fps) Summary for Pond FBE: FB EAST Inflow Area = 45,959 sf, 69.24% Impervious, Inflow Depth= 5.28" for 100 -Year event Inflow = 7.41 cfs @ 12.06 hrs, Volume= 20,214 cf Outflow = 7.12 cfs @ 12.07 hrs, Volume= 20,066 cf, Atten= 4 %, Lag= 0.6 min Discarded = 0.00 cfs @ 11.80 hrs, Volume= 114 cf Primary = 7.12 cfs @ 12.07 hrs, Volume= 19,952 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.71' @ 12.07 hrs Surf.Area= 350 sf Storage= 375 cf Flood Elev= 227.00' Surf.Area= 350 sf Storage= 375 cf Plug -Flow detention time= 16.8 min calculated for 20,052 cf (99% of inflow) Center -of -Mass det. time= 13.9 min ( 800.2 - 786.2 ) Volume Invert Avail.Storage Storage Description #1 224.00' 375 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 224.00 0 0 0 225.00 50 25 25 226.00 150 100 125 227.00 350 250 375 Device Routing Invert Outlet Devices #1 Primary 226.50' 2.0' long x 10.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #2 Discarded 224.00' 0.090 in /hr Exfiltration over Surface area Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 62 Discarded OutFlow Max =0.00 cfs @ 11.80 hrs HW= 227.05' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =6.87 cfs @ 12.07 hrs HW= 227.68' (Free Discharge) L1 =Broad -Crested Rectangular Weir(Weir Controls 6.87 cfs @ 2.92 fps) Summary for Pond FBW: FB WEST Inflow Area = 52,143 sf, 41.98% Impervious, Inflow Depth= 3.73" for 100 -Year event Inflow = 5.13 cfs @ 12.09 hrs, Volume= 16,195 cf Outflow = 5.09 cfs @ 12.11 hrs, Volume= 16,195 cf, Atten= 1 %, Lag= 1.1 min Discarded = 0.00 cfs @ 12.11 hrs, Volume= 36 cf Primary = 3.48 cfs @ 12.11 hrs, Volume= 15,465 cf Secondary = 1.61 cfs @ 12.10 hrs, Volume= 694 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.35' @ 12.11 hrs Surf.Area= 536 sf Storage= 484 cf Flood Elev= 231.50' Surf.Area= 732 sf Storage= 896 cf Plug -Flow detention time= 3.2 min calculated for 16,184 cf (100% of inflow) Center -of -Mass det. time= 3.2 min ( 819.7 - 816.5 ) Volume Invert Avail.Storage Storage Description #1 229.00' 896 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 229.00 199 54.0 0 0 199 230.00 445 84.0 314 314 536 231.00 732 108.0 583 896 915 Device Routing Invert Outlet Devices #1 Primary 229.00' 12.0" Round Culvert L= 31.0' CMP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 229.00'/227.00' S=0.0645'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Secondary 230.00' 3.0' long x 13.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.60 2.64 2.70 2.66 2.65 2.66 2.65 2.63 #3 Discarded 229.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 12.11 hrs HW= 230.34' (Free Discharge) L3= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =3.46 cfs @ 12.11 hrs HW= 230.34' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.46 cfs @ 4.41 fps) Secondary OutFlow Max =1.55 cfs @ 12.10 hrs HW= 230.34' (Free Discharge) L2= Broad -Crested Rectangular Weir (Weir Controls 1.55 cfs @ 1.53 fps) Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 63 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.50' @ 12.17 hrs Surf.Area= 3,477 sf Storage= 6,654 cf Plug -Flow detention time= 40.0 min calculated for 38,638 cf (100% of inflow Center -of -Mass det. time= 40.1 min ( 853.0 - 812.9 ) Volume Invert Summary for Pond IBE: INF.BASIN E Inflow Area = 110,258 sf, 50.43% Impervious, Inflow Depth = 4.21" for 100 -Year event Inflow = 10.42 cfs @ 12.10 hrs, Volume= 38,665 cf Outflow = 9.74 cfs @ 12.17 hrs, Volume= 38,665 cf, Atten= 7 %, Lag= 3.8 min Discarded = 0.01 cfs @ 12.17 hrs, Volume= 195 cf Primary = 9.73 cfs @ 12.17 hrs, Volume= 38,470 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.50' @ 12.17 hrs Surf.Area= 3,477 sf Storage= 6,654 cf Plug -Flow detention time= 40.0 min calculated for 38,638 cf (100% of inflow Center -of -Mass det. time= 40.1 min ( 853.0 - 812.9 ) Volume Invert Avail.Storage Storage Description #1 223.00' 8,617 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 223.00 620 0 0 224.00 1,418 1,019 1,019 225.00 2,097 1,758 2,777 226.00 2,621 2,359 5,136 227.00 4,341 3,481 8,617 Device Routing Invert Outlet Devices #1 Primary 223.00' 15.0" Round BASIN OUTLET CULVERT L= 30.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 223.00'/222.60' S=0.0133'/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf #2 Device 1 223.00' 4.0" Vert. LOW FLOW ORIFICE C= 0.600 #3 Device 1 225.25' 12.0" W x 12.0" H Vert. WEIR NOTCH C= 0.600 #4 Device 1 226.25' 48.0" Horiz. SPILLWAY C= 0.600 Limited to weir flow at low heads #5 Discarded 223.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.01 cfs @ 12.17 hrs HW= 226.49' (Free Discharge) T 5= Exfiltration ( Exfiltration Controls 0.01 cfs) Primary OutFlow Max =9.49 cfs @ 12.17 hrs HW= 226.49' (Free Discharge) L1 =BASIN OUTLET CULVERT (Passes 9.49 cfs of 9.99 cfs potential flow) 12 =LOW FLOW ORIFICE (Orifice Controls 0.77 cfs @ 8.77 fps) 3 =WEIR NOTCH (Orifice Controls 4.04 cfs @ 4.04 fps) 4=SPILLWAY (Weir Controls 4.68 cfs @ 1.59 fps) Summary for Pond IBW: INF. BASIN W Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 64 Inflow Area = 64,299 sf, 36.99% Impervious, Inflow Depth= 3.97" for 100 -Year event Inflow = 6.66 cfs @ 12.10 hrs, Volume= 21,269 cf Outflow = 4.71 cfs @ 12.19 hrs, Volume= 21,269 cf, Atten= 29 %, Lag= 5.2 min Discarded = 0.01 cfs @ 12.19 hrs, Volume= 742 cf Primary = 1.96 cfs @ 12.19 hrs, Volume= 17,258 cf Secondary = 2.74 cfs @ 12.19 hrs, Volume= 3,268 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.64' @ 12.19 hrs Surf.Area= 2,625 sf Storage= 3,461 cf Plug -Flow detention time= 58.5 min calculated for 21,254 cf (100% of inflow) Center -of -Mass det. time= 60.1 min ( 876.6 - 816.4 ) Volume Invert Avail.Storage Storage Description #1 227.00' 4,452 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 227.00 1,607 0 0 228.00 2,221 1,914 1,914 229.00 2,854 2,538 4,452 Device Ro Invert Outlet Devices #1 Secondary 228.00' 2.0' long x 20.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 #2 Discarded 227.00' 0.090 in /hr Exfiltration over Surface area #3 Primary 225.00' 8.0" Round Culvert L= 62.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0081 T Cc= 0.900 n=0.013, Flow Area= 0.35 sf #4 Device 3 227.28' 8.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.01 cfs @ 12.19 hrs HW= 228.63' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max =1.95 cfs @ 12.19 hrs HW= 228.63' (Free Discharge) L3= Culvert (Passes 1.95 cfs of 2.37 cfs potential flow) L4= Orifice /Grate (Orifice Controls 1.95 cfs @ 5.60 fps) Secondary OutFlow Max =2.70 cfs @ 12.19 hrs HW= 228.63' (Free Discharge) 't--1 =Broad-Crested Rectangular Weir (Weir Controls 2.70 cfs @ 2.14 fps) Summary for Pond INF1: U/G INF. Inflow Area = 7,577 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.29 cfs @ 12.07 hrs, Volume= 4,584 cf Outflow = 0.05 cfs @ 12.10 hrs, Volume= 4,584 cf, Atten= 96 %, Lag= 1.8 min Discarded = 0.05 cfs @ 12.10 hrs, Volume= 4,584 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 65 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 237.12' @ 15.08 hrs Surf.Area= 2,085 sf Storage= 2,639 cf Flood Elev= 239.50' Surf.Area= 2,085 sf Storage= 3,269 cf Plug -Flow detention time= 529.6 min calculated for 4,581 cf (100% of inflow) Center -of -Mass det. time= 529.8 min ( 1,271.0 - 741.1 ) Volume Invert Avail.Storage Storage Description #1A 234.00' 279 cf 21.50'W x 17.44'L x 2.33'H Field A 875 cf Overall - 177 cf Embedded = 698 cf x 40.0% Voids #2A 234.50' 177 cf ADS_StormTech SC -310 +Cap x 12 Inside #1 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.121 = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 6 Rows of 2 Chambers #313 234.00' 102 cf 11.34'W x 18.00'L x 3.17'H Field B 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #413 234.50' 267 cf Concrete Dry Well 500gal x 4 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 2 Chambers #5C 234.00' 176 cf 11.34'W x 34.00'L x 3.17'H Field C 1,222 cf Overall - 783 cf Embedded = 439 cf x 40.0% Voids #6C 234.50' 534 cf Concrete Dry Well 500gal x 8 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 4 Chambers #7D 235.00' 220 cf 16.01'W x 34.00'L x 3.17'H Field D 1,726 cf Overall - 1,175 cf Embedded = 551 cf x 40.0% Voids #8D 235.50' 800 cf Concrete Dry Well 500gal x 12 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 4 Chambers #9E 236.00' 419 cf 18.17'W x 31.68'L x 2.33'H Field E 1,343 cf Overall - 295 cf Embedded = 1,048 cf x 40.0% Voids #10E 236.50' 295 cf ADS _StormTech SC -310 +Cap x 20 Inside #9 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.121 = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 5 Rows of 4 Chambers 3,269 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Storage Group E created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 234.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 239.50' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 66 Discarded OutFlow Max =0.05 cfs @ 12.10 hrs HW= 236.14' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 234.00' (Free Discharge) L2= Orifice /Grate ( Controls 0.00 cfs) Summary for Pond INF2: U/G INF. Inflow Area = 64,299 sf, 36.99% Impervious, Inflow Depth= 3.22" for 100 -Year event Inflow = 1.96 cfs @ 12.19 hrs, Volume= 17,258 cf Outflow = 1.98 cfs @ 12.17 hrs, Volume= 17,258 cf, Atten= 0 %, Lag= 0.0 min Discarded = 0.02 cfs @ 10.95 hrs, Volume= 1,813 cf Primary = 1.96 cfs @ 12.17 hrs, Volume= 15,445 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.33' @ 12.17 hrs Surf.Area= 681 sf Storage= 964 cf Plug -Flow detention time= 80.6 min calculated for 17,258 cf (100% of inflow) Center -of -Mass det. time= 80.4 min ( 934.1 - 853.6 ) Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 67 Volume Invert Avail.Storage Storage Description #113 227.50' 109 cf 8.17'W x 17.44'L x 2.33'H Field B 332 cf Overall - 59 cf Embedded = 273 cf x 40.0% Voids #213 228.00' 59 cf ADS_StormTech SC -310 +Cap x 4 Inside #1 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap 2 Rows of 2 Chambers #3C 226.50' 45 cf 6.67'W x 10.00'L x 3.17'H Field C 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #4C 227.00' 67 cf Concrete Dry Well 500gal Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #5D 226.00' 45 cf 6.67'W x 10.00'L x 3.17'H Field D 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #6D 226.50' 67 cf Concrete Dry Well 500gal Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #7E 225.00' 78 cf 6.67'W x 18.00'L x 3.25'H Field E 391 cf Overall - 196 cf Embedded = 195 cf x 40.0% Voids #8E 225.50' 133 cf Concrete Dry Well 500gal x 2 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf #9F 225.00' 67 cf 4.83'W x 17.44'L x 2.33'H Field F 197 cf Overall - 29 cf Embedded = 167 cf x 40.0% Voids #10F 225.50' 29 cf ADS _StormTech SC -310 +Cap x 2 Inside #9 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #11G 224.50' 67 cf 4.83'W x 17.44'L x 2.33'H Field G 197 cf Overall - 29 cf Embedded = 167 cf x 40.0% Voids #12G 225.00' 29 cf ADS _StormTech SC -310 +Cap x 2 Inside #11 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #13H 224.00' 41 cf 4.83'W x 10.32'L x 2.33'H Field H 116 cf Overall - 15 cf Embedded = 102 cf x 40.0% Voids #14H 224.50' 15 cf ADS _StormTech SC -310 +Cap Inside #13 Effective Size= 28.9 "W x 16.0 "H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0 "W x 16.0 "H x 7.561 with 0.44' Overlap #151 224.00' 45 cf 6.67'W x 10.00'L x 3.17'H Field 1 211 cf Overall - 98 cf Embedded = 114 cf x 40.0% Voids #161 224.50' 67 cf Concrete Dry Well 500gal Inside #15 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 964 cf Total Available Storage Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Storage Group E created with Chamber Wizard Storage Group F created with Chamber Wizard Storage Group G created with Chamber Wizard Storage Group H created with Chamber Wizard Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 68 Storage Group I created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 233.00' 12.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.02 cfs @ 10.95 hrs HW= 227.55' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =1.93 cfs @ 12.17 hrs HW= 233.33' (Free Discharge) L2= Orifice /Grate (Weir Controls 1.93 cfs @ 1.87 fps) Summary for Pond INF3: U/G INF. Inflow Area = 13,748 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 2.34 cfs @ 12.07 hrs, Volume= 8,318 cf Outflow = 2.65 cfs @ 12.06 hrs, Volume= 8,318 cf, Atten= 0 %, Lag= 0.0 min Discarded = 0.02 cfs @ 8.65 hrs, Volume= 3,553 cf Primary = 2.63 cfs @ 12.06 hrs, Volume= 4,765 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 245.17' @ 12.06 hrs Surf.Area= 1,006 sf Storage= 1,854 cf Plug -Flow detention time= 343.2 min calculated for 8,318 cf (100% of inflow) Center -of -Mass det. time= 343.0 min ( 1,084.1 - 741.1 ) Volume Invert Avail.Storage Storage Description #1A 232.50' 139 cf 11.34'W x 26.00'L x 3.17'H Field A 935 cf Overall - 588 cf Embedded = 347 cf x 40.0% Voids #2A 233.00' 400 cf Concrete Dry Well 500gal x 6 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 3 Chambers #313 231.50' 175 cf 16.01'W x 26.00'L x 3.17'H Field B 1,320 cf Overall - 881 cf Embedded = 438 cf x 40.0% Voids #413 232.00' 600 cf Concrete Dry Well 500gal x 9 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 3 Chambers #5C 231.00' 139 cf 11.34'W x 26.00'L x 3.17'H Field C 935 cf Overall - 588 cf Embedded = 347 cf x 40.0% Voids #6C 231.50' 400 cf Concrete Dry Well 500gal x 6 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 3 Chambers 1,854 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 69 Device Routing Invert Outlet Devices #1 Discarded 231.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 237.50' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.02 cfs @ 8.65 hrs HW= 232.51' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max =2.52 cfs @ 12.06 hrs HW= 244.60' (Free Discharge) L2= Orifice /Grate (Orifice Controls 2.52 cfs @ 12.83 fps) Summary for Pond INF4: U/G INF. Inflow Area = 3,261 sf, 100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 0.55 cfs @ 12.07 hrs, Volume= 1,973 cf Outflow = 0.02 cfs @ 17.35 hrs, Volume= 593 cf, Atten= 97 %, Lag= 316.8 min Discarded = 0.00 cfs @ 10.55 hrs, Volume= 466 cf Primary = 0.02 cfs @ 17.35 hrs, Volume= 127 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.01' @ 17.35 hrs Surf.Area= 943 sf Storage= 1,719 cf Plug -Flow detention time= 1,561.1 min calculated for 593 cf (30% of inflow) Center -of -Mass det. time= 1,355.3 min ( 2,096.4 - 741.1 ) Volume Invert Avail.Storage Storage Description #1A 225.50' 106 cf 20.68'W x 10.00'L x 3.17'H Field A 656 cf Overall - 392 cf Embedded = 264 cf x 40.0% Voids #2A 226.00' 267 cf Concrete Dry Well 500gal x 4 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 4 Rows of 1 Chambers #313 225.50' 102 cf 11.34'W x 18.00'L x 3.17'H Field B 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #413 226.00' 267 cf Concrete Dry Well 500gal x 4 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 2 Rows of 2 Chambers #5C 224.50' 159 cf 20.68'W x 18.00'L x 3.17'H Field C 1,180 cf Overall - 783 cf Embedded = 397 cf x 40.0% Voids #6C 225.00' 534 cf Concrete Dry Well 500gal x 8 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 4 Rows of 2 Chambers #7D 224.00' 86 cf 16.01'W x 10.00'L x 3.17'H Field D 508 cf Overall - 294 cf Embedded = 214 cf x 40.0% Voids #8D 224.50' 200 cf Concrete Dry Well 500gal x 3 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.001 = 97.9 cf 3 Rows of 1 Chambers Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 70 1,719 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.00' 0.090 in /hr Exfiltration over Surface area #2 Primary 230.00' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max =0.00 cfs @ 10.55 hrs HW= 225.51' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.01 cfs @ 17.35 hrs HW= 230.01' (Free Discharge) L2= Orifice /Grate (Weir Controls 0.01 cfs @ 0.38 fps) Summary for Pond INF5: U/G INF. Inflow Area = 9,451 sf, 100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.61 cfs @ 12.07 hrs, Volume= 5,718 cf Outflow = 0.29 cfs @ 12.53 hrs, Volume= 5,718 cf, Atten= 82 %, Lag= 27.8 min Discarded = 0.03 cfs @ 6.95 hrs, Volume= 4,870 cf Primary = 0.26 cfs @ 12.53 hrs, Volume= 848 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 239.13' @ 12.55 hrs Surf.Area= 1,230 sf Storage= 2,943 cf Plug -Flow detention time= 758.0 min calculated for 5,718 cf (100% of inflow) Center -of -Mass det. time= 757.9 min ( 1,499.0 - 741.1 ) Volume Invert Avail.Storage Storage Description #1A 234.00' 756 cf 98.39'W x 12.50'L x 3.83'H Field A 4,710 cf Overall - 2,821 cf Embedded = 1,889 cf x 40.0% Voids #2A 234.50' 2,187 cf Concrete Dry Well 1000gal x 17 Inside #1 Inside= 62.0 "W x 30.0 "H => 12.86 sf x 10.001 = 128.6 cf Outside= 68.0 "W x 34.0 "H => 15.81 sf x 10.501 = 166.0 cf 17 Rows of 1 Chambers 2,943 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 234.00' 1.020 in /hr Exfiltration over Surface area #2 Primary 239.00' 6.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 71 Discarded OutFlow Max =0.03 cfs @ 6.95 hrs HW= 234.05' (Free Discharge) L1= Exfiltration ( Exfiltration Controls 0.03 cfs) Primary OutFlow Max =0.24 cfs @ 12.53 hrs HW= 239.13' (Free Discharge) L2= Orifice /Grate (Weir Controls 0.24 cfs @ 1.19 fps) Summary for Pond P -CB1 *: Inflow Area = 10,049 sf, 70.76% Impervious, Inflow = 1.55 cfs @ 12.07 hrs, Volume= Outflow = 1.55 cfs @ 12.07 hrs, Volume= Primary = 1.55 cfs @ 12.07 hrs, Volume= Inflow Depth = 4,994 cf 4,994 cf, 4,994 cf 5.96" for 100 -Year event Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.67' @ 12.07 hrs Flood Elev= 236.77' Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 231.00' 12.0" Round Culvert L= 33.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 231.00'/230.00' S=0.0303'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =1.50 cfs @ 12.07 hrs HW= 231.65' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.50 cfs @ 2.75 fps) Summary for Pond P -C1132: Inflow Area = 2,252 sf, 13.54% Impervious, Inflow = 0.22 cfs @ 12.08 hrs, Volume= Outflow = 0.22 cfs @ 12.08 hrs, Volume= Primary = 0.22 cfs @ 12.08 hrs, Volume= Inflow Depth = 676 cf 676 cf, 676 cf 3.60" for 100 -Year event Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.26' @ 12.08 hrs Flood Elev= 229.50' Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 225.00' 12.0" Round Culvert L= 82.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0061 T Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.21 cfs @ 12.08 hrs HW= 225.25' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.21 cfs @ 2.03 fps) Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 72 Summary for Pond P -C1133: Inflow Area = 41,288 sf, 74.21% Impervious, Inflow Depth = 5.35" for 100 -Year event Inflow = 6.84 cfs @ 12.06 hrs, Volume= 18,406 cf Outflow = 6.84 cfs @ 12.06 hrs, Volume= 18,406 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.84 cfs @ 12.06 hrs, Volume= 18,406 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.47' @ 12.06 hrs Flood Elev= 229.10' Device Routing Invert Outlet Devices #1 Primary 225.00' 15.0" Round Culvert L= 81.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 225.00'/224.50' S=0.0062'/' Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =6.53 cfs @ 12.06 hrs HW= 227.33' (Free Discharge) 't--1 =Culvert (Barrel Controls 6.53 cfs @ 5.32 fps) Summary for Pond P -C1134: Inflow Area = 11,426 sf, 53.74% Impervious, Inflow Depth = 6.08" for 100 -Year event Inflow = 1.79 cfs @ 12.07 hrs, Volume= 5,789 cf Outflow = 1.79 cfs @ 12.07 hrs, Volume= 5,789 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.79 cfs @ 12.07 hrs, Volume= 5,789 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.48' @ 12.07 hrs Flood Elev= 229.23' Device Ro Invert Outlet Devices #1 Primary 225.70' 12.0" Round Culvert L= 96.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.70'/225.00' S=0.0073'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =1.72 cfs @ 12.07 hrs HW= 226.47' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.72 cfs @ 3.70 fps) Summary for Pond P -DMH2: Inflow Area = 7,577 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.29 cfs @ 12.07 hrs, Volume= 4,584 cf Outflow = 1.29 cfs @ 12.07 hrs, Volume= 4,584 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.29 cfs @ 12.07 hrs, Volume= 4,584 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 73 Peak Elev= 238.10' @ 12.07 hrs Flood Elev= 242.00' Device Routing Invert Outlet Devices #1 Primary 237.50' 12.0" Round Culvert L= 36.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 237.50'/237.00' S=0.0139'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =1.24 cfs @ 12.07 hrs HW= 238.08' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.24 cfs @ 2.60 fps) Summary for Pond P -DMH3: Inflow Area = 3,261 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 0.55 cfs @ 12.07 hrs, Volume= 1,973 cf Outflow = 0.55 cfs @ 12.07 hrs, Volume= 1,973 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.55 cfs @ 12.07 hrs, Volume= 1,973 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.92' @ 12.07 hrs Flood Elev= 230.50' Device Routing Invert Outlet Devices #1 Primary 227.50' 12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.50'/227.40' S=0.0125'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.53 cfs @ 12.07 hrs HW= 227.91' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.53 cfs @ 2.61 fps) Summary for Pond P -DMH4: Inflow Area = 13,748 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 2.34 cfs @ 12.07 hrs, Volume= 8,318 cf Outflow = 2.34 cfs @ 12.07 hrs, Volume= 8,318 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.34 cfs @ 12.07 hrs, Volume= 8,318 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.28' @ 12.07 hrs Flood Elev= 239.00' Device Routing Invert Outlet Devices #1 Primary 234.40' 12.0" Round Culvert L= 8.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 234.40'/234.00' S=0.0500'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 74 Primary OutFlow Max =2.25 cfs @ 12.07 hrs HW= 235.26' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.25 cfs @ 3.15 fps) Summary for Pond P -DMH5: Inflow Area = 9,451 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.61 cfs @ 12.07 hrs, Volume= 5,718 cf Outflow = 1.61 cfs @ 12.07 hrs, Volume= 5,718 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.61 cfs @ 12.07 hrs, Volume= 5,718 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 238.68' @ 12.07 hrs Flood Elev= 243.80' Device Routing Invert Outlet Devices #1 Primary 238.00' 12.0" Round Culvert L= 26.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 238.00'/236.00' S=0.0769'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =1.55 cfs @ 12.07 hrs HW= 238.67' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.55 cfs @ 2.78 fps) Summary for Pond P. C -1: NW CULVERT Inflow Area = 28,591 sf, 22.20% Impervious, Inflow Depth = 3.82" for 100 -Year event Inflow = 2.94 cfs @ 12.08 hrs, Volume= 9,099 cf Outflow = 2.93 cfs @ 12.09 hrs, Volume= 9,099 cf, Atten= 0 %, Lag= 0.6 min Discarded = 0.00 cfs @ 12.09 hrs, Volume= 1 cf Primary = 2.93 cfs @ 12.09 hrs, Volume= 9,098 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.50' @ 12.09 hrs Surf.Area= 92 sf Storage= 35 cf Plug -Flow detention time= (not calculated: outflow precedes inflow) Center -of -Mass det. time= 0.0 min ( 831.1 - 831.1 ) Volume Invert Avail.Storage Storage Description #1 236.00' 777 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 236.00 51 31.0 0 0 51 237.00 145 57.0 94 94 238 238.00 334 86.0 233 327 576 239.00 576 117.0 450 777 1,087 Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 75 Device Routing Invert Outlet Devices #1 Primary 235.40' 12.0" Round Culvert L= 100.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 235.40'/234.40' S=0.0100'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Discarded 236.00' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 12.09 hrs HW= 236.48' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =2.86 cfs @ 12.09 hrs HW= 236.47' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.86 cfs @ 3.65 fps) Summary for Pond P. P -1: OFF -SITE DEPRESSION Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow = 223.91 cfs @ 12.10 hrs, Volume= Outflow = 3.26 cfs @ 22.82 hrs, Volume= Discarded = 1.03 cfs @ 22.82 hrs, Volume= Primary = 2.23 cfs @ 22.82 hrs, Volume= Secondary = 0.00 cfs @ 0.00 hrs, Volume= Tertiary = 0.00 cfs @ 0.00 hrs, Volume= Inflow Depth= 3.69" for 100 -Year event 718,581 cf 558,550 cf, 207,791 cf 350,759 cf 0 cf 0 cf Atten= 99 %, Lag= 643.2 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 220.74' @ 22.82 hrs Surf.Area= 494,129 sf Storage= 582,626 cf Plug -Flow detention time= 1,572.1 min calculated for 558,162 cf (78% of inflow) Center -of -Mass det. time= 1,489.6 min ( 2,324.3 - 834.7 ) Volume Invert #1 219.00' MV01 e Description 1,815,231 cf Custom Stage Data (Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 219.00 0 0 0 220.00 452,595 226,298 226,298 221.00 508,615 480,605 706,903 222.00 557,476 533,046 1,239,948 223.00 593,089 575,283 1,815,231 Device Routing Invert Outlet Devices #1 Primary 218.80' 18.0" W x 18.0" H Box Exist. Culvert X 0.20 L= 16.0' RCP, end - section conforming to fill, Ke= 0.500 Inlet/ Outlet Invert= 218.80'/218.60' S=0.0125'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 2.25 sf #2 Secondary 221.80' Asymmetrical Weir, C= 3.27 Offset (feet) 0.00 9.00 11.00 20.00 Height (feet) 1.20 0.00 0.00 1.20 #3 Discarded 219.00' 0.090 in /hr Exfiltration over Surface area #4 Tertiary 222.00' 384.0" W x 72.0" H, R= 384.0" Arch Prop. Culvert L= 55.0' Box, headwall w/3 square edges, Ke= 0.500 Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 76 Inlet/ Outlet Invert= 222.00'/222.00' S=0.0000'/' Cc= 0.900 n=0.025 Corrugated metal, Flow Area= 147.57 sf Discarded OutFlow Max =1.03 cfs @ 22.82 hrs HW= 220.74' (Free Discharge) L3= Exfiltration ( Exfiltration Controls 1.03 cfs) Primary OutFlow Max =2.24 cfs @ 22.82 hrs HW= 220.74' (Free Discharge) 't--1 =Exist. Culvert (Barrel Controls 2.24 cfs @ 1.03 fps) Secondary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L2= Asymmetrical Weir ( Controls 0.00 cfs) Tertiary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 219.00' (Free Discharge) L4 =Prop. Culvert ( Controls 0.00 cfs) Summary for Link 1 L: Pre AP1 Inflow Area = 2,840,536 sf, 16.98% Impervious, Inflow Depth > 2.35" for 100 -Year event Inflow = 60.31 cfs @ 12.11 hrs, Volume= 555,947 cf Primary = 60.31 cfs @ 12.11 hrs, Volume= 555,947 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 100 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP1.hce Summary for Link 2L: Pre AP2 Inflow Area = 341,168 sf, 43.52% Impervious, Inflow Depth = 5.39" for 100 -Year event Inflow = 45.51 cfs @ 12.07 hrs, Volume= 153,341 cf Primary = 45.51 cfs @ 12.07 hrs, Volume= 153,341 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 100 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP2.hce Summary for Link 3L: Pre AP3 Inflow Area = 2,323,148 sf, 14.18% Impervious, Inflow Depth > 1.81" for 100 -Year event Inflow = 2.24 cfs @ 22.78 hrs, Volume= 350,809 cf Primary = 2.24 cfs @ 22.78 hrs, Volume= 350,809 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 100 -Year Primary Outflow Imported from 151067 2017 PRE-Link AP3.hce Brookhaven, Lexington, MA 151067 2017 POST Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 77 Summary for Link AP1: Inflow Area = 2,840,536 sf, 21.06% Impervious, Inflow Depth > 2.42" for 100 -Year event Inflow = 50.64 cfs @ 12.18 hrs, Volume= 572,878 cf Primary = 50.64 cfs @ 12.18 hrs, Volume= 572,878 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Summary for Link AP2: FROM "POST AP2" Inflow Area = 347,640 sf, 57.70% Impervious, Inflow Depth= 5.66" for 100 -Year event Inflow = 36.94 cfs @ 12.15 hrs, Volume= 164,096 cf Primary = 36.94 cfs @ 12.15 hrs, Volume= 164,096 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 100 -Year Primary Outflow Imported from 151067 2017 POST AP2-Link AP2.hce Summary for Link AP3: Inflow Area = 2,333,768 sf, 14.66% Impervious, Inflow Depth > 1.80" for 100 -Year event Inflow = 2.23 cfs @ 22.82 hrs, Volume= 350,759 cf Primary = 2.23 cfs @ 22.82 hrs, Volume= 350,759 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs _____ Subcat Reach on Link MHi MOD.EX. I�T BASIN uxi A ce1 81 ST ce1 - -- 0 �_ s- 50_,� / \ B3 B4 ec Ea / \ xscn 1, / ca xeca 't3L x112 UIG'IET � � =e -oMx NF6 Q �—/sF� - U /tF. \ exsc- AB, sCI (I sC -I 11 2� Q \ __ \ 11 2) _____ Subcat Reach on Link Brookhaven, Lexington, MA 151067 2017 POST AP2 Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq -ft) (s u bcatch me nt -n u m be rs) 70,683 61 >75% Grass cover, Good, HSG B (EX. SC -17, EX. SC -18, EX. SC -20, EX. SC -21, EX. SC -22, EX. SC -3, P. SC -11, P. SC -12, P. SC -13, P. SC -5, P. SC -6, P. SC -7, P. SC -E4) 43,334 80 >75% Grass cover, Good, HSG D (EX. SC -1, EX. SC -18, EX. SC -3, P. SC -10, P. SC -12, P. SC -5, P. SC -6, P. SC -8, P. SC -9, P. SC -C1, P. SC -C2, P. SC -E4) 48,325 98 Paved parking, HSG B (EX. SC -17, EX. SC -18, EX. SC -19, EX. SC -20, EX. SC -21, EX. SC -22, EX. SC -3, P. SC -11, P. SC -12, P. SC -13, P. SC -5, P. SC -6, P. SC -7, P. SC -E4) 66,028 98 Paved parking, HSG D (EX. SC -1, EX. SC -18, EX. SC -19, EX. SC -2, EX. SC -3, P. SC -10, P. SC -12, P. SC -5, P. SC -6, P. SC -8, P. SC -9, P. SC -E4) 76,636 98 Roofs, HSG B (EX. SC -17, EX. SC -18, EX. SC -20, EX. SC -21, EX. SC -22, EX. SC -R, EX. SC -ST, P. SC -E4, P. SC -R1, P. SC -R3, P. SC -R9) 9,589 98 Roofs, HSG D (EX. SC -18, P. SC -12, P. SC -R2) 33,045 77 Woods, Good, HSG D (P. SC -C1, P. SC -C2) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment EX. SC -1: Runoff = 0.18 cfs @ 12.07 hrs, Volume= 570 cf, Depth= 1.80" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 1,735 80 >75% Grass cover, Good, HSG D 2,065 98 Paved parking, HSG D 3,800 90 Weighted Average 1,735 45.66% Pervious Area 2,065 54.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -17: Runoff = 0.33 cfs @ 12.08 hrs, Volume= 1,029 cf, Depth= 1.42" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 1,325 98 Roofs, HSG B 2,993 61 >75% Grass cover, Good, HSG B 4.366 98 Paved oarkina. HSG B 8,684 85 Weighted Average 2,993 34.47% Pervious Area 5,691 65.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -18: Runoff = 1.76 cfs @ 12.08 hrs, Volume= 5,466 cf, Depth= 1.64" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 4 Area (so CN Description 13,935 98 Roofs, HSG B 803 98 Roofs, HSG D 9,943 61 >75% Grass cover, Good, HSG B 2,229 80 >75% Grass cover, Good, HSG D 8,923 98 Paved parking, HSG B 4.124 98 Paved oarkina. HSG D 39,957 88 Weighted Average 12,172 30.46% Pervious Area 27,785 69.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -19: Runoff = 0.66 cfs @ 12.07 hrs, Volume= 2,244 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 5,245 98 Paved parking, HSG B 5,234 98 Paved parking, HSG D 10,479 98 Weighted Average 10,479 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -2: Runoff = 0.20 cfs @ 12.07 hrs, Volume= 681 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 3,181 98 Paved parking, HSG D 3,181 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment EX. SC -20: Runoff = 0.53 cfs @ 12.09 hrs, Volume= 1,725 cf, Depth= 0.88" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 7,685 98 Roofs, HSG B 13,660 61 >75% Grass cover, Good, HSG B 2,108 98 Paved parking, HSG B 23,453 76 Weighted Average 13,660 58.24% Pervious Area 9,793 41.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -21: Runoff = 0.78 cfs @ 12.08 hrs, Volume= 2,417 cf, Depth= 1.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 5,373 98 Roofs, HSG B 5,318 61 >75% Grass cover, Good, HSG B 7,833 98 Paved parking, HSG B 18,524 87 Weighted Average 5,318 28.71 % Pervious Area 13,206 71.29% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -22: Runoff = 0.56 cfs @ 12.09 hrs, Volume= 1,780 cf, Depth= 0.99" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 6 Area (so CN Description 1,599 98 Roofs, HSG B 11,736 61 >75% Grass cover, Good, HSG B 8,266 98 Paved parking, HSG B 21,601 78 Weighted Average 11,736 71 54.33% Pervious Area 9,865 45.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment EX. SC -3: Runoff = 0.20 cfs @ 12.09 hrs, Volume= 719 cf, Depth= 0.65" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 6,580 61 >75% Grass cover, Good, HSG B 6,168 80 >75% Grass cover, Good, HSG D 263 98 Paved parking, HSG B 302 98 Paved parking, HSG D 13,313 71 Weighted Average 12,748 95.76% Pervious Area 565 4.24% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -R: Runoff = 0.32 cfs @ 12.07 hrs, Volume= 1,090 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 5,090 98 Roofs, HSG B 5,090 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment EX. SC -ST: Runoff = 0.53 cfs @ 12.07 hrs, Volume= 1,813 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 8,470 98 Roofs, HSG B 8,470 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -10: Runoff = 0.14 cfs @ 12.07 hrs, Volume= 427 cf, Depth= 1.89" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 1,023 80 >75% Grass cover, Good, HSG D 1,692 98 Paved parking, HSG D 2,715 91 Weighted Average 1,023 37.68% Pervious Area 1,692 62.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -11: Runoff = 0.03 cfs @ 12.09 hrs, Volume= 89 cf, Depth= 0.69" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 1,072 61 >75% Grass cover, Good, HSG B 467 98 Paved parking, HSG B 1,539 72 Weighted Average 1,072 69.66% Pervious Area 467 30.34% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 8 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -12: Runoff = 2.18 cfs @ 12.07 hrs, Volume= 6,789 cf, Depth= 1.89" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 1,039 98 Roofs, HSG D 4,014 61 >75% Grass cover, Good, HSG B 7,822 80 >75% Grass cover, Good, HSG D 2,473 98 Paved parking, HSG B 27,857 98 Paved parking, HSG D 43,205 91 Weighted Average 11,836 27.39% Pervious Area 31,369 72.61 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -13: Runoff = 0.03 cfs @ 12.09 hrs, Volume= 118 cf, Depth= 0.74" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 1,280 61 >75% Grass cover, Good, HSG B 643 98 Paved parking, HSG B 1,923 73 Weighted Average 1,280 66.56% Pervious Area 643 33.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -5: Runoff = 1.00 cfs @ 12.08 hrs, Volume= 3,085 cf, Depth= 1.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 9 Area (sf) CN Description 2,793 61 >75% Grass cover, Good, HSG B 8,051 80 >75% Grass cover, Good, HSG D 249 98 Paved parking, HSG B 12,549 98 Paved parking, HSG D 23,642 87 Weighted Average 10,844 45.87% Pervious Area 12,798 54.13% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -6: Runoff = 0.11 cfs @ 12.08 hrs, Volume= 327 cf, Depth= 1.29" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 1,176 61 >75% Grass cover, Good, HSG B 163 80 >75% Grass cover, Good, HSG D 1,318 98 Paved parking, HSG B 392 98 Paved parking, HSG D 3,049 83 Weighted Average 1,339 43.92% Pervious Area 1,710 56.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -7: Runoff = 0.05 cfs @ 12.09 hrs, Volume= 174 cf, Depth= 0.65" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 2,315 61 >75% Grass cover, Good, HSG B 907 98 Paved parking, HSG B 3,222 71 Weighted Average 2,315 71.85% Pervious Area 907 28.15% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 10 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -8: Runoff = 0.40 cfs @ 12.07 hrs, Volume= 1,252 cf, Depth= 2.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 2,049 80 >75% Grass cover, Good, HSG D 5.235 98 Paved oarkina. HSG D 7,284 93 Weighted Average 2,049 28.13% Pervious Area 5,235 71.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -9: Runoff = 0.20 cfs @ 12.07 hrs, Volume= 643 cf, Depth= 2.36" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 347 80 >75% Grass cover, Good, HSG D 2,929 98 Paved parking, HSG D 3,276 96 Weighted Average 347 10.59% Pervious Area 2,929 89.41% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C1: Runoff = 0.51 cfs @ 12.08 hrs, Volume= 1,630 cf, Depth= 1.04" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 11 Area (sf) CN Description 11,805 80 >75% Grass cover, Good, HSG D 6,928 77 Woods, Good, HSG D 18,733 79 Weighted Average 18,733 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C2: Runoff = 0.67 cfs @ 12.09 hrs, Volume= 2,160 cf, Depth= 0.93" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (sf) CN Description 1,605 80 >75% Grass cover, Good, HSG D 26,117 77 Woods, Good, HSG D 27,722 77 Weighted Average 27,722 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -E4: Runoff = 0.48 cfs @ 12.08 hrs, Volume= 1,510 cf, Depth= 1.10" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 2,571 98 Roofs, HSG B 7,803 61 >75% Grass cover, Good, HSG B 337 80 >75% Grass cover, Good, HSG D 5,264 98 Paved parking, HSG B 468 98 Paved parking, HSG D 16,443 80 Weighted Average 8,140 49.50% Pervious Area 8,303 50.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 12 Summary for Subcatchment P. SC -R1: Runoff = 0.24 cfs @ 12.07 hrs, Volume= 821 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 3,833 98 Roofs, HSG B 3,833 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R2: Runoff = 0.48 cfs @ 12.07 hrs, Volume= 1,659 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 7,747 98 Roofs, HSG D 7,747 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R3: Runoff = 1.35 cfs @ 12.07 hrs, Volume= 4,624 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 21,598 98 Roofs, HSG B 21,598 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 13 Summary for Subcatchment P. SC -R9: Runoff = 0.32 cfs @ 12.07 hrs, Volume= 1,104 cf, Depth= 2.57" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 2 -Year Rainfall= 2.80" Area (so CN Description 5,157 98 Roofs, HSG B 5,157 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Pond C1131: Inflow Area = 3,800 sf, 54.34% Impervious, Inflow Depth = 1.80" for 2 -Year event Inflow = 0.18 cfs @ 12.07 hrs, Volume= 570 cf Outflow = 0.18 cfs @ 12.07 hrs, Volume= 570 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.18 cfs @ 12.07 hrs, Volume= 570 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.46' @ 12.07 hrs Flood Elev= 224.92' Device Routing Invert Outlet Devices #1 Primary 224.92' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads #2 Primary 221.25' 12.0" Round Culvert L= 15.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 221.25'/218.16' S=0.1994'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.18 cfs @ 12.07 hrs HW= 221.45' (Free Discharge) t1= Orifice /Grate ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.18 cfs @ 1.54 fps) Summary for Pond CB16: Inflow Area = 43,205 sf, 72.61 % Impervious, Inflow Depth = 1.89" for 2 -Year event Inflow = 2.18 cfs @ 12.07 hrs, Volume= 6,789 cf Outflow = 2.18 cfs @ 12.07 hrs, Volume= 6,789 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.18 cfs @ 12.07 hrs, Volume= 6,789 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.55' @ 12.07 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 14 Device Routing Invert Outlet Devices #1 Primary 225.71' 12.0" Round Culvert L= 9.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.71'/222.83' S=0.3200'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 229.50' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =2.10 cfs @ 12.07 hrs HW= 226.52' (Free Discharge) t1= Culvert (Inlet Controls 2.10 cfs @ 3.07 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond CB17: Inflow Area = 8,684 sf, 65.53% Impervious, Inflow Depth= 1.42" for 2 -Year event Inflow = 0.33 cfs @ 12.08 hrs, Volume= 1,029 cf Outflow = 0.33 cfs @ 12.08 hrs, Volume= 1,029 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.33 cfs @ 12.08 hrs, Volume= 1,029 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.56' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 225.13' 12.0" Round Culvert L= 80.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.13'/225.07' S=0.0008'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 228.31' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.32 cfs @ 12.08 hrs HW= 225.56' (Free Discharge) �--2=Orifi 1= Culve rt (Barrel Controls 0.32 cfs @ 1.49 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB18: Inflow Area = 39,957 sf, 69.54% Impervious, Inflow Depth= 1.64" for 2 -Year event Inflow = 1.76 cfs @ 12.08 hrs, Volume= 5,466 cf Outflow = 1.76 cfs @ 12.08 hrs, Volume= 5,466 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.76 cfs @ 12.08 hrs, Volume= 5,466 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.06' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 230.25' 12.0" Round Culvert L= 14.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.25'/230.10' S=0.0103'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 234.91' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 15 Limited to weir flow at low heads Primary OutFlow Max =1.71 cfs @ 12.08 hrs HW= 231.05' (Free Discharge) �--2=Orifi 1= Culve rt (Barrel Controls 1.71 cfs @ 3.50 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB19: Inflow Area = 10,479 sf,100.00% Impervious, Inflow Depth= 2.57" for 2 -Year event Inflow = 0.66 cfs @ 12.07 hrs, Volume= 2,244 cf Outflow = 0.66 cfs @ 12.07 hrs, Volume= 2,244 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.66 cfs @ 12.07 hrs, Volume= 2,244 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.64' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 230.16' 12.0" Round Culvert L= 6.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.16'/230.10' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 235.05' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.63 cfs @ 12.07 hrs HW= 230.63' (Free Discharge) �--2=Orifi 1= Culve rt (Barrel Controls 0.63 cfs @ 2.57 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond C1132: Inflow Area = 6,981 sf, 75.15% Impervious, Inflow Depth= 2.15" for 2 -Year event Inflow = 0.38 cfs @ 12.07 hrs, Volume= 1,251 cf Outflow = 0.38 cfs @ 12.07 hrs, Volume= 1,251 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.38 cfs @ 12.07 hrs, Volume= 1,251 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 218.58' @ 12.07 hrs Flood Elev= 225.01' Device Routing Invert Outlet Devices #1 Primary 218.16' 12.0" Round Culvert L= 135.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.16'/ 217.88' S= 0.0021 T Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 225.01' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.37 cfs @ 12.07 hrs HW= 218.57' (Free Discharge) t1= Culvert (Barrel Controls 0.37 cfs @ 1.80 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 16 Summary for Pond CB20: Inflow Area = 23,453 sf, 41.76% Impervious, Inflow Depth = 0.88" for 2 -Year event Inflow = 0.53 cfs @ 12.09 hrs, Volume= 1,725 cf Outflow = 0.53 cfs @ 12.09 hrs, Volume= 1,725 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.53 cfs @ 12.09 hrs, Volume= 1,725 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.45' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 235.70' 6.0" Round Culvert L= 143.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 235.70'/228.93' S=0.0472'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 0.20 sf #2 Primary 239.00' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.51 cfs @ 12.09 hrs HW= 236.43' (Free Discharge) �--2=Orifi 1= Culve rt (Inlet Controls 0.51 cfs @ 2.62 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB21: Inflow Area = 18,524 sf, 71.29% Impervious, Inflow Depth= 1.57" for 2 -Year event Inflow = 0.78 cfs @ 12.08 hrs, Volume= 2,417 cf Outflow = 0.78 cfs @ 12.08 hrs, Volume= 2,417 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.78 cfs @ 12.08 hrs, Volume= 2,417 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.35' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 243.80' 12.0" Round Culvert L= 25.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.80'/243.70' S=0.0039'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 247.80' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.76 cfs @ 12.08 hrs HW= 244.34' (Free Discharge) t1= Culvert (Barrel Controls 0.76 cfs @ 2.55 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond CB22: Inflow Area = 21,601 sf, 45.67% Impervious, Inflow Depth = 0.99" for 2 -Year event Inflow = 0.56 cfs @ 12.09 hrs, Volume= 1,780 cf Outflow = 0.56 cfs @ 12.09 hrs, Volume= 1,780 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.56 cfs @ 12.09 hrs, Volume= 1,780 cf Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 17 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.13' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 243.70' 12.0" Round Culvert L= 16.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.70'/243.60' S=0.0062'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 247.90' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.54 cfs @ 12.09 hrs HW= 244.13' (Free Discharge) t1= Culvert (Barrel Controls 0.54 cfs @ 2.48 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond C1133: Inflow Area = 36,766 sf, 28.17% Impervious, Inflow Depth= 0.80" for 2 -Year event Inflow = 0.73 cfs @ 12.09 hrs, Volume= 2,444 cf Outflow = 0.73 cfs @ 12.09 hrs, Volume= 2,444 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.73 cfs @ 12.09 hrs, Volume= 2,444 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.36' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 228.93' 12.0" Round Culvert L= 16.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.93'/227.98' S=0.0576'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 231.88' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.71 cfs @ 12.09 hrs HW= 229.36' (Free Discharge) �--2=Orifi 1= Culve rt (Inlet Controls 0.71 cfs @ 2.23 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond C1134: Inflow Area = 16,443 sf, 50.50% Impervious, Inflow Depth = 1.10" for 2 -Year event Inflow = 0.48 cfs @ 12.08 hrs, Volume= 1,510 cf Outflow = 0.48 cfs @ 12.08 hrs, Volume= 1,510 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.48 cfs @ 12.08 hrs, Volume= 1,510 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.98' @ 12.08 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 18 Device Routing Invert Outlet Devices #1 Primary 229.64' 12.0" Round Culvert L= 31.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.64'/227.96' S=0.0542'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 232.11' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.46 cfs @ 12.08 hrs HW= 229.98' (Free Discharge) t1= Culvert (Inlet Controls 0.46 cfs @ 1.98 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 220.31' @ 12.29 hrs Surf.Area= 6,138 sf Storage= 5,224 cf Plug -Flow detention time= 13.9 min calculated for 37,881 cf (100% of inflow Center -of -Mass det. time= 11.7 min ( 840.3 - 828.6 ) Volume Invert Summary for Pond DB: MOD.EX. DET.BASIN Inflow Area = 319,918 sf, 62.70% Impervious, Inflow Depth = 1.42" for 2 -Year event Inflow = 10.37 cfs @ 12.09 hrs, Volume= 37,979 cf Outflow = 6.06 cfs @ 12.29 hrs, Volume= 37,881 cf, Atten= 42 %, Lag= 12.0 min Primary = 6.06 cfs @ 12.29 hrs, Volume= 37,881 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 220.31' @ 12.29 hrs Surf.Area= 6,138 sf Storage= 5,224 cf Plug -Flow detention time= 13.9 min calculated for 37,881 cf (100% of inflow Center -of -Mass det. time= 11.7 min ( 840.3 - 828.6 ) Volume Invert Avail.Storage Storage Description #1 218.00' 18,957 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 218.00 331 121.0 0 0 331 219.00 961 165.0 619 619 1,343 220.00 5,260 601.0 2,823 3,442 27,922 221.00 8,303 630.0 6,724 10,166 30,829 222.00 9,288 647.0 8,791 18,957 32,671 Device Routing Invert Outlet Devices #1 Primary 218.25' 12.0" Round Culvert L= 16.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 218.25'/217.81' S=0.0267'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Primary 220.00' 4.0' long x 15.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max =6.04 cfs @ 12.29 hrs HW= 220.31' (Free Discharge) �__1= Culvert (Inlet Controls 4.17 cfs @ 5.31 fps) 2= Broad - Crested Rectangular Weir (Weir Controls 1.87 cfs @ 1.50 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 19 Summary for Pond DMH1: Inflow Area = 53,209 sf, 35.07% Impervious, Inflow Depth = 0.89" for 2 -Year event Inflow = 1.21 cfs @ 12.09 hrs, Volume= 3,955 cf Outflow = 1.21 cfs @ 12.09 hrs, Volume= 3,955 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.21 cfs @ 12.09 hrs, Volume= 3,955 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 222.93' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 222.31' 12.0" Round Culvert L= 77.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 222.31'/219.41' S=0.0374'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.18 cfs @ 12.09 hrs HW= 222.92' (Free Discharge) L1= Culvert (Inlet Controls 1.18 cfs @ 2.35 fps) Summary for Pond DMH10: Inflow Area = 8,470 sf, 100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.53 cfs @ 12.07 hrs, Volume= 1,813 cf Outflow = 0.53 cfs @ 12.07 hrs, Volume= 1,813 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.53 cfs @ 12.07 hrs, Volume= 1,813 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.32' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 228.95' 12.0" Round Culvert L= 36.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.95'/228.59' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.51 cfs @ 12.07 hrs HW= 229.31' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.51 cfs @ 2.97 fps) Summary for Pond DMH11: Inflow Area = 90,561 sf, 67.73% Impervious, Inflow Depth = 1.58" for 2 -Year event Inflow = 3.75 cfs @ 12.08 hrs, Volume= 11,906 cf Outflow = 3.75 cfs @ 12.08 hrs, Volume= 11,906 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.75 cfs @ 12.08 hrs, Volume= 11,906 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.47' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 230.00' 12.0" Round Culvert Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 20 L= 142.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.00'/224.85' S=0.0363'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =3.63 cfs @ 12.08 hrs HW= 231.42' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.63 cfs @ 4.62 fps) Summary for Pond DMH12: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 1.26" for 2 -Year event Inflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Outflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.11' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 232.50' 12.0" Round Culvert L= 68.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 232.50'/230.00' S=0.0368'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.29 cfs @ 12.08 hrs HW= 233.10' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.29 cfs @ 2.64 fps) Summary for Pond DMH12A: Inflow Area = 7,747 sf,100.00% Impervious, Inflow Depth = 0.00" for 2 -Year event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.00' @ 0.00 hrs Flood Elev= 232.20' Device Routing Invert Outlet Devices #1 Primary 225.00' 12.0" Round Culvert L= 31.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.00'/223.00' S=0.0645'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Primary 231.00' 6.0' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 225.00' (Free Discharge) �__1= Culvert ( Controls 0.00 cfs) 2= Broad - Crested Rectangular Weir( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 21 Summary for Pond DMH13: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth= 1.26" for 2 -Year event Inflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Outflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.21' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 234.60' 12.0" Round Culvert L= 104.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 234.60'/232.50' S=0.0202'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.29 cfs @ 12.08 hrs HW= 235.20' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.29 cfs @ 2.64 fps) Summary for Pond DMH14: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth= 1.26" for 2 -Year event Inflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Outflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.41' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 235.80' 12.0" Round Culvert L= 58.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 235.80'/234.60' S=0.0207'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.29 cfs @ 12.08 hrs HW= 236.40' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.29 cfs @ 2.64 fps) Summary for Pond DMH15: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 1.26" for 2 -Year event Inflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Outflow = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.34 cfs @ 12.08 hrs, Volume= 4,197 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.11' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 243.50' 12.0" Round Culvert Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 22 L= 228.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.50'/236.30' S=0.0315'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.29 cfs @ 12.08 hrs HW= 244.10' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.29 cfs @ 2.64 fps) Summary for Pond DMH4: Inflow Area = 180,561 sf, 72.40% Impervious, Inflow Depth = 1.61" for 2 -Year event Inflow = 7.35 cfs @ 12.08 hrs, Volume= 24,194 cf Outflow = 7.35 cfs @ 12.08 hrs, Volume= 24,194 cf, Atten= 0 %, Lag= 0.0 min Primary = 7.35 cfs @ 12.08 hrs, Volume= 24,194 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.14' @ 12.08 hrs Flood Elev= 229.00' Device Routing Invert Outlet Devices #1 Primary 219.80' 24.0" Round TO EX. 24" FES IN EX. DET.BASIN L= 29.3' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 219.80'/219.44' S=0.0123'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =7.12 cfs @ 12.08 hrs HW= 221.11' (Free Discharge) t--1 =TO EX. 24" FES IN EX. DET.BASIN (Barrel Controls 7.12 cfs @ 4.63 fps) Summary for Pond DMH5: Inflow Area = 150,920 sf, 70.81 % Impervious, Inflow Depth = 1.63" for 2 -Year event Inflow = 6.25 cfs @ 12.08 hrs, Volume= 20,561 cf Outflow = 6.25 cfs @ 12.08 hrs, Volume= 20,561 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.25 cfs @ 12.08 hrs, Volume= 20,561 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.12' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 222.83' 18.0" Round Culvert L= 282.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.83'/220.70' S=0.0076'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 1.77 sf Primary OutFlow Max =6.05 cfs @ 12.08 hrs HW= 224.09' (Free Discharge) t--1 =Culvert (Inlet Controls 6.05 cfs @ 3.82 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 23 Summary for Pond DMH6: Inflow Area = 107,715 sf, 70.09% Impervious, Inflow Depth = 1.53" for 2 -Year event Inflow = 4.08 cfs @ 12.08 hrs, Volume= 13,773 cf Outflow = 4.08 cfs @ 12.08 hrs, Volume= 13,773 cf, Atten= 0 %, Lag= 0.0 min Primary = 4.08 cfs @ 12.08 hrs, Volume= 13,773 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.12' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 224.14' 24.0" Round Culvert 11.70 hrs, L= 89.5' CPP, projecting, no headwall, Ke= 0.900 1,254 cf Inlet/ Outlet Invert= 224.14'/222.83' S=0.0146'/' Cc= 0.900 2.08 cfs @ n=0.010 PVC, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =3.95 cfs @ 12.08 hrs HW= 225.10' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.95 cfs @ 2.64 fps) Summary for Pond INF6: U/G INF. Inflow Area = 60,434 sf, 76.01% Impervious, Inflow Depth = 2.01" for 2 -Year event Inflow = 3.06 cfs @ 12.07 hrs, Volume= 10,120 cf Outflow = 2.08 cfs @ 12.17 hrs, Volume= 8,202 cf, Atten= 32 %, Lag= 5.6 min Discarded = 0.01 cfs @ 11.70 hrs, Volume= 1,254 cf Primary = 2.08 cfs @ 12.17 hrs, Volume= 6,948 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.31' @ 12.17 hrs Surf.Area= 2,670 sf Storage= 3,994 cf Plug -Flow detention time= 385.0 min calculated for 8,196 cf (81 % of inflow) Center -of -Mass det. time= 311.6 min ( 1,094.6 - 783.0 ) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 24 Volume Invert Avail.Storage Storage Description #1A 227.00' 310 cf 25.35'W x 34.00'L x 3.17'H Field A 2,732 cf Overall - 1,958 cf Embedded = 774 cf x 40.0% Voids #2A 227.50' 1,334 cf Concrete Dry Well 500gal x 20 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 5 Rows of 4 Chambers #313 226.00' 265 cf 20.68'W x 34.00'L x 3.17'H Field B 2,229 cf Overall - 1,567 cf Embedded = 662 cf x 40.0% Voids #413 226.50' 1,067 cf Concrete Dry Well 500gal x 16 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 4 Rows of 4 Chambers #5C 225.00' 310 cf 16.01'W x 50.00'L x 3.17'H Field C 2,538 cf Overall - 1,763 cf Embedded = 775 cf x 40.0% Voids #6C 225.50' 1,201 cf Concrete Dry Well 500gal x 18 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 3 Rows of 6 Chambers #7D 224.50' 102 cf 11.34'W x 18.00'L x 3.17'H Field D 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #8D 225.00' 267 cf Concrete Dry Well 500gal x 4 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 2 Rows of 2 Chambers #9 224.50' 402 cf 8.00'D x 4.00'H Vertical Cone /Cvlinderx 2 5,258 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.50' 0.090 in /hr Exfiltration over Surface area #2 Primary 227.50' 12.0" Round Culvert L= 23.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 227.50'/ 224.30' S= 0.1391 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max =0.01 cfs @ 11.70 hrs HW= 227.04' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max =2.03 cfs @ 12.17 hrs HW= 228.29' (Free Discharge) L2= Culvert (Inlet Controls 2.03 cfs @ 3.03 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 25 Summary for Pond INF7: U/G INF. Inflow Area = 7,747 sf, 100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.48 cfs @ 12.07 hrs, Volume= 1,659 cf Outflow = 0.00 cfs @ 4.80 hrs, Volume= 206 cf, Atten= 100 %, Lag= 0.0 min Discarded = 0.00 cfs @ 4.80 hrs, Volume= 206 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.47' @ 24.12 hrs Surf.Area= 402 sf Storage= 1,597 cf Plug -Flow detention time= 1,816.4 min calculated for 206 cf (12% of inflow) Center -of -Mass det. time= 1,511.8 min ( 2,270.1 - 758.4 ) Volume Invert Avail.Storage Storage Description #1 226.50' 1,608 cf 8.00'D x 4.00'H Vertical Cone /Cylinderx 8 Device Routing Invert Outlet Devices #1 Primary 230.50' 12.0" Round Culvert L= 48.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 230.50'/225.00' S=0.1146'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Discarded 226.50' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 4.80 hrs HW= 226.55' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.00 cfs @ 0.00 hrs HW= 226.50' (Free Discharge) 't--1 =Culvert ( Controls 0.00 cfs) Summary for Pond P -C11310: Inflow Area = 2,715 sf, 62.32% Impervious, Inflow Depth= 1.89" for 2 -Year event Inflow = 0.14 cfs @ 12.07 hrs, Volume= 427 cf Outflow = 0.14 cfs @ 12.07 hrs, Volume= 427 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.14 cfs @ 12.07 hrs, Volume= 427 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.18' @ 12.07 hrs Flood Elev= 231.40' Device Routing Invert Outlet Devices #1 Primary 224.00' 12.0" Round Culvert L= 20.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 224.00'/222.00' S=0.1000'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.13 cfs @ 12.07 hrs HW= 224.17' (Free Discharge) L1= Culvert (Inlet Controls 0.13 cfs @ 1.41 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 26 Summary for Pond P -C11311: Inflow Area = 3,462 sf, 32.06% Impervious, Inflow Depth = 0.72" for 2 -Year event Inflow = 0.06 cfs @ 12.09 hrs, Volume= 207 cf Outflow = 0.06 cfs @ 12.09 hrs, Volume= 207 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.06 cfs @ 12.09 hrs, Volume= 207 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.12' @ 12.09 hrs Flood Elev= 231.30' Device Routing Invert Outlet Devices #1 Primary 226.00' 12.0" Round Culvert L= 44.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 226.00'/225.00' S=0.0227'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.06 cfs @ 12.09 hrs HW= 226.11' (Free Discharge) L1= Culvert (Inlet Controls 0.06 cfs @ 1.15 fps) Summary for Pond P -C11313: Inflow Area = 1,923 sf, 33.44% Impervious, Inflow Depth = 0.74" for 2 -Year event Inflow = 0.03 cfs @ 12.09 hrs, Volume= 118 cf Outflow = 0.03 cfs @ 12.09 hrs, Volume= 118 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.03 cfs @ 12.09 hrs, Volume= 118 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.89' @ 12.09 hrs Flood Elev= 231.76' Device Ro Invert Outlet Devices #1 Primary 227.80' 12.0" Round Culvert L= 65.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.80'/226.00' S=0.0277'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.03 cfs @ 12.09 hrs HW= 227.89' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.03 cfs @ 1.00 fps) Summary for Pond P -C1135: Inflow Area = 23,642 sf, 54.13% Impervious, Inflow Depth= 1.57" for 2 -Year event Inflow = 1.00 cfs @ 12.08 hrs, Volume= 3,085 cf Outflow = 1.00 cfs @ 12.08 hrs, Volume= 3,085 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.00 cfs @ 12.08 hrs, Volume= 3,085 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 27 Peak Elev= 225.51' @ 12.08 hrs Flood Elev= 228.89' Device Routing Invert Outlet Devices #1 Primary 225.00' 15.0" Round Culvert L= 70.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0071 T Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =0.97 cfs @ 12.08 hrs HW= 225.50' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.97 cfs @ 3.10 fps) Summary for Pond P -C1136: Inflow Area = 6,271 sf, 41.73% Impervious, Inflow Depth = 0.96" for 2 -Year event Inflow = 0.15 cfs @ 12.09 hrs, Volume= 501 cf Outflow = 0.15 cfs @ 12.09 hrs, Volume= 501 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.15 cfs @ 12.09 hrs, Volume= 501 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.19' @ 12.09 hrs Flood Elev= 230.80' Device Routing Invert Outlet Devices #1 Primary 227.00' 12.0" Round Culvert L= 43.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.00'/225.50' S=0.0349'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.15 cfs @ 12.09 hrs HW= 227.19' (Free Discharge) L1= Culvert (Inlet Controls 0.15 cfs @ 1.47 fps) Summary for Pond P -C1137: Inflow Area = 3,222 sf, 28.15% Impervious, Inflow Depth= 0.65" for 2 -Year event Inflow = 0.05 cfs @ 12.09 hrs, Volume= 174 cf Outflow = 0.05 cfs @ 12.09 hrs, Volume= 174 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.05 cfs @ 12.09 hrs, Volume= 174 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.64' @ 12.09 hrs Flood Elev= 231.50' Device Routing Invert Outlet Devices #1 Primary 228.50' 8.0" Round Culvert L= 73.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 228.50'/228.00' S=0.0068'/' Cc= 0.900 n=0.013, Flow Area= 0.35 sf Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 28 Primary OutFlow Max =0.05 cfs @ 12.09 hrs HW= 228.63' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.05 cfs @ 1.44 fps) Summary for Pond P -C1138: Inflow Area = 7,284 sf, 71.87% Impervious, Inflow = 0.40 cfs @ 12.07 hrs, Volume= Outflow = 0.40 cfs @ 12.07 hrs, Volume= Primary = 0.40 cfs @ 12.07 hrs, Volume= Inflow Depth = 2.06" 1,252 cf 1,252 cf, 1,252 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.55' @ 12.07 hrs Flood Elev= 231.10' for 2 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 224.20' 12.0" Round Culvert L= 15.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 224.20'/224.00' S=0.0133'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.38 cfs @ 12.07 hrs HW= 224.55' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.38 cfs @ 1.58 fps) Summary for Pond P -C1139: Inflow Area = 3,276 sf, 89.41 % Impervious, Inflow = 0.20 cfs @ 12.07 hrs, Volume= Outflow = 0.20 cfs @ 12.07 hrs, Volume= Primary = 0.20 cfs @ 12.07 hrs, Volume= Inflow Depth = 2.36" 643 cf 643 cf, 643 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.71' @ 12.07 hrs Flood Elev= 231.76' for 2 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 223.50' 12.0" Round Culvert L= 56.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 223.50'/222.00' S=0.0268'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.18 cfs @ 12.07 hrs HW= 223.71' (Free Discharge) L1= Culvert (Inlet Controls 0.18 cfs @ 1.55 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 29 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.13' @ 12.08 hrs Flood Elev= 231.15' Device Routing Invert Outlet Devices #1 Primary 222.00' 24.0" Round Culvert L= 132.5' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 222.00'/221.00' S=0.0075'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =6.05 cfs @ 12.08 hrs HW= 223.11' (Free Discharge) 't--1 =Culvert (Barrel Controls 6.05 cfs @ 4.88 fps) Summary for Pond P -DMH6: Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow Depth = 1.38" for 2 -Year event Inflow = 1.96 cfs @ 12.21 hrs, Volume= 6,948 cf Outflow = 1.96 cfs @ 12.21 hrs, Volume= 6,948 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.96 cfs @ 12.21 hrs, Volume= 6,948 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.17' @ 12.21 hrs Flood Elev= 226.70' Device Routing Invert Outlet Devices #1 Primary 220.55' 24.0" Round Culvert L= 21.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 220.55'/219.50' S=0.0500'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =1.93 cfs @ 12.21 hrs HW= 221.17' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.93 cfs @ 2.36 fps) Summary for Pond P -DMH7: Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow Depth = 1.38" for 2 -Year event Inflow = 2.08 cfs @ 12.17 hrs, Volume= 6,948 cf Outflow = 2.08 cfs @ 12.17 hrs, Volume= 6,948 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.08 cfs @ 12.17 hrs, Volume= 6,948 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Summary for Pond P- DMH12: Inflow Area = 158,667 sf, 72.23% Impervious, Inflow Depth = 1.56" for 2 -Year event Inflow = 6.25 cfs @ 12.08 hrs, Volume= 20,561 cf Outflow = 6.25 cfs @ 12.08 hrs, Volume= 20,561 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.25 cfs @ 12.08 hrs, Volume= 20,561 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.13' @ 12.08 hrs Flood Elev= 231.15' Device Routing Invert Outlet Devices #1 Primary 222.00' 24.0" Round Culvert L= 132.5' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 222.00'/221.00' S=0.0075'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =6.05 cfs @ 12.08 hrs HW= 223.11' (Free Discharge) 't--1 =Culvert (Barrel Controls 6.05 cfs @ 4.88 fps) Summary for Pond P -DMH6: Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow Depth = 1.38" for 2 -Year event Inflow = 1.96 cfs @ 12.21 hrs, Volume= 6,948 cf Outflow = 1.96 cfs @ 12.21 hrs, Volume= 6,948 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.96 cfs @ 12.21 hrs, Volume= 6,948 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.17' @ 12.21 hrs Flood Elev= 226.70' Device Routing Invert Outlet Devices #1 Primary 220.55' 24.0" Round Culvert L= 21.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 220.55'/219.50' S=0.0500'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =1.93 cfs @ 12.21 hrs HW= 221.17' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.93 cfs @ 2.36 fps) Summary for Pond P -DMH7: Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow Depth = 1.38" for 2 -Year event Inflow = 2.08 cfs @ 12.17 hrs, Volume= 6,948 cf Outflow = 2.08 cfs @ 12.17 hrs, Volume= 6,948 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.08 cfs @ 12.17 hrs, Volume= 6,948 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 30 Peak Elev= 231.35' @ 12.17 hrs Flood Elev= 233.00' Device Routing Invert Outlet Devices #1 Primary 225.00' 24.0" Round Culvert L= 78.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.00'/223.50' S=0.0192'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf #2 Device 1 230.00' 0.5' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =2.03 cfs @ 12.17 hrs HW= 231.32' (Free Discharge) 't--1 =Culvert (Passes 2.03 cfs of 34.90 cfs potential flow) L2= Broad -crested Rectangular Weir (Weir Controls 2.03 cfs @ 3.06 fps) Summary for Pond P -DMH8: Inflow Area = 21,598 sf, 100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 1.35 cfs @ 12.07 hrs, Volume= 4,624 cf Outflow = 1.35 cfs @ 12.07 hrs, Volume= 4,624 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.35 cfs @ 12.07 hrs, Volume= 4,624 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.56' @ 12.07 hrs Flood Elev= 232.42' Device Routina Invert Outlet Devices #1 Primary 228.00' 15.0" Round Culvert L= 134.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 228.00'/ 224.50' S= 0.0261 T Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =1.30 cfs @ 12.07 hrs HW= 228.55' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.30 cfs @ 2.52 fps) Summary for Pond P -DMH9: Inflow Area = 170,001 sf, 72.10% Impervious, Inflow Depth = 1.57" for 2 -Year event Inflow = 6.76 cfs @ 12.08 hrs, Volume= 22,299 cf Outflow = 6.76 cfs @ 12.08 hrs, Volume= 22,299 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.76 cfs @ 12.08 hrs, Volume= 22,299 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 222.14' @ 12.08 hrs Flood Elev= 232.70' Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 31 Device Routing Invert Outlet Devices #1 Primary 221.00' 24.0" Round DOGHOUSE JUNCTION TO EX. 24" HDPE L= 107.5' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 221.00'/219.90' S=0.0102'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =6.54 cfs @ 12.08 hrs HW= 222.12' (Free Discharge) L1= DOGHOUSE JUNCTION TO EX. 24" HDPE(Inlet Controls 6.54 cfs @ 3.61 fps) Summary for Pond ST: Inflow Area = 8,470 sf, 100.00% Impervious, Inflow Depth = 2.57" for 2 -Year event Inflow = 0.53 cfs @ 12.07 hrs, Volume= 1,813 cf Outflow = 0.25 cfs @ 12.27 hrs, Volume= 838 cf, Atten= 54 %, Lag= 11.8 min Primary = 0.25 cfs @ 12.27 hrs, Volume= 838 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.38' @ 12.27 hrs Surf.Area= 0 sf Storage= 1,017 cf Plug -Flow detention time= 274.9 min calculated for 838 cf (46% of inflow) Center -of -Mass det. time= 143.3 min ( 901.7 - 758.4 ) Volume Invert Avail.Storage Storage Description #1 223.40' 1,360 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 223.40 0 231.40 1,360 Device Routing Invert Outlet Devices #1 Primary 229.14' 12.0" Round Culvert L= 27.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.14'/224.85' S=0.1589'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.22 cfs @ 12.27 hrs HW= 229.37' (Free Discharge) t--1 =Culvert (Inlet Controls 0.22 cfs @ 1.64 fps) Summary for Pond SWM1: U/G DET. Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow Depth = 1.38" for 2 -Year event Inflow = 2.08 cfs @ 12.17 hrs, Volume= 6,948 cf Outflow = 1.96 cfs @ 12.21 hrs, Volume= 6,948 cf, Atten= 6 %, Lag= 2.8 min Primary = 1.96 cfs @ 12.21 hrs, Volume= 6,948 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.42' @ 12.21 hrs Surf.Area= 560 sf Storage= 261 cf Flood Elev= 226.00' Surf.Area= 560 sf Storage= 1,211 cf Brookhaven, Lexington, MA 151067 2017 POST AP2 Type/// 24 -hr 2 -Year Rainfall= 2.80" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 32 Plug -Flow detention time= 3.9 min calculated for 6,943 cf (100% of inflow) Center -of -Mass det. time= 4.0 min ( 871.0 - 867.0 ) Volume Invert Avail.Storage Storage Description #1A 220.50' 359 cf 14.00'W x 40.00'L x 3.50'H Field A 1,960 cf Overall - 1,063 cf Embedded = 897 cf x 40.0% Voids #2A 220.50' 852 cf ADS N -12 36" x 6 Inside #1 Inside= 36.1 "W x 36.1 "H => 7.10 sf x 20.001 = 142.0 cf Outside= 42.0 "W x 42.0 "H => 8.86 sf x 20.001 = 177.1 cf 3 Rows of 2 Chambers Primary OutFlow Max =1.94 cfs @ 12.21 hrs HW= 221.41' (Free Discharge) T_71 =Culvert (Inlet Controls 1.94 cfs @ 2.57 fps) L2 =LOW FLOW ORIFICE (Passes 1.94 cfs of 2.45 cfs potential flow) 3= Broad -Crested Rectangular Weir( Controls 0.00 cfs) Summary for Link AP2: Inflow Area = 347,640 sf, 57.70% Impervious, Inflow Depth= 1.38" for 2 -Year event Inflow = 6.38 cfs @ 12.28 hrs, Volume= 40,040 cf Primary = 6.38 cfs @ 12.28 hrs, Volume= 40,040 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 1,211 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 220.50' 12.0" Round Culvert L= 21.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 220.50'/219.00' S=0.0714'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Device 1 220.50' 12.0" Vert. LOW FLOW ORIFICE C= 0.600 #3 Primary 224.00' 0.5' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =1.94 cfs @ 12.21 hrs HW= 221.41' (Free Discharge) T_71 =Culvert (Inlet Controls 1.94 cfs @ 2.57 fps) L2 =LOW FLOW ORIFICE (Passes 1.94 cfs of 2.45 cfs potential flow) 3= Broad -Crested Rectangular Weir( Controls 0.00 cfs) Summary for Link AP2: Inflow Area = 347,640 sf, 57.70% Impervious, Inflow Depth= 1.38" for 2 -Year event Inflow = 6.38 cfs @ 12.28 hrs, Volume= 40,040 cf Primary = 6.38 cfs @ 12.28 hrs, Volume= 40,040 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment EX. SC -1: Runoff = 0.32 cfs @ 12.07 hrs, Volume= 1,015 cf, Depth= 3.20" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 1,735 80 >75% Grass cover, Good, HSG D 2,065 98 Paved parking, HSG D 3,800 90 Weighted Average 1,735 45.66% Pervious Area 2,065 54.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -17: Runoff = 0.63 cfs @ 12.08 hrs, Volume= 1,974 cf, Depth= 2.73" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 1,325 98 Roofs, HSG B 2,993 61 >75% Grass cover, Good, HSG B 4.366 98 Paved oarkina. HSG B 8,684 85 Weighted Average 2,993 34.47% Pervious Area 5,691 65.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -18: Runoff = 3.20 cfs @ 12.07 hrs, Volume= 10,018 cf, Depth= 3.01" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 34 Area (so CN Description 13,935 98 Roofs, HSG B 803 98 Roofs, HSG D 9,943 61 >75% Grass cover, Good, HSG B 2,229 80 >75% Grass cover, Good, HSG D 8,923 98 Paved parking, HSG B 4.124 98 Paved oarkina. HSG D 39,957 88 Weighted Average 12,172 30.46% Pervious Area 27,785 69.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -19: Runoff = 1.02 cfs @ 12.07 hrs, Volume= 3,549 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 5,245 98 Paved parking, HSG B 5,234 98 Paved parking, HSG D 10,479 98 Weighted Average 10,479 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -2: Runoff = 0.31 cfs @ 12.07 hrs, Volume= 1,077 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 3,181 98 Paved parking, HSG D 3,181 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 35 Summary for Subcatchment EX. SC -20: Runoff = 1.24 cfs @ 12.08 hrs, Volume= 3,853 cf, Depth= 1.97" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 7,685 98 Roofs, HSG B 13,660 61 >75% Grass cover, Good, HSG B 2,108 98 Paved parking, HSG B 23,453 76 Weighted Average 13,660 58.24% Pervious Area 9,793 41.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -21: Runoff = 1.44 cfs @ 12.07 hrs, Volume= 4,497 cf, Depth= 2.91" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 5,373 98 Roofs, HSG B 5,318 61 >75% Grass cover, Good, HSG B 7,833 98 Paved parking, HSG B 18,524 87 Weighted Average 5,318 28.71 % Pervious Area 13,206 71.29% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -22: Runoff = 1.24 cfs @ 12.08 hrs, Volume= 3,832 cf, Depth= 2.13" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 36 Area (so CN Description 1,599 98 Roofs, HSG B 11,736 61 >75% Grass cover, Good, HSG B 8,266 98 Paved parking, HSG B 21,601 78 Weighted Average 11,736 71 54.33% Pervious Area 9,865 45.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment EX. SC -3: Runoff = 0.56 cfs @ 12.08 hrs, Volume= 1,779 cf, Depth= 1.60" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 6,580 61 >75% Grass cover, Good, HSG B 6,168 80 >75% Grass cover, Good, HSG D 263 98 Paved parking, HSG B 302 98 Paved parking, HSG D 13,313 71 Weighted Average 12,748 95.76% Pervious Area 565 4.24% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -R: Runoff = 0.49 cfs @ 12.07 hrs, Volume= 1,724 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 5,090 98 Roofs, HSG B 5,090 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 37 Summary for Subcatchment EX. SC -ST: Runoff = 0.82 cfs @ 12.07 hrs, Volume= 2,869 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 8,470 98 Roofs, HSG B 8,470 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -10: Runoff = 0.23 cfs @ 12.07 hrs, Volume= 748 cf, Depth= 3.31" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 1,023 80 >75% Grass cover, Good, HSG D 1,692 98 Paved parking, HSG D 2,715 91 Weighted Average 1,023 37.68% Pervious Area 1,692 62.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -11: Runoff = 0.07 cfs @ 12.08 hrs, Volume= 215 cf, Depth= 1.67" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 1,072 61 >75% Grass cover, Good, HSG B 467 98 Paved parking, HSG B 1,539 72 Weighted Average 1,072 69.66% Pervious Area 467 30.34% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 38 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -12: Runoff = 3.74 cfs @ 12.07 hrs, Volume= 11,900 cf, Depth= 3.31" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 1,039 98 Roofs, HSG D 4,014 61 >75% Grass cover, Good, HSG B 7,822 80 >75% Grass cover, Good, HSG D 2,473 98 Paved parking, HSG B 27,857 98 Paved parking, HSG D 43,205 91 Weighted Average 11,836 27.39% Pervious Area 31,369 72.61 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -13: Runoff = 0.09 cfs @ 12.08 hrs, Volume= 280 cf, Depth= 1.75" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 1,280 61 >75% Grass cover, Good, HSG B 643 98 Paved parking, HSG B 1,923 73 Weighted Average 1,280 66.56% Pervious Area 643 33.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -5: Runoff = 1.84 cfs @ 12.07 hrs, Volume= 5,739 cf, Depth= 2.91" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 39 Area (sf) CN Description 2,793 61 >75% Grass cover, Good, HSG B 8,051 80 >75% Grass cover, Good, HSG D 249 98 Paved parking, HSG B 12,549 98 Paved parking, HSG D 23,642 87 Weighted Average 10,844 45.87% Pervious Area 12,798 54.13% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -6: Runoff = 0.21 cfs @ 12.08 hrs, Volume= 648 cf, Depth= 2.55" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 1,176 61 >75% Grass cover, Good, HSG B 163 80 >75% Grass cover, Good, HSG D 1,318 98 Paved parking, HSG B 392 98 Paved parking, HSG D 3,049 83 Weighted Average 1,339 43.92% Pervious Area 1,710 56.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -7: Runoff = 0.14 cfs @ 12.08 hrs, Volume= 430 cf, Depth= 1.60" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 2,315 61 >75% Grass cover, Good, HSG B 907 98 Paved parking, HSG B 3,222 71 Weighted Average 2,315 71.85% Pervious Area 907 28.15% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 40 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -8: Runoff = 0.66 cfs @ 12.07 hrs, Volume= 2,132 cf, Depth= 3.51" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 2,049 80 >75% Grass cover, Good, HSG D 5.235 98 Paved oarkina. HSG D 7,284 93 Weighted Average 2,049 28.13% Pervious Area 5,235 71.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -9: Runoff = 0.31 cfs @ 12.07 hrs, Volume= 1,048 cf, Depth= 3.84" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 347 80 >75% Grass cover, Good, HSG D 2,929 98 Paved parking, HSG D 3,276 96 Weighted Average 347 10.59% Pervious Area 2,929 89.41% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C1: Runoff = 1.11 cfs @ 12.08 hrs, Volume= 3,449 cf, Depth= 2.21" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 41 Area (sf) CN Description 11,805 80 >75% Grass cover, Good, HSG D 6,928 77 Woods, Good, HSG D 18,733 79 Weighted Average 18,733 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C2: Runoff = 1.53 cfs @ 12.08 hrs, Volume= 4,734 cf, Depth= 2.05" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (sf) CN Description 1,605 80 >75% Grass cover, Good, HSG D 26,117 77 Woods, Good, HSG D 27,722 77 Weighted Average 27,722 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -E4: Runoff = 1.02 cfs @ 12.08 hrs, Volume= 3,141 cf, Depth= 2.29" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 2,571 98 Roofs, HSG B 7,803 61 >75% Grass cover, Good, HSG B 337 80 >75% Grass cover, Good, HSG D 5,264 98 Paved parking, HSG B 468 98 Paved parking, HSG D 16,443 80 Weighted Average 8,140 49.50% Pervious Area 8,303 50.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 42 Summary for Subcatchment P. SC -R1: Runoff = 0.37 cfs @ 12.07 hrs, Volume= 1,298 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 3,833 98 Roofs, HSG B 3,833 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R2: Runoff = 0.75 cfs @ 12.07 hrs, Volume= 2,624 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 7,747 98 Roofs, HSG D 7,747 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R3: Runoff = 2.10 cfs @ 12.07 hrs, Volume= 7,315 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 21,598 98 Roofs, HSG B 21,598 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 43 Summary for Subcatchment P. SC -R9: Runoff = 0.50 cfs @ 12.07 hrs, Volume= 1,747 cf, Depth= 4.06" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 10 -Year Rainfall= 4.30" Area (so CN Description 5,157 98 Roofs, HSG B 5,157 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Pond C1131: Inflow Area = 3,800 sf, 54.34% Impervious, Inflow Depth= 3.20" for 10 -Year event Inflow = 0.32 cfs @ 12.07 hrs, Volume= 1,015 cf Outflow = 0.32 cfs @ 12.07 hrs, Volume= 1,015 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.32 cfs @ 12.07 hrs, Volume= 1,015 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.53' @ 12.07 hrs Flood Elev= 224.92' Device Routing Invert Outlet Devices #1 Primary 224.92' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads #2 Primary 221.25' 12.0" Round Culvert L= 15.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 221.25'/218.16' S=0.1994'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.31 cfs @ 12.07 hrs HW= 221.52' (Free Discharge) t1= Orifice /Grate ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.31 cfs @ 1.78 fps) Summary for Pond CB16: Inflow Area = 43,205 sf, 72.61 % Impervious, Inflow Depth = 3.31" for 10 -Year event Inflow = 3.74 cfs @ 12.07 hrs, Volume= 11,900 cf Outflow = 3.74 cfs @ 12.07 hrs, Volume= 11,900 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.74 cfs @ 12.07 hrs, Volume= 11,900 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.18' @ 12.07 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 44 Device Routing Invert Outlet Devices #1 Primary 225.71' 12.0" Round Culvert L= 9.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.71'/222.83' S=0.3200'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 229.50' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =3.60 cfs @ 12.07 hrs HW= 227.12' (Free Discharge) t1= Culvert (Inlet Controls 3.60 cfs @ 4.58 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond CB17: Inflow Area = 8,684 sf, 65.53% Impervious, Inflow Depth= 2.73" for 10 -Year event Inflow = 0.63 cfs @ 12.08 hrs, Volume= 1,974 cf Outflow = 0.63 cfs @ 12.08 hrs, Volume= 1,974 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.63 cfs @ 12.08 hrs, Volume= 1,974 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.73' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 225.13' 12.0" Round Culvert L= 80.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.13'/225.07' S=0.0008'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 228.31' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.61 cfs @ 12.08 hrs HW= 225.72' (Free Discharge) �--2=Orifi 1= Culve rt (Barrel Controls 0.61 cfs @ 1.85 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB18: Inflow Area = 39,957 sf, 69.54% Impervious, Inflow Depth = 3.01" for 10 -Year event Inflow = 3.20 cfs @ 12.07 hrs, Volume= 10,018 cf Outflow = 3.20 cfs @ 12.07 hrs, Volume= 10,018 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.20 cfs @ 12.07 hrs, Volume= 10,018 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.54' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 230.25' 12.0" Round Culvert L= 14.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.25'/230.10' S=0.0103'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 234.91' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 45 Limited to weir flow at low heads Primary OutFlow Max =3.09 cfs @ 12.07 hrs HW= 231.50' (Free Discharge) �--2=Orifi 1= Culve rt (Barrel Controls 3.09 cfs @ 4.04 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB19: Inflow Area = 10,479 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 1.02 cfs @ 12.07 hrs, Volume= 3,549 cf Outflow = 1.02 cfs @ 12.07 hrs, Volume= 3,549 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.02 cfs @ 12.07 hrs, Volume= 3,549 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.78' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 230.16' 12.0" Round Culvert L= 6.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.16'/230.10' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 235.05' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.98 cfs @ 12.07 hrs HW= 230.76' (Free Discharge) �--2=Orifi 1= Culve rt (Barrel Controls 0.98 cfs @ 2.84 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond C1132: Inflow Area = 6,981 sf, 75.15% Impervious, Inflow Depth = 3.60" for 10 -Year event Inflow = 0.63 cfs @ 12.07 hrs, Volume= 2,092 cf Outflow = 0.63 cfs @ 12.07 hrs, Volume= 2,092 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.63 cfs @ 12.07 hrs, Volume= 2,092 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 218.70' @ 12.07 hrs Flood Elev= 225.01' Device Routing Invert Outlet Devices #1 Primary 218.16' 12.0" Round Culvert L= 135.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.16'/ 217.88' S= 0.0021 T Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 225.01' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.61 cfs @ 12.07 hrs HW= 218.69' (Free Discharge) t1= Culvert (Barrel Controls 0.61 cfs @ 2.07 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 46 Summary for Pond CB20: Inflow Area = 23,453 sf, 41.76% Impervious, Inflow Depth = 1.97" for 10 -Year event Inflow = 1.24 cfs @ 12.08 hrs, Volume= 3,853 cf Outflow = 1.24 cfs @ 12.08 hrs, Volume= 3,853 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.24 cfs @ 12.08 hrs, Volume= 3,853 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 238.69' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 235.70' 6.0" Round Culvert L= 143.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 235.70'/228.93' S=0.0472'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 0.20 sf #2 Primary 239.00' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =1.20 cfs @ 12.08 hrs HW= 238.54' (Free Discharge) �--2=Orifi 1= Culve rt (Inlet Controls 1.20 cfs @ 6.11 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB21: Inflow Area = 18,524 sf, 71.29% Impervious, Inflow Depth = 2.91" for 10 -Year event Inflow = 1.44 cfs @ 12.07 hrs, Volume= 4,497 cf Outflow = 1.44 cfs @ 12.07 hrs, Volume= 4,497 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.44 cfs @ 12.07 hrs, Volume= 4,497 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.58' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 243.80' 12.0" Round Culvert L= 25.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.80'/243.70' S=0.0039'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 247.80' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =1.39 cfs @ 12.07 hrs HW= 244.57' (Free Discharge) t1= Culvert (Barrel Controls 1.39 cfs @ 2.98 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond CB22: Inflow Area = 21,601 sf, 45.67% Impervious, Inflow Depth = 2.13" for 10 -Year event Inflow = 1.24 cfs @ 12.08 hrs, Volume= 3,832 cf Outflow = 1.24 cfs @ 12.08 hrs, Volume= 3,832 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.24 cfs @ 12.08 hrs, Volume= 3,832 cf Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 47 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.39' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 243.70' 12.0" Round Culvert L= 16.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.70'/243.60' S=0.0062'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 247.90' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =1.20 cfs @ 12.08 hrs HW= 244.38' (Free Discharge) t1= Culvert (Barrel Controls 1.20 cfs @ 3.00 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond C1133: Inflow Area = 36,766 sf, 28.17% Impervious, Inflow Depth = 1.84" for 10 -Year event Inflow = 1.80 cfs @ 12.08 hrs, Volume= 5,631 cf Outflow = 1.80 cfs @ 12.08 hrs, Volume= 5,631 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.80 cfs @ 12.08 hrs, Volume= 5,631 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.66' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 228.93' 12.0" Round Culvert L= 16.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.93'/227.98' S=0.0576'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 231.88' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =1.74 cfs @ 12.08 hrs HW= 229.65' (Free Discharge) �--2=Orifi 1= Culve rt (Inlet Controls 1.74 cfs @ 2.89 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond C1134: Inflow Area = 16,443 sf, 50.50% Impervious, Inflow Depth= 2.29" for 10 -Year event Inflow = 1.02 cfs @ 12.08 hrs, Volume= 3,141 cf Outflow = 1.02 cfs @ 12.08 hrs, Volume= 3,141 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.02 cfs @ 12.08 hrs, Volume= 3,141 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.16' @ 12.08 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 48 Device Routing Invert Outlet Devices #1 Primary 229.64' 12.0" Round Culvert L= 31.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.64'/227.96' S=0.0542'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 232.11' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =0.98 cfs @ 12.08 hrs HW= 230.15' (Free Discharge) t1= Culvert (Inlet Controls 0.98 cfs @ 2.43 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond DB: MOD.EX. DET.BASIN Inflow Area = 319,918 sf, 62.70% Impervious, Inflow Depth = 2.74" for 10 -Year event Inflow = 21.06 cfs @ 12.08 hrs, Volume= 73,045 cf Outflow = 14.58 cfs @ 12.19 hrs, Volume= 72,947 cf, Atten= 31 %, Lag= 6.4 min Primary = 14.58 cfs @ 12.19 hrs, Volume= 72,947 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 220.94' @ 12.19 hrs Surf.Area= 8,109 sf Storage= 9,693 cf Plug -Flow detention time= 11.4 min calculated for 72,896 cf (100% of inflow) Center -of -Mass det. time= 10.6 min ( 823.3 - 812.6 ) Volume Invert Avail.Storage Storage Description #1 218.00' 18,957 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 218.00 331 121.0 0 0 331 219.00 961 165.0 619 619 1,343 220.00 5,260 601.0 2,823 3,442 27,922 221.00 8,303 630.0 6,724 10,166 30,829 222.00 9,288 647.0 8,791 18,957 32,671 Device Routing Invert Outlet Devices #1 Primary 218.25' 12.0" Round Culvert L= 16.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 218.25'/217.81' S=0.0267'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Primary 220.00' 4.0' long x 15.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max =14.50 cfs @ 12.19 hrs HW= 220.94' (Free Discharge) �__1= Culvert (Inlet Controls 4.94 cfs @ 6.28 fps) 2= Broad - Crested Rectangular Weir (Weir Controls 9.57 cfs @ 2.55 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 49 Summary for Pond DMH1: Inflow Area = 53,209 sf, 35.07% Impervious, Inflow Depth = 1.98" for 10 -Year event Inflow = 2.81 cfs @ 12.08 hrs, Volume= 8,772 cf Outflow = 2.81 cfs @ 12.08 hrs, Volume= 8,772 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.81 cfs @ 12.08 hrs, Volume= 8,772 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.52' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 222.31' 12.0" Round Culvert L= 77.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 222.31'/219.41' S=0.0374'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =2.73 cfs @ 12.08 hrs HW= 223.48' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.73 cfs @ 3.47 fps) Summary for Pond DMH10: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.82 cfs @ 12.07 hrs, Volume= 2,869 cf Outflow = 0.82 cfs @ 12.07 hrs, Volume= 2,869 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.82 cfs @ 12.07 hrs, Volume= 2,869 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.42' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 228.95' 12.0" Round Culvert L= 36.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.95'/228.59' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.79 cfs @ 12.07 hrs HW= 229.41' (Free Discharge) 't--1 =Culvert (Barrel Controls 0.79 cfs @ 3.27 fps) Summary for Pond DMH11: Inflow Area = 90,561 sf, 67.73% Impervious, Inflow Depth = 2.90" for 10 -Year event Inflow = 6.90 cfs @ 12.07 hrs, Volume= 21,896 cf Outflow = 6.90 cfs @ 12.07 hrs, Volume= 21,896 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.90 cfs @ 12.07 hrs, Volume= 21,896 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.79' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 230.00' 12.0" Round Culvert Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 50 L= 142.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.00'/224.85' S=0.0363'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =6.65 cfs @ 12.07 hrs HW= 233.59' (Free Discharge) 't--1 =Culvert (Inlet Controls 6.65 cfs @ 8.46 fps) Summary for Pond DMH12: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 2.49" for 10 -Year event Inflow = 2.67 cfs @ 12.08 hrs, Volume= 8,329 cf Outflow = 2.67 cfs @ 12.08 hrs, Volume= 8,329 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.67 cfs @ 12.08 hrs, Volume= 8,329 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.49' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 232.50' 12.0" Round Culvert L= 68.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 232.50'/230.00' S=0.0368'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =2.59 cfs @ 12.08 hrs HW= 233.46' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.59 cfs @ 3.34 fps) Summary for Pond DMH12A: Inflow Area = 7,747 sf,100.00% Impervious, Inflow Depth = 1.47" for 10 -Year event Inflow = 0.26 cfs @ 12.37 hrs, Volume= 950 cf Outflow = 0.26 cfs @ 12.37 hrs, Volume= 950 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.26 cfs @ 12.37 hrs, Volume= 950 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.26' @ 12.37 hrs Flood Elev= 232.20' Device Routing Invert Outlet Devices #1 Primary 225.00' 12.0" Round Culvert L= 31.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.00'/223.00' S=0.0645'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Primary 231.00' 6.0' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =0.22 cfs @ 12.37 hrs HW= 225.23' (Free Discharge) �__1= Culvert (Inlet Controls 0.22 cfs @ 1.64 fps) 2= Broad - Crested Rectangular Weir( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 51 Summary for Pond DMH13: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 2.67 cfs @ 12.08 hrs, Volume= Outflow = 2.67 cfs @ 12.08 hrs, Volume= Primary = 2.67 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.49" 8,329 cf 8,329 cf, 8,329 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.59' @ 12.08 hrs for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 234.60' 12.0" Round Culvert L= 104.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 234.60'/232.50' S=0.0202'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =2.59 cfs @ 12.08 hrs HW= 235.56' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.59 cfs @ 3.34 fps) Summary for Pond DMH14: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 2.67 cfs @ 12.08 hrs, Volume= Outflow = 2.67 cfs @ 12.08 hrs, Volume= Primary = 2.67 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.49" 8,329 cf 8,329 cf, 8,329 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.79' @ 12.08 hrs for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 235.80' 12.0" Round Culvert L= 58.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 235.80'/234.60' S=0.0207'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =2.59 cfs @ 12.08 hrs HW= 236.76' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.59 cfs @ 3.34 fps) Summary for Pond DMH15: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 2.67 cfs @ 12.08 hrs, Volume= Outflow = 2.67 cfs @ 12.08 hrs, Volume= Primary = 2.67 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.49" 8,329 cf 8,329 cf, 8,329 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.49' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 243.50' 12.0" Round Culvert for 10 -Year event Atten= 0 %, Lag= 0.0 min Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 52 L= 228.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.50'/236.30' S=0.0315'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =2.59 cfs @ 12.08 hrs HW= 244.46' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.59 cfs @ 3.34 fps) Summary for Pond DMH4: Inflow Area = 180,561 sf, 72.40% Impervious, Inflow = 13.92 cfs @ 12.07 hrs, Volume= Outflow = 13.92 cfs @ 12.07 hrs, Volume= Primary = 13.92 cfs @ 12.07 hrs, Volume= Inflow Depth = 2.98" 44,782 cf 44,782 cf, 44,782 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.87' @ 12.07 hrs Flood Elev= 229.00' for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 219.80' 24.0" Round TO EX. 24" FES IN EX. DET.BASIN L= 29.3' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 219.80'/219.44' S=0.0123'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =13.43 cfs @ 12.07 hrs HW= 221.81' (Free Discharge) t--1 =TO EX. 24" FES IN EX. DET.BASIN (Inlet Controls 13.43 cfs @ 4.28 fps) Summary for Pond DMH5: Inflow Area = 150,920 sf, 70.81 % Impervious, Inflow = 12.06 cfs @ 12.07 hrs, Volume= Outflow = 12.06 cfs @ 12.07 hrs, Volume= Primary = 12.06 cfs @ 12.07 hrs, Volume= Inflow Depth = 2.99" 37,663 cf 37,663 cf, 37,663 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.37' @ 12.07 hrs for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 222.83' 18.0" Round Culvert L= 282.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.83'/220.70' S=0.0076'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 1.77 sf Primary OutFlow Max =11.62 cfs @ 12.07 hrs HW= 226.16' (Free Discharge) t--1 =Culvert (Barrel Controls 11.62 cfs @ 6.58 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 53 Summary for Pond DMH6: Inflow Area = 107,715 sf, 70.09% Impervious, Inflow = 8.29 cfs @ 12.08 hrs, Volume= Outflow = 8.29 cfs @ 12.08 hrs, Volume= Primary = 8.29 cfs @ 12.08 hrs, Volume= Inflow Depth = 2.87" 25,763 cf 25,763 cf, 25,763 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.64' @ 12.08 hrs for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 224.14' 24.0" Round Culvert L= 89.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 224.14'/222.83' S=0.0146'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =8.03 cfs @ 12.08 hrs HW= 225.61' (Free Discharge) 't--1 =Culvert (Inlet Controls 8.03 cfs @ 3.25 fps) Summary for Pond INF6: U/G INF. Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow = 5.15 cfs @ 12.07 hrs, Volume= Outflow = 3.88 cfs @ 12.15 hrs, Volume= Discarded = 0.01 cfs @ 10.40 hrs, Volume= Primary = 3.88 cfs @ 12.15 hrs, Volume= Inflow Depth = 3.41" 17,155 cf 15,232 cf, 1,284 cf 13,949 cf for 10 -Year event Atten= 25 %, Lag= 4.5 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.05' @ 12.15 hrs Surf.Area= 2,670 sf Storage= 4,751 cf Plug -Flow detention time= 240.7 min calculated for 15,222 cf (89% of inflow) Center -of -Mass det. time= 189.0 min ( 962.7 - 773.7 ) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 54 Volume Invert Avail.Storage Storage Description #1A 227.00' 310 cf 25.35'W x 34.00'L x 3.17'H Field A 2,732 cf Overall - 1,958 cf Embedded = 774 cf x 40.0% Voids #2A 227.50' 1,334 cf Concrete Dry Well 500gal x 20 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 5 Rows of 4 Chambers #313 226.00' 265 cf 20.68'W x 34.00'L x 3.17'H Field B 2,229 cf Overall - 1,567 cf Embedded = 662 cf x 40.0% Voids #413 226.50' 1,067 cf Concrete Dry Well 500gal x 16 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 4 Rows of 4 Chambers #5C 225.00' 310 cf 16.01'W x 50.00'L x 3.17'H Field C 2,538 cf Overall - 1,763 cf Embedded = 775 cf x 40.0% Voids #6C 225.50' 1,201 cf Concrete Dry Well 500gal x 18 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 3 Rows of 6 Chambers #7D 224.50' 102 cf 11.34'W x 18.00'L x 3.17'H Field D 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #8D 225.00' 267 cf Concrete Dry Well 500gal x 4 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 2 Rows of 2 Chambers #9 224.50' 402 cf 8.00'D x 4.00'H Vertical Cone /Cvlinderx 2 5,258 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.50' 0.090 in /hr Exfiltration over Surface area #2 Primary 227.50' 12.0" Round Culvert L= 23.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 227.50'/ 224.30' S= 0.1391 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max =0.01 cfs @ 10.40 hrs HW= 227.02' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max =3.87 cfs @ 12.15 hrs HW= 229.05' (Free Discharge) L2= Culvert (Inlet Controls 3.87 cfs @ 4.92 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 55 Summary for Pond INF7: U/G INF. Inflow Area = 7,747 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.75 cfs @ 12.07 hrs, Volume= 2,624 cf Outflow = 0.26 cfs @ 12.37 hrs, Volume= 1,160 cf, Atten= 66 %, Lag= 18.2 min Discarded = 0.00 cfs @ 3.35 hrs, Volume= 210 cf Primary = 0.26 cfs @ 12.37 hrs, Volume= 950 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.77' @ 12.37 hrs Surf.Area= 402 sf Storage= 1,608 cf Plug -Flow detention time= 549.5 min calculated for 1,160 cf (44% of inflow) Center -of -Mass det. time= 408.0 min ( 1,157.7 - 749.7 ) Volume Invert Avail.Storage Storage Description #1 226.50' 1,608 cf 8.00'D x 4.00'H Vertical Cone /Cylinderx 8 Device Routing Invert Outlet Devices #1 Primary 230.50' 12.0" Round Culvert L= 48.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 230.50'/225.00' S=0.1146'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Discarded 226.50' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 3.35 hrs HW= 226.55' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =0.23 cfs @ 12.37 hrs HW= 230.73' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.23 cfs @ 1.64 fps) Summary for Pond P -C11310: Inflow Area = 2,715 sf, 62.32% Impervious, Inflow Depth = 3.31" for 10 -Year event Inflow = 0.23 cfs @ 12.07 hrs, Volume= 748 cf Outflow = 0.23 cfs @ 12.07 hrs, Volume= 748 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.23 cfs @ 12.07 hrs, Volume= 748 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.24' @ 12.07 hrs Flood Elev= 231.40' Device Routing Invert Outlet Devices #1 Primary 224.00' 12.0" Round Culvert L= 20.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 224.00'/222.00' S=0.1000'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.22 cfs @ 12.07 hrs HW= 224.23' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.22 cfs @ 1.64 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 56 Summary for Pond P -C11311: Inflow Area = 3,462 sf, 32.06% Impervious, Inflow Depth = 1.71" for 10 -Year event Inflow = 0.16 cfs @ 12.08 hrs, Volume= 495 cf Outflow = 0.16 cfs @ 12.08 hrs, Volume= 495 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.16 cfs @ 12.08 hrs, Volume= 495 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.19' @ 12.08 hrs Flood Elev= 231.30' Device Routing Invert Outlet Devices #1 Primary 226.00' 12.0" Round Culvert L= 44.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 226.00'/225.00' S=0.0227'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.15 cfs @ 12.08 hrs HW= 226.19' (Free Discharge) L1= Culvert (Inlet Controls 0.15 cfs @ 1.47 fps) Summary for Pond P -C11313: Inflow Area = 1,923 sf, 33.44% Impervious, Inflow Depth = 1.75" for 10 -Year event Inflow = 0.09 cfs @ 12.08 hrs, Volume= 280 cf Outflow = 0.09 cfs @ 12.08 hrs, Volume= 280 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.09 cfs @ 12.08 hrs, Volume= 280 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.94' @ 12.08 hrs Flood Elev= 231.76' Device Ro Invert Outlet Devices #1 Primary 227.80' 12.0" Round Culvert L= 65.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.80'/226.00' S=0.0277'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.08 cfs @ 12.08 hrs HW= 227.94' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.08 cfs @ 1.27 fps) Summary for Pond P -C1135: Inflow Area = 23,642 sf, 54.13% Impervious, Inflow Depth = 2.91" for 10 -Year event Inflow = 1.84 cfs @ 12.07 hrs, Volume= 5,739 cf Outflow = 1.84 cfs @ 12.07 hrs, Volume= 5,739 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.84 cfs @ 12.07 hrs, Volume= 5,739 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 57 Peak Elev= 225.72' @ 12.07 hrs Flood Elev= 228.89' Device Routing Invert Outlet Devices #1 Primary 225.00' 15.0" Round Culvert L= 70.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0071 T Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =1.77 cfs @ 12.07 hrs HW= 225.71' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.77 cfs @ 3.58 fps) Summary for Pond P -C1136: Inflow Area = 6,271 sf, 41.73% Impervious, Inflow Depth = 2.06" for 10 -Year event Inflow = 0.34 cfs @ 12.08 hrs, Volume= 1,078 cf Outflow = 0.34 cfs @ 12.08 hrs, Volume= 1,078 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.34 cfs @ 12.08 hrs, Volume= 1,078 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.29' @ 12.08 hrs Flood Elev= 230.80' Device Routing Invert Outlet Devices #1 Primary 227.00' 12.0" Round Culvert L= 43.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.00'/225.50' S=0.0349'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.33 cfs @ 12.08 hrs HW= 227.28' (Free Discharge) L1= Culvert (Inlet Controls 0.33 cfs @ 1.81 fps) Summary for Pond P -C1137: Inflow Area = 3,222 sf, 28.15% Impervious, Inflow Depth = 1.60" for 10 -Year event Inflow = 0.14 cfs @ 12.08 hrs, Volume= 430 cf Outflow = 0.14 cfs @ 12.08 hrs, Volume= 430 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.14 cfs @ 12.08 hrs, Volume= 430 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.73' @ 12.08 hrs Flood Elev= 231.50' Device Routing Invert Outlet Devices #1 Primary 228.50' 8.0" Round Culvert L= 73.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 228.50'/228.00' S=0.0068'/' Cc= 0.900 n=0.013, Flow Area= 0.35 sf Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 58 Primary OutFlow Max =0.13 cfs @ 12.08 hrs HW= 228.72' (Free Discharge) L1= Culvert (Inlet Controls 0.13 cfs @ 1.27 fps) Summary for Pond P -C1138: Inflow Area = 7,284 sf, 71.87% Impervious, Inflow = 0.66 cfs @ 12.07 hrs, Volume= Outflow = 0.66 cfs @ 12.07 hrs, Volume= Primary = 0.66 cfs @ 12.07 hrs, Volume= Inflow Depth = 3.51" 2,132 cf 2,132 cf, 2,132 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.67' @ 12.07 hrs Flood Elev= 231.10' for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 224.20' 12.0" Round Culvert L= 15.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 224.20'/224.00' S=0.0133'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.63 cfs @ 12.07 hrs HW= 224.66' (Free Discharge) L1= Culvert (Inlet Controls 0.63 cfs @ 1.81 fps) Summary for Pond P -C1139: Inflow Area = 3,276 sf, 89.41 % Impervious, Inflow = 0.31 cfs @ 12.07 hrs, Volume= Outflow = 0.31 cfs @ 12.07 hrs, Volume= Primary = 0.31 cfs @ 12.07 hrs, Volume= Inflow Depth = 3.84" 1,048 cf 1,048 cf, 1,048 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.77' @ 12.07 hrs Flood Elev= 231.76' for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 223.50' 12.0" Round Culvert L= 56.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 223.50'/222.00' S=0.0268'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.30 cfs @ 12.07 hrs HW= 223.77' (Free Discharge) t--1 =Culvert (Inlet Controls 0.30 cfs @ 1.76 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 59 Summary for Pond P- DMH12: Inflow Area = 158,667 sf, 72.23% Impervious, Inflow = 12.06 cfs @ 12.07 hrs, Volume= Outflow = 12.06 cfs @ 12.07 hrs, Volume= Primary = 12.06 cfs @ 12.07 hrs, Volume= Inflow Depth = 2.92" 38,614 cf 38,614 cf, 38,614 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.71' @ 12.07 hrs Flood Elev= 231.15' for 10 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 222.00' 24.0" Round Culvert L= 132.5' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 222.00'/221.00' S=0.0075'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =11.62 cfs @ 12.07 hrs HW= 223.67' (Free Discharge) 't--1 =Culvert (Barrel Controls 11.62 cfs @ 5.61 fps) Summary for Pond P -DMH6: Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow = 3.49 cfs @ 12.22 hrs, Volume= Outflow = 3.49 cfs @ 12.22 hrs, Volume= Primary = 3.49 cfs @ 12.22 hrs, Volume= Inflow Depth = 2.77" 13,949 cf 13,949 cf, 13,949 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.39' @ 12.22 hrs Flood Elev= 226.70' Device Ro Invert Outlet Devices for 10 -Year event Atten= 0 %, Lag= 0.0 min #1 Primary 220.55' 24.0" Round Culvert L= 21.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 220.55'/219.50' S=0.0500'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =3.46 cfs @ 12.22 hrs HW= 221.39' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.46 cfs @ 2.76 fps) Summary for Pond P -DMH7: Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow = 3.88 cfs @ 12.15 hrs, Volume= Outflow = 3.88 cfs @ 12.15 hrs, Volume= Primary = 3.88 cfs @ 12.15 hrs, Volume= Inflow Depth = 2.77" 13,949 cf 13,949 cf, 13,949 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs for 10 -Year event Atten= 0 %, Lag= 0.0 min Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 60 Peak Elev= 232.03' @ 12.15 hrs Flood Elev= 233.00' Device Routing Invert Outlet Devices #1 Primary 225.00' 24.0" Round Culvert L= 78.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.00'/223.50' S=0.0192'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf #2 Device 1 230.00' 0.5' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =3.87 cfs @ 12.15 hrs HW= 232.03' (Free Discharge) L1= Culvert (Passes 3.87 cfs of 37.13 cfs potential flow) L2= Broad -crested Rectangular Weir (Weir Controls 3.87 cfs @ 3.82 fps) Summary for Pond P -DMH8: Inflow Area = 21,598 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 2.10 cfs @ 12.07 hrs, Volume= 7,315 cf Outflow = 2.10 cfs @ 12.07 hrs, Volume= 7,315 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.10 cfs @ 12.07 hrs, Volume= 7,315 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.72' @ 12.07 hrs Flood Elev= 232.42' Device Routina Invert Outlet Devices #1 Primary 228.00' 15.0" Round Culvert L= 134.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 228.00'/ 224.50' S= 0.0261 T Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =2.02 cfs @ 12.07 hrs HW= 228.70' (Free Discharge) 't--1 =Culvert (Inlet Controls 2.02 cfs @ 2.85 fps) Summary for Pond P -DMH9: Inflow Area = 170,001 sf, 72.10% Impervious, Inflow Depth = 2.94" for 10 -Year event Inflow = 12.95 cfs @ 12.07 hrs, Volume= 41,603 cf Outflow = 12.95 cfs @ 12.07 hrs, Volume= 41,603 cf, Atten= 0 %, Lag= 0.0 min Primary = 12.95 cfs @ 12.07 hrs, Volume= 41,603 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 222.73' @ 12.07 hrs Flood Elev= 232.70' Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 61 Device Routing Invert Outlet Devices #1 Primary 221.00' 24.0" Round DOGHOUSE JUNCTION TO EX. 24" HDPE L= 107.5' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 221.00'/219.90' S=0.0102'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =12.49 cfs @ 12.07 hrs HW= 222.69' (Free Discharge) L1= DOGHOUSE JUNCTION TO EX. 24" HDPE(Inlet Controls 12.49 cfs @ 4.42 fps) Summary for Pond ST: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 4.06" for 10 -Year event Inflow = 0.82 cfs @ 12.07 hrs, Volume= 2,869 cf Outflow = 0.81 cfs @ 12.09 hrs, Volume= 1,893 cf, Atten= 1 %, Lag= 1.3 min Primary = 0.81 cfs @ 12.09 hrs, Volume= 1,893 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.60' @ 12.09 hrs Surf.Area= 0 sf Storage= 1,054 cf Plug -Flow detention time= 195.5 min calculated for 1,893 cf (66% of inflow) Center -of -Mass det. time= 94.7 min ( 844.4 - 749.7 ) Volume Invert Avail.Storage Storage Description #1 223.40' 1,360 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 223.40 0 231.40 1,360 Device Routing Invert Outlet Devices #1 Primary 229.14' 12.0" Round Culvert L= 27.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.14'/224.85' S=0.1589'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.79 cfs @ 12.09 hrs HW= 229.59' (Free Discharge) t--1 =Culvert (Inlet Controls 0.79 cfs @ 2.29 fps) Summary for Pond SWM1: U/G DET. Inflow Area = 60,434 sf, 76.01% Impervious, Inflow Depth = 2.77" for 10 -Year event Inflow = 3.88 cfs @ 12.15 hrs, Volume= 13,949 cf Outflow = 3.49 cfs @ 12.22 hrs, Volume= 13,949 cf, Atten= 10 %, Lag= 4.2 min Primary = 3.49 cfs @ 12.22 hrs, Volume= 13,949 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 222.36' @ 12.22 hrs Surf.Area= 560 sf Storage= 654 cf Flood Elev= 226.00' Surf.Area= 560 sf Storage= 1,211 cf Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 10 -Year Rainfall= 4.30" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 62 Plug -Flow detention time= 3.3 min calculated for 13,939 cf (100% of inflow) Center -of -Mass det. time= 3.4 min ( 841.4 - 838.1 ) Volume Invert Avail.Storage Storage Description #1A 220.50' 359 cf 14.00'W x 40.00'L x 3.50'H Field A 1,960 cf Overall - 1,063 cf Embedded = 897 cf x 40.0% Voids #2A 220.50' 852 cf ADS N -12 36" x 6 Inside #1 Inside= 36.1 "W x 36.1 "H => 7.10 sf x 20.001 = 142.0 cf Outside= 42.0 "W x 42.0 "H => 8.86 sf x 20.001 = 177.1 cf 3 Rows of 2 Chambers Primary OutFlow Max =3.46 cfs @ 12.22 hrs HW= 222.34' (Free Discharge) T_71 =Culvert (Inlet Controls 3.46 cfs @ 4.41 fps) L2 =LOW FLOW ORIFICE (Passes 3.46 cfs of 4.38 cfs potential flow) 3= Broad -Crested Rectangular Weir( Controls 0.00 cfs) Summary for Link AP2: Inflow Area = 347,640 sf, 57.70% Impervious, Inflow Depth= 2.68" for 10 -Year event Inflow = 15.66 cfs @ 12.17 hrs, Volume= 77,681 cf Primary = 15.66 cfs @ 12.17 hrs, Volume= 77,681 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 1,211 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 220.50' 12.0" Round Culvert L= 21.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 220.50'/219.00' S=0.0714'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Device 1 220.50' 12.0" Vert. LOW FLOW ORIFICE C= 0.600 #3 Primary 224.00' 0.5' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =3.46 cfs @ 12.22 hrs HW= 222.34' (Free Discharge) T_71 =Culvert (Inlet Controls 3.46 cfs @ 4.41 fps) L2 =LOW FLOW ORIFICE (Passes 3.46 cfs of 4.38 cfs potential flow) 3= Broad -Crested Rectangular Weir( Controls 0.00 cfs) Summary for Link AP2: Inflow Area = 347,640 sf, 57.70% Impervious, Inflow Depth= 2.68" for 10 -Year event Inflow = 15.66 cfs @ 12.17 hrs, Volume= 77,681 cf Primary = 15.66 cfs @ 12.17 hrs, Volume= 77,681 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 63 Summary for Subcatchment EX. SC -1: Runoff = 0.61 cfs @ 12.07 hrs, Volume= 1,999 cf, Depth= 6.31" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 1,735 80 >75% Grass cover, Good, HSG D 2,065 98 Paved parking, HSG D 3,800 90 Weighted Average 1,735 45.66% Pervious Area 2,065 54.34% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -17: Runoff = 1.30 cfs @ 12.07 hrs, Volume= 4,148 cf, Depth= 5.73" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 1,325 98 Roofs, HSG B 2,993 61 >75% Grass cover, Good, HSG B 4.366 98 Paved oarkina. HSG B 8,684 85 Weighted Average 2,993 34.47% Pervious Area 5,691 65.53% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -18: Runoff = 6.26 cfs @ 12.07 hrs, Volume= 20,245 cf, Depth= 6.08" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 64 Area (so CN Description 13,935 98 Roofs, HSG B 803 98 Roofs, HSG D 9,943 61 >75% Grass cover, Good, HSG B 2,229 80 >75% Grass cover, Good, HSG D 8,923 98 Paved parking, HSG B 4.124 98 Paved oarkina. HSG D 39,957 88 Weighted Average 12,172 30.46% Pervious Area 27,785 69.54% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -19: Runoff = 1.78 cfs @ 12.07 hrs, Volume= 6,340 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 5,245 98 Paved parking, HSG B 5,234 98 Paved parking, HSG D 10,479 98 Weighted Average 10,479 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -2: Runoff = 0.54 cfs @ 12.07 hrs, Volume= 1,925 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 3,181 98 Paved parking, HSG D 3,181 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 65 Summary for Subcatchment EX. SC -20: Runoff = 2.96 cfs @ 12.08 hrs, Volume= 9,196 cf, Depth= 4.71" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 7,685 98 Roofs, HSG B 13,660 61 >75% Grass cover, Good, HSG B 2,108 98 Paved parking, HSG B 23,453 76 Weighted Average 13,660 58.24% Pervious Area 9,793 41.76% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -21: Runoff = 2.86 cfs @ 12.07 hrs, Volume= 9,206 cf, Depth= 5.96" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 5,373 98 Roofs, HSG B 5,318 61 >75% Grass cover, Good, HSG B 7,833 98 Paved parking, HSG B 18,524 87 Weighted Average 5,318 28.71 % Pervious Area 13,206 71.29% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -22: Runoff = 2.86 cfs @ 12.07 hrs, Volume= 8,876 cf, Depth= 4.93" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 66 Area (so CN Description 1,599 98 Roofs, HSG B 11,736 61 >75% Grass cover, Good, HSG B 8,266 98 Paved parking, HSG B 21,601 78 Weighted Average 11,736 71 54.33% Pervious Area 9,865 45.67% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 (ft/ft) Direct Entry, Summary for Subcatchment EX. SC -3: Runoff = 1.49 cfs @ 12.08 hrs, Volume= 4,602 cf, Depth= 4.15" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 6,580 61 >75% Grass cover, Good, HSG B 6,168 80 >75% Grass cover, Good, HSG D 263 98 Paved parking, HSG B 302 98 Paved parking, HSG D 13,313 71 Weighted Average 12,748 95.76% Pervious Area 565 4.24% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment EX. SC -R: Runoff = 0.87 cfs @ 12.07 hrs, Volume= 3,080 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 5,090 98 Roofs, HSG B 5,090 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 67 Summary for Subcatchment EX. SC -ST: Runoff = 1.44 cfs @ 12.07 hrs, Volume= 5,125 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 8,470 98 Roofs, HSG B 8,470 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -10: Runoff = 0.44 cfs @ 12.07 hrs, Volume= 1,455 cf, Depth= 6.43" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 1,023 80 >75% Grass cover, Good, HSG D 1,692 98 Paved parking, HSG D 2,715 91 Weighted Average 1,023 37.68% Pervious Area 1,692 62.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -11: Runoff = 0.18 cfs @ 12.08 hrs, Volume= 546 cf, Depth= 4.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 1,072 61 >75% Grass cover, Good, HSG B 467 98 Paved parking, HSG B 1,539 72 Weighted Average 1,072 69.66% Pervious Area 467 30.34% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 68 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -12: Runoff = 7.01 cfs @ 12.07 hrs, Volume= 23,155 cf, Depth= 6.43" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 1,039 98 Roofs, HSG D 4,014 61 >75% Grass cover, Good, HSG B 7,822 80 >75% Grass cover, Good, HSG D 2,473 98 Paved parking, HSG B 27,857 98 Paved parking, HSG D 43,205 91 Weighted Average 11,836 27.39% Pervious Area 31,369 72.61 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -13: Runoff = 0.23 cfs @ 12.08 hrs, Volume= 700 cf, Depth= 4.37" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 1,280 61 >75% Grass cover, Good, HSG B 643 98 Paved parking, HSG B 1,923 73 Weighted Average 1,280 66.56% Pervious Area 643 33.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -5: Runoff = 3.66 cfs @ 12.07 hrs, Volume= 11,749 cf, Depth= 5.96" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 69 Area (sf) CN Description 2,793 61 >75% Grass cover, Good, HSG B 8,051 80 >75% Grass cover, Good, HSG D 249 98 Paved parking, HSG B 12,549 98 Paved parking, HSG D 23,642 87 Weighted Average 10,844 45.87% Pervious Area 12,798 54.13% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -6: Runoff = 0.44 cfs @ 12.07 hrs, Volume= 1,398 cf, Depth= 5.50" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 1,176 61 >75% Grass cover, Good, HSG B 163 80 >75% Grass cover, Good, HSG D 1,318 98 Paved parking, HSG B 392 98 Paved parking, HSG D 3,049 83 Weighted Average 1,339 43.92% Pervious Area 1,710 56.08% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -7: Runoff = 0.36 cfs @ 12.08 hrs, Volume= 1,114 cf, Depth= 4.15" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 2,315 61 >75% Grass cover, Good, HSG B 907 98 Paved parking, HSG B 3,222 71 Weighted Average 2,315 71.85% Pervious Area 907 28.15% Impervious Area Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 70 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -8: Runoff = 1.20 cfs @ 12.07 hrs, Volume= 4,047 cf, Depth= 6.67" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 2,049 80 >75% Grass cover, Good, HSG D 5.235 98 Paved oarkina. HSG D 7,284 93 Weighted Average 2,049 28.13% Pervious Area 5,235 71.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -9: Runoff = 0.55 cfs @ 12.07 hrs, Volume= 1,917 cf, Depth= 7.02" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 347 80 >75% Grass cover, Good, HSG D 2,929 98 Paved parking, HSG D 3,276 96 Weighted Average 347 10.59% Pervious Area 2,929 89.41% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C1: Runoff = 2.53 cfs @ 12.07 hrs, Volume= 7,874 cf, Depth= 5.04" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 71 Area (sf) CN Description 11,805 80 >75% Grass cover, Good, HSG D 6,928 77 Woods, Good, HSG D 18,733 79 Weighted Average 18,733 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -C2: Runoff = 3.59 cfs @ 12.07 hrs, Volume= 11,130 cf, Depth= 4.82" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (sf) CN Description 1,605 80 >75% Grass cover, Good, HSG D 26,117 77 Woods, Good, HSG D 27,722 77 Weighted Average 27,722 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -E4: Runoff = 2.27 cfs @ 12.07 hrs, Volume= 7,068 cf, Depth= 5.16" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 2,571 98 Roofs, HSG B 7,803 61 >75% Grass cover, Good, HSG B 337 80 >75% Grass cover, Good, HSG D 5,264 98 Paved parking, HSG B 468 98 Paved parking, HSG D 16,443 80 Weighted Average 8,140 49.50% Pervious Area 8,303 50.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 72 Summary for Subcatchment P. SC -R1: Runoff = 0.65 cfs @ 12.07 hrs, Volume= 2,319 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 3,833 98 Roofs, HSG B 3,833 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R2: Runoff = 1.32 cfs @ 12.07 hrs, Volume= 4,687 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 7,747 98 Roofs, HSG D 7,747 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment P. SC -R3: Runoff = 3.67 cfs @ 12.07 hrs, Volume= 13,068 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 21,598 98 Roofs, HSG B 21,598 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 73 Summary for Subcatchment P. SC -R9: Runoff = 0.88 cfs @ 12.07 hrs, Volume= 3,120 cf, Depth= 7.26" Runoff by SCS TR -20 method, UH =SCS, Weighted -CN, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Type III 24 -hr 100 -Year Rainfall= 7.50" Area (so CN Description 5,157 98 Roofs, HSG B 5,157 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft /sec) (cfs) 5.0 Direct Entry, Summary for Pond C1131: Inflow Area = 3,800 sf, 54.34% Impervious, Inflow Depth = 6.31" for 100 -Year event Inflow = 0.61 cfs @ 12.07 hrs, Volume= 1,999 cf Outflow = 0.61 cfs @ 12.07 hrs, Volume= 1,999 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.61 cfs @ 12.07 hrs, Volume= 1,999 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.64' @ 12.07 hrs Flood Elev= 224.92' Device Routing Invert Outlet Devices #1 Primary 224.92' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads #2 Primary 221.25' 12.0" Round Culvert L= 15.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 221.25'/218.16' S=0.1994'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =0.59 cfs @ 12.07 hrs HW= 221.63' (Free Discharge) t1= Orifice /Grate ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.59 cfs @ 2.11 fps) Summary for Pond CB16: Inflow Area = 43,205 sf, 72.61 % Impervious, Inflow Depth = 6.43" for 100 -Year event Inflow = 7.01 cfs @ 12.07 hrs, Volume= 23,155 cf Outflow = 7.01 cfs @ 12.07 hrs, Volume= 23,155 cf, Atten= 0 %, Lag= 0.0 min Primary = 7.01 cfs @ 12.07 hrs, Volume= 23,155 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.61' @ 12.07 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 74 Device Routing Invert Outlet Devices #1 Primary 225.71' 12.0" Round Culvert L= 9.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.71'/222.83' S=0.3200'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 229.50' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =6.75 cfs @ 12.07 hrs HW= 229.40' (Free Discharge) t1= Culvert (Inlet Controls 6.75 cfs @ 8.60 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond CB17: Inflow Area = 8,684 sf, 65.53% Impervious, Inflow Depth= 5.73" for 100 -Year event Inflow = 1.30 cfs @ 12.07 hrs, Volume= 4,148 cf Outflow = 1.30 cfs @ 12.07 hrs, Volume= 4,148 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.30 cfs @ 12.07 hrs, Volume= 4,148 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.01' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 225.13' 12.0" Round Culvert L= 80.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 225.13'/225.07' S=0.0008'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 228.31' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =1.26 cfs @ 12.07 hrs HW= 225.99' (Free Discharge) �--2=Orifi 1= Culve rt (Barrel Controls 1.26 cfs @ 2.33 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB18: Inflow Area = 39,957 sf, 69.54% Impervious, Inflow Depth= 6.08" for 100 -Year event Inflow = 6.26 cfs @ 12.07 hrs, Volume= 20,245 cf Outflow = 6.26 cfs @ 12.07 hrs, Volume= 20,245 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.26 cfs @ 12.07 hrs, Volume= 20,245 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 233.46' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 230.25' 12.0" Round Culvert L= 14.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.25'/230.10' S=0.0103'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 234.91' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 75 Limited to weir flow at low heads Primary OutFlow Max =6.03 cfs @ 12.07 hrs HW= 233.29' (Free Discharge) �--2=Orifi 1= Culve rt (Inlet Controls 6.03 cfs @ 7.68 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond CB19: Inflow Area = 10,479 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.78 cfs @ 12.07 hrs, Volume= 6,340 cf Outflow = 1.78 cfs @ 12.07 hrs, Volume= 6,340 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.78 cfs @ 12.07 hrs, Volume= 6,340 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.03' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 230.16' 12.0" Round Culvert L= 6.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.16'/230.10' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 235.05' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =1.72 cfs @ 12.07 hrs HW= 231.01' (Free Discharge) �--2=Orifi 1= Culve rt (Barrel Controls 1.72 cfs @ 3.27 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond C1132: Inflow Area = 6,981 sf, 75.15% Impervious, Inflow Depth = 6.75" for 100 -Year event Inflow = 1.15 cfs @ 12.07 hrs, Volume= 3,924 cf Outflow = 1.15 cfs @ 12.07 hrs, Volume= 3,924 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.15 cfs @ 12.07 hrs, Volume= 3,924 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 218.92' @ 12.07 hrs Flood Elev= 225.01' Device Routing Invert Outlet Devices #1 Primary 218.16' 12.0" Round Culvert L= 135.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 218.16'/ 217.88' S= 0.0021 T Cc= 0.900 n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 225.01' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =1.11 cfs @ 12.07 hrs HW= 218.91' (Free Discharge) t1= Culvert (Barrel Controls 1.11 cfs @ 2.45 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 76 Summary for Pond CB20: Inflow Area = 23,453 sf, 41.76% Impervious, Inflow Depth = 4.71" for 100 -Year event Inflow = 2.96 cfs @ 12.08 hrs, Volume= 9,196 cf Outflow = 2.96 cfs @ 12.08 hrs, Volume= 9,196 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.96 cfs @ 12.08 hrs, Volume= 9,196 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 250.78' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 235.70' 6.0" Round Culvert L= 143.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 235.70'/228.93' S=0.0472'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 0.20 sf #2 Primary 239.00' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =2.86 cfs @ 12.08 hrs HW= 249.83' (Free Discharge) �--2=Orifi 1= Culve rt (Barrel Controls 2.42 cfs @ 12.35 fps) ce /Grate (Orifice Controls 0.44 cfs @ 15.85 fps) Summary for Pond CB21: Inflow Area = 18,524 sf, 71.29% Impervious, Inflow Depth = 5.96" for 100 -Year event Inflow = 2.86 cfs @ 12.07 hrs, Volume= 9,206 cf Outflow = 2.86 cfs @ 12.07 hrs, Volume= 9,206 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.86 cfs @ 12.07 hrs, Volume= 9,206 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 245.10' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 243.80' 12.0" Round Culvert L= 25.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.80'/243.70' S=0.0039'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 247.80' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =2.76 cfs @ 12.07 hrs HW= 245.06' (Free Discharge) t1= Culvert (Barrel Controls 2.76 cfs @ 3.60 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond CB22: Inflow Area = 21,601 sf, 45.67% Impervious, Inflow Depth = 4.93" for 100 -Year event Inflow = 2.86 cfs @ 12.07 hrs, Volume= 8,876 cf Outflow = 2.86 cfs @ 12.07 hrs, Volume= 8,876 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.86 cfs @ 12.07 hrs, Volume= 8,876 cf Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 77 Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 244.92' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 243.70' 12.0" Round Culvert L= 16.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.70'/243.60' S=0.0062'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 247.90' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =2.76 cfs @ 12.07 hrs HW= 244.89' (Free Discharge) t1= Culvert (Barrel Controls 2.76 cfs @ 3.73 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond C1133: Inflow Area = 36,766 sf, 28.17% Impervious, Inflow Depth = 4.50" for 100 -Year event Inflow = 4.44 cfs @ 12.08 hrs, Volume= 13,798 cf Outflow = 4.44 cfs @ 12.08 hrs, Volume= 13,798 cf, Atten= 0 %, Lag= 0.0 min Primary = 4.44 cfs @ 12.08 hrs, Volume= 13,798 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.80' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 228.93' 12.0" Round Culvert L= 16.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.93'/227.98' S=0.0576'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 231.88' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =4.30 cfs @ 12.08 hrs HW= 230.73' (Free Discharge) �--2=Orifi 1= Culve rt (Inlet Controls 4.30 cfs @ 5.48 fps) ce /Grate ( Controls 0.00 cfs) Summary for Pond C1134: Inflow Area = 16,443 sf, 50.50% Impervious, Inflow Depth= 5.16" for 100 -Year event Inflow = 2.27 cfs @ 12.07 hrs, Volume= 7,068 cf Outflow = 2.27 cfs @ 12.07 hrs, Volume= 7,068 cf, Atten= 0 %, Lag= 0.0 min Primary = 2.27 cfs @ 12.07 hrs, Volume= 7,068 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 230.50' @ 12.07 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 78 Device Routing Invert Outlet Devices #1 Primary 229.64' 12.0" Round Culvert L= 31.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.64'/227.96' S=0.0542'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf #2 Primary 232.11' 2.0" x 2.0" Horiz. Orifice /Grate C= 0.600 Limited to weir flow at low heads Primary OutFlow Max =2.18 cfs @ 12.07 hrs HW= 230.48' (Free Discharge) t1= Culvert (Inlet Controls 2.18 cfs @ 3.11 fps) 2=Orifi ce/G rate ( Controls 0.00 cfs) Summary for Pond DB: MOD.EX. DET.BASIN Inflow Area = 319,918 sf, 62.70% Impervious, Inflow Depth = 5.74" for 100 -Year event Inflow = 49.13 cfs @ 12.09 hrs, Volume= 153,064 cf Outflow = 34.43 cfs @ 12.16 hrs, Volume= 152,966 cf, Atten= 30 %, Lag= 4.0 min Primary = 34.43 cfs @ 12.16 hrs, Volume= 152,966 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 221.94' @ 12.16 hrs Surf.Area= 9,229 sf Storage= 18,420 cf Plug -Flow detention time= 10.8 min calculated for 152,966 cf (100% of inflow) Center -of -Mass det. time= 9.9 min ( 802.7 - 792.8 ) Volume Invert Avail.Storage Storage Description #1 218.00' 18,957 cf Custom Stage Data (Irregular)Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq -ft) (feet) (cubic -feet) (cubic -feet) (sq-ft) 218.00 331 121.0 0 0 331 219.00 961 165.0 619 619 1,343 220.00 5,260 601.0 2,823 3,442 27,922 221.00 8,303 630.0 6,724 10,166 30,829 222.00 9,288 647.0 8,791 18,957 32,671 Device Routing Invert Outlet Devices #1 Primary 218.25' 12.0" Round Culvert L= 16.5' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 218.25'/217.81' S=0.0267'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Primary 220.00' 4.0' long x 15.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max =34.10 cfs @ 12.16 hrs HW= 221.93' (Free Discharge) �__1= Culvert (Inlet Controls 5.95 cfs @ 7.57 fps) 2= Broad - Crested Rectangular Weir (Weir Controls 28.15 cfs @ 3.65 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 79 Summary for Pond DMH1: Inflow Area = 53,209 sf, 35.07% Impervious, Inflow Depth = 4.71" for 100 -Year event Inflow = 6.70 cfs @ 12.08 hrs, Volume= 20,865 cf Outflow = 6.70 cfs @ 12.08 hrs, Volume= 20,865 cf, Atten= 0 %, Lag= 0.0 min Primary = 6.70 cfs @ 12.08 hrs, Volume= 20,865 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.80' @ 12.08 hrs Device Routing Invert Outlet Devices #1 Primary 222.31' 12.0" Round Culvert L= 77.5' RCP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 222.31'/219.41' S=0.0374'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =6.49 cfs @ 12.08 hrs HW= 226.59' (Free Discharge) 't--1 =Culvert (Inlet Controls 6.49 cfs @ 8.26 fps) Summary for Pond DMH10: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.44 cfs @ 12.07 hrs, Volume= 5,125 cf Outflow = 1.44 cfs @ 12.07 hrs, Volume= 5,125 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.44 cfs @ 12.07 hrs, Volume= 5,125 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.61' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 228.95' 12.0" Round Culvert L= 36.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 228.95'/228.59' S=0.0100'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.39 cfs @ 12.07 hrs HW= 229.60' (Free Discharge) 't--1 =Culvert (Barrel Controls 1.39 cfs @ 3.67 fps) Summary for Pond DMH11: Inflow Area = 90,561 sf, 67.73% Impervious, Inflow Depth = 5.92" for 100 -Year event Inflow = 13.77 cfs @ 12.07 hrs, Volume= 44,667 cf Outflow = 13.77 cfs @ 12.07 hrs, Volume= 44,667 cf, Atten= 0 %, Lag= 0.0 min Primary = 13.77 cfs @ 12.07 hrs, Volume= 44,667 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 250.86' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 230.00' 12.0" Round Culvert Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 80 L= 142.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 230.00'/224.85' S=0.0363'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =13.26 cfs @ 12.07 hrs HW= 249.30' (Free Discharge) 't--1 =Culvert (Barrel Controls 13.26 cfs @ 16.88 fps) Summary for Pond DMH12: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow Depth = 5.41" for 100 -Year event Inflow = 5.72 cfs @ 12.07 hrs, Volume= 18,082 cf Outflow = 5.72 cfs @ 12.07 hrs, Volume= 18,082 cf, Atten= 0 %, Lag= 0.0 min Primary = 5.72 cfs @ 12.07 hrs, Volume= 18,082 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 235.27' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 232.50' 12.0" Round Culvert L= 68.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 232.50'/230.00' S=0.0368'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =5.51 cfs @ 12.07 hrs HW= 235.12' (Free Discharge) L1= Culvert (Inlet Controls 5.51 cfs @ 7.02 fps) Summary for Pond DMH12A: Inflow Area = 7,747 sf,100.00% Impervious, Inflow Depth = 4.66" for 100 -Year event Inflow = 1.45 cfs @ 12.09 hrs, Volume= 3,011 cf Outflow = 1.45 cfs @ 12.09 hrs, Volume= 3,011 cf, Atten= 0 %, Lag= 0.0 min Primary = 1.45 cfs @ 12.09 hrs, Volume= 3,011 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.64' @ 12.09 hrs Flood Elev= 232.20' Device Routing Invert Outlet Devices #1 Primary 225.00' 12.0" Round Culvert L= 31.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.00'/223.00' S=0.0645'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Primary 231.00' 6.0' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =1.37 cfs @ 12.09 hrs HW= 225.62' (Free Discharge) �__1= Culvert (Inlet Controls 1.37 cfs @ 2.68 fps) 2= Broad - Crested Rectangular Weir( Controls 0.00 cfs) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 81 Summary for Pond DMH13: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 5.72 cfs @ 12.07 hrs, Volume= Outflow = 5.72 cfs @ 12.07 hrs, Volume= Primary = 5.72 cfs @ 12.07 hrs, Volume= Inflow Depth = 5.41" 18,082 cf 18,082 cf, 18,082 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 237.37' @ 12.07 hrs for 100 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 234.60' 12.0" Round Culvert L= 104.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 234.60'/232.50' S=0.0202'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =5.51 cfs @ 12.07 hrs HW= 237.22' (Free Discharge) L1= Culvert (Inlet Controls 5.51 cfs @ 7.02 fps) Summary for Pond DMH14: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 5.72 cfs @ 12.07 hrs, Volume= Outflow = 5.72 cfs @ 12.07 hrs, Volume= Primary = 5.72 cfs @ 12.07 hrs, Volume= Inflow Depth = 5.41" 18,082 cf 18,082 cf, 18,082 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 238.57' @ 12.07 hrs for 100 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 235.80' 12.0" Round Culvert L= 58.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 235.80'/234.60' S=0.0207'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =5.51 cfs @ 12.07 hrs HW= 238.42' (Free Discharge) L1= Culvert (Inlet Controls 5.51 cfs @ 7.02 fps) Summary for Pond DMH15: Inflow Area = 40,125 sf, 57.50% Impervious, Inflow = 5.72 cfs @ 12.07 hrs, Volume= Outflow = 5.72 cfs @ 12.07 hrs, Volume= Primary = 5.72 cfs @ 12.07 hrs, Volume= Inflow Depth = 5.41" 18,082 cf 18,082 cf, 18,082 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 246.27' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 243.50' 12.0" Round Culvert for 100 -Year event Atten= 0 %, Lag= 0.0 min Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 82 L= 228.5' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 243.50'/236.30' S=0.0315'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =5.51 cfs @ 12.07 hrs HW= 246.12' (Free Discharge) L1= Culvert (Inlet Controls 5.51 cfs @ 7.02 fps) Summary for Pond DMH4: Inflow Area = 180,561 sf, 72.40% Impervious, Inflow Depth = 6.04" for 100 -Year event Inflow = 28.16 cfs @ 12.07 hrs, Volume= 90,915 cf Outflow = 28.16 cfs @ 12.07 hrs, Volume= 90,915 cf, Atten= 0 %, Lag= 0.0 min Primary = 28.16 cfs @ 12.07 hrs, Volume= 90,915 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.20' @ 12.07 hrs Flood Elev= 229.00' Device Routing Invert Outlet Devices #1 Primary 219.80' 24.0" Round TO EX. 24" FES IN EX. DET.BASIN L= 29.3' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 219.80'/219.44' S=0.0123'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =27.20 cfs @ 12.07 hrs HW= 224.95' (Free Discharge) t--1 =TO EX. 24" FES IN EX. DET.BASIN (Inlet Controls 27.20 cfs @ 8.66 fps) Summary for Pond DMH5: Inflow Area = 150,920 sf, 70.81% Impervious, Inflow Depth = 6.05" for 100 -Year event Inflow = 23.47 cfs @ 12.07 hrs, Volume= 76,119 cf Outflow = 23.47 cfs @ 12.07 hrs, Volume= 76,119 cf, Atten= 0 %, Lag= 0.0 min Primary = 23.47 cfs @ 12.07 hrs, Volume= 76,119 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 238.17' @ 12.07 hrs Device Routing Invert Outlet Devices #1 Primary 222.83' 18.0" Round Culvert L= 282.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 222.83'/220.70' S=0.0076'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 1.77 sf Primary OutFlow Max =22.61 cfs @ 12.07 hrs HW= 237.18' (Free Discharge) t--1 =Culvert (Barrel Controls 22.61 cfs @ 12.79 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 83 Summary for Pond DMH6: Inflow Area = 107,715 sf, 70.09% Impervious, Inflow = 16.46 cfs @ 12.07 hrs, Volume= Outflow = 16.46 cfs @ 12.07 hrs, Volume= Primary = 16.46 cfs @ 12.07 hrs, Volume= Inflow Depth = 5.90" 52,964 cf 52,964 cf, 52,964 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.02' @ 12.07 hrs for 100 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 224.14' 24.0" Round Culvert L= 89.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 224.14'/222.83' S=0.0146'/' Cc= 0.900 n=0.010 PVC, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =15.86 cfs @ 12.07 hrs HW= 226.90' (Free Discharge) 't--1 =Culvert (Inlet Controls 15.86 cfs @ 5.05 fps) Summary for Pond INF6: U/G INF. Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow = 9.65 cfs @ 12.07 hrs, Volume= Outflow = 11.07 cfs @ 12.09 hrs, Volume= Discarded = 0.01 cfs @ 8.20 hrs, Volume= Primary = 11.06 cfs @ 12.09 hrs, Volume= Inflow Depth = 6.50" 32,728 cf 30,805 cf, 1,320 cf 29,486 cf for 100 -Year event Atten= 0 %, Lag= 1.3 min Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 236.49' @ 12.10 hrs Surf.Area= 2,670 sf Storage= 5,258 cf Plug -Flow detention time= 143.6 min calculated for 30,805 cf (94% of inflow) Center -of -Mass det. time= 110.5 min ( 873.0 - 762.5 ) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 84 Volume Invert Avail.Storage Storage Description #1A 227.00' 310 cf 25.35'W x 34.00'L x 3.17'H Field A 2,732 cf Overall - 1,958 cf Embedded = 774 cf x 40.0% Voids #2A 227.50' 1,334 cf Concrete Dry Well 500gal x 20 Inside #1 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 5 Rows of 4 Chambers #313 226.00' 265 cf 20.68'W x 34.00'L x 3.17'H Field B 2,229 cf Overall - 1,567 cf Embedded = 662 cf x 40.0% Voids #413 226.50' 1,067 cf Concrete Dry Well 500gal x 16 Inside #3 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 4 Rows of 4 Chambers #5C 225.00' 310 cf 16.01'W x 50.00'L x 3.17'H Field C 2,538 cf Overall - 1,763 cf Embedded = 775 cf x 40.0% Voids #6C 225.50' 1,201 cf Concrete Dry Well 500gal x 18 Inside #5 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 3 Rows of 6 Chambers #7D 224.50' 102 cf 11.34'W x 18.00'L x 3.17'H Field D 647 cf Overall - 392 cf Embedded = 255 cf x 40.0% Voids #8D 225.00' 267 cf Concrete Dry Well 500gal x 4 Inside #7 Inside= 50.0 "W x 28.0 "H => 9.53 sf x 7.001 = 66.7 cf Outside= 56.0 "W x 32.0 "H => 12.24 sf x 8.00'L = 97.9 cf 2 Rows of 2 Chambers #9 224.50' 402 cf 8.00'D x 4.00'H Vertical Cone /Cvlinderx 2 5,258 cf Total Available Storage Storage Group A created with Chamber Wizard Storage Group B created with Chamber Wizard Storage Group C created with Chamber Wizard Storage Group D created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 224.50' 0.090 in /hr Exfiltration over Surface area #2 Primary 227.50' 12.0" Round Culvert L= 23.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 227.50'/ 224.30' S= 0.1391 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Discarded OutFlow Max =0.01 cfs @ 8.20 hrs HW= 227.01' (Free Discharge) L1= Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max =10.59 cfs @ 12.09 hrs HW= 235.85' (Free Discharge) L2= Culvert (Inlet Controls 10.59 cfs @ 13.49 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 85 Summary for Pond INF7: U/G INF. Inflow Area = 7,747 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.32 cfs @ 12.07 hrs, Volume= 4,687 cf Outflow = 1.46 cfs @ 12.09 hrs, Volume= 3,224 cf, Atten= 0 %, Lag= 1.3 min Discarded = 0.00 cfs @ 2.00 hrs, Volume= 213 cf Primary = 1.45 cfs @ 12.09 hrs, Volume= 3,011 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 231.14' @ 12.09 hrs Surf.Area= 402 sf Storage= 1,608 cf Plug -Flow detention time= 281.4 min calculated for 3,221 cf (69% of inflow) Center -of -Mass det. time= 185.1 min ( 926.2 - 741.1 ) Volume Invert Avail.Storage Storage Description #1 226.50' 1,608 cf 8.00'D x 4.00'H Vertical Cone /Cylinderx 8 Device Routing Invert Outlet Devices #1 Primary 230.50' 12.0" Round Culvert L= 48.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 230.50'/225.00' S=0.1146'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Discarded 226.50' 0.090 in /hr Exfiltration over Surface area Discarded OutFlow Max =0.00 cfs @ 2.00 hrs HW= 226.55' (Free Discharge) L2= Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max =1.37 cfs @ 12.09 hrs HW= 231.12' (Free Discharge) 't--1 =Culvert (Inlet Controls 1.37 cfs @ 2.68 fps) Summary for Pond P -C11310: Inflow Area = 2,715 sf, 62.32% Impervious, Inflow Depth = 6.43" for 100 -Year event Inflow = 0.44 cfs @ 12.07 hrs, Volume= 1,455 cf Outflow = 0.44 cfs @ 12.07 hrs, Volume= 1,455 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.44 cfs @ 12.07 hrs, Volume= 1,455 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.33' @ 12.07 hrs Flood Elev= 231.40' Device Routing Invert Outlet Devices #1 Primary 224.00' 12.0" Round Culvert L= 20.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 224.00'/222.00' S=0.1000'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.42 cfs @ 12.07 hrs HW= 224.32' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.42 cfs @ 1.93 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 86 Summary for Pond P -C11311: Inflow Area = 3,462 sf, 32.06% Impervious, Inflow Depth= 4.32" for 100 -Year event Inflow = 0.40 cfs @ 12.08 hrs, Volume= 1,246 cf Outflow = 0.40 cfs @ 12.08 hrs, Volume= 1,246 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.40 cfs @ 12.08 hrs, Volume= 1,246 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.31' @ 12.08 hrs Flood Elev= 231.30' Device Routing Invert Outlet Devices #1 Primary 226.00' 12.0" Round Culvert L= 44.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 226.00'/225.00' S=0.0227'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.39 cfs @ 12.08 hrs HW= 226.31' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.39 cfs @ 1.89 fps) Summary for Pond P -C11313: Inflow Area = 1,923 sf, 33.44% Impervious, Inflow Depth = 4.37" for 100 -Year event Inflow = 0.23 cfs @ 12.08 hrs, Volume= 700 cf Outflow = 0.23 cfs @ 12.08 hrs, Volume= 700 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.23 cfs @ 12.08 hrs, Volume= 700 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.03' @ 12.08 hrs Flood Elev= 231.76' Device Ro Invert Outlet Devices #1 Primary 227.80' 12.0" Round Culvert L= 65.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.80'/226.00' S=0.0277'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.22 cfs @ 12.08 hrs HW= 228.03' (Free Discharge) L1= Culvert (Inlet Controls 0.22 cfs @ 1.62 fps) Summary for Pond P -C1135: Inflow Area = 23,642 sf, 54.13% Impervious, Inflow Depth = 5.96" for 100 -Year event Inflow = 3.66 cfs @ 12.07 hrs, Volume= 11,749 cf Outflow = 3.66 cfs @ 12.07 hrs, Volume= 11,749 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.66 cfs @ 12.07 hrs, Volume= 11,749 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 87 Peak Elev= 226.11' @ 12.07 hrs Flood Elev= 228.89' Device Routing Invert Outlet Devices #1 Primary 225.00' 15.0" Round Culvert L= 70.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 225.00'/ 224.50' S= 0.0071 T Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =3.52 cfs @ 12.07 hrs HW= 226.08' (Free Discharge) 't--1 =Culvert (Barrel Controls 3.52 cfs @ 4.17 fps) Summary for Pond P -C1136: Inflow Area = 6,271 sf, 41.73% Impervious, Inflow Depth = 4.81" for 100 -Year event Inflow = 0.81 cfs @ 12.07 hrs, Volume= 2,512 cf Outflow = 0.81 cfs @ 12.07 hrs, Volume= 2,512 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.81 cfs @ 12.07 hrs, Volume= 2,512 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 227.46' @ 12.07 hrs Flood Elev= 230.80' Device Routing Invert Outlet Devices #1 Primary 227.00' 12.0" Round Culvert L= 43.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 227.00'/225.50' S=0.0349'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =0.77 cfs @ 12.07 hrs HW= 227.45' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.77 cfs @ 2.28 fps) Summary for Pond P -C1137: Inflow Area = 3,222 sf, 28.15% Impervious, Inflow Depth = 4.15" for 100 -Year event Inflow = 0.36 cfs @ 12.08 hrs, Volume= 1,114 cf Outflow = 0.36 cfs @ 12.08 hrs, Volume= 1,114 cf, Atten= 0 %, Lag= 0.0 min Primary = 0.36 cfs @ 12.08 hrs, Volume= 1,114 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 228.89' @ 12.08 hrs Flood Elev= 231.50' Device Routing Invert Outlet Devices #1 Primary 228.50' 8.0" Round Culvert L= 73.5' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 228.50'/228.00' S=0.0068'/' Cc= 0.900 n=0.013, Flow Area= 0.35 sf Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 88 Primary OutFlow Max =0.35 cfs @ 12.08 hrs HW= 228.89' (Free Discharge) 't--1 =Culvert (Inlet Controls 0.35 cfs @ 1.67 fps) Summary for Pond P -C1138: Inflow Area = 7,284 sf, 71.87% Impervious, Inflow = 1.20 cfs @ 12.07 hrs, Volume= Outflow = 1.20 cfs @ 12.07 hrs, Volume= Primary = 1.20 cfs @ 12.07 hrs, Volume= Inflow Depth = 6.67" 4,047 cf 4,047 cf, 4,047 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 224.86' @ 12.07 hrs Flood Elev= 231.10' for 100 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 224.20' 12.0" Round Culvert L= 15.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 224.20'/224.00' S=0.0133'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf Primary OutFlow Max =1.16 cfs @ 12.07 hrs HW= 224.85' (Free Discharge) L1= Culvert (Inlet Controls 1.16 cfs @ 2.16 fps) Summary for Pond P -C1139: Inflow Area = 3,276 sf, 89.41 % Impervious, Inflow = 0.55 cfs @ 12.07 hrs, Volume= Outflow = 0.55 cfs @ 12.07 hrs, Volume= Primary = 0.55 cfs @ 12.07 hrs, Volume= Inflow Depth = 7.02" 1,917 cf 1,917 cf, 1,917 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 223.87' @ 12.07 hrs Flood Elev= 231.76' for 100 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 223.50' 12.0" Round Culvert L= 56.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 223.50'/222.00' S=0.0268'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max =0.53 cfs @ 12.07 hrs HW= 223.86' (Free Discharge) t--1 =Culvert (Inlet Controls 0.53 cfs @ 2.05 fps) Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 89 Summary for Pond P- DMH12: Inflow Area = 158,667 sf, 72.23% Impervious, Inflow = 24.70 cfs @ 12.08 hrs, Volume= Outflow = 24.70 cfs @ 12.08 hrs, Volume= Primary = 24.70 cfs @ 12.08 hrs, Volume= Inflow Depth = 5.98" 79,130 cf 79,130 cf, 79,130 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.02' @ 12.08 hrs Flood Elev= 231.15' for 100 -Year event Atten= 0 %, Lag= 0.0 min Device Routing Invert Outlet Devices #1 Primary 222.00' 24.0" Round Culvert L= 132.5' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 222.00'/221.00' S=0.0075'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =23.86 cfs @ 12.08 hrs HW= 225.82' (Free Discharge) 't--1 =Culvert (Barrel Controls 23.86 cfs @ 7.60 fps) Summary for Pond P -DMH6: Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow = 11.44 cfs @ 12.10 hrs, Volume= Outflow = 11.44 cfs @ 12.10 hrs, Volume= Primary = 11.44 cfs @ 12.10 hrs, Volume= Inflow Depth = 5.85" 29,486 cf 29,486 cf, 29,486 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 222.28' @ 12.10 hrs Flood Elev= 226.70' Device Ro Invert Outlet Devices for 100 -Year event Atten= 0 %, Lag= 0.0 min #1 Primary 220.55' 24.0" Round Culvert L= 21.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet/ Outlet Invert= 220.55'/219.50' S=0.0500'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =11.29 cfs @ 12.10 hrs HW= 222.27' (Free Discharge) L1= Culvert (Inlet Controls 11.29 cfs @ 3.93 fps) Summary for Pond P -DMH7: Inflow Area = 60,434 sf, 76.01 % Impervious, Inflow = 11.06 cfs @ 12.09 hrs, Volume= Outflow = 11.06 cfs @ 12.09 hrs, Volume= Primary = 11.06 cfs @ 12.09 hrs, Volume= Inflow Depth = 5.85" 29,486 cf 29,486 cf, 29,486 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs for 100 -Year event Atten= 0 %, Lag= 0.0 min Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 90 Peak Elev= 233.99' @ 12.09 hrs Flood Elev= 233.00' Device Routing Invert Outlet Devices #1 Primary 225.00' 24.0" Round Culvert L= 78.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 225.00'/223.50' S=0.0192'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf #2 Device 1 230.00' 0.5' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =10.50 cfs @ 12.09 hrs HW= 233.85' (Free Discharge) L1= Culvert (Passes 10.50 cfs of 42.38 cfs potential flow) L2= Broad -crested Rectangular Weir (Weir Controls 10.50 cfs @ 5.46 fps) Summary for Pond P -DMH8: Inflow Area = 21,598 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 3.67 cfs @ 12.07 hrs, Volume= 13,068 cf Outflow = 3.67 cfs @ 12.07 hrs, Volume= 13,068 cf, Atten= 0 %, Lag= 0.0 min Primary = 3.67 cfs @ 12.07 hrs, Volume= 13,068 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.02' @ 12.07 hrs Flood Elev= 232.42' Device Routina Invert Outlet Devices #1 Primary 228.00' 15.0" Round Culvert L= 134.0' CPP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 228.00'/ 224.50' S= 0.0261 T Cc= 0.900 n= 0.013, Flow Area= 1.23 sf Primary OutFlow Max =3.54 cfs @ 12.07 hrs HW= 228.99' (Free Discharge) 't--1 =Culvert (Inlet Controls 3.54 cfs @ 3.39 fps) Summary for Pond P -DMH9: Inflow Area = 170,001 sf, 72.10% Impervious, Inflow Depth = 6.00" for 100 -Year event Inflow = 26.41 cfs @ 12.08 hrs, Volume= 84,951 cf Outflow = 26.41 cfs @ 12.08 hrs, Volume= 84,951 cf, Atten= 0 %, Lag= 0.0 min Primary = 26.41 cfs @ 12.08 hrs, Volume= 84,951 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 225.02' @ 12.08 hrs Flood Elev= 232.70' Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 91 Device Routing Invert Outlet Devices #1 Primary 221.00' 24.0" Round DOGHOUSE JUNCTION TO EX. 24" HDPE L= 107.5' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 221.00'/219.90' S=0.0102'/' Cc= 0.900 n=0.013 Corrugated PE, smooth interior, Flow Area= 3.14 sf Primary OutFlow Max =25.52 cfs @ 12.08 hrs HW= 224.85' (Free Discharge) L1= DOGHOUSE JUNCTION TO EX. 24" HDPE(Inlet Controls 25.52 cfs @ 8.12 fps) Summary for Pond ST: Inflow Area = 8,470 sf,100.00% Impervious, Inflow Depth = 7.26" for 100 -Year event Inflow = 1.44 cfs @ 12.07 hrs, Volume= 5,125 cf Outflow = 1.42 cfs @ 12.09 hrs, Volume= 4,149 cf, Atten= 1 %, Lag= 1.1 min Primary = 1.42 cfs @ 12.09 hrs, Volume= 4,149 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 229.77' @ 12.09 hrs Surf.Area= 0 sf Storage= 1,084 cf Plug -Flow detention time= 146.6 min calculated for 4,149 cf (81 % of inflow) Center -of -Mass det. time= 70.8 min ( 811.9 - 741.1 ) Volume Invert Avail.Storage Storage Description #1 223.40' 1,360 cf Custom Stage Data Listed below Elevation Cum.Store (feet) (cubic -feet) 223.40 0 231.40 1,360 Device Routing Invert Outlet Devices #1 Primary 229.14' 12.0" Round Culvert L= 27.0' RCP, sq.cut end projecting, Ke= 0.500 Inlet/ Outlet Invert= 229.14'/224.85' S=0.1589'/' Cc= 0.900 n=0.012 Concrete pipe, finished, Flow Area= 0.79 sf Primary OutFlow Max =1.38 cfs @ 12.09 hrs HW= 229.76' (Free Discharge) t--1 =Culvert (Inlet Controls 1.38 cfs @ 2.69 fps) Summary for Pond SWM1: U/G DET. Inflow Area = 60,434 sf, 76.01% Impervious, Inflow Depth = 5.85" for 100 -Year event Inflow = 11.06 cfs @ 12.09 hrs, Volume= 29,486 cf Outflow = 11.44 cfs @ 12.10 hrs, Volume= 29,486 cf, Atten= 0 %, Lag= 0.5 min Primary = 11.44 cfs @ 12.10 hrs, Volume= 29,486 cf Routing by Stor -Ind method, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Peak Elev= 226.27' @ 12.10 hrs Surf.Area= 560 sf Storage= 1,211 cf Flood Elev= 226.00' Surf.Area= 560 sf Storage= 1,211 cf Brookhaven, Lexington, MA 151067 2017 POST AP2 Type 111 24 -hr 100 -Year Rainfall= 7.50" Prepared by Goldsmith, Prest & Ringwall, Inc. Printed 7/14/2017 HydroCAD® 10.00 -20 s/n 01036 © 2017 HydroCAD Software Solutions LLC Page 92 Plug -Flow detention time= 3.3 min calculated for 29,486 cf (100% of inflow) Center -of -Mass det. time= 3.1 min ( 813.8 - 810.7 ) Volume Invert Avail.Storage Storage Description #1A 220.50' 359 cf 14.00'W x 40.00'L x 3.50'H Field A 1,960 cf Overall - 1,063 cf Embedded = 897 cf x 40.0% Voids #2A 220.50' 852 cf ADS N -12 36" x 6 Inside #1 Inside= 36.1 "W x 36.1 "H => 7.10 sf x 20.001 = 142.0 cf Outside= 42.0 "W x 42.0 "H => 8.86 sf x 20.001 = 177.1 cf 3 Rows of 2 Chambers Primary OutFlow Max =11.20 cfs @ 12.10 hrs HW= 226.20' (Free Discharge) T_71 =Culvert (Inlet Controls 6.81 cfs @ 8.67 fps) L2 =LOW FLOW ORIFICE (Passes 6.81 cfs of 8.62 cfs potential flow) 3= Broad -Crested Rectangular Weir (Weir Controls 4.40 cfs @ 4.00 fps) Summary for Link AP2: Inflow Area = 347,640 sf, 57.70% Impervious, Inflow Depth= 5.66" for 100 -Year event Inflow = 36.94 cfs @ 12.15 hrs, Volume= 164,096 cf Primary = 36.94 cfs @ 12.15 hrs, Volume= 164,096 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs 1,211 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Primary 220.50' 12.0" Round Culvert L= 21.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 220.50'/219.00' S=0.0714'/' Cc= 0.900 n=0.013, Flow Area= 0.79 sf #2 Device 1 220.50' 12.0" Vert. LOW FLOW ORIFICE C= 0.600 #3 Primary 224.00' 0.5' long x 4.0' breadth Broad - Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max =11.20 cfs @ 12.10 hrs HW= 226.20' (Free Discharge) T_71 =Culvert (Inlet Controls 6.81 cfs @ 8.67 fps) L2 =LOW FLOW ORIFICE (Passes 6.81 cfs of 8.62 cfs potential flow) 3= Broad -Crested Rectangular Weir (Weir Controls 4.40 cfs @ 4.00 fps) Summary for Link AP2: Inflow Area = 347,640 sf, 57.70% Impervious, Inflow Depth= 5.66" for 100 -Year event Inflow = 36.94 cfs @ 12.15 hrs, Volume= 164,096 cf Primary = 36.94 cfs @ 12.15 hrs, Volume= 164,096 cf, Atten= 0 %, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00 -72.00 hrs, dt= 0.05 hrs Stormwater Management Standard 3 GROUNDWATER RECHARGE Pre - Development Conditions Total Subcatchment Areas Total Subcatchment Areas On -Site Total Area of Hydrolic Soil Groups On -Site Surface Type Areas Brookhaven at Lexington 960 -1010 Waltham St, Lexington, MA Project No. 151067 Area (sf) Area Ac 2,840,536 65.2 662,078 15.2 662,078 15.2 A 0 0.0 B 339,841 7.8 C 0 0.0 D 322,237 7.4 Roofs 0.60 71,836 1.6 C B 63,578 1.5 D 8258 0.2 Lawn Good ( >75 %) 165,100 3.8 B 95,059 2.2 D 70,041 1.6 Pavement 81,021 1.9 B 53,621 1.2 D 27,400 0.6 Roofs =Lawn Good ( >75 %) 8,635 0.2 B 8,459 0.2 D 176 0.0 Pavement =Lawn Good ( >75 %) 32,259 0.7 B 528 0.0 D 31,731 0.7 Woods, Good 297,369 6.8 B 115,758 2.7 D 181,611 4.2 Ledge 2,838 0.1 B 2,838 0.1 D 0 0.0 Gravel 3,020 0.1 B 0 0.0 D 3,020 0.1 Total Impervious Area On -Site (B) 120,037 2.8 Total Impervious Area On -Site (D) 35,658 0.8 *Note: Roof/Pave ment= Lawn not included Infiltration Volume Inches of Recharge per Storm Event A 0.60 B 0.35 C 0.25 D 0.10 Infiltration Volume =1 {[(Total Subcatchment Area within HSG) - (Total Impervious Area within HSG)] x (inches of Recharge Per Storm)) Infiltration Volume 8,799 CF Goldsmith, Prest and Ringwall, Inc. 151067 - Brookhaven at Lexington Stormwater Management Standard 3 GROUNDWATER RECHARGE Post Development Conditions Total Subcatchment Areas Total Subcatchment Areas On -Site Total Area of Hydrolic Soil Groups On -Site Surface Type Areas Brookhaven at Lexington 960 -1010 Waltham St, Lexington, MA Project No. 151067 Area (sf) Area Ac 2,840,536 65.2 662,078 15.2 662,078 15.2 Total Impervious Area On -Site (B) Total Impervious Area On -Site (D) Infiltration Volume 192,715 4.4 83,287 1.9 Inches of Recharge per Storm Event A 0.60 B 0.35 C 0.25 D 0.10 Infiltration Volume = {[(Total Subcatchment Area within HSG) - (Total Impervious Area within HSG)] x (inches of Recharge Per Storm)} Natural Infiltration Volume Pre - Development Infiltration Volume Required Infiltration Volume 6,411 CF 8,799 CF 2,388 CF Goldsmith, Prest and Ringwall, Inc. 151067 - Brookhaven at Lexington A 0 0.0 B 346,020 7.9 C 0 0.0 D 316,010 7.3 Roofs 120,262 2.8 B 110,673 2.5 D 9,589 0.2 Lawn Good ( >75 %) 188,555 4.3 B 107,953 2.5 D 80,602 1.9 Pavement 152,902 3.5 B 79,204 1.8 D 73,698 1.7 Woods, Good 197,473 4.5 B 45,352 1.0 D 152,121 3.5 Ledge 2,838 0.1 B 2,838 0.1 D 0 0.0 Total Impervious Area On -Site (B) Total Impervious Area On -Site (D) Infiltration Volume 192,715 4.4 83,287 1.9 Inches of Recharge per Storm Event A 0.60 B 0.35 C 0.25 D 0.10 Infiltration Volume = {[(Total Subcatchment Area within HSG) - (Total Impervious Area within HSG)] x (inches of Recharge Per Storm)} Natural Infiltration Volume Pre - Development Infiltration Volume Required Infiltration Volume 6,411 CF 8,799 CF 2,388 CF Goldsmith, Prest and Ringwall, Inc. 151067 - Brookhaven at Lexington Stormwater Management Standard 3 GROUNDWATER RECHARGE Brookhaven at Lexington Post Development Conditions 960 -1010 Waltham St, Lexington, MA Project No. 151067 Provided Infiltration Volume Underground Infiltration Chambers INF1 3,269 CF Volume below 239.50' Orifice Underground Infiltration Chambers INF2 896 CF Volume below 233.00' Orifice Underground Infiltration Chambers IN3 1,854 CF Volume below 237.50' Orifice Underground Infiltration Chambers INF4 850 CF Volume below 230.00' Orifice Underground Infiltration Chamber INF5 2,943 CF Volume below 239.00' Orifice Underground Infiltration Chambers INF6 2,790 CF Volume below 227.50' Piped Outlet Underground Infiltration Chamber INF7 1,608 CF Volume below 230.50' Piped Outlet Infiltration Basin East 0 CF Volume below 223.00' Piped Outlet Infiltration Basin West 0 CF Volume below 225.00' Piped Outlet Total Provided Infiltration Volume 14,210 77CF] Goldsmith, Prest and Ringwall, Inc. 151067 - Brookhaven at Lexington Stormwater Management Standard 4 WATER QUALITY RETENTION VOLUME Parameter Unit Quantity On -Site Watershed area sf 662,078 Predevelopment on -site impervious area sf 155,695 Total impervious area added sf 120,307 Total impervious aree sf 276,002 Total impervious area required for retention sf 120,307 Runoff depth over impervious area Required Water Quality Volume Provided Water Quality Volume IN 0.5 CF 5,013 Brookhaven at Lexington 960 -1010 Waltham St, Lexington, MA Project No. 151067 Remarks Underground Infiltration Chambers INF1 3,269 CF Volume below 239.50' Orifice Underground Infiltration Chambers INF2 896 CF Volume below 233.00' Orifice Underground Infiltration Chambers IN3 1,854 CF Volume below 237.50' Orifice Underground Infiltration Chambers INF4 850 CF Volume below 230.00' Orifice Underground Infiltration Chamber INF5 2,943 CF Volume below 239.00' Orifice Underground Infiltration Chambers INF6 2,790 CF Volume below 227.50' Piped Outlet Underground Infiltration Chamber INF7 1,608 CF Volume below 230.50' Piped Outlet Infiltration Basin East 0 CF Volume below 223.00' Piped Outlet Infiltration Basin West 0 CF Volume below 225.00' Piped Outlet DESIGN VOLUME PROVIDED CF 14,210 Goldsmith, Prest and Ringwall, Inc. 151067 - Brookhaven at Lexington s=Qr- 0 2 (0 C � � a J C� O Z O J U R fn 0 Y E d O r m >C, O O 01 le L R Y c a E N R c R N R 3 O Yi v R j O v O J o 0 0 o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O In CO M O O O M M O In to O O N 0 O In N 0 0 0 0 0 0 0 0 0 0 0 O N— ID O O M ID � O N N O O N N O N N 0 0 0 0 0 0 0 0 0 0 0 R In (O CO LO I- In N N N LO r r N (O I- N N N N r r N (O I- N N N r N N I— O o0 M N N I— N N N I- r E 0 o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 d 0 In M 0 O- � to 0 0 0 0 0 0 0 O In O 0- 0 O O 0 0- 0 O to O 0- O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 In 00 00 C\j N N I O I N (O In 00 In N V In O M N (O In 00 In N V In O N (O In O N (O N r In O N (O In O O N (O O E Q O J V% 0 0 0 0 0 0 0 ° o o ° 0 0 0 ° o o ° o ° o ° o ° o ° 0 0 0 O LO (N M O N D O O O M 0 0 LO � O 0 In 0 O N 0 O O In O O N 0 O In O N 0 0 O 0 0 O 0 0 O 0 0 O 0 0 0 O O tm 0 LO (0 co o � I� 0LO LO , LO 0 � r r 0 LO (0 LO LO 0 LO (0 LO 0 LO 0 O 0 LO 0 LO LO t' R U) a/ R R >0000000000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 000000000 0 0 0 0 0 0 0 0 0 O 0 0 0 0 0 0 0 0 0 0 0 0 wN In to O O N In 00 to O O to O N 00 In N 00 to to O N N 00 to O to O N 00 N 00 to to O N N CO to O N CO to O N CO O O — CO to O N CO to O N CO O co F C N T R R C C N T R R C .N C N T R R C m .N C T R N R C C N T R R C C N R C N R am C C N R C R N H R O O U U— U U U U- ~ O m (4 LL L U 0 O m N O L LL U O m N LL U o O m N N LL U 0 O N LL U 0 N N U N O U a) > a N a) 0 a) a) U a U CL a5 w '� U .4 w a5 a5 �� w CL a E E N E o N E E E E o E E E E o E o E o E o = 15 iz — iz — iz — iz — iz — iz CL a lz CL E 0 0 0 0 0 0 0 0 0 U) LL y d Q 00 r (O c r (0 0 V M r O r M V O 001 Cl a/ E A A A W m n m LU m m m A n E a5 m 0 R m m m A d d a > m H U) m n m n m n LU w m a a R m n U LL LL m LL n W N LL V LL d LL Z_ U) d U) U) > m Z — Z — 0 0 LL m LL z z_ U n z Z Z z 3 a m a` E o UNIVERSITY OF MASSACHUSETTS Massachusetts Stormwater Evaluation Project AT AMHERST Water Resources Research Center (413) 545 -5532 Blaisdell House, UMass (413) 545 -2304 FAX 310 Hicks Way www.mastep.net Amherst, MA 01003 MASTEP Technology Review Technology Name: Stormwater Buffer Zone Studies Reviewed: Verification Testing of a 4 -ft Stormwater Buffer Zone Stormwater Catch Basin Treatment Unit, Alden Laboratory 2012 Date: 1/7/2013 Reviewer: Jerry Schoen Rating: 2 Brief rationale for rating: This laboratory study in general followed New Jersey protocols for laboratory testing, but only test 7 runs were performed (15 or more recommended). The report lacks details on quality control procedures. Other Comments: • ASTM 3977, the Suspended Sediment Concentration method was used. • Influent sediment concentration generally 200 mg /I range, within NJCAT guidelines. • Sediment mix used had a mean particle size of 70 microns, within NJCAT guidelines. • 5 flow rates tested, ranging from < 10% to 125% of system design flow. • Scour test was performed according to NJCAT guidelines. No scour found. • Sediment removal efficiency ranged from 41% - 77 %, depending on flow rates tested. Overall removal efficiency of 62.6% reported. Water Resources Research Center Page 1 University of Massachusetts — Amherst 1/7/2013 72 -Hour Infiltration Drawdown Time Infiltration Basin East Time Inflow forage (hours) (cfs) (cubic-feet) 0.010 0.00 0 2.50 0.00 0 5.0,0 0.00 0 7.50 0.04 9 10.00 D., 1 20,6 12.5 0 4.23 5,971 15.60 0.88 3,446 17.50 0.42 1,865 20.60 0.27 404 22.50 0.20 194 2,5.0,0 0.00 4.8 2.50 0.00 6 80.80 0.0,0 1 2;2.50 0.0,0 0 25.0,0 0.00 0 Drawdown Time = 30 Infiltration Basin West Time Inflow Storage (hours) (cfs) (cubic-feet) 0.00 0.00 0 2.50 0.00 0 5.00 0.00 0 7.50 0.00 0 10.00 8,8 <0 12.50 0,28 752 15.00 0.05 571 17.50 0.03 511 20.00 0.02 5227 2.2.50 0.02 52:1 2,5.00 0.00 49' 2 7.50 0.010 462 20.0,0 0.00 42'9 22.50 0.010 3,96 35.00 0.00 2:62, 27.50 0.00 221 40.00 0.010 2:98 42.50 0.00 266 45.00 0.00 2221 47.50 0.00 2'02 50.00 0.010 171 52.50 0.00 140 55.00 0.00 109 57.50 0.00 78 60.00 0.00 4.8 62.50 0.00 2'O 65.00 0.00 8 67.50 0.00 2 70.00 0.00 1 72.50 0.00 0 Drawdown Time = 70 Directly Connected Impervious Area (DCIA) Calculations Post - Development Conditions Subcatchment Total Area (SF) Total Impervious On -Site Area (SF) DCIA (SF) Disconnected Impervious Area (SF) EX. SC -R 5,090 5,090 0 5,090 EX. SC -ST 8,470 8,470 8,470 0 EX. SC -1 3,800 2,065 2,065 0 EX. SC -2 3,181 3,181 3,181 0 EX. SC -3 13,313 6,470 6,470 0 EX. SC -17 8,684 5,691 5,691 0 EX. SC -18 39,957 27,785 27,785 0 EX. SC -19 10,479 10,479 10,479 0 EX. SC -20 23,453 9,793 9,793 0 EX. SC -21 18,524 13,206 13,206 0 EX. SC -22 21,601 9,865 9,865 0 P. SC -NWC 28,591 6,348 0 6,348 P. SC -FBW 5,926 855 0 855 P. SC -FBE 2,419 881 0 881 P. SC -P 12,156 1,893 0 1,893 P. SC -R1 3,833 3,833 0 3,833 P. SC -R2 7,747 7,747 0 7,747 P. SC -R3 21,598 21,598 0 21,598 P. SC -R4 13,748 13,748 0 13,748 P. SC -R5 7,577 7,577 0 7,577 P. SC -R6 2,922 4,922 0 4,922 P. SC -R7 5,261 3,261 0 3,261 P. SC -R8 4,529 4,529 0 4,529 P. SC -R9 5,157 5,157 5157 0 P. SC -1 10,049 7,111 0 7,111 P. SC -2 2,252 305 0 305 P. SC -3 16,114 9,758 0 9,758 P. SC -4 11,426 6,140 0 6,140 P. SC -5 23,642 12,798 0 12,798 P. SC -6 3,049 1,710 0 1,710 P. SC -7 3,222 907 0 907 P. SC -8 7,284 5,235 5,235 0 P. SC -9 3,276 2,929 2,929 0 P. SC -10 2,715 1,692 1,692 0 P. SC -11 1,539 467 467 0 P. SC -12 43,205 31,369 31,369 0 P. SC -13 1,923 643 643 0 P. SC -E4 16,443 8,303 8,303 0 P. SC -C1 18,733 0 0 0 P. SC -C2 27,722 0 0 0 P. SC -C3 48,870 0 0 0 P. SC -D 2,321,056 2,871 2,871 0 TOTAL 2,840,536 276,682 155,671 121,011 TOTAL PARCEL AREA (32.14 Ac] 1,398,276 276,682 155,671 121,011 OF PARCEL AREA 19.8% 11.1% 8.7% Impervious Area Summary Pre - Development Watershed Existing Subcatchment Impervious Area (SF) Impervious Area = Lawn (SF) EX. SC -R 5,090 0 EX. SC -ST 8,470 0 EX. SC -1 2,065 0 EX. SC -2 3,071 110 EX. SC -3 6,470 0 EX. SC -4 10,857 143 EX. SC -5 0 4,324 EX. SC -6 1,621 11,243 EX. SC -8 10,206 12,094 EX. SC -9 0 1,680 EX. SC -15 0 1,734 EX. SC -16 23,773 9,566 EX. SC -17 5,691 0 EX. SC -18 27,785 0 EX. SC -19 10,479 0 EX. SC -20 9,793 0 EX. SC -21 13,206 0 EX. SC -22 9,865 0 EX. SC -A 4,247 0 EX. SC -B 0 0 EX. SC -C 46 0 EX. SC -D 329,501 0 SUBTOTAL 482,236 40,894 TOTAL IMPERVIOUS AREA 523,130 Impervious Area Summary Post - Development Watershed Proposed Subcatchment Impervious Area (SF) EX. SC -R 5,090 EX. SC -ST 8,470 EX. SC -1 2,065 EX. SC -2 3,181 EX. SC -3 6,470 EX. SC -17 5,691 EX. SC -18 27,785 EX. SC -19 10,479 EX. SC -20 9,793 EX. SC -21 13,206 EX. SC -22 9,865 P. SC -NWC 6,348 P. SC -FBW 855 P. SC -FBE 881 P. SC -P 1,893 P. SC -R1 3,833 P. SC -R2 7,747 P. SC -R3 21,598 P. SC -R4 13,748 P. SC -R5 7,577 P. SC -R6 4,922 P. SC -R7 3,261 P. SC -R8 4,529 P. SC -R9 5,157 P. SC -1 7,111 P. SC -2 305 P. SC -3 9,758 P. SC -4 6,140 P. SC -5 12,798 P. SC -6 1,710 P. SC -7 907 P. SC -8 5,235 P. SC -9 2,929 P. SC -10 1,692 P. SC -11 467 P. SC -12 31,369 P. SC -13 643 P. SC -E4 8,303 P. SC -C1 0 P. SC -C2 0 P. SC -C3 0 P. SC -D 329,412 TOTAL 603,223 Stormwater Management Facilities Summary Existing Stormwater Management Facility Treated Subcatchment Treated Impervious Area (SF) Sediment Tank (ST) EX. SC -R 5,090 Exist. 36" ADS HDPE Recharge System (EX. INF) EX. SC -ST 8,470 TOTAL 13,560 Proposed Stormwater Management Facility Treated Subcatchment(s) Treated Impervious Area (SF) Sediment Tank (ST) EX. SC -ST 8,470 INF1 P. SC -R5 7,577 INF4 P. SC -R7 3,261 INF5 P. SC -R6 4,922 P. SC -R8 4,529 TOTAL 9,451 SWM1 + INF6 P. SC -5 12,798 P. SC -6 1,710 P. SC -7 907 EX. SC -R 5,090 P. SC -R1 3,833 P. SC -R3 21,598 TOTAL 45,936 INF7 P. SC -R2 7,747 NW Culvert Forebay (P. C -1) + West Swale (R3) P. SC -NWC 6,348 FBW+ IBW+ FBE + IBE + INF2 + INF3 P. SC -1 7,111 P. SC -FBW 855 P. SC -P 1,893 P. SC -2 305 P. SC -FBE 881 P. SC -3 9,758 P. SC -4 6,140 P. SC -R4 13,748 P. SC -C3 0 TOTAL 40,691 TOTAL ON SITE 129,481 '�. wry, ww� C C s 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Stormwater Pollution Prevention Plan (SWPPP) For Construction Activities At: Property shown on Lexington Assessors Map 5, Lots 16A, 19C, 20 and 21 A. These two properties contain a total of approximately 32 acres. SWPPP Prepared For: Brookhaven at Lexington 1010 Waltham Street Lexington, MA 02421 781 - 863 -9660 (Main) SWPPP Operator: C.E. Floyd Company Inc. 135 South Road Bedford, MA 01730 SWPPP Prepared By: Integrated Engineering & Sciences, Inc. 44 Wood Ave Mansfield, MA 02048 774 -357 -1095 biohnsonCie- si.com SWPPP Preparation Date: 07/11/2017 Estimated Project Dates: Project Start Date: TBD Project Completion Date: TBD Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Contents SECTION1: CONTACT INFORMATION /RESPONSIBLE PARTIES ................. ..............................2 1.1 Operator(s) / Subcontractor(s) .......................... ............................... 2 1.2 Stormwater Team ............................................... ..............................2 SECTION2: SITE EVALUATION, ASSESSMENT, AND PLANNING ............... ............................... Z 2.1 Project /Site Information .................................... ............................... 2 2.2 Discharge Information ...................................... ............................... 2 2.3 Nature of the Construction Activity .................. ............................... 5 2.4 Sequence and Estimated Dates of Construction Activities ............. 6 2.5 Allowable Non - Stormwater Discharges ........... ............................... 6 2.6 Site Maps ............................................................ ..............................6 SECTION 3: DOCUMENTATION OF COMPLIANCE WITH OTHER FEDERAL REQUIREMENTS oo— o...00 —o.7 3.1 Endangered Species Protection ......................... ............................... 7 3.2 Historic Preservation ......................................... ............................... 8 3.3 Safe Drinking Water Act Underground Injection Control Requirements................................................................ ............................... 9 SECTION4: EROSION AND SEDIMENT CONTROLS .............................. ..............................9 4.1 Natural Buffers or Equivalent Sediment Controls .........................11 4.2 Perimeter Controls ............................................ .............................12 4.3 Sediment Track - Out .......................................... .............................15 4.4 Stockpiled Sediment or Soil .............................. .............................15 4.5 Minimize Dust ................................................... .............................16 4.6 Minimize the Disturbance of Steep Slopes ....... .............................17 4.7 Topsoil ............................................................... .............................17 4.8 Soil Compaction ................................................ .............................18 4.9 Storm Drain Inlets ............................................. .............................18 4.10 Constructed Stormwater Conveyance Channels ............................20 4.11 Sediment Basins .............................................. ............................... 20 4.12 Chemical Treatment .......................................... .............................20 4.13 Dewatering Practices ......................................... .............................20 4.14 Other Stormwater Controls ............................. ............................... 20 4.15 Site Stabilization ............................................. ............................... 21 ii Stormwater Pollution Prevention Plan ( SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA SECTION5: POLLUTION PREVENTION STANDARDS ............................. .............................23 5.1 Potential Sources of Pollution ......................... ............................... 23 5.2 Spill Prevention and Response ....................... ............................... 24 5.3 Fueling and Maintenance of Equipment or Vehicles .................... 25 5.4 Washing of Equipment and Vehicles .............. ............................... 25 5.5 Storage, Handling, and Disposal of Construction Products, Materials, and Wastes ................................................... .............................26 5.6 Washing of Applicators and Containers used for Paint, Concrete orOther Materials ...................................................... ............................... 29 5.7 Fertilizers ........................................................... .............................29 5.8 Other Pollution Prevention Practices ................ .............................30 SECTION6: INSPECTION AND CORRECTIVE ACTION .......................... .............................31 6.1 Inspection Personnel and Procedures ............. ............................... 31 6.2 Corrective Action .............................................. .............................32 6.3 Delegation of Authority .................................. ............................... 32 SECTION7: TRAINING ............................................................. .............................33 SECTION8: CERTIFICATION AND NOTIFICATION .............................. .............................34 SWPPPAPPENDICES ............................................................... .............................35 iii Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Appendix A - Site Maps Appendix 8 - Copy of 2017 CGP Appendix C - NOI and EPA Authorization Email Appendix D - Inspection Form Appendix E - Corrective Action Form Appendix F - SWPPP Amendment Log Appendix G - Subcontractor Certifications /Agreements Appendix H - Grading and Stabilization Activities Log Appendix 1- Training Log Appendix J - Delegation of Authority Appendix K - Endangered Species Documentation Appendix L - Historic Preservation Documentation Appendix M - Impaired Waters Documentation Appendix N - Order of Conditions Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA SECTION 1: CONTACT INFORMATION /RESPONSIBLE PARTIES 1.1 Operator(s) / Subcontractor(s) Owner: Brookhaven at Lexington 1010 Waltham Street, Suite 600 Lexington, MA 02421 Engineer: Integrated Engineering & Sciences, Inc. GPR, Inc. 44 Wood Ave 39 Main Street, Suite 301 Mansfield, MA 02048 Ayer, MA 01432 774 - 357 -1095 978 - 772 -1590 biohnson @ie- si.com Operator: Emergency 24 -Hour Contact: C.E. Floyd Company, Inc. C.E. Floyd Company, Inc. 135 South Road Normand Fournier Bedford, MA 01730 -2355 781 - 271 -9006 781 - 271 -9006 (0) Subcontractor(s): 1.2 Stormwater Team Proiect Manager Proiect Superintendent C.E. Floyd Company, Inc. C.E. Floyd Company, Inc. Normand Fournier Normand Fournier Construction operators must post a sign or other notice of permit coverage at a safe, publicly accessible location in close proximity to the construction site. This notice must also include information informing the public on how to contact EPA to obtain a copy of the SWPPP, and how to contact EPA if stormwater pollution is observed in the discharge. P Stormwater Pollution Prevention Plan ( SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA SECTION 2: SITE EVALUATION, ASSESSMENT, AND PLANNING 2.1 Project /Site Information Project Name and Address Project /Site Name: Project Street/ Location: City: State: ZIP Code: County or Similar Subdivision: Project Latitude /Longitude Brookhaven at Lexington 960 -1010 Waltham Street Lexington Massachusetts 02421 Middlesex Latitude: Longitude: 1. _ _ ° _ _ ' _ _" N (degrees, minutes, seconds) 1. _ _ ° _ -'- _" W (degrees, minutes, seconds) 2. _ _ ° _ _ . _ _' N (degrees, minutes, decimal) 2. _ _ ° _ _ . _ -'W (degrees, minutes, decimal) 3.42.41390' N (decimal) 3. - 71.229350 W (decimal) Method for determining latitude /longitude: ❑ USGS topographic map (specify scale: ) ❑ EPA Web site ❑ GPS ® Other (please specify): Gooale Earth Horizontal Reference Datum: ❑ NAD 27 ® NAD 83 or WGS 84 ❑ Unknown Additional Project Information Is the project /site located on Indian country lands, or located on a property of religious or cultural significance to an Indian tribe? ❑ Yes ® No Are you applying for permit coverage as a "federal operator" as defined in Appendix A of the 2017 CGP? ❑ Yes ® No Note: Some template language has been incorporated in this SWPPP as a quick reference for on -site personnel that may not be familiar with the 2017 CGP. The 2017 CGP is attached as Appendix B. 2.2 Discharge Information Does your project /site discharge stormwater into a Municipal Separate Storm Sewer System (MS4)? ❑ Yes ® No Are there any surface waters that are located within 50 feet of your construction disturbances? ® Yes ❑ No O IL J E 3 \ .0 J e § \ .0 3 % \ e 5 4 E 0 V) (D � ■ u ■ / (D E a 2 � ■ 3 � - \ / E / / / \ { E 2:- \ \ \ E \ ( �\ \ \ & \ \ \ 3 E / E � a k E � \ co � } U 0 ■ � § % ■ � (D � I � ■ � � - @ e 4 V) 0 0 ± 4 CL \ E / § O 4 g ./ O D- E § 0 $ 2 \ \ \ 0 D- 0 k E « 0 ^2 0 / / 3 c CL 2 » : /\ o -C ƒ� / \ \\ 0 2 x \ k % d 2 $ £ \ ■ E w ƒ \Q / 'A / f �/ � ^ ƒ�0 \ $ e22 \ E / / E - / k J 0 / \ k 3 \ _ (D(D � M \ / / / \ (» O \ = 7 w 2 .t I F E e N ( ❑ /�/ \�o / 2 _ \ w 0 CL 2 \ / )2 §� c = E bE v2 a g [ « k � }z \ \�a k / \\ El L =k g \kE w a22 � @ e 4 V) 0 0 ± 4 CL \ E / § O 4 g ./ O D- E § 0 $ 2 \ \ 0 D- E « 0 \ / / & : /\ -C / \ \\ 0 2 x ,c§ $ £ 2 % d 2 $ £ \ ■ c \ ƒ \Q \\ �/ � ^ ƒ�0 e22 \ E / / E - \ J 0 / _ j \ O 3 \ _ (D(D M / / / \ \ = 7 w 2 .t I F E e N ) \ /�/ \�o 0 _ § ■ $ 0 CL 2 # Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 2.3 Nature of the Construction Activity General Description of Project The work under this contract will consist of furnishing all necessary labor, materials and equipment required to construct a new independent living facility on the lands north of Chester Brook, making a single vehicular and pedestrian connection to the existing Brookhaven facility, as well as expanding the existing Commons facilities at Brookhaven. The North Building (for independent living) includes an integral underground parking garage that is partially exposed above grade at the northwest and northeast corners. Some surface parking will also be provided near the North Building. An emergency fire access lane will be installed north of the North Building, with a hammerhead -type turnaround for fire trucks and emergency vehicles. An "Entrance Only" emergency /fire access entrance from Waltham Street will be provided at the northwest corner of the property by reconstructing a former driveway entrance and moving a utility pole. The North Building will be connected to the existing Brookhaven facility via a raised roadway bounded by mechanically stabilized earth retaining walls (MSE walls). An arch span culvert is proposed to support the roadway crossing over an existing culvert in Chester Brook without disturbing the existing culvert and minimizing impacts to adjacent wetlands. The MSE walls and the arch span culvert are measures proposed after consultation with the Lexington Conservation Commission about ways to minimize wetland and buffer encroachments. New utility service connections for water, sewer, natural gas, electricity and telecommunications will be tapped in the Waltham Street right -of -way and brought to the west end of the North Building. Potable water service to the North Building will be tapped into the 10" water main in Waltham Street at the northwest corner of the property and will be connected to the water main being relocated with the Commons Expansion to provide a looped water system. A telecommunications duct bank will also connect the North Building to the Commons Expansion. Other work associated with the project includes realignment of the Commons Road access aisle adjacent to the Commons Expansion, reconfiguration of existing parking areas, as well as utility relocations for water, sewer, natural gas, electrical, telecommunications and drainage lines and facilities. New electrical transformers and emergency generators will be set at both the North Building and the Commons Expansion. Size of Construction Project SIZE OF PROPERTY ESTIMATED: 32.14 acres TOTAL AREA OF CONSTRUCTION DISTURBANCES ESTIMATED: 6 acres MAXIMUM AREA TO BE DISTURBED AT ANY ONE TIME ESTIMATED < 6 acres 5 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 2.4 Sequence and Estimated Dates of Construction Activities Working hours will be as allowed by permit with the Town of Lexington. The Project will not be constructed in phases. The project is expected to commence on or about TBD and will be completed by TBD. 2.5 Allowable Non - Stormwater Discharges List of Allowable Non - Stormwater Discharges Present at the Site Type of Allowable Non - Stormwater Discharge Likely to be Present at Your Site? Discharges from emergency fire-fighting activities ❑ YES ® NO Fire hydrant flushing ❑ YES ® NO Landscape irrigation ® YES ❑ NO Waters used to wash vehicles and equipment ❑ YES ® NO Water used to control dust ® YES ❑ NO Potable water including uncontaminated water line flushing ® YES ❑ NO Routine external building wash down ❑ YES ® NO Pavement wash waters ❑ YES ® NO Uncontaminated air conditioning or compressor condensate ❑ YES ® NO Uncontaminated, non - turbid discharges of ground water or spring water ❑ YES ® NO Foundation or footing drains ❑ YES ® NO Construction clewatering water ❑ YES ® NO New to the 2017 CGP is an explicit prohibition of non- stormwater discharges of external building wash down waters containing hazardous substances, such as paint or caulk containing polychlorinated biphenyls (PCBs). 2.6 Site Maps Site Map and Contract Drawings are attached as Appendix A. 0 Stormwater Pollution Prevention Plan ( SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA SECTION 3: DOCUMENTATION OF COMPLIANCE WITH OTHER FEDERAL REQUIREMENTS 3.1 Endangered Species Protection Eligibility Criterion Under which criterion listed in Appendix D are you eligible for coverage under this permit? ®A ❑B El ❑D ❑E For reference purposes, the eligibility criteria listed in Appendix D are as follows: Criterion A. No federally - listed threatened or endangered species or their designated critical habitat(s) are likely to occur in your site's "action area" as defined in Appendix A of this permit. Criterion B. The construction site's discharges and discharge - related activities were already addressed in another operator's valid certification of eligibility for your action area under eligibility Criterion A, C, D, E, or F and there is no reason to believe that federally - listed species or federally- designated critical habitat not considered in the prior certification may be present or located in the "action area ". To certify your eligibility under this Criterion, there must be no lapse of NPDES permit coverage in the other operator's certification. By certifying eligibility under this Criterion, you agree to comply with any effluent limitations or conditions upon which the other operators certification was based. You must include in your NOI the tracking number from the other operator's notification of authorization under this permit. If your certification is based on another operator's certification under Criterion C, you must provide EPA with the relevant supporting information required of existing dischargers in Criterion C in your NOI form. Criterion C. Federally - listed threatened or endangered species or their designated critical habitat(s) are likely to occur in or near your site's "action area," and your site's discharges and discharge - related activities are not likely to adversely affect listed threatened or endangered species or critical habitat. This determination may include consideration of any stormwater controls and /or management practices you will adopt to ensure that your discharges and discharge - related activities are not likely to adversely affect listed species and critical habitat. Tc make this certification, you must include the following in your NOI: 1) any federally listed species and /or designated habitat located in your "action area "; and 2) the distance between your site and the listed species or designated critical habitat (in miles). You must also include a copy of your site map with your NOI. Criterion D. Coordination between you and the Services has been concluded. The coordination must have addressed the effects of your site's discharges and discharge - related activities on federally - listed threatened or endangered species and federally- designated critical habitat, and must have resulted in a written concurrence from the relevant Service(s) that your site's discharges and discharge - related activities are not likely to adversely affect listed species or critical habitat. You must include copies of the correspondence between yourself and the Services in your SWPPP and your NOI. Stormwater Pollution Prevention Plan ( SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Criterion E. Consultation between a Federal Agency and the U.S. Fish and Wildlife Service and /or the National Marine Fisheries Service under section 7 of the ESA has been concluded. The consultation must have addressed the effects of the construction site's discharges and discharge - related activities on federally - listed threatened or endangered species and federally- designated critical habitat. The result of this consultation must be either: Criterion F. Your construction activities are authorized through the issuance of a permit under section 10 of the ESA, and this authorization addresses the effects of the site's discharges and discharge - related activities on federally - listed species and federally- designated critical habitat. You must include copies of the correspondence between yourself and the Services in your SWPPP and your NOI. Supporting Documentation For criterion A, Check the applicable source of information that was relied upon: ❑ Specific communication with staff of the U.S. Fish & Wildlife Service or National Marine Fisheries Service. ® Publicly available species list. Records were reviewed via the Massachusetts Office of Geographic Information two 2008 data layers developed by the Natural Heritage and Endangered Species Program - Priority Habitats and Estimated Habitats. (http: / /maps.massgis. state .ma.us /PRI- EST- HAB /viewer.htm) A figure depicting the data layer is attached in Appendix K. 3.2 Historic Preservation Appendix E, Step 1 Do you plan on installing any of the following stormwater controls at your site? Check all that apply below, and proceed to Appendix E, Step 2. ❑ Dike ❑ Berm ® Catch Basin ® Pond ® Stormwater Conveyance Channel (e.g., ditch, trench, perimeter drain, swale, etc.) ® Culvert ❑ Other type of ground- disturbing stormwater control: 0 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Appendix E, Step 2 If you answered yes in Step 1, have prior surveys or evaluations conducted on the Site already determined that historic properties do not exist, or that prior disturbances at the Site have precluded the existence of historic properties? ❑ YES ® NO Appendix E, Step 3 If you answered no in Step 2, have you determined that your installation of subsurface earth - disturbing stormwater controls will have no effect on historic properties? ® YES ❑ NO The National Register of Historic Places and the National Parks Service National Register of Historic Places KML file (http: / /nrhp. focus. nps. gov /natreghome.do ?searchtype= natreghome) were searched. 3.3 Safe Drinking Water Act Underground Injection Control Requirements Do you plan to install any of the following controls? ® YES ❑ NO Check all that apply below. ❑ Infiltration trenches (if stormwater is directed to any bored, drilled, driven shaft or dug hole that is deeper than its widest surface dimension, or has a subsurface fluid distribution system) ® Commercially manufactured pre -cast or pre -built proprietary subsurface detention vaults, chambers, or other devices designed to capture and infiltrate stormwater flow. ❑ Drywells, seepage pits, or improved sinkholes (if stormwater is directed to any bored, drilled, driven shaft or dug hole that is deeper than its widest surface dimension, or has a subsurface fluid distribution system) SECTION 4: EROSION AND SEDIMENT CONTROLS Operators must design, install and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. At a minimum, such controls must be designed, installed and maintained to: a. Control stormwater volume and velocity to minimize soil erosion in order to minimize pollutant discharges; b. Control stormwater discharges, including both peak flowrates and total stormwater volume, to minimize channel and streambank erosion and scour in the immediate vicinity of discharge points; c. Minimize the amount of soil exposed during construction activity; d. Minimize the disturbance of steep slopes; e. Minimize sediment discharges from the site. The design, installation and maintenance of erosion and sediment controls must address factors such as the amount, frequency, intensity and duration of Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA precipitation, the nature of resulting stormwater discharge, and soil characteristics, including the range of soil particle sizes expected to be present on the site; f. Provide and maintain natural buffers around waters of the United States, direct stormwater to vegetated areas and maximize stormwater infiltration to reduce pollutant discharges, unless infeasible; g. Minimize soil compaction. Minimizing soil compaction is not required where the intended function of a specific area of the site dictates that it be compacted; and h. Unless infeasible, preserve topsoil. Preserving topsoil is not required where the intended function of a specific area of the site dictates that the topsoil be disturbed or removed. Ice Stormwater Pollution Prevention Plan ( SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 4.1 Natural Buffers or Equivalent Sediment Controls Buffer Compliance Alternatives Are there any surface waters within 50 feet of your project's earth disturbances? ® YES ❑ NO (Note: If no, no further documentation is required for the SWPPP Template.) ❑ I will provide and maintain a 50 -foot undisturbed natural buffer. ® I will provide and maintain an undisturbed natural buffer that is less than 50 feet and is supplemented by additional erosion and sediment controls, which in combination achieves the sediment load reduction equivalent to a 50 -foot undisturbed natural buffer. ❑ It is infeasible to provide and maintain an undisturbed natural buffer of any size; therefore, I will implement erosion and sediment controls that achieve the sediment load reduction equivalent to a 50 -foot undisturbed natural buffer. ❑ I qualify for one of the exceptions in Part 2.1.2.1.e. (If you have checked this box, provide information on the applicable buffer exception that applies, below.) Buffer Exceptions Which of the following exceptions to the buffer requirements applies to your site? ❑ There is no discharge of stormwater to the surface water that is located 50 feet from my construction disturbances. ❑ No natural buffer exists due to preexisting development disturbances that occurred prior to the initiation of planning for this project. ❑ For a "linear project" (defined in Appendix A), site constraints (e.g., limited right -of -way) make it infeasible for me to meet any of the CGP Part 2.1.2.1.a compliance alternatives. ❑ The project qualifies as "small residential lot" construction (defined in Part 2.1.2.1.e.iv and in Appendix A). ❑ Buffer disturbances are authorized under a CWA Section 404 permit. ❑ Buffer disturbances will occur for the construction of a water - dependent structure or water access area (e.g., pier, boat ramp, and trail). Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 4.2 Perimeter Controls General ■ During construction use erosion and perimeter control measures of sedimentation to avoid and minimize impacts to any resource areas. The construction plans call for silt sacs in catch basins. In the event that the engineer feels measures that are more aggressive are needed to prevent stormwater and silt from entering public water supply areas a larger list of recommended erosion and sedimentation controls are provided below. ■ Protect Conservation Resource Areas by sedimentation fencing, compost filter tubes, geotextile netting, silt sacs in the catch basins, or other appropriate measures as needed by the Contractor's means and methods of construction. ■ Any perimeter, erosion control measures will be installed before construction activity starts and will be inspected, maintained, and repaired, as needed, during the construction period according to Construction Plans in Appendix A. The integrity of the erosion control measures will be periodically checked and after each rainfall event and repaired, as needed. Contractor shall periodically remove and dispose of off -site accumulated silts and debris. Specific Perimeter Controls Perimeter Control # I Perimeter Control Description -Compost Filter Tubes Compost filter tubes will be maintained in effective condition throughout the construction period. A stockpile of extra compost filter tubes will be kept on -Site throughout the construction work. This material will be installed at the direction of the Engineer to mitigate any erosion or sedimentation conditions which may arise. Installation ■ Fill material for the filter tubes shall be compost meeting M 1.06.0, except that no manure or biosolids shall be used. In addition, no kiln -dried wood or construction debris shall be allowed. • Compost shall pass through a 3 inch (75mm) sieve. • Tubes for compost filters shall be a minimum of 12 inches, a maximum of 18" in diameter, and shall be jute mesh or approved biodegradable material. Additional tubes may be used at the direction of the Engineer. • As shown in the drawing details, the 1 foot wide by 2 inch deep wedge of compost spread along the top of the filter tube shall be incidental to this item. • Stakes for anchors shall be a minimum of 1 " x 1 " x 3 ft. untreated hardwood stakes, up to 5 ft. apart • Install tubes along contours and perpendicular to sheet or concentrated flow. • Provide 3 ft. (914mm) minimum overlap at ends to join in a continuous barrier Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA ■ When staking is not possible, such as when tubes must be placed on pavement, heavy concrete or cinder blocks can be used behind tubes up to 5 ft. (1.5m) apart or as required to secure tubes in place. ■ As shown in the detail, the 1 foot (0.2 meters) wide by 2 inch (50 mm) deep wedge of compost spread along the top of the filter tube shall be incidental to this item. Stakes for anchors, if required, shall be a minimum of 1 " x 1 " x 3 ft. untreated, hardwood stakes up to 5 ft. apart. ■ Tubes of compost maybe filled on site or shipped. Tubes shall be placed, filled and staked in place as required to ensure stability against water flows. Maintenance Requirements ■ The Contractor will ensure that the compost filter tubes function as intended at all times. Filter tubes will be inspected weekly, after each rainfall of 0.25- inches, and at least daily during prolonged rainfall. Inspection will be frequent and repair or replacement will be made promptly as directed by the Engineer. Filter tubes will be removed when they have served their usefulness so as not to block or impede storm flow or drainage. All erosion and sedimentation control measures will be maintained in effective condition throughout the construction period. The contractor will remove accumulated sediment from behind control measures as necessary. All erosion and sedimentation control measures found to be in need of repair or replacement will be immediately corrected so as to maintain the integrity of installed systems Perimeter Control # 2 Perimeter Control Description - Geotextile Matting ■ Matting for erosion control shall be a porous, biodegradable geotextile matting specifically manufactured to retain soil moisture, to hold soil temperatures and to temporarily stabilize soils until turf is established. Installation ■ Matting for erosion control shall be manufactured and constructed by weaving or bonding fibers made from synthetic and /or natural, biodegradable materials. Mulch matting is typically made of jute, straw or wood fibers that are preformed into sheets of mulch and delivered to the site in rolls. Netting is typically made of jute, wood fiber, plastic, or cotton and used to hold the mulch matting together. ■ Netting and matting shall be held to the ground with biodegradable staples or anchors as furnished and installed in accordance with blanket manufacturer's recommendations and as approved by the Authority Representative. Blanket shall be constructed to begin degradation 2 months after installation. ■ Matting for erosion control shall be installed as shown on the Drawings and as directed by the Engineer in accordance with manufacturers instructions. ■ Materials shall meet ASTM D6818 standards for Rolled Erosion Control Products. Maintenance Requirements 13 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA • The Contractor will ensure that the erosion control matting functions as intended at all times. Matting will be inspected weekly, after each rainfall of 0.25- inches, and at least daily during prolonged rainfall. Inspection will be frequent and repair or replacement will be made promptly as directed by the Engineer. All erosion and sedimentation control measures will be maintained in effective condition throughout the construction period. The contractor will remove accumulated sediment from behind control measures as necessary. All erosion and sedimentation control measures found to be in need of repair or replacement will be immediately corrected so as to maintain the integrity of installed systems. Perimeter Control # 3 Perimeter Control Description - Siltation Fence and Straw Bales ■ Silt fencing and Straw Bales shall be utilized to control run -off and prevent siltation of open and subsurface drainage systems, areas outside work limits, and undisturbed areas, if necessary. Installation • Manufactured product including siltation control geotextile and support posts. Geotextile shall be a polypropylene, ultraviolet resistant material. • Support posts shall be softwood measuring 1 -1 /2 inches by 1 -1 /2 inches or oak measuring 1 " by 1 ". • Filter fabric shall extend 6 inches below undisturbed ground ( "toed into ground "). • Straw Bales shall be staked at an angle and also perpendicular as per the Plans. Maintenance Requirements • Inspect all erosion and sediment controls daily. Also, inspect all erosion and sediment controls before an anticipated storm greater than 0.25 inches, and following a significant storm event (0.25 inches or greater total rainfall). • All erosion and sediment control devices shall be maintained in proper functioning order until final grading and stabilization is completed. • Any silt fence that becomes damaged during construction operations shall be repaired or replaced immediately at no additional cost to the Authority. • Silt fences shall have sediment removed before depth of sediment is half height of fence. • Remove built up debris and sediment where devices are used for catch basin protection, so that ponding or flooding does not occur. • Dispose of sediment deposits off -site, in accordance with all Federal, State, and local regulations. 14 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 4.3 Sediment Track -Out General • The Contractor will provide a mechanical sweeper equipped with a water tank, spray assembly to control dust, a pick -up broom, a dual gutter broom, and a dirt hopper during the milling operations. • Temporary Gravel tracking pads may be used at construction entrances /exits to prevent tracking or flowing of sediment out of the construction area. Compost filter tubes will be utilized in conjunction with the gravel tracking pads to channelize runoff. • Contractor may utilize calcium chloride, as necessary, for dust control, which will limit the amount of track -out. Specific Track -Out Controls Track -Out Control # I Track -Out Control Description ■ The sweeper will be capable of removing millings and loose debris from the underlying surface. All existing pavement surfaces will be swept as necessary. Installation ■ Sweeping operations will begin as needed. Additionally, as directed by the Engineer, sweeping and cleaning of surfaces will be conducted beyond the limits of the project to clean up material caused by spillage or vehicular tracking during the various phases of the work. ■ Gravel tracking pads will be constructed 12' wide with a minimum of 6" in thickness of modified rockfill. A 20' radius is required at the roadway, per the plans. Maintenance Requirements ■ Prior to opening a milled area to traffic, the milled surface will be thoroughly swept with a mechanical sweeper to remove all remaining millings and dust. This operation will be conducted in a manner so as to minimize the potential for creation of a traffic hazard and to comply with local, State, and Federal air pollution control laws and regulations. ■ The gravel tracking pads shall be maintained in a condition that will prevent tracking or flowing of sediment. Gravel will be added as necessary. 4.4 Stockpiled Sediment or Soil General The stockpiling of sediment at the project site will be protected by straw bales. Stockpiled topsoil will be covered or temporarily seeded until ready for use. Soil stockpiles will be located outside of the wetland buffer zone. 15 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Specific Stockpile Controls Stockpile Control Stockpiled Sediment /Soil Control Description ■ Asphalt related stockpiles, if needed, will be placed on a free draining base, kept separate from the other virgin aggregates and covered. If sediments or soils must be stockpiled at the Site they will be surrounded with straw bales to prevent and control siltation and erosion. Stockpiles that will remain exposed for more than 30 days will be stabilized. Soils potentially impacted by oil and /or hazardous materials will be surrounded with staked compost filter tubes (or straw bales) and siltation fences, placed on a 6 -mil polyethylene base liner and covered with a 6 -mil polyethylene cover. Soil stockpiles will be located outside of the buffer zone of any area subject to the Massachusetts Wetlands Protection and outside of direct stormwater flow path. Piles will be located outside of any natural buffers and physically separated from other stormwater controls. ■ Piles will be covered to protect from wind and precipitation. Installation ■ If required, stockpiles will be established during construction activities as required by the contractor or as directed by the Engineer. Stockpiles that will remain exposed for more than 30- days will be stabilized with mulch or seeded for temporary vegetative cover. Maintenance Requirements ■ If stockpiles are required, inspections of site conditions will take place on a weekly basis as well as after each incidence of rainfall exceeding 0.25- inches in twenty -four hours. Areas on or around the stockpile(s) that have eroded will be stabilized immediately with erosion controls. 4.5 Minimize Dust General • The Contractor will provide a mechanical sweeper equipped with a water tank, spray assembly to control dust, a pick -up broom, a dual gutter broom, and a dirt hopper. Additionally, a mechanical hand sweeper with a water wagon will be utilized throughout the project as needed. Specific Dust Controls Dust Control # I Dust Control Description ■ The Contractor will provide for the removal of all dirt spilled from his trucks on existing pavement over which it is hauled, or otherwise deposited thereon whenever, in the judgment of the Engineer, the accumulation is sufficient to cause the formation of mud or dust, interfere with drainage, or create a traffic hazard. Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Installation ■ Water and /or calcium chloride will be applied as needed or as directed by the Engineer. Maintenance Requirements ■ Potentially dusty areas will be swept or sprayed as needed and prior to rain events. 4.6 Minimize the Disturbance of Steep Slopes General ■ The project is limited to the right -of -way in a developed area and will not include disturbance to steep slopes greater than 2:1. Geotextile fabric under Modified Rockfill will be used for stabilization in all areas as directed and approved by the engineer and anchored with u -shape wire staples. 4.7 Topsoil General ■ The work shall include placing topsoil that has been obtained from within the project limits or that has been previously stockpiled and made available to the Contractor which is to be used on areas to be seeded or planted. Specific Topsoil Controls Topsoil Control # I Topsoil Control Description Compost topsoil will consist of fertile, friable, natural topsoil typical of the location, without admixture of subsoil, refuse or other foreign materials, and will be obtained from a well- drained arable site. It will be such a mixture of san, silt and clay particles as to exhibit sandy and clayey properties in and about equal proportions. It will be reasonably free of stumps, roots, heavy or stiff clay, stones larger than 1 -inch in diameter, lumps, coarse sand, noxious weeds, sticks, brush or other litter. ■ Prior to stripping (if required) the loam will have demonstrated by the occurrence upon it of healthy crops, grass or other vegetative growth that is reasonably well drained and that does not contain toxic amounts of either acid or alkaline elements. Installation ■ Topsoil will contain not less than 4% or more than 20% organic matter. Damage to vegetation by excessive watering or silt accumulation in the project area will be prevented. Maintenance Requirements ■ Site conditions will be inspected weekly and after storm events of 0.25- inches of rainfall and greater. 17 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 4.8 Soil Compaction General To the extent possible, soil compaction will be avoided within the root zone. Construction activities including, but not limited to, vehicle movement, excavation, embankment, staging and storage of materials or equipment will not occur underneath the canopy (drip line) of trees to remain. Where these activities will occur within 10 feet (3 meters) of the canopy of trees, the Contractor will provide Individual Tree Protection as specified. 4.9 Storm Drain Inlets General • Silt sacks shall be installed prior to construction, at the same time that silt fence and compost filter tubes are installed. • Stormwater protection will include furnishing, installation, maintenance, and removal of reusable fabric sacks to be installed in drainage structures for the protection of wetlands and other resource areas and the prevention of silt and sediment from the construction site from entering the storm water collection system. All curb openings will be blocked to prevent stormwater from bypassing the inserts. • Care will be taken to prevent sediments from entering the structures when emptying the silt sacks. Any silt or debris found in the drainage system at the end of construction will be removed. Specific Storm Drain Inlet Controls Storm Drain Inlet Control # I Storm Drain Inlet Control Description ■ Silt sacks will be installed in retained existing and proposed catch basins within the project limits and as required by the Resident Engineer. Silt sacks shall be made of non -woven polypropylene and shall fit freely suspended inside the catch basin. The filter shall have a polypropylene boot at the top on which the grate rests to hold it in place. A manufactured overflow opening shall be provided near the top of the filter, below the boot. The filter shall have the following properties: Construction Material Non -woven polypropylene Maximum overflow rate: >200 GPM Maximum filtration rate: >50 GPM (Type - S) Absorbent material: Polypropylene Maximum filtration rate: >5 -8 GPM (Type - O) Boot adapter dimensions: 36" x 36" Nominal depth: 18" ■ Silt sack shall be Siltsack by ACF Environmental or equivalent approved by the engineer. ■ The silt sack will be as manufactured to fit the opening of the drainage structure under regular flow conditions, and will be mounted under the grate. The insert will be secured from the surface such that the grate can be removed without the insert discharging into the structure. The filter material will be installed and maintained in accordance with the manufacturer's written literature and as directed by the Engineer. IN Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA ■ Silt sacks will remain in place until the placement of the pavement overlay or top course and the graded areas have become permanently stabilized by vegetative growth. All materials used for the filter fabric will become the property of the Contractor and will be removed from the site. Silt sacks will be cleaned periodically to remove and disposed of accumulated debris as required. Silt sacks, which become damaged during construction operations, will be repaired or replaced immediately. When emptying the silt sack, the contractor will take all due care to prevent sediment from entering the structure. Any silt or other debris found in the drainage system at the end of construction will be removed. The silt and sediment from the silt sack will be legally disposed of offsite. Under no condition will silt and sediment from the insert be deposited on site and used in construction. ■ All curb openings will be blocked to prevent stormwater from bypassing the device. All debris accumulated in silt sacks will be handled and disposed of. ■ The Contractor will remove the accumulated dirt, refuse, and other debris from drainage pipes as directed by the Engineer. The cast iron hood will be removed from all catch basins so equipped, prior to cleaning. No casting will be removed until immediately preceding the work and will be replaced immediately after the cleaning of the drainage pipes is completed. The uncovered catch basin leading to the designated drainage pipes will not be left unattended at any time. ■ Special conditions such as location, extraordinary shape due to conduits or public utility pipes, or off pavement work, etc., may require hand work. Hydraulic lift trucks should be used during drainage structure and pipe cleaning operations so that the material can be decanted at the site. ■ After material from several drainage structures along the same system is loaded onto the truck, the truck should be elevated so any free flowing liquid may drain back into the drainage structure. Material must arrive at the disposal facility sufficiently dry to pass the Paint Filter Liquids Test (or no liquid drips from it when a handful is taken and squeezed). ■ All material removed from the drainage structures and pipes will be properly handled and disposed of by the Contractor, and this must be done in accordance with all MassDEP regulations, policies, and guidance. The responsibility for the proper handling and disposal of this material will be solely the Contractor's. Material removed from drainage structures and pipes will be transported immediately to the place of disposal in machines or trucks that will not spill the material along the roadway. Any material falling on the roadway will be removed. Drainage structure and pipe cleanings are classified as a solid waste by the Massachusetts Department of Environmental Protection (MassDEP) and may be disposed of at any landfill that is permitted by MassDEP to accept solid waste. Materials containing free - flowing liquids are prohibited from being accepted at landfills. The MassDEP encourages the beneficial reuse of this material whenever possible; however, use not in accordance with MassDEP determination, or disposal or use as fill in an unapproved location is not acceptable. It is anticipated that most, if not all, of the material will be landfilled. Installation ■ Devices will be installed in all catch basins prior to the start of construction activities as directed by the Engineer. R Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Maintenance Requirements The Contractor will inspect the condition of silt sacks weekly and after each rainstorm exceeding 0.25- inches rain fall. When work is being conducted on the catch basin the silt sack shall be removed, cleaned, and temporarily stored until the drainage structure work has been completed, at which time the silt sack shall be either reset or removed, as applicable to the finished function of the structure. Silt sacks shall be removed and disposed at the conclusion of the work on the project or as directed by the Engineer. 4.10 Constructed Stormwater Conveyance Channels • Constructed stormwater conveyance channels will not be utilized at the Site. Water quality swales will be updated as per the Plans. 4.11 Sediment Basins • Sediment basins will not be utilized at the Site. 4.12 Chemical Treatment Treatment chemicals will not be utilized at the Site. 4.13 Dewatering Practices • Dewatering activities required during construction are potential sources of sediment and can lead to erosion during construction. If groundwater is encountered during the installation of the underground utilities, all discharges associated with the dewatering operation will be directed to a settling basin or sedimentation tank before entering the on -site stormwater system. If needed, dewatering basins will be constructed of staked Straw Bales in a square or semi - circle pattern to "pond" the collected water and retain sediments. As a mitigation measure, the location of all areas to receive dewatering discharge, if required, will be positioned in such a way as to minimize and reduce soil erosion. Following completion of construction, permanent erosion control measures including re- vegetation will be implemented to ensure site stabilization. All applicable permits and approvals will be obtained prior to the commencement of the project. Licensed Site Professional should be consulted in the event that dewatering is deemed necessary to perform site excavation work. 4.14 Other Stormwater Controls • No other Stormwater controls are anticipated; however, other Stormwater controls may be implemented at the request of the Engineer. 20 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 4.15 Site Stabilization Operators must initiate at a minimum soil stabilization measures immediately whenever any clearing, grading, excavating or other earth disturbing activities have permanently ceased on any portion of the site, or temporarily ceased on any portion of the site and will not resume for a period exceeding 14 calendar days. In arid, semiarid, and drought- stricken areas where initiating vegetative stabilization measures immediately is infeasible, alternative stabilization measures must be employed as specified by the permitting authority. Stabilization must be completed within a period of time determined by the permitting authority. In limited circumstances, stabilization may not be required if the intended function of a specific area of the site necessitates that it remain disturbed. Site Stabilization Practice ® Vegetative ❑ Non - Vegetative ❑ Temporary ® Permanent Description of Practice ■ A combination of Site stabilization practices including geotextile fabric and vegetation will be utilized with approved compost topsoil, lime, fertilizer, seeding, and planting to finish areas denoted on the plans or restore disturbed areas as directed by the Engineer. ■ Refer to Plans for specific planting areas of trees, shrubs and grasses. ■ Straw mulching will be employed on all inactive and disturbed areas that will remain unstabilized for more than 14 days. Mulch materials will be spread uniformly by hand or machine at a rate of approximately 100 pounds per 1,000 square feet. Mulch will be spread such that at least 75 percent of the ground surface is covered. Mulching may be used with temporary or permanent seeding, or with slope stabilization techniques. ■ Plants listed on the latest Massachusetts Department of Agricultural Resources Prohibited Plant list shall not be planted on the property. Installation ■ Compost topsoil will meet with Material Specifications M.1.07.0. Compost topsoil will pass a 3/8" screen and lay in a minimum depth of 6" after compacted and shall be free of grass and other unsuitable materials. ■ Disturbed areas will be landscaped or seeded with an erosion control seed mix. Permanent restoration and revegetation measures serve to control erosion and sedimentation by establishing a vegetative cover. In the event that weather conditions prevent final restoration, temporary erosion and sedimentation measures will be employed until the weather is suitable for final cleanup. ■ A final inspection will insure that the project site is cleared of all project debris and that erosion and sedimentation controls are functioning properly. Straw Bales and silt fencing will remain in place after the completion of construction. 21 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA ■ The contractor will be responsible for watering the seeded and planted areas daily for a minimum of two weeks or until the trees, shrubs, and grasses have become established. Maintenance Requirements ■ Inspections of site conditions will take place on a weekly basis as well as after each incidence of rainfall exceeding 0.25- inches in twenty -four hours. 22 Stormwater Pollution Prevention Plan ( SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA SECTION 5: POLLUTION PREVENTION STANDARDS Operators must design, install, implement, and maintain effective pollution prevention measures to minimize the discharge of pollutants. At a minimum, such measures must be designed, installed, implemented and maintained to: a. Minimize the discharge of pollutants from equipment and vehicle washing, wheel wash water, and other wash waters. Wash waters must be treated in a sediment basin or alternative control that provides equivalent or better treatment prior to discharge; b. Minimize the exposure of building materials, building products, construction wastes, trash, landscape materials, fertilizers, pesticides, herbicides, detergents, sanitary waste and other materials present on the site to precipitation and to stormwater. Minimization of exposure is not required in cases where the exposure to precipitation and to stormwater will not result in a discharge of pollutants, or where exposure of a specific material or product poses little risk of stormwater contamination (such as final products and materials intended for outdoor use); and c. Minimize the discharge of pollutants from spills and leaks and implement chemical spill and leak prevention and response procedures. 5.1 Potential Sources of Pollution Construction Site Pollutants Pollutant- Generating Activity Pollutants or Pollutant Constituents (that could be discharged if expose to stormwater) Location on Site (or reference SWPPP site map where this is shown) Vehicle Traffic /Construction Vehicles Oils and Lubricants Throughout Site Vehicle Traffic /Construction Vehicles Sediment Throughout Site Concrete Washout Concrete Near Washout Area [Include additional rows as necessary.] 23 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 5.2 Spill Prevention and Response ■ Employees will be trained via tailgate sessions. ■ Vehicles and equipment will be maintained off - site. All vehicles and equipment including subcontractor vehicles will be checked for leaking oil and fluids. Vehicles leaking fluids will not be allowed on -site. ■ Hazardous materials will be stored in accordance with applicable federal, state and municipal regulations. ■ Spill kits will be kept within the storage area. ■ All spills will be cleaned immediately upon discovery. Spent absorbent materials and rags will be disposed of off -site in accordance with applicable federal, state and municipal regulations. Spills large enough to discharge to surface water will be reported to the National Response Center at 1- 800 - 424 -8802. Spills large enough to exceed the applicable reportable quantity listed in the Massachusetts Contingency Plan (MCP at 310 CM 40.0000) and the Massachusetts Oil and Hazardous Materials List (MOHML at 310 CM 40.1600) will be reported to the Massachusetts Department of Environmental Protection within two hours of identifying the release. ■ Material Safety Data Sheets (MSDS), a material inventory, and emergency contact information will be maintained in the construction trailer. Lexington Public Health Department 1625 Massachusetts Ave. Lexington, MA 02420 781 - 698 -4507 Lexington Conservation Commission 1625 Massachusetts Ave. Lexington, MA 02420 781 - 698 -4531 Massachusetts Department of Environmental Protection Northeast Regional Office 205B Lowell Street Wilmington, MA 01887 Main telephone: 978 - 694 -3200 Service Center: 978 - 694 -3200 Emergency Contact: 888 - 304 -1133 Lexington Police Department 1575 Massachusetts Ave. Lexington, MA 02420 781 - 862 -1212 Emergency: 911 Lexington Fire Department 45 Bedford Street Lexington, MA 02420 781 - 862 -0272 Emergency: 911 24 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 5.3 Fueling and Maintenance of Equipment or Vehicles General ■ Fuels, oils, or other pollutants used in vehicle and equipment operation and maintenance are prohibited discharges. Care will be taken to provide an effective means of eliminating the discharge of spilled or leaked chemicals, including fuel, from the area where these activities will take place. Specific Pollution Prevention Practices Pollution Prevention Practice # 1 Description Mr. Nathanael Seiler of C.E. Floyd Company, Inc. will be responsible for the detection of and response to spills and leaks. A variety of vehicles and equipment will be used on -site throughout the project including graders, excavators, loaders, paving equipment, rollers, trucks and trailers, and backhoes. All major equipment /vehicle fueling and maintenance will be performed off -site. When vehicle fueling must occur on -site, the fueling activity will occur in the staging area. Only minor equipment maintenance will occur on -site. All equipment fluids generated from maintenance activities will be disposed of into designated drums stored on spill pallets. Absorbent, spill - cleanup materials and spill kits will be available at the staging area. Installation Vehicle fueling and maintenance best management practices (BMPs) will begin at the start of the project. Maintenance Requirements ■ Inspect equipment /vehicle storage areas and /or fuel tanks weekly and after storm events exceeding 0.25- inches. Vehicles and equipment will be inspected on each day of use. Leaks will be repaired immediately, or the problem vehicles) or equipment will be removed from the project site. Keep an ample supply of spill - cleanup materials on -site and immediately clean up spills and dispose of materials properly. 5.4 Washing of Equipment and Vehicles General • All equipment and vehicle washing will take place off -Site. Discharges from soaps or solvents used in vehicle and equipment washing are prohibited. 25 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 5.5 Storage, Handling, and Disposal of Construction Products, Materials, and Wastes 5.5.1 Building Products • Construction equipment and maintenance materials will be stored at a combined staging area and materials storage area. Specific Pollution Prevention Practices Pollution Prevention Practice # 2 Description • Snow fencing will be placed around the perimeter to designate the staging and materials storage area. A watertight shipping container will be used to store hand tools, small parts and other construction materials. Installation The materials storage area will be installed before any infrastructure is constructed at the site. Maintenance Requirements • The storage area will be inspected weekly and after storm events exceeding 0.25- inches. The storage area will be kept clean, well- organized and equipped with ample clean up supplies as appropriate for the materials being stored. Perimeter controls, containment structures, covers and liners will be repaired or replaced as required to maintain proper function. 5.5.2 Pesticides, Herbicides, Insecticides, Fertilizers, and Landscape Materials General • Pesticides, herbicides, insecticides, fertilizers, and landscape materials will be stored at a combined staging area and materials storage area. Pollution Prevention Practice # 3 Description Pesticides, herbicides, insecticides, fertilizers, and landscape materials will be stored at a combined staging area and materials storage area. Snow fencing will be placed around the perimeter to designate the staging and materials storage area. A watertight shipping container will be used to store hand tools, small parts and other construction materials. All hazardous materials such as oil filters, petroleum products, paint, and equipment maintenance fluids will be stored in structurally sound and sealed containers under cover within the hazardous materials storage area. Installation The materials storage area will be installed before any infrastructure is constructed at the site. 26 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Maintenance Requirements • The storage area will be inspected weekly and after storm events exceeding 0.25- inches. The storage area will be kept clean, well- organized and equipped with ample clean up supplies as appropriate for the materials being stored. Perimeter controls, containment structures, covers and liners will be repaired or replaced as required to maintain proper function. 5.5.3 Diesel Fuel, Oil, Hydraulic Fluids, Other Petroleum Products, and Other Chemicals General • Diesel fuel, oil, hydraulic fluids, other petroleum products, and other chemicals will be limited in scope of use and preferably stored off -Site; if they must be stored on Site they will be stored at a combined staging area and materials storage area. Specific Pollution Prevention Practices Pollution Prevention Practice # 4 Description If necessary, diesel fuel, oil, hydraulic fluids, other petroleum products, and other chemicals will be stored at a combined staging area and materials storage area. Snow fencing will be placed around the perimeter to designate the staging and materials storage area. A watertight shipping container will be used to store hand tools, small parts and other construction materials. All hazardous materials such as oil filters, petroleum products, paint, and equipment maintenance fluids will be stored in structurally sound and sealed containers under cover within the hazardous materials storage area. Installation The materials storage area will be installed before any infrastructure is constructed at the site. Maintenance Requirements • The storage area will be inspected weekly and after storm events exceeding 0.25- inches. The storage area will be kept clean, well- organized and equipped with ample clean up supplies as appropriate for the materials being stored. Perimeter controls, containment structures, covers and liners will be repaired or replaced as required to maintain proper function. 5.5.4 Hazardous or Toxic Waste (Note: Examples include paints, solvents, petroleum -based products, wood preservatives, additives, curing compounds, acids.) General • Hazardous or toxic waste will be limited in scope of use and preferably stored off -Site; if they must be stored on Site they will be stored at a combined staging area and materials storage area. 27 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Specific Pollution Prevention Practices Pollution Prevention Practice # Description If necessary, hazardous or toxic waste will be stored at a combined staging area and materials storage area. Snow fencing will be placed around the perimeter to designate the staging and materials storage area. A watertight shipping container will be used to store hand tools, small parts and other construction materials. All hazardous materials such as oil filters, petroleum products, paint, and equipment maintenance fluids will be stored in structurally sound and sealed containers under cover within the hazardous materials storage area. Installation The materials storage area will be installed before any infrastructure is constructed at the site. Maintenance Requirements The storage area will be inspected weekly and after storm events exceeding 0.25- inches. The storage area will be kept clean, well- organized and equipped with ample clean up supplies as appropriate for the materials being stored. Perimeter controls, containment structures, covers and liners will be repaired or replaced as required to maintain proper function. 5.5.5 Construction and Domestic Waste General • Construction and domestic waste will be stored in appropriate waste containers at a combined staging area and materials storage area. Dumpsters will be covered at night and when not in use. Specific Pollution Prevention Practices Pollution Prevention Practice # 6 Description Snow fencing will be placed around the perimeter to designate the construction and domestic waste storage area. Installation • The appropriate waste containers will be installed in the materials storage area before any infrastructure is constructed at the site. Maintenance Requirements The storage area will be inspected weekly and after storm events exceeding 0.25- inches. The storage area will be kept clean, well- organized and equipped with ample clean up supplies as appropriate for the materials being stored. Perimeter controls, containment structures, covers and liners will be repaired or replaced as required to maintain proper function. Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 5.5.6 Sanitary Waste General • Temporary sanitary facilities (portable toilets) will be provided at the site throughout the construction phase. Specific Pollution Prevention Practices Pollution Prevention Practice # 7 Description The toilets will be placed as needed to provide convenient access by construction workers. The portable toilets will be located away from concentrated stormwater flow paths and traffic flow. Installation The portable toilets will be brought on site once construction has commenced. Maintenance Requirements • Sanitary waste will be collected from the portable facilities a minimum of once per week. The portable toilets will be inspected weekly for evidence of leaking holding tanks. Toilets with leaking holding tanks will be removed and replaced with new portable toilets. 5.6 Washing of Applicators and Containers used for Paint, Concrete or Other Materials General • Washout and cleanout of stucco, paint, concrete, form release oils, curing compounds, and other construction materials will not be allowed. • Concrete washout will be performed in specified concrete washout areas (specified on plans) only and will adhere to treatment requirements set forth by the Engineer. 5.7 Fertilizers General • Fertilizers will be stored at a combined staging area and materials storage area in order to minimize discharges of fertilizers containing nitrogen and phosphorus. Specific Pollution Prevention Practices Pollution Prevention Practice # 8 Description Fertilizers will be stored at a combined staging area and materials storage area. Snow fencing will be placed around the perimeter to designate the staging and materials storage area. A watertight shipping container will be used to store hand tools, small parts and other construction materials. All hazardous materials such as oil filters, petroleum products, paint, and equipment maintenance fluids will be stored in structurally sound and sealed containers under cover within the hazardous materials storage area. 29 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA Installation • The appropriate waste containers will be installed in the materials storage area before any infrastructure is constructed at the site. Maintenance Requirements • The storage area will be inspected weekly and after storm events exceeding 0.25- inches. The storage area will be kept clean, well- organized and equipped with ample clean up supplies as appropriate for the materials being stored. Perimeter controls, containment structures, covers and liners will be repaired or replaced as required to maintain proper function. 5.8 Other Pollution Prevention Practices General No additional pollution prevention practices are applicable. 30 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA SECTION 6: INSPECTION AND CORRECTIVE ACTION 6.1 Inspection Personnel and Procedures Personnel Responsible for Inspections C. E. Floyd Company, Inc. 135 South Road Bedford, MA 01730 Mr. Normand Fournier Inspection Schedule Specific Inspection Frequency Inspections of all erosion controls and site conditions will be conducted on a weekly basis as well as after each incidence of rainfall exceeding 0.25- inches in twenty -four hours. In the case of multi -day storm events, inspections will occur during or after the first day and after the end of the event. Any corrective actions will be implemented immediately after any deficiencies or violations are identified. Rain Gauge Location (if applicable) The following website will be utilized to gauge rainfall amounts; http: / /www.nws.noaa.gov /climate /index.php ?wfo =box Inspection Report Forms Copies of the inspection report forms are attached as Appendix D. 31 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA 6.2 Corrective Action Personnel Responsible for Corrective Actions Mr. Normand Fournier Project Superintendent 781 - 271 -9006 Corrective Action Forms For a copy of the corrective action forms please refer to Appendix E. 6.3 Delegation of Authority Duly Authorized Representative(s) or Position(s): C.E. Floyd Company, Inc. 135 South Road Bedford, MA 01730 Mr. Normand Fournier 781 - 271 -9006 32 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA SECTION 7: TRAINING Provide proof of completion of a 4 hour minimum sedimentation and erosion control training class current to the latest CGP. The documentation shall be included as Appendix I. Table 7 -1: Documentation for Completion of Training Name I Date Trainina Completed 33 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA SECTION 8: CERTIFICATION AND NOTIFICATION I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Name: Normand Fournier Signature: Title: Project Manager Date: x /xx /201x 34 Stormwater Pollution Prevention Plan (SWPPP) Expansion of Brookhaven at Lexington - Lexington, MA SWPPP APPENDICES Attach the following documentation to the SWPPP: Appendix A - Site Maps Appendix B - Copy of 2017 CGP Appendix C - NOI and EPA Authorization Email Appendix D - Inspection Form Appendix E - Corrective Action Form Appendix F - SWPPP Amendment Log Appendix G - Subcontractor Certifications /Agreements Appendix H - Grading and Stabilization Activities Log Appendix 1- Training Log Appendix J - Delegation of Authority Appendix K - Endangered Species Documentation Appendix L - Historic Preservation Documentation Appendix M - Impaired Waters Documentation Appendix N - Order of Conditions 35 Appendix A - Site Maps TO BE ADDED Appendix B - Copy of 2017 CGP TO BE ADDED Appendix C - Copy of NOI and EPA Authorization email TO BE ADDED Appendix D - Copy of Inspection Form TO BE ADDED Appendix E - Copy of Corrective Action Form TO BE ADDED Appendix F - SWPPP Amendment Log TO BE ADDED Appendix F - SWPPP Amendment Log No. Description of the Amendment Date of I Amendment Prepared by Amendment I iName(sl and Titlel Appendix G - Subcontractor Certifications /Agreements TO BE ADDED Appendix G - Subcontractor Certifications /Agreements SUBCONTRACTOR CERTIFICATION STORMWATER POLLUTION PREVENTION PLAN Project Number: Project Title: Operator(s): As a subcontractor, you are required to comply with the Stormwater Pollution Prevention Plan (SWPPP) for any work that you perform on -site. Any person or group who violates any condition of the SWPPP may be subject to substantial penalties or loss of contract. You are encouraged to advise each of your employees working on this project of the requirements of the SWPPP. A copy of the SWPPP is available for your review at the office trailer. Each subcontractor engaged in activities at the construction site that could impact stormwater must be identified and sign the following certification statement: I certify under the penalty of law that I have read and understand the terms and conditions of the SWPPP for the above designated project and agree to follow the practices described in the SWPPP. This certification is hereby signed in reference to the above named project: Company: Address: Telephone Number: Type of construction service to be provided: Signature: Title: Date: a� 0 N V Q C O N N C C C1 C C i I p = w K � c Q w Q. m C. Q 0 � � � / u « § � � ƒ � � § � I � � d � _ x � � ■ � � § / - 2� \2 ■ � § � �A ■� � ■ ■ E ƒ � � � ■ ■ § � � � A % § § � �o G � � § � : u « � I � � d % § : § ■ 0 ■�: % �U «� Appendix I - SWPPP Training Log TO BE ADDED Appendix I - SWPPP Training Log Project Name: Project Location: Instructor's Name(s): Instructor's Title(s): Course Location: Course Length (hours): Stormwater Pollution Prevention Training Log Expansion of Brookhaven at Lexington Lexington, MA Stormwater Training Topic: (check as appropriate) ❑ Sediment and Erosion Controls ❑ Stabilization Controls ❑ Pollution Prevention Measures Specific Training Objective: Date: ❑ Emergency Procedures ❑ Inspections /Corrective Actions Attendee Roster: (attach additional pages as necessary) No. Name of Attendee Company 1 2 3 4 5 6 7 8 Appendix J - Delegation of Authority Form TO BE ADDED Appendix J - Delegation of Authority Form Delegation of Authority I, (name), hereby designate the person or specifically described position below to be a duly authorized representative for the purpose of overseeing compliance with environmental requirements, including the Construction General Permit, at the construction site. The designee is authorized to sign any reports, stormwater pollution prevention plans and all other documents required by the permit. (name of person or position) (company) (address) (city, state, zip) (phone) By signing this authorization, I confirm that I meet the requirements to make such a designation as set forth in Appendix I of EPA's Construction General Permit (CGP), and that the designee above meets the definition of a "duly authorized representative" as set forth in Appendix 1. I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Name: Company: Title: Signature: Date: Appendix K - Endangered Species Documentation TO BE ADDED Appendix L - Historic Properties Documentation TO BE ADDED Appendix M - Impaired Waters Documentation TO BE ADDED Appendix N - Order of Conditions '�. wry, ww� C C s 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent STORMWATER OPERATIONS and MAINTENANCE PLAN BROOKHAVEN AT LEXINGTON 960 -1010 WALTHAM STREET LEXINGTON, MA 02421 Prepared by: OHI ENGINEERING, INC. 44 WOOD AVENUE MANSFIELD, MA 02048 508 - 339 -3929 508 - 339 -3140 (FAX) OHI PROJECT # 15 -1664 Report Date: JULY 18, 2017 Mansfield, MA Amherst, MA Chester; VT TABLE OF CONTENTS Stormwater Operations and Maintenance Plan 960 -1010 Waltham Street Lexington, Massachusetts 1.0 Introduction .......................................................... ..............................1 2.0 Site Owner's Agreement ..................................... ............................... 2 2.1 Operation and Maintenance Compliance Statement ............. ............................... 2 2.2 Stormwater Maintenance Easements .................................... ............................... 2 2.3 Record Keeping ..................................................................... ............................... 2 2.4 Training ................................................................................. ............................... 3 3.0 Long -Term Pollution Prevention Plan .............. ............................... 4 3.1 Storage of Materials and Waste ............................................ ............................... 4 3.2 Vehicle Washing ................................................................... ............................... 4 3.3 Routine Inspection and Maintenance of Stormwater BMPs . ............................... 4 3.4 Spill Prevention and Response .............................................. ............................... 4 3.5 Maintenance of Lawns, gardens, and other Landscaped Areas ........................... 5 3.6 Storage and Use of Fertilizers, Herbicides, and Pesticides ... ............................... 5 3.7 Pet waste Management .......................................................... ............................... 5 3.9 Snow and Deicing Chemical Management ........................... ............................... 5 3.10 Nutrient Management Plan ................................................ ............................... 6 4.0 Long -Term Operation and Maintenance Plan . ............................... 7 4.1 Stormwater Management System Components .................... ............................... 7 4.2 Inspection and Maintenance Schedules ................................. ............................... 8 4.2.1 General Maintenance for Mosquito Control ....................... ............................... 8 4.2.2 Deep Sump and Hooded Catch Basins ............................... ............................... 8 4.2.3 Proprietary Separators ......................................................... ............................... 9 4.2.4 Gravel Diaphragm and Grass Filter Strips........ Error! Bookmark not defined. 4.2.5 Infiltration basins .............................................................. ............................... 10 4.2.6 Stormwater Outfalls .......................................................... ............................... 11 4.3 Estimated Operation and Maintenance Budget ................... ............................... 12 4.4 Public Safety Features ......................................................... ............................... 12 5.0 Emergency Contacts ............................................ .............................14 List of Figures Figure 1 Site Locus Figure 2 Site Plan Stormwater Operations and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, Massachusetts Page i Tables Table 1— Soil Data Table 2 —Tank Field Soil Data Table 3 — August 2015 Groundwater Results Table 4 — Gauging Table Stormwater Operations and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, Massachusetts Page ii 1.0 INTRODUCTION The Stormwater Operations and Maintenance Plan complies with the Long -Term Pollution Prevention Plan (standard 4) and the Long -Term Operation and Maintenance Plan (Standard 9) requirements of the 2008 Massachusetts Department of Environmental Protection (DEP) Stormwater Handbook. The Plan outlines source control and pollution prevention measures and maintenance requirements of Stormwater best management practices (BMPs) associated with the proposed development. Brookhaven was incorporated in December 1984 as a Massachusetts Not - for - Profit corporation to meet the housing and health care needs of the elderly. The proposed project includes the addition of 49 Independent Living units, expansion of the existing Commons Building, and the construction of the associated access drives, parking utilities, landscaping, and sidewalks. Portions of the proposed project are located within areas subject to the jurisdiction of the Massachusetts Wetlands Protection Act (WPA) at MGL c131 §140 and its implementing regulations (310 CMR 10.00) and the Code of the Town of Lexington for Wetland Protection, Chapter 130. The proposed activities include the alteration of • Altering 513 square feet of bordering vegetated wetlands (BVW); • Altering 7,685 square feet of area within the 25 -foot buffer zone to BVW including 1,132 square feet of BVW replication; • Altering 85,305 square feet of area within the 100 -foot buffer zone to BVW; • Altering 77 square feet within the buffer zone to a vernal pool; and, • Temporary alteration of 15 linear feet of bank to an Intermittent Stream. The proposed project will meet the water quality requirements set in Standard 4 by using several on -site treatment controls to remove 80% of the average annual post - construction load of Total Suspended Solids (TSS). The on -site Stormwater management system has been designed to mitigate Stormwater through both structural practices and non - structural good housekeeping measures. All proposed Stormwater BMPs will be operated and maintained to ensure continuous water quality treatment of runoff. This Plan will be available during and post - development to ensure continuous maintenance of the BMPs and the control and pollution prevention measures following development. Structural BMPs include catch basins, deep sump hooded catch basins, Stormwater infiltration recharge chambers, and infiltration basins. Source control, pollution prevention measures, and regular maintenance of the on -site Stormwater BMPs are proposed and stated below. Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 1 2.0 SITE OWNER'S AGREEMENT 2.1 OPERATION AND MAINTENANCE COMPLIANCE STATEMENT Site Owner /Operator: Brookhaven at Lexington James Freehling 1010 Waltham Street Lexington, MA 02421 Phone: 781 - 863 -9660 Responsible Party: Michael Brennan, Director of Plant Maintenance Brookhaven at Lexington or their successors shall maintain ownership of the on -site Stormwater management system as well as the responsibility for operation and maintenance during the post - development stages of the project. The site has been inspected for erosion and appropriate measures have been taken to permanently stabilize any eroded areas. All aspects of Stormwater BMPs have been inspected for damage, wear and malfunction, and appropriate steps have been taken to repair or replace the system or portions of the system so that the Stormwater at the site may be managed in accordance with the Stormwater Management Standards. Future responsible parties shall be notified of their continuing legal responsibility to operate and maintain the BMPs. The operation and maintenance plan for the Stormwater BMPs is being implemented. Responsible Party Date 2.2 STORMWATER MAINTENANCE EASEMENTS No off -site Stormwater control areas are utilized; therefore, no Stormwater management easements are required. The Site Owner will have access to all Stormwater practices for regular inspections and maintenance. 2.3 RECORD KEEPING The Site Owner shall maintain a rolling log on -Site, in which all inspections and maintenance activities for the past three years shall be recorded. The Operation and Maintenance Log includes information pertaining to inspections, repairs, maintenance, and disposal relevant to the project's Stormwater management system. The Log is provided in Appendix A. The Operation and Maintenance Log shall be made readily available to the Conservation Commission and the DEP upon request. The Conservation Commission and the DEP shall be Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 2 allowed to enter and inspect the premises to evaluate and ensure that the responsible party complies with each BMPs maintenance requirements. 2.4 TRAINING Employees involved in inspections, maintenance, and emergency response will be educated on the general concepts of Stormwater management and groundwater protection. The Stormwater Operations and Maintenance Plan will be reviewed with the maintenance employees. The employees will be trained on the proper course of action for specific events expected to be incurred during routine maintenance or emergency situations. Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 3 3.0 LONG -TERM POLLUTION PREVENTION PLAN This section outlines source control and pollution prevention measures to be employed on -site following construction. The measures are in compliance with Standard 4 of the 2008 DEP Stormwater Management Handbook. 3.1 STORAGE OF MATERIALS AND WASTE The Site shall be kept clear of trash and debris at all times. Certain materials and waste products shall be stored inside or outside upon an impervious surface and covered, as required by local and state regulation. 3.2 VEHICLE WASHING No commercial vehicle washing shall take place on Site. 3.3 ROUTINE INSPECTION AND MAINTENANCE OF STORMWATER BM PS See Section 4.0 Long -Term Operation and Maintenance Plan, for routine inspection and maintenance requirements for all proposed Stormwater BMPs. 3.4 SPILL PREVENTION AND RESPONSE A contingency plan shall be implemented to address the spill or release of petroleum products and hazardous materials and will include the following measures: Equipment necessary to quickly attend to inadvertent spills or leaks shall be stored on- Site in a secure but accessible location. Such equipment shall include, but are not limited to the following: safety goggles, chemically resistant gloves and overshoe boots, water and chemical fire extinguishers, sand and shovels, suitable absorbent materials, storage containers and first aid equipment (a spill containment kit or equivalent). • Spills or leaks shall be treated properly according to material type, volume of spillage, and location of spill. Mitigation shall include preventing further spillage, containing the spilled material in the smallest practical area, removing spilled material in a safe and environmentally - friendly manner, and remediation of any damage to the environment. • For large spills, the Site Owner's Licensed Site Professional (LSP) shall be notified and the Massachusetts DEP Hazardous Waste Incident Response Group shall be notified at (888) 41111, 5 1 9M • In the event of a spill, care shall be taken to protect all catch basins, area drains, and water quality inlets from receiving hazardous material. Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 4 If petroleum products are stored on the Site, an area will be designated to provide full containment for these products in the event of a spill or tank failure. A surrounding berm is proposed to be lined with an impervious core, preventing contamination from seeping into the ground. Stormwater in this area would be directed to a sump within the containment area, which would have a drain pipe with a gate valve left in the closed position. The gate valve will only be opened once maintenance personnel have confirmed that no sheen is present. No petroleum products are currently proposed to be stored on site. 3.5 MAINTENANCE OF LAWNS, GARDENS, AND OTHER LANDSCAPED AREAS Lawns, gardens, and other landscaped areas shall be maintained regularly by the Site Owner. Vegetated and landscaped BMPs will be maintained as outlines in Section 4.0. • Leaf litter shall be removed from the site in the fall and spring each year, at a minimum. • Special care should be taken to ensure that all vegetation is maintained in accordance with the design specifications for each BMP structure. • Where possible, use native and drought- resistant vegetation. Vegetation should be irrigated regularly during the establishment phase and if necessary, during excessively dry periods for long -term maintenance. • Weedy and dead vegetation should be removed regularly to prevent clogging of BMP structures and to encourage the growth of desired vegetation. 3.6 STORAGE AND USE OF FERTILIZERS, HERBICIDES, AND PESTICIDES Fertilizers, herbicides, and pesticides that contain phosphorus will not be used on -Site. All fertilizers, herbicides, and pesticides shall be stored in accordance with local, state, and federal regulations. 3.7 PET WASTE MANAGEMENT Pets are not anticipated to be on -Site. Pet owners shall be required to pick up after their animals and dispose of waste in the trash. 3.9 SNOW AND DEICING CHEMICAL MANAGEMENT Snow removal and use of deicing chemicals at the proposed development shall comply with the following requirements: Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 5 • Plowed snow shall be placed in the areas outside of the wetland boundaries and the Stormwater BMPs. The following maintenance measures shall be undertaken at all snow disposal sites: • Debris shall be cleared from an area prior to using it for snow disposal • Debris and accumulated sediments shall be cleared from the site and properly disposed of at the end of the snow season and no later than May 151H • In accordance with the Massachusetts General Laws, Chapter 85, Section 7A, salt and other de -icing chemicals will be stored in an indoor location. Salt and other deicing chemicals shall be stored in accordance with Massachusetts General Law. • Sand piles shall be contained and stabilized to prevent the discharge of sand to wetlands or water bodies, and, where feasible, covered. Sand piles shall not be placed in close vicinity to the wetland boundaries or the Stormwater BMPs. • Salt storage piles shall be located outside of the 100 -year floodplain, wetlands, and Stormwater BMPs. • The application of salt on the proposed parking areas and driveway shall at no time exceed state or local requirements. 3.10 NUTRIENT MANAGEMENT PLAN A nutrient management plan is required if a Total Maximum Daily Load (TMDL) has been developed that indicates that use of fertilizers containing nutrients or other specific pollutants must be reduced. The proposed project is located within the Charles River Basin, which has a final TMDL issued for pathogens and nutrients. The proposed Stormwater management plan has been developed to comply with requirements of 2008 MA DEP Stormwater Handbook and to goals of the TMDLs. Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 6 4.0 LONG -TERM OPERATION AND MAINTENANCE PLAN This section outlines the Stormwater BMPs associated with the proposed Stormwater management system and identifies the long -term inspection and maintenance requirements for each BMP. 4.1 STORMWATER MANAGEMENT SYSTEM COMPONENTS The Stormwater BMPs quantity and location are outlined in the table below. For the exact location of the BMPs, refer to Figure 2 provided. BMP Quantity Location Deep Sump Hooded Catch Basins 5 Located along paved driveway and parking areas around North Building and in Waltham Street. Stormwater Infiltration Recharge Chamber Facilities 7 Three —West of North Building Two — East of North Building One — West of Commons Expansion Building One — East of Commons Expansion Building Underground Stormwater Detention System 1 Located north of Infiltration Recharge Chambers 6. Infiltration Basins 2 (West and East) Located in western portion of the site, near Infiltration Recharge Chamber Facility 2. Sediment Forebay 2 (West and East) Located in the vicinity of the Infiltration Basins. Catch Basins 2 Located between Skilled Nursing and Commons Expansion. Level Spreader for Off -Site Drainage 1 Located north of North Building. Silt Prison "" 7 New Catch Basins 2 Retrofit Catch Basin Inserts Located along Commons Expansion driveway, Wellness Courtyard, and retrofits at eastern limits of work before loading dock area Detention Basin 1 Located northwest of Commons Expansion Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 7 The deep sump hooded catch basins are utilized around the North Building where the availability of open drainage allows for the use of forebays and infiltration basins. Silt PrisonT"^ devices consist of inverted cone filtration, and will be installed in the several new, and retrofitted into two existing deep sump catch basins where space is constrained around the Commons Expansion. The Level 3 plaza is a vegetated roof with pavers, common terraces, and planters with an innovative drainage system collected after filtration through the soil media and infiltrated into Infiltration Recharge Chamber Facilities 1 and 5. All basins, manholes, and chamber facilities are accessible for maintenance from either the paved or gravel driveways or parking areas. 4.2 INSPECTION AND MAINTENANCE SCHEDULES 4.2.1 GENERAL MAINTENANCE FOR MOSQUITO CONTROL To minimize mosquito breeding, if necessary, larvicide, such as Bacillus sphaericus (Bs), may be applied by a licensed pesticide applicator to all catch basins. The larvicides shall be applied in compliance with the pesticide instructions during or immediately after wet weather, unless the product can withstand extended dry periods. To reduce the possibility of mosquitoes laying eggs in standing water, all manholes covers and inspection ports shall be secured close. 4.2.2 DEEP SUMP AND HOODED CATCH BASINS Catch Basins shall be inspected four times per year, including after the foliage season for leaf debris. Other inspection and maintenance requirements include: • Catch basins shall be cleaned of organic material, sediment, trash, hydrocarbons, etc. once per year or whenever the depth of the deposits is greater than or equal to one half the depth from the bottom of the lowest pipe invert in the basin. The clean out will be completed after street sweeping. • In the event that evidence of hydrocarbons is encountered, the impacted material shall be removed immediately using absorbent pads or other suitable measures and disposed of legally. • Other accumulated debris inside or surrounding the catch basins will be removed as necessary. • The transport and disposal of accumulated sediment and debris off -site shall be performed in accordance with applicable local, state, and federal guidelines and regulations. Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 8 4.2.3 PROPRIETARY SEPARATORS Maintenance of proprietary separators shall be performed according to the recommendations of the manufacturer. A copy of the manufacturers manual is provided in Appendix B. Information pertaining to the inspection and maintenance procedures for the proprietary devices is provided below. • Units shall be inspected post- construction, prior to start -up. • Following installation, units shall be inspected no less than twice per year and no less than once per year thereafter. • Units shall be inspected immediately following any oil, fuel, or chemical spill. • Inspections shall include checking the oil level and sediment depth in each unit. • Removal of sediments /oils shall follow manufacturers recommendations. • In the event of an oil, chemical, or fuel spill, a licensed waste management company shall remove and dispose of any petroleum waste from the unit. • If entry into a unit is required, OSHA confined space entry protocols shall be followed. 4.2.4 DETENTION BASIN A detention basin is a stormwater runoff impoundment that uses a pool of water as the primary mechanism to treat stormwater runoff. The pool allows sediment to settle and removes soluble pollutants. Detention basins also provide additional capacity to control peak discharge rates. The functions of detention basin basins include: • Reduce peak discharge flows; • Remove both solid and soluble pollutants from stormwater runoff. At a minimum, the detention basin shall be inspected after every major storm event (1- inch of rain or greater) for the first six (6) months, then monthly thereafter. Sediment and debris should be removed a minimum of four (4) times peryear, starting in the spring and spaced at even time increments until the late fall season, thereafter. If standing water is present during inspections, the filter stone within the check dam may need to be cleaned or replaced so that the detention basin drains within 72 hours after a storm. Grass vegetation within the detention basin shall be mowed, at a minimum of twice a year, keeping the height of the grass between three (3) and six (6) inches. Inspections should identify areas of rilling and gullying or other areas which need to be reestablished. Replace any vegetation damaged during cleaning by reseeding or resodding. When reseeding, incorporate practices such as hydroseeding with a tackifier, blanket or similar practice to ensure that no scour occurs in the detention basin, while the seeds germinate and develop roots. Remove any woody vegetation (trees or shrubs) from the detention Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 9 basin immediately upon detection. Collected sediment and debris will be properly disposed of per local, state and federal requirements. Any sediment and debris removed from the detention basin deemed to be contaminated must be evaluated in accordance with the Hazardous Waste Regulations, 310 CMR 30.000, and handled as hazardous waste. the filter stone within the check dam may need to be cleaned or replaced so that the detention basin drains within 72 hours after a storm. 4.2.5 INFILTRATION BASINS The infiltration basins and sediment forebays shall be inspected and maintained after any major storm event (rainfall totals are greater than 2.5 inches in 24 hours) during the first three months of operation, then twice a year and when there are discharge through the overflow spillway thereafter. All pretreatment BMPs shall be inspected in accordance with the minimal requirements specified for those practices and after all major storm events. Inspection and maintenance requirements include: • During and after major storm events, the length of time standing water remains in the basin shall be recorded. • If greater than 72 hours, the infiltration basin shall be inspected for signs of clogging. • A corrective action plan may be developed by a qualified professional to restore infiltrative function. Once determined, the Site Owner shall take immediate action to implement these corrective measures. • During inspection, identify any areas of sediment accumulation, differential settlement, cracking, and erosion within the infiltration basin. • Inspection of the embankments for leakage, sinking, erosion, cracking, and tree growth and health of vegetation within the basin and embankments. • Inspection of outlet structures for any evidence of clogging. • Inspection for damage to the emergency spillway. Based on inspection, corrective measures shall be taken immediately. If evidence of hydrocarbons is found during the inspection, the material shall be immediately removed using absorbent pads or other suitable measures and disposed of legally. Preventative measures shall be taken and shall include the following activities: • If vegetated, mow the basin surrounding buffer area, bottom, and sides. Remove any clippings following mowing. • Remove accumulated trash, debris, and organic matter. • If evidence of clogging is present, remove and replace impacted soils at the bottom of the basin. Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 10 4.2.6 UNDERGROUND DETENTION FACILITY An underground detention facility is an underground area consisting of prefabricated chambers storing captured stormwater runoff conveyed to it by other BMP's and the waters are then slowly discharged via a control structure until the facility is empty. The functions of an underground detention facility area include: • Provide a temporaryvolume for stormwater runoff to be held and slowly released back to the surface; • Reduce runoff velocities and peak flow rates; • Reduce required development land disturbance footprint when compared to surface BMPs, such as detention basins. A negligible amount of sediment should reach the outlet control structure, but at a minimum, the outlet control structure should be inspected twice per year for the accumulation of sediment and debris. If an excessive amount of sediment is found, investigate the sediment depth, and inspect the next upstream drainage structure. Insert a stadia rod into inspection ports a minimum of once every two (2) years to determine depth of sediment within the chambers. 4.2.7 SUBSURFACE INFILTRATION RECHARGEIRETENTION CHAMBER FACILITIES Subsurface infiltration recharge /retention chamber facilities are an underground area comprised of a variety of prefabricated chambers installed in a volume of crushed stone which all stores captured stormwater runoff conveyed to it by other BMP's until it infiltrates into the groundwater through gravel and the present parent material of the site. The functions of a subsurface infiltration area include: • Provide a volume of stormwater runoff per storm to be recharged into the ground and eventually groundwater; • Reduce runoff velocities and volumes on impervious surfaces; • Reduce required development land disturbance footprint when compared to surface BMPs, such as detention and infiltration basins. A negligible amount of sediment should reach the intake chamber, but at a minimum, the intake chamber should be inspected twice peryearforthe accumulation of sediment and debris. If an excessive amount of sediment is found within either the intake chamber and /or control structure, investigate the sediment depth within other inspection ports. • Insert a stadia rod into inspection ports a minimum of once every two (2) years to determine depth of sediment within i chambers. Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 11 4.2.8 STORMWATER OUTFALLS Stormwater outfalls, with the associated flared end sections and riprap spillways, shall be inspected at least once per year and after any major storm event (rainfall greater than 2.5 inches in 24 hours). Inspection is necessary to ensure that the stability of the outlet area is maintained and cleared of debris such as trash, organic matter, and sediment. If riprap displacement or downstream channel scour is observed, repairs shall be made immediately. 4.3 ESTIMATED OPERATION AND MAINTENANCE BUDGET In compliance with the DEP Stormwater Management Policy, an estimated operation and maintenance budget was prepared to approximate the annual cost for inspections and maintenance. The annual cost was estimated for each proposed BMP based on the requirements noted in Section 4.2. BMP # of BMPs Annual Operation and Maintenance Cost per BMP Total Cost Catch Basin 15 $200 -$400 $3,000 - $6,000 Mosquito Control 15 $50 -$100 $750 - $1,500 Area Drains - -- $50 -$100 Infiltration Basin 2 $200 -$400 $400 -$800 Sediment Forebay 2 Silt PrisonT"^ 9 $100 -$300 $900 - $2,700 Riprap Spillway 6 $50 -$100 $300 -$600 Recharge Facility 7 $100 -$300 $700 - $2,100 Detention Facility 1 $100 -$200 $100 -$200 4.4 PUBLIC SAFETY FEATURES No proposed fuel containment areas are included in the project development. In the event that a containment area is necessary, a Stormwater management system will be designed to provide containment in the event of a leak or spill. The design will include an impervious berm to Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 12 prevent seepage of contaminants and a closed drainage system requiring an employee to assess the area prior to allowing the Stormwater to discharge. Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 13 5.0 EMERGENCY CONTACTS In the event of an emergency, development of hazardous site conditions, or significant changes in the work plan, communications will be established. The list of the emergency contacts are noted below: • Brookhaven at Lexington, Mr. Michael Brennan (781) 863 -9660 • Town of Lexington Fire Department (911) o 45 Bedford Street, Lexington, MA o (781)862 -0272 • Town of Lexington Police Department (911) o 1575 Massachusetts Avenue, Lexington, MA o (781) 862 -1212 • Massachusetts DEP Hazardous Waste Incident Response Group (888) 304 -1133 Stormwater Operation and Maintenance Plan 960 -1010 Waltham Street Brookhaven at Lexington July 2017 Lexington, MA Page 14 '�. wry, ww� C C s 960 -1010 Waltham Street Brookhaven at Lexington Lexington, MA Notice of Intent � LL co LL � + 2 2 \ 2 2« 2 § f / \ < < < < < < < < < < 2 2 z \ 2 ± ± ± ± ± ± ± ± ± # % / / = e e E \ \e E 0 L G s 2 G $ o$ $ o$ o $$ 0 0 0 / o E2 )$ »_» »_ »_ » »___ m 2 0 p % 0 _ n G f \ % � n J 6 % \ CF) 0 f _0 c g � 3 \ 0 2 _ ® + / 5 $ \ ■# .§ 0 5 E = y y y y y y y y y y y y @ 0 —° z\) w a e a e o e e e e e 2 0 S — \ 2 t y[ e a m— m a s y = � \ \ / $ ƒ o e n f D / ƒ \ ) d .E ) _ \ 0 \ j — _ C: a » 0 7 / \ = o + \ m 5 m E §\ o r r o o r o r / x 0 0 0 0 / E ƒ k / ° 0 \ \ \ / \ \ \ \ ° \ \ \ \ \ 3 z \ k § / / U LU m 2/\ £ E ° CD § $ 0 / a I/# .\ .. -0 E-0 \ \ LU < \ _ # = 2 \ 2 0 + °= $ = E 0 0 0 k g o = z 0 0 o m ■ � % G 2 # 2 / / / c / \ \ \ 0 @ 7 \ _ a- -0 $ \ e e e m \ \ / _ \ E » 7 ¥ % ® _% k 3 D 3 0 / \ k / } .\ G - @ � § % 'E $ .( \ / \ » 7 ' m + \ e R g /_ 2 C$ m /a.e 22\ § D E _« n CO / %B 2 2 7 2@ k m f * \ \ \ § \ \ \ \ \ \ \ ( \ ( \ E D > s/ 2 E °® 2 a E 2 \ Q g* ® C: 2 C: ® / k / 2 / 3 \ \ / % « \ 0 f & k f ± ) \ 3 3 m- § 2 o o n/ a o �.5� o= o q >3: \ o /) �) �E _ 0 IL /\ 0 \ $ \§ % \ ± ���qe 0 W= n> > > m _ _ 22� _ _ —(n ¥oo 7 = E (n E S _ ¥ _ E n n ■ e# e \ m m -0 § 0 E 4 ��� ®\\ %[\ /( / \ @ % § 2 D_] k /[ \/[ 2 t/ ° ' o 0 t f G 2 t z=_ E / Q- < ± o a m¥ CO :E o z X522/ m E 0 7 \sEf2 m E> 2= > 2 — n* c c* « ❑ 0 Q Q- 0 00 0 / \ 0 \ = / a 0 \ -r- � $ \ ® f Cl. / 0 \ = -0 e ƒ .. _ / 2 \ ® \ / .g § j / $f ® ? _* $ w > U ) ® 3 ® ƒ t / a \ \ » / * e 0 \ / c co ° \ / 7 ƒ k ~ \ \ E / / } ® ® ® ° + ( 0) » 7 I = 0) o _ k \ \ $ \ J \ \ e o $ / / 2 k \ \ � ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ � � � / ƒ _ 0 a) / 0 . 7 2 & \ k \ $ E ° i / o > / x & U) e 2 $ 2 o z LO / � e m 2 m t_ , 2: ° / » \ / \ k f o i / _ \ � / $ -6 � E \ 3 U) ® Q- o S: ` ° ° m =2 k ® £ � \ / /® § o 0 ® I 2 c M ) w\ G o §_ o u§ a 4— °' } k \£\ / e f a j k 2 \ e 2 3� E a¥ ;0 o / § $ E E oEe /a 2 &$ 7 CL ) 4 k§ U) 0§ f E k » § k 4- c >1 0 k ] § $ & / � 2 2 $ - \ \0a m CL� \} U) 7 2 k S 3 U 3 0\ / E] m� � /•• 2 •�U-4 % . � 7 = £ ° _ § 2 S . / § f \m/ 2z§ w D \J J w 3 ƒ< , C14 co q < 7 +« 2 2\ 2 \« E u § \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ # % / / = e e E \ \e E a \_ a) m 0 LL G s 2 2 G $ $ o $ 0 0 0 $ $ $ / $ E ® ® _ ® _ _ _ * * * m » .E $ 0 p % 0 _ n G f \ % _ n J 6 % \ CF) 0 f _0 c g � 3 \ 0 2O _ + / 5 $ \ .§ ■# 0 5 ? = y y y y a y y y © 0 J/ z\) w t/ & m/\ r r r 2 0 S t 0 r CO a w a y = � \ g� \ / $ ƒ o e n f D / ƒ \ ) d .E ) _ \ 0 Lo \ j Lo - _ C: a 0 - .2 / \ _ 9 / \ � m n co E� \ §� o o r e o r r r o r e o r r E _ ° f= 2 0 0= a a d 6 6 6 6 6 r a 6 a = z E 0< _ # g o0 em ea am ea CO / U LU m 2/\ £ E ° CD § / $ 0 a I/# .\ .. -0 E= \ \ \ < \ _ = m 2 0 + # $ = E 0 0 0 °= g o = z 0 0 o k m ■ (D 0) 2 / \ \ \ 0 @ 7 \ _ a- -0 $ 0 e e e \ \ _ \ ( E s » \ E / s _0 F = _ _ � n o / © § 7 0 - \ % '[ \.( \ _0 ' ) \ -0 (D } . _ 2/ E 3 % / $ \\ = n a CO 2 / ( . \ 2( 0\ e 2 k f * '■ 0 f _ f = 2 0 -o co . 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J � m tC , ° / » \ % \ k o r J E o @ ¥ " t 0 -6 9 LD o \ e ° ® 7 2 U) L5 ® \ 7 Q- 7 u 02 t / % _ _ § 0 7 = 0 2 ~ � § } 0 ou Q ® + °' § \ 5 )/ x m 4 § 2 F } k 7 4 e a s 2 (§ C m E E e y E E§< a* *� 2 2 & o■ — o a 7 T ) 6 E § — o E U) °§ f Q- » § 2 k >1 \/k]§0a8 \ /k .! 2 $ k _ > 0 a m X 3 3 CL 0\\ \ _ 7 2 E S U) / E] m� Q- /•• 2 • -0-4 " � 7 = £ ° _ § 2 S v 9 $ / /§ 2/ § �_2 \m< 2z§ w D \J co J w 3ƒ< � / co m + 2 \ 2 2 % 2 \ § \ \ / \ \ \ \ \ \ \ / \ / / # % = e e E 0 n e E 0 LL G s 2 kE p % 0 n ��F f \ % k n J 6 % \ M § f _0 c g � 3 \ � � _ ® + / 5 $ \ .§ ■# 0 5 ? = y y y y y y a @\ -° z\) a o 0 o e e »& 2 \ F \ 2 t y[ e m r r m m© a y = � \ \ / $ a- o e n f D / ƒ \ ) d .E ) _ \ ( \ j - Lo - -0 a. » 0 / \ = o + ' m n I E §\ 0 0 9 r r o 0 o r o \ E f k / ° \ \ \ 6 6 \ \ \ \ \ ® z ) 0 k / § U LU m 2/\ £ E ° CD § / $ ( [ a I .\ # \ \ \ < \ _ # = 2 n 2 0 + °= $ = E 0 0 0 k g o = z 0 0 o m ■ _0 (D 2 \ \ \ 0 @ 7 \ _ a- -0 $ \ e e e n \ \ / % _ \ ¥ % E » 7 k k @ _ # / = 0 - k 2 E \ E .\ F Q » § \ f % / ƒ 2 k° �� \� �2 \ CO 2 \ \ + § \2 kE $\ E }\ E$ Q e g 0 / \ k / � \ § \ \ {/ \\ 0 _IX o o / \ ) _ �/ k \§ » �2 W= k> 2 >> E �\ F =� f k� (D= 0- - §[ _ D a . 2 E 2 2 n- o ■° e _ (n m J m\ §» E .. f % = o ' ® t @ % m ° + m / 3 g E * =o== % n 2 \ / � 9 § / ® CO + 2 _ ' Q- e = a n m�� -- ® 5 �z =e£ c Q.E -_% of D a Q- < = o� El 11 m< ■ t a o n* = 2 m'$ E _&/ E c > z 7 « ❑ 0 Q cu Q- ƒ \ 0 \ = / a 0 \ -r- � $ \ ® f Cl. / 0 \ = -0 e ƒ .. _ / 2 \ ® \ / .g § j / $f ® ? _* $ w > U ) ® 3 ® ƒ t / a \ \ » / * e 0 \ / c co ° \ / 7 ƒ k ~ \ \ E / / } ® ® ® ° + ( 0) 0) o _ k \ \ $ J \ e o $ / / k \ \ � ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ � � � / ƒ _ 0 a) / 0 . 7 2 & \ k \ $ E ° i / o > / x & U) e � 2 $ 2 k 2 Cl. J m t& , ° 8 ± \ / k o i -0 \/ k $ 'U) ` / 2 e / a = /_ o ® u 2 / } $ . E 7 7 0 ] \ § 2 I 4- c ° ) G � o \ \ / < fay j �k t } E v 4§ o± f o\\ d » ° L: " f 0 [ S % a & Q- _ § M $ � EU) § °§ f Q- » § 2 / k ] § $ _ & j / k c 2 2$- \0 a e CL a ± U) 7 t k S X 3 U) 3 0\% \ / E] m Q- -0 2 • 0 � " U 7 = £ ° § 2 S v $ / /§ 2N § _2 \m<< 2z§ w 2 \J J w 3 ƒ< � co C14 � 22 4 44 e \ \ § \ \ / 2 \ \ \ z \ \ \ # % :/ = e e E \ \e E a \_ n 0 LL G s 2 E 2 G $ $ $ $ o $ o $ o / $ » E * * * * _ * _ * _ $ ( p % 0 _ n G ��F f \ % k 3 n J 6 % \ iTL f Q- c .2 � 3 \ 0 2 _ ® + / 5 $ \ ■# .§ 0 5 E = y yyy yyyy 0 @ 0 -° z\) / a a a» a a G 2 \ F \ 2 t y[ co rm© m� y = 77D \ \ / $ ƒ o e n f D / ƒ \ ) d .E ) _ \ ( \ j - Lo - _ E � » 0 7 / \ o + ' m n I E 9+\ a- r r o 0 o r \ o 0 0 0 \ f n �°LU f=/ 2= 6 6 6666 m wawa o = z E 0< = 7 g g 2 e e e e m e m a / U Lu m 2/ Q a) § / w \ ( [ - I/# .. U / E= > > > < _ # = 2 2 0 + $ = E o 0 0 g z m ■ -0 % o 2 # 2 / \ \ \ / / / / A 45 7 2 k ± ® \ a E % » 7 ¥ % ■ = 2 F ° = � � £ � _ � © 7 0 \ ( \ \ § \ @ § % E $ / .( \ 7 ' m + \ } 3 o---, % ® c_j /k U)2 \ \/( \f \§ k a o f / f\ \ E t �/ Et # \ g f @ a n+ g n ._ \ m 3 m e / \ k \ \ \ .m m O &/ k z.T %% 0 2 o o n/ E o= a = 3 -�- k # �) - _ � o / \ \ 5 $ + _ / �� ** ) &� of » W= _ k> = > > *o 2E o n -3$ %2 ƒ2�/ °% + £ /"q E = o _ < n.= \3a= c g» _ E �ƒ/�__ § g ' E * E 2 ° ® % \ \ \ ( Q- o _ U n = m o.- c= E f = \.@f & .g _� °�_* of _ a Q- < = o� E m < ■.- o£ =E mSEa* =7\2.% >z 2 « ❑ ❑ ❑ 0 Q cu # B B 0 B / \ 0 \ / a = \ $ 0 ® -r- � / \ f Cl. = e .. _ 0 \ -0 ƒ / 2 .g \ ® $f \ / § j $ w / ® ? _* ) > U t / \ l U) » ® 0 * 3 ® 0 \/ c c ƒ co a ° \ k e \ \ / 0 ƒ � E \ E / / } ® ® ® ° + _ = f 2 I = ' k ( k k/ /\ � $ » 7 g ¥ 2 /= y _ o _ e u f o $ j j / j / \ / \ J \ 2 \ \ / ƒ \ � ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ � � � / _ 0 a) / 0 . 7 2 & / k k � > G ± \ CL i 0 E > a E & / k 0 $ ■ ° k y ( ^ J \ \ m t- N ° / ± \ / k o i -0 \/ k $ o � E \ 3 \2 0 U) .2 LD t/ o o } m L. = 2 E 2 7 0 e >. \ �§ �/g 2 I> � c \ § \ \� f// j 2/ 2 }/ .. v E o \2 E a= r '� ° C " f .. S» a & Q- k T ) � R E § \ 8[ U) o § f & » § 2 7 $ 2 2 / v / 7 2 ! ) ° ° r c 2 = • # — . u § . § = 8 \ CL = 7 �. 2 $- k ± o r- 0 w 3 U m— 3 0 \\ \ / E] m 7-5 2 E S J = \ - o •° u q 0 v § , 7 § 2 S . $ / /§ 0/ § f 2 a- m e o \ e o: 2 w\ <� wI<I w oLL < � I-- 2 C14 C14 A 7 + 2 2 2 \\ 2 E g \ f / G < < - u\ E < < < < < < < < o n g \ 2 ± ± z = ± ± ± z ± ± ± z # % / / = e e E \ \e E a \_ 0 L G s 2 E2 G o$ o $$ o$ o $$$ o / o 2 )$ _ »_ » »_ »_ » » »_ m ( p % 0 _ n G f \ % CF) _ n J 6 % \ § f c g � 3 \ 0 2O _ + / 5 $ \ ■# .§ 0 5 ? = y y y y y y y a y y y @¥ -° z\) o t o o % & a r c» 2 \ S - \ 2 t y[ - e- m a t a a® y = � \ \ / $ a- o e n f D / ƒ \ ) d .E ) _ \ ( \ j - Lo - _ � a. » 0 7 / \ = o + \ m 5 co E 2 §\ r o c o c o r e r / o 0 o r \ E \ k / ° \ \ ƒ \ \ \ \ \ ° \ \ \ \ ® z \ k § / § / U LU m 2/\ £ E ° Q a) § / $ ( [ a I/# .\ .. / E= \ \ \ < \ _ # = m 2 0 + °= $ = E 0 0 0 k g o = z 0 0 o m ■ % 0 2 / \ \ \ 0 @ 7 \ _ a- _ $ \ e e e Cl) \ \ / _ E % » D = F = / £ n (D CD \\ c 7 E § 5 ) a F Q © § m + _ D(D Q)E CD / \ \ G �_ 2 = 2 3 E' a# e E o e g f @ a n+ g e > o m a® 2 m e e= §\ E k k \\ t/ _ 0 \\ & » ' t a ) \%\ 2 °' f f % 7 m.m k = E o = _ _.- CO < co � m ®_ t / / �.2 (D w� \ \ \ - 0 u oo + 2 k2 I a= =E n E ■no e ƒf /$ /\ §» ? f ® S •• E t @ ®\ t m= a = a °_ _ n . g E * % n c m® o n o G- .0 n = - z g E @'- t+ ° . g g \ / = _ 2 2 _ / 2 \ = g ° 2 \ Q- < = o� El 11 m ¥ ■ _ !- \ / on*� \ \ = o _ = - mz=$*E f \ \ =��&c >> \ - =a « ❑ 0 Q cu F -Fu 0 El 0 0 ƒ cu 0 \ = / a 0 \ -r- � $ \ ® f Cl. / 0 \ = -0 e ƒ .. _ / 2 \ ® \ / .g § j $f _* $ > ) ® 3 ® c ƒ tU) / a \ \ » / * e 0 \ / c co ° \ / 7 ƒ k ~ \ \ E / / } ® ® ® ° + ( 0) » 7 I / = 0) o _ k \ \ $ g J ¥ \ \ e o $ / / 2 k \ \ � ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ � � � / ƒ _ 0 a) 0 . 7 2 & § > $ E ° / -E k ® j § i a o E > / k g 0 ® & ■ o z / / ¥ 2 \ & / z m t & § , F ° / ± o CI. / \/ 2 $ -6 � E \ 3 \2 § Q- o .: ` ° t ° m = 2 S ® ° \ ® \ U E /§ - 0 0 ._ > z § 5 0ma 0 / 4— ° k \ k \ \ k } U) £ 4 ° o / \ ' 2 - " E ��& rE $ R § f 8[S»a ° § f _ E » � E § \ �$ 2 m / � v / 72§§ =a ] k - \ \22§ %'tea± �2 7 2 E k S w 3 U 3 0\\ \ / E] m m Q- -0 2 •� � � � 7 _ § 2 S v 9 $ / /§ 2N § �_2 \m< 2z§ w 2 \J co J w 3ƒ< � co m CI4 § f / \ < < < < < < < < < o \ n g 2± LL ± _± z 2 ±± z± \ # % / / = e e E \ \e E 0 (n s 2 2 G $ $ o o $ $ $ $ $ $ $ o / o E E * * _ _ * * * * * * * _ 2 $ ( p % 0 _ r) G f \ % CF) _ n J 6 % \ § f _0 c g � 3 \ 0 2 _ ® + / 5 $ \ ■# .§ 0 5 E = y y y y y y y y y y @¥ -° z\) m o e» m r r r r a a a» r 2 \ S - \ 2 t y[ a t m a m a r r r y = 7F) \ \ / $ a- o e n m D / CO \ ) d .E ) _ \ ( Lo \ j - Lo - -0 C: a_ » / \ . + / o m J co E 2 §\ o o r r \ o 0 0 0 \ o 0 o r \ E \ o k / ° \ \ \ \ ® \ \ \ \ © \ \ \ \ z \ k § / § / U LU m 2/\ £ E ° CD § / $ ( [ a I .\ # / \ \ \ <\ _ # = 2 20 + °= $ = E 0 0 0 k g o = z 0 0 o m ■ % 2 / \ \ \ @ 7 \ _ a- E _- $\ e e e 2 e _ (D E % » 7 \ ¥ % = _0 F _ = / £ n a) m D 3 0 = a \ _ f / § } \ k = E a j \ \ b x m = _ § (D � ® c a =« = = n aE m yy g �'T %e #� % D ' a § f @ a n+ g n ._ ¥> m 2 3 > c o m e E$ n k \ \ k \ / \ f 0= �t &» ' \ = 2 =- �/ co e \ m) m e m 7 \\ = o Ef / 5 2 > \§ 2\�\ / /\ +« u� / �2 2 2 \ \ / -=§6a (D of W= E n g n �\ D .. f .= o =_ 2 = E _ ■ c/) £ n E _ m«+ o g o E _ n % g (e..� E* n® o n m- a [ o® >_� _ n' E( - g k n 2_ n �.- _. Q- < / o m¥ k /[ /E o* z m k \ \M[ m o E= z \:\5\ =& > 2 \ - o s 0)--) « 0 Q Q- 0 00 0 / \ 0 \ = / a 0 \ -r- � $ \ ® f Cl. / 0 \ = -0 e ƒ .. _ / 2 \ ® \ / .g § j / $f ® ? _* $ w > U ) ® 3 ® ƒ t / a \ \ » / * e 0 \ / c co ° \ / 7 ƒ k ~ \ \ E / / } ® ® ® ° + ( 0) » 7 I = 0) o _ k \ \ $ \ J \ \ e o $ / / 2 k \ \ � ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ � � � / ƒ _ 0 a) / 0 . 7 2 & \ k \ $ ) ° i / o > a E $ & < / k 0 / 2 k y ( - \ _ m *- 0 / }/ 2 k o - -0 \/ k $ ° / 7 ` \ \ e � o = U) u / / \ ] \ i \\ \ 4— ° o \ f/ j �>,2 Cl.- k. e t } \ / .. a v E o± f m\ r § t 2 °� \ " f 0 [S ��& Q- $ R § ° § f » § \ C � E U) Q- r$ 2 2 / k]§§= G j / k: �c 2 2 $ - \ \2a e'� ± U) -0 7 2 E k S 3 3 o \\ \ / E] m m Q- -0 2 •� 0 � % : U 7 = £ ° § 2 S . v $ / /§ 2N § �_2 \m< 2z§ w 2 \J co J w 3ƒ< � co n A co \ \ \ \ / \ \ \ \ \ \ \ z \ \ \ # % / / = e e E \ \e E 0 \_ LO 0 0 G s 2 2 G $ $ $ $ 0 0 0 E E * * * * _ _ _ * * * * m 2 $ 0 p % 0 _ n G f \ % � n J 6 % \ CF) 0 f _0 c g L 3 \ � \ � _ CO _ / _ $ $\ /\ E y% y y y y w y y y y 0 \ 2 / / / / y y ? & w w ? / / / _ S = e /.R 2 � \ / � \ ƒ 2 \ f CO / ) d ( § \ 3 = o = _ C: a » 0 7 / \ = o + \ m \ co E a. §\ . 0 0 \ o r r r o / o 0 0 \ \ ƒ k / ° 0 \ \ \ ® \ \ \ \ \ © \ \ \ ® z \ k § / / U LU m 2 / \ £ E ° CD § / $ 0 a I/# .\ .. -0 E-0 \ \ \ < \ # 2 0 + °= $ = E 0 0 0 k g o = z 0 0 o m ■ � % G 2 # 2 / / / c / \ \ \ 0 @ 7 \ _ a- -0 $ \ e e e m \ \ / _ \ ¥ % E 0- » 7 = F = / £ n (D ( _0 k f 9 2 = g E f 2 ./ a - F Q »\ $ u Jo \ 7 ) f x m + - / � § 7 o co m § % ® \ \ n CO 2 2 % ) % E \ \ .3 2 % \ \ . c a = f #•- g f o f e E g•= m u e E 2 w 2¥ m a % o= = 2 E$ n k k k \ $ $ 2 k / 0£ \ \ _0 ) CU a off k/ k 0 k %\ § �$Z000 2/ % \ 2 / 2 > k b \ \ F / \ _ � \ k 0 \ W = / > > 2 E / D \ ±_ o / o a $ 2 = E t % / k 0 '' _= t @ 2 g\ E Z3 0* g o / 3 g E* 0+ n 2/ n 0 ®( E/® t+ ' g � / - 2 E _ _ _ _ ] t 2 2 z 0 ° E / Q- < = o m¥ �Etf o S 2* �.@f2o5 m o 3: z E =E.� _\& E 2= > z 2 « 0 Q Q- 0 00 0 / \ 0 \ = / a 0 \ -r- � $ \ ® f Cl. / 0 \ = -0 e ƒ .. _ / 2 \ ® \ / .g § j $f _* $ > ) ® 3 ® c ƒ tU) / a \ \ » / * e 0 \ / c co ° \ / 7 ƒ k ~ \ \ E / / } ® ® ® ° + ( 0) » 7 I / = 0) o _ k \ \ $ g J ¥ \ \ e o $ / / 2 k \ \ � ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ � � � / ƒ _ 0 a) 0 . 7 2 & \ k \ $ E ° i / o � > / x & U) e � 2 $ 2 k 2 ^- J r_ m t& , ° / ± \ / k o i -0 \/ ® k $ '� ` / 2 e / a = /$ = o ® u t \ U E 0 - // 0 0 ]\ . ~ § 0 0 I- ° k \ § \ � 0) k } L k £ 4\ ° E o j \ ' 2 - ��& r _ $ § 8[S»a ° § f » § \ � E U) Q- C v .2 L4Ag =% ] 2 k � - \ \ 0 2 § % ' + f \ 7 2 E k S w 3 U 3 0\/ 3 / E] m m Q- -0 2 •� � � � 7 § 2 S v 9 $ / /§ 2N § �_2 \m<co 2z§ w 2 \J J w 3ƒ< # _ E E ± e E a 0 2 LL G < m E 0 p�2 � k 3 c 0 e g $ 0 c - D � LO LO Q_ U / S S w Q U T <m c ■ � Q / � 2 @ � C § - � F c r_j . 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Use: senior living/ assisted living facility. LOCATION AND TRANSPORTATION LTcl LEED for Neighborhood Development Project is not located in LEED for Neighborhood Development Location LTc2 Sensitive Land Protection The project is located on a site that was previously developed and is not classified as prime farmland or on a floodplain. LTc3 High Priority Site Project is NOT located on a brownfield site, or similar. LTc4 Surrounding Density and Diverse Uses Project is not located in an area within t/4 mile that meets following density criteria (2 points) Residential density 7 DU/ acre per 22,000 sf/ acre of buildable land OR Nonresidential density (FAR) of 0.5 per 22,000 sf/ acre of buildable land Or located in area with diverse uses (within Y2 mile of building entrance) LTc5 Access to Quality Transit Project is not located in t /4 —' /z mile walking distance to transit LTc6 Bicycle Facilities Project is not located within 200 yards of a bicycle network and will not provide short term or long term bicycle storage. LTc7 Reduced Parking Footprint Project WILL? or WILL NOT? provide parking that is 20% less than required by zoning LTc8 Green Vehicles Project DOES? Or DOES NOT? have a plan to provide either: Architecture I Interior Design I Planning MEMORANDUM July 14`2O17 Page 596 of parking spaces are preferred parking for green vehicles (defined 8sminimum score of 45 on ACHE annual vehicle rating guide) Project DOES NOT plan to dedicate 2|2[th[ vehicle charging stations for 296 of parking spaces. 1 FS are r MEMORANDUM July 14, 2017 Page 3 SUSTAINABLE SITES SSp1 Construction Activity Pollution Prevention (Required) Project will create and implement a sedimentation control plan for all construction activities associated with the project to meet EPA guidelines for CGP. SS c1 Site Assessment The design team has conducted a bioclimatic and detailed site analysis which influenced building orientation and placement. The assessment included the following information: Topography, Hydrology, Climate, Vegetation, Soils, Human Use and Human Health Effects. SS c2 Site Development — Protect and Restore Habitat Project may include on -site restoration of 30% (including building footprint) of all portions of the site identified as previously disturbed. SS c3 Open Space Project will include landscaped and open areas that are greater than or equal to 30% of the site area. SS c4 Rainwater Management Project will manage on site runoff from the developed site for the 95'" percentile of regional or local rainfall events using low- impact development and green infrastructure. SS c5 Heat Island Reduction Project will address both non -roof and roof areas to reduce heat island effect. The roof will have SRI of at least 82 for low sloped areas and 39 for any steeply sloped areas. Plants or structures will shade paved areas. SS c6 Light Pollution Reduction Project will specify outdoor lighting that uses the BUG method and meets Dark Sky criteria. SS c7 Tenant Design and Construction Guidelines Project is not a speculative core and shell building that will have tenants but will be owner - operated and residential in nature. i FS a er MEMORANDUM July 14, 2017 Page 4 WATER EFFICIENCY WE p1 Outdoor Water Use Reduction (Required). Project will reduce landscape water usage by 30% from calculated baseline of site's peak watering month. WE p2 Indoor Water Use Reduction (Required) Project will reduce indoor potable water use by at least 20% from the baseline. Baseline use for fixtures are as follows: Toilets 1.6 gpf; Urinals 1.0 gpf; Public lav faucets 0.5 gpm; private lav faucets 2.2 gpm; Kitchen faucets 2.2 gp; showerhead 2.5 gpm. WEp3 Building Level Water Metering (Required) Project will install building level water meters to measure the total potable water use for building and grounds. WEc1 Outdoor Water Use Reduction Project plans to reduce landscape water use by 50% from calculated baseline of site's peak watering month. WEc2 Indoor Water Use Reduction Project anticipates reducing indoor water use by 25% from the baseline. WEc3 Cooling Tower Water Use Project will not include a cooling tower so is not eligible for this credit. WEc4 Water Metering Project does or does not anticipate installing permanent water meters on two additional water subsystems. i FS a er MEMORANDUM July 14, 2017 Page 5 ENERGY AND ATMOSPHERE EAp1 Fundamental Commissioning and Verification (Required) Project will conduct fundamental commissioning fo MEP systems according to ASHRAE Guideline 0 -2005 and ASHRAE Guidline1.1 -2007. Project will develop OPR and BOD for HVAC &R systems. EAp2 Minimum Energy Performance (Required) Project will achieve a minimum of 5% improvement complared with baseline building performance. Project will demonstrate performance improvement using energy model per ASHRAE 90.1 -2010 Appendix G OR by following prescriptive provisions of ASHRAE 50% Advanced Energy Design Guide. EAp3 Building -Level Energy Metering (Required) Project will include building level energy meters to measure total building energy consumption (electricity, natural gas, chilled water, steam, fuel ooil, propane, biomass, etc.) EAp4 Fundamental Refrigerant Management (Required) Project will not use CFC based refrigerants in new heating, ventilating, air - conditioning, and refrigeration systems. EAc1 Enhanced Commissioning Project will conduct enhanced systems commissioning of HVAC &R systems. Does NOT plan to develop monitoring -based procedures to be measured and evaluated to assess performance of energy and water consuming systems. Does NOT plan to conduct envelope commissioning. EAc2 Optimize Energy Performance Project plans to achieve an energy reduction of 11 % from the baseline performance. EAc3 Advanced Energy Metering Project does not plan to install additional energy meters. EAc4 Demand Response Project utility company does not offer this incentive for this location. EAc5 Renewable Energy Production Project does not plan on installing renewable energy sources. EAc6 Green Power and Carbon Offsets Project does not plan on purchasing RECs to offset GHG emissions or green power. i FS a er MEMORANDUM July 14, 2017 Page 6 MATERIALS AND RESOURCES MRp1 Storage and Collection of Recyclables (Required) Project will dedicate area for recyclables for waste haulers and building occupants. MRp2 Construction and Demolition Waste Management Planning (Required) Project CM team will develop and implement a construction waste management plan. MRc1 Building Life -Cycle Impact Reduction Project does not plan to conduct a Life -Cycle assessment. MRc2 Building Product Disclosure and Optimization — Environmental Product Declarations Project will select at least 20 products with EPDs from at least 5 suppliers for disclosure point. MRc3 Building Product Disclosure and Optimization — Sourcing of Raw Materials Project will select 25% (by cost) of products to meet one of the options: take back program, bio- based, salvaged, recycled content, or "legal wood" for optimization point. MRc4 Building Product Disclosure and Optimization — Material Ingredients Project will select at least 20 products from at least 5 different manufacturers for material ingredients disclosure point. MRc5 Construction and Demolition Waste Management Project plans to divert at least 75% of total construction and demolition material and at least four material streams. i FS a er MEMORANDUM July 14, 2017 Page 7 INDOOR ENVIRONMENTAL QUALITY EQp1 Minimum Indoor Air Quality Performance (Required) Project plans to mechanically ventilate per ASHRAE standard 62.1 -2010. EQp2 Environmental Tobacco Smoke Control (Required) Project will prohibit smoking. EQc1 Enhanced Indoor Air Quality Strategies Project plans to comply with minimum ventilation strategies and cross - contamination prevention (removable walk -off mat of at least 10 ft length) and filtration levels of MERV 13. EQc2 Low - Emitting Materials Project plans to comply with VOC limits for at least 5 of the 6 categories of materials: 1/ Interior paints and coatings, 21 Interior adhesives and sealants, 3/ flooring, 4 /composite wood, 5/ ceilings, walls, thermal, and acoustic insulation, 6/ furniture EQc3 Construction Indoor Air Quality Management Plan Project will develop and implement an indoor air quality (IAQ) management plan for the construction and pre- occupancy phases of the building. EQc4 Daylight Project is NOT demonstrating through simulation that regularly occupied spaces have sDA (spatial Daylight autonomy) of at least 55 %. EQc5 Quality Views Project is NOT demonstrating that 75% of all regularly occupied spaces achieve a direct line of sight to the outdoors with clear image of the exterior and demonstrate at least two of the four kinds of quality views. i FS a er MEMORANDUM July 14, 2017 Page 8 INNOVATION IDc1 ID: Walkable Project Site (Innovation Catalog) Project may design and build project to achieve at least 8 of the 9 listed featuers. IDc2 ID: Design for Flexibility (Innovation Catalog) Project may design project for ease of future adaptation per credit requirements. IDc3 ID: Occupant Comfort Survey (Innovation Catalog) Project may conduct an occupant comfort survey post- occupancy. IDc4 ID: Purchasing- Lamps (Innovation Catalog) Project may implement purchasing plan that specifies overall building average of 70 picograms of mercury per lumen -hour or less of all mercury containing lamps purchased for building and associated grounds. IDc6 LEED Accredited Professional Project will NOT have a LEED AP BD +C (speciality required) on the project team. i FS a er MEMORANDUM July 14`2O17 Page REGIONAL PRIORITY RPc1 RP Projects in Lexington, MA are eligible for 8n additional R2OiOn8| Priority credit if they achieve the following credits: - Renewable Energy Production Optimize Energy Performance (if achieve 8t least points) Surrounding Density and Diverse Uses Access to quality transit Building life-cycle impact reduction - Site Development — Protect or restore habitat 1 FS are r July 21, 2017 Alex Adkins DiMella Shaffer 281 Summer Street Boston, MA 02210 Subject: Community Sound Evaluation Brookhaven Repositioning and North Building Lexington, MA Acentech Project No. 626591 Dear Alex: Moulton Street Cambridge MA 02138 617 499 8000 Kraen(e(( hcoln This letter presents our review and recommendations on the proposed rooftop equipment for the Brookhaven Repositioning and North Building project in Lexington, MA. This project site needs to comply with the Town of Lexington noise regulation as well as the Massachusetts state regulation. APPLICABLE NOISE REGULATION The Lexington Noise By -Law is identical to the Massachusetts Division of Air Quality Control Noise Policy. It defines noise pollution by the condition resulting when: • A broadband noise source raises the noise level by 10 or more dBA above the ambient noise • A tonal sound source that raises its octave band noise level by three decibels or more above the adjacent octave band levels. • In determination of noise violation on private property, the noise measurement shall be made at the boundary of the property in which the offending sound source is located. The ambient noise level, Lso, is the sound level that is exceeded 90% of the time. 111N!Iiw.wstwcs I wlllbw a�lciin ,°WOur! x ,WW kounps J iii,fl IW Y 0 , Y II A.. 7 AMBIENT SOUND LEVEL MEASUREMENT PROTOCOL We visited the project site to install three noise monitors at the three locations shown in Figure 1 that collected background sound levels over approximately five days —from May 31 to June 5, 2017 —at ten - minute measurement intervals. Statistical background sound levels were collected continuously as part of the measurement protocol to carefully document the existing background sound levels to be used as the reference for our sound analysis, which included L01, Leq, and L90. The three locations are representative of the background sound levels of the general area, north /west, east, and south of the Brookhaven campus. The same measurements can be made at the three locations along the property lines for verification as needed. Figure 1 – Sound monitoring locations near Brookhaven at Lexington The results of our sound measurements are summarized below. Refer to Figures 2, 3, and 4 attached in the Appendix at the end of this report for the complete collected sound levels at the project site. The emergency generators will be tested during the daytime hours, per the noise ordinance between 7AM and 8PM for maintenance power equipment. Table 1 shows the average lowest ambient sound level as defined in this time range, and Table 2 shows the average lowest ambient sound level during nighttime hours. Table 1 – Average Lowest Daytime Ambient Sound Levels (7AM - 8PM) Location A -weighted Lso, dBA 1 44 2 40 3 45 10, E TEC ,°WOur! x ,WW kouns J iii,fl IW Y 0 , Y II n.. 7 Table 2 — Average Lowest Nighttime Ambient Sound Levels (other times) Location A -weighted Lso, (dBA) 1 37 2 32 3 39 Based on the results of the measurements at Brookhaven, the broadband sound emissions by the facility should not exceed 50 -55 dBA during the daytime hours and 42 -49 dBA during the nighttime hours, depending on the receiver location. PREDICTED SOUND LEVELS The design team has provided us with the preliminary rooftop equipment layout and sound data. Most equipment are located on the roof level and the generators are located on grade. We have predicted the sound levels of the future equipment to the property lines with our CadnaA computer modeling software. We have also included some major existing equipment as part of our evaluation. We have assumed that for typical nighttime and daytime conditions, all outdoor mechanical equipment will operate at full capacity in the worst -case scenario. One exclusion to this is the existing cooling towers; Based on our existing measurements it was clear that the existing cooling towers were not operating during the quietest times of the nighttime hours. Therefore, this has been excluded from our prediction for the nighttime conditions. In addition, for generator testing daytime conditions, we have assumed that one emergency generator will be tested at a time. The list of preliminary new equipment and existing major equipment included in our study is as follows: North Illilif a li II d li in g • One new 600 kW diesel emergency generator within a sound enclosure, similar to Pritchard Brown enclosure • Two air handling units serving the North Building, approximately 5000 cfm each, similar to Lennox LHA120 • 50 to 60 small air - cooled condensing units serving the North Building residences, 1.5 ton to 3 ton, similar to Lennox HS Coinninnoins Ill:l:fulilldliing • One new 600 kW diesel emergency generator within a sound enclosure, located next to the existing loading dock • One new dehumidification air handling unit, approximately 17,000 cfm, similar to Munter unit with plenum fans. • Two new energy recovery units, approximately 5400 cfm each, similar to Valent VPRE • One new air cooled condensing unit, 15 ton, similar to Lennox LHA180 • Three existing cooling towers next to the loading dock, operating mostly during the day and generally off during late evening hours • Three existing air handling / energy recovery units on the roof at two locations 10, E TEC ,°WOur! x ,WW kounps J iii,fl IW Y 0 , Y II A.. 7 • One existing 500 kW diesel emergency generator at the existing loading dock (indoors). Figure 5, attached in the Appendix at the end of this report, shows the preliminary roof plans of the North Building and the Common Building indicating the approximate location of the MEP outdoor equipment. As the design develops, these locations may adjust slightly but should not impact the results of our predictions significantly. As the design develops we will update these units accordingly to confirm that sound levels will still be within the allowable limits. Figure 6 below shows the closest residential receivers to the project. Sound produced by the project with the above proposed equipment are projected to these receivers. Figure 6 — Sound receiver locations Tables 3 and 4 shows the results of our sound predictions, during daytime and nighttime hours, respectively: Table 3 — Predicted Daytime Sound Levels 10, E TEC Predicted Daytime Predicted Daytime Daytime Sound Receiver Location Sound Levels with One Sound Levels without Limit (dBA) Generator On* dBA Generators dBA 1 51 50 54 2 54 42 54 3 54 52 54 4 49 43 50 5 42 42 55 10, E TEC ,°WOur! x ,WW kounps J iii,fl IW Y 0 , Y II A.. 7 * The sound levels are predicted based on the closest generator being tested to the respective receiver. These are representative of worst -case condition at each receiver location when the generators are being tested. Table 4 — Predicted Nighttime Sound Levels Tables 3 and 4 show that the predicted A- weighted levels with the noise control implementations described in the equipment list above will be within the allowable sound limits. TONE EVALUATION Based on the equipment sound data and the predicted sound levels to the receivers, we found the sound levels with the noise control implementations described above will not produce tonal sound to the area. CONCLUSION Based on our preliminary evaluation of the outdoor equipment for Brookhaven Repositioning and North Building project, the equipment sound levels the community are within the acceptable sound limits and will not produce any tonal sound. I trust this letter provides the information that you need at this time. If you have questions, please call me on my direct line at 617.499.8080. Sincerely, "S g'' J,. Rose Mary Su Senior Consultant Encl: Kristen Murphy cc: Appendix — Figures 2, 3, 4, and 5 3: \626xxx \6265xx \626591 - DS - Brookhaven Lexington AC \Reports \03- rms -DS- Brookhaven community sound study.docx ' A C IE N T E C Predicted Nighttime Sound Receiver Location Nighttime Sound Limit (d BA) Levels d13 1 44 47 2 40 47 3 41 47 4 38 42 5 42 49 Tables 3 and 4 show that the predicted A- weighted levels with the noise control implementations described in the equipment list above will be within the allowable sound limits. TONE EVALUATION Based on the equipment sound data and the predicted sound levels to the receivers, we found the sound levels with the noise control implementations described above will not produce tonal sound to the area. CONCLUSION Based on our preliminary evaluation of the outdoor equipment for Brookhaven Repositioning and North Building project, the equipment sound levels the community are within the acceptable sound limits and will not produce any tonal sound. I trust this letter provides the information that you need at this time. If you have questions, please call me on my direct line at 617.499.8080. Sincerely, "S g'' J,. Rose Mary Su Senior Consultant Encl: Kristen Murphy cc: Appendix — Figures 2, 3, 4, and 5 3: \626xxx \6265xx \626591 - DS - Brookhaven Lexington AC \Reports \03- rms -DS- Brookhaven community sound study.docx ' A C IE N T E C APPENDIX - FIGURE 2 17�oq FINI 2.;µ,µr„1 IF, M 4 (M I 6::00 1 8 00 P M 2�00 A M 2' � 00 A W1 4:4110 AM 6:()() AM &04) A M 10�00 Am 12 0�1 F1 rO ,;QQ I M 6:00 PNI 8 00 P M 10 IOG IF) m 12�µx) A W1 2:?.01111 ArA 4:04.) A10 6:0(..1 A111+'1 8 �CO A M 1,W20 ,A, N11 12 0(3 PM 2:a D I M 4:0C I 0 6 00 1 Qj '. 8 00 P M ID t, C) � 0 "� PM I ?1?,.)Q A rj/1 2:QU,1 A PA 4:(N) A FA 6:1)() AM 8 �00 A I 10':00 AM 12:(in I 2:00 1 4 00 IPM 6 00 IF, M 9 D"T µ'M LO�00 FIN1 I AM ,N �10 AM 4:1)() A Fil 6A,114) AM 8':00' A M IWDO Am 12:0('] IPrO 2 :Grj I rVI 4 00 1 6 A)G 1µ41+F1 8 OG 141,E 1. C1 11,M I 2()o AF/I AM 6 ;CO A N11 &00 AM I A N11 12Urj 1prVI A-weightedsoand level (dB ire- Ipflaa � ryoim NO Q'I "dox ,WW kins Jii,fly ?� 11 � 7 16 of 9 6" A C E N T E C H APPENDIX — FIGURE 3 I I Wo ANA, I to PINA W PPO T Do W ADD RM too Hm 1100 mm IAO AM 100 AM 510 AM, T of.,) AM, W AM 3 110 ArKV I mo KAI 00 F'M T Do PRA too Hm 910 mm 1100 Rm 1' 110 AM 3,0C) PAN, 100 AM TQQ ANA" 91:00 AM I Ito AM I 00 F'M Wo Pm wou prvl Tmo Rm 9mo KA 1 Ito Pm zi L tCIO ATV 3 3�00 AM 5�QIQ AM 7M0 AM SAID AM, 11:: t:' 0 AM Ito R0 3 TO PP14 too Rm ADO RRA too mm lKs Rm LOO AP4 310 AM 510 AN1, 710 AM, 910 AM 1100 AN$ 100 111M I Do prvi Too mm Too mm IDD mm I Ito PNm I 00 ATIO, 310 ArV 110 AN4, I" 00 AM lA0 AN$ 11,00 AM A-weighted sound leve� (dB, re; 201 pRa) 11�1 It IS, �j 9 1 "dox ,WW kJills Jii,fly ? 0, ?Cll � 7 PMe 7 d 9 6" A C E N T E C H APPENDIX - FIGURE 4 10:()0 AM 12: 00 PNI 2:00 PNA 4'00 PM fi�oo PM S,Qo PM 10,A)0 r%11 12 00 AM 2,00 ANA 4 00 AM 61,10 AM U10 Nlyl 1(.')':00 AM 12:01) PNI 2: CIO PM 4:00 PNA Gd) pm ?1 00 PNII I() QQ Plyl 12.00 AWl 2,00 AM d 00 AM 6 00 AM 1,101;1116 AM 121"If".1 Ppe 2 01.) PM U 4 CO PPA cj, 8:0(l Pflvl 3 00 AM 2:00 ANI m, 11:A(P APA 6:00 AM &00 ANA :LO III,) APO 12 � 00 PP-A 2 1"(7.1 PIN4 4; 00 PNA (S 0 0 P ki 800 PNi 1(): (.)0 0' ° " "'I 12 011D AM 2'C110 AM "1:0c) AM 6:�QQ AM 8:A0 AM 10:00 ANA 62 00 PM 2:00 PNI 4,00 PM 6:;Qo Ppo 8.00 PM 111 00 PNIl 12 00 ANA 7 00 ANA �l 010 AM 6°00 AM 8:Ul AM 10':00 AN11 kwnghted sound leve� i(dB re� 20 pPa) W d.. "r, 'Y' Op ll-' U U ID LD D ,, Our! x ,WW kJills Jii,fly ? 0 , ?� 11 n 7 IPage 8 of 9 6" A C E N T E C H ,, Our! x ,WW koilpls J iii,fl IW Y 0 , Y II A.. 7 APPENDIX - FIGURE 5 (PRELIMINARY OUTDOOR EQUIPMENT LOCATIONS) AGENDA ITEM SUMMARY LEXINGTON PLANNING BOARD AGENDA ITEM TITLE: 45-65 Hayden Ave - Potential Planned Development District PRESENTER: ITEM NUMBER: SUMMARY: This item is to discuss with the owners of 45-65 Hayden Avenue, King Street Properties, their proposal for up- zoning the site at this falls Special Town Meeting. SUGGESTED MOTION: There is no action anticipated for this item. FOLLOW-UP: Apublic hearing on this proposal is planned for September 13. Special Town Meeting is expected to take up this item on October 18. DATE AND APPROXIMATE TIME ON AGENDA: 8/16/2017 ATTACHMENTS: Description Type D DRAFITSDUP - 45-55-65 1 Layden Avenue Backup Material D DRAFITSDUP Reg Plans .45-55-65 1 Layden Ave Backup Material D DRAFITSDUP Non-Reg Plans .45-55-65 1 Layden Backup Material ARTICLE AMEND ZONING BYLAW 45,55 and 65 HAYDEN AVENUE, LEXINGTON, MA PROPOSED MOTION That the Zoning Map and Bylaw of the Town be amended to create the Preliminary Site Development and Use Plan ( "PSDUP ") for the Planned Development District PD -2 consisting of the land located at 45,55 and 65 Hayden Avenue, Lexington, MA (the "Site ") as described below: PLANNED DEVELOPMENT DISTRICT PD -2 FORMERLY KNOWN AS PLANNED COMMERCIAL DISTRICT CD -9 1. AUTHORITY TO ESTABLISH A PLANNED DEVELOPMENT DISTRICT. This Planned Development District is prepared under the provisions of Chapter 135 of the Code of the Town of Lexington (the "Town") as amended through annual Town Meeting 2016 (the "Zoning Bylaw "), § 7.3, Planned Development Districts, and Chapter 176 of the Code of the Town (the "Planning Board Zoning Regulations "), § 8.0, Planned Development Districts. 2. HISTORY AND DESCRIPTION OF DISTRICT. This Planned Development District consists of the Site, which is comprised of Lots 20B and 21A on Town Assessors Map 17, as depicted in the PSDUP. Redevelopment of the Site commenced in 1997 with the approval by Town Meeting of a Preliminary Site Development and Use Plan in the Fall of 1997 (the "Original PSDUP ") for which a Definitive Site Development and Use Plan ("Original DSDUP ") and Special Permit with Site Plan Review ( "Original Special Permit") were approved by the Town Zoning Board of Appeals ( "ZBA ") on January 5, 1998, and recorded with the Middlesex South Registry of Deeds (the "Registry ") at Book 28123, Page 254. To allow for the addition of the building and parking garage located at 65 Hayden Avenue, the Original PSDUP was subsequently amended by the Amended Preliminary Site Development and Use Plan approved by Town Meeting in the Fall of 2009 (the "2009 APSDUP "), for which a Definitive Site Development and Use Plan (the "2010 DSDUP ") and "Special Permit" were approved by the ZBA on June 3, 2010, recorded with the Registry at Book 54965, Page 45. The Special Permit was modified in 2012 for minor site changes, as recorded with the Registry at Book 27724 Page 170, and again in 2017 for parking and related improvements, as recorded with the Registry at Book 68484, Page 87. This PSDUP supersedes any and all prior site development and use plans and other special zoning for the Site, including the Original PSDUP, Original DSDUP, Original Special Permit, 2009 APSDUP, 2010 DSDUP and Special Permit, as modified; however, notwithstanding, the improvements shown on the Regulatory Plans (as hereinafter defined) shall be considered in conformance with all applicable zoning provisions. 3. ZONING BYLAW APPLICABILITY. 3.1 In the event of inconsistency or conflict between the text and Regulatory Plans of this PSDUP and other Zoning Bylaw provisions applicable to this Planned Development District, the text and Regulatory Plans of this PSDUP control. 3.2 Unless herein noted otherwise, where the text and Regulatory Plans of this PSDUP are silent with respect to any provision of the Zoning Bylaw applicable to this Planned Development District, the Zoning Bylaw shall control. Subsequent amendments to the 8975196 Zoning Bylaw shall not apply to this Planned Development District unless expressly stated otherwise. Terms used and not otherwise defined herein shall have the meanings as may be ascribed to them in the Zoning Bylaw. 4. PSDUP TO BE EFFECTIVE UPON TRANSFER. This PSDUP establishes the zoning for the PD -2 District, and any successors and assigns in interest in the Site are bound to the terms and conditions of this PSDUP. The land within this PD -2 District may be legally subdivided into separate parcels or lots, for example, for purposes of financing or conveying interests, but any successors shall be bound by the provisions and controls in this PSDUP, which shall remain in effect with respect to each such parcel or lot, unless amended by vote of Town Meeting. 5. PLANS AND DOCUMENTS. 5.1 Regulatory Material. In the event of conflict or inconsistency between the text of this PSDUP and the plans and documents incorporated by reference within it, the text of this PSDUP controls. The following plan set prepared by Highpoint Engineering, titled "Proposed Life Sciences Campus Expansion for the Planned Development District PD -2" and dated August 8, 2017 (the "Re ug latory Plans"), is incorporated within and made part of this PSDUP: Regulatory Plans C1 Title Sheet C2 Property Rights & Dimensional Standards Plan C3 Site Construction Plan C4 Landscape Planting Plan 5.2. Non - Regulatory Material. All parts of the PSDUP application previously submitted and not included in Section 5.1 above, if any, are considered explanations, background information, and justification for the rezoning, and do not supersede the text of this PSDUP or the Regulatory Plans. The complete PSDUP application is on file with the Planning Office. 6. PERMITTED USES. 6.1. Principal Uses. All of the following uses or any combination thereof are permitted in this Planned Development District, subject to, and consistent with, the dimensional and other standards provided in Sections 7 to 10 below: Institutional Uses (i) Child care center (ii) Park, playground Office Uses (i) Medical, dental, psychiatric office, but not a clinic (ii) Medical, dental, psychiatric office, but not a clinic, with related laboratory (iii) Business or professional office Personal, Business or General Service Uses (i) Medical clinic for outpatient services (ii) School not exempt by statute 8975196 (iii) Nonprofit community service center or charitable organization Manufacturing Uses (i) Light manufacturing (ii) Laboratory engaged in research, experimental and testing activities, which may include the development of mock -ups and prototypes (iii) Manufacturing in the fields of biotechnology, medical, pharmaceutical, physical, biological and behavioral sciences and technology, environmental science, toxicology, genetic engineering, comparative medicine, bioengineering, cell biology, human and animal nutrition including the production of equipment, apparatus, machines and devices for research, development, manufacturing and advance and practical application in any such field or area, and including, office, administrative and support facilities related to any of the foregoing activities; all uses shall comply with applicable federal, state and local laws, regulations and ordinances including, without limitation, laws, regulations and ordinances governing air pollution, water pollution control, noise and illumination Utilities, Communications and Transportation Uses (i) Radio, television studio, but without transmitting or receiving towers (ii) Wireless communication facility Temporary Uses (i) Temporary building or trailer incidental to the construction of the building or development (ii) Temporary structures and uses not otherwise permitted in the district, provided the Building Commissioner finds that the proposed structure or use is compatible with the neighborhood 6.2. Accessory Uses. All accessory uses or structures normally incidental to the principal uses or structures included in Section 6.1 above (which principal uses are also permitted as accessory uses), § 3.2.1 of the Zoning Bylaw, or the accessory uses in Section 6.2 hereunder, including, without limitation the following (which also include some new enumerated items): (i) Beauty parlor, barber shop (ii) Shoe repair (iii) Bank or credit union (iv) Automatic teller machine (v) (vi) (vii) (viii) (ix) (x) (xi) Travel agency, ticket agency Photocopying reproduction services bought on a daily basis such as food, candy, newspapers, etc. Convenience goods often Cafeterias, dining rooms, outdoor food trucks, conference rooms, function rooms, auditoriums, public meeting rooms, community space and recreational facilities Laundry or dry cleaning pickup station with processing done elsewhere; laundry or dry cleaning with processing on the premises, self - service laundromat or dry cleaning Parking, surface or in a garage or other structure Town - sponsored uses for the neighborhood and public such as outdoor uses for festivals, concerts, community and recreational events, farmers' and artists' markets, performances, presentations and other like uses and indoor uses for Town recreational and community use from time to time 7. DIMENSIONAL STANDARDS. 8975196 For this Planned Development District, the following dimensional standards apply: 8. PARCELS OR LOTS WITHIN THE PD -2 DISTRICT. The dimensional standards and other zoning provisions as prescribed herein shall remain in effect where the boundaries of this PD -2 District adjoin other zoning districts, while the standards and provisions that apply within, but not on the perimeter of the district shall be modified as set forth below. 1. In this PD -2 District, any single lot may exceed the maximum Dimensional Standards identified in Section 7 so long as all of the lots in the aggregate PD -2 District do not exceed the maximum Dimensional Standards. 2. Parking spaces existing within this PD -2 District as of the filing of this PSDUP which may be required for one lot may be located on a separate lot, which may be in separate ownership, notwithstanding any regulations or provisions to the contrary as may be stated in the Zoning Bylaw, so long as where such lot is not in the same ownership, a lease or easement guaranteeing long -term use of such spaces, and satisfactory in form to the Town Counsel, is executed and filed in the Middlesex South Registry of Deeds. 3. Driveways on one lot may lead to a parking space or loading bay on another lot, or straddle the lot line and serve a parking space or loading bay on two or more lots, notwithstanding any regulations or provisions to the contrary stated in the Zoning Bylaw, so long as where such lot is not in the same ownership, a binding agreement between the applicable property owners satisfactory in form to the Town Counsel, is executed and filed in the Middlesex South Registry of Deeds. 4. There shall be no required setback from the side and rear lot lines in the PD -2 District for the paved parts of parking spaces, driveways or maneuvering aisles, and these features may extend up to the side and rear lot lines, except that parking spaces along a lot line that 8975196 Required Provided Minimum Lot Area 5 acres 37.38 acres Minimum Lot Frontage 300 feet 2,089 feet Minimum Front Yard Setback 100 feet 123 feet Minimum Side Yard Setback 50 feet There shall be no side and � Y setback from any internal lot line within the PD -2 District) 152.3 feet Minimum Rear Yard Setback 50 feet 118.1 feet Minimum Site and Rear Yard Facing Residential District N/A N/A Maximum Site Coverage Ratio 25% 15.23% Maximum Floor Area Ratio 0.5 0.41 Maximum Building Height 98 feet 87.5 feet 8. PARCELS OR LOTS WITHIN THE PD -2 DISTRICT. The dimensional standards and other zoning provisions as prescribed herein shall remain in effect where the boundaries of this PD -2 District adjoin other zoning districts, while the standards and provisions that apply within, but not on the perimeter of the district shall be modified as set forth below. 1. In this PD -2 District, any single lot may exceed the maximum Dimensional Standards identified in Section 7 so long as all of the lots in the aggregate PD -2 District do not exceed the maximum Dimensional Standards. 2. Parking spaces existing within this PD -2 District as of the filing of this PSDUP which may be required for one lot may be located on a separate lot, which may be in separate ownership, notwithstanding any regulations or provisions to the contrary as may be stated in the Zoning Bylaw, so long as where such lot is not in the same ownership, a lease or easement guaranteeing long -term use of such spaces, and satisfactory in form to the Town Counsel, is executed and filed in the Middlesex South Registry of Deeds. 3. Driveways on one lot may lead to a parking space or loading bay on another lot, or straddle the lot line and serve a parking space or loading bay on two or more lots, notwithstanding any regulations or provisions to the contrary stated in the Zoning Bylaw, so long as where such lot is not in the same ownership, a binding agreement between the applicable property owners satisfactory in form to the Town Counsel, is executed and filed in the Middlesex South Registry of Deeds. 4. There shall be no required setback from the side and rear lot lines in the PD -2 District for the paved parts of parking spaces, driveways or maneuvering aisles, and these features may extend up to the side and rear lot lines, except that parking spaces along a lot line that 8975196 coincides with the perimeter of the district (as opposed to spaces along a lot line that is in the interior of the district) shall be required to comply with a ten foot setback from the lot line. 9. DEFINITIONS. The definitions within the Zoning Bylaw shall be applicable to the Site, with the following changes: 1. The following shall be added to the end of the definition of Net Floor Area: Alternatively, the calculation of Net Floor Area shall be 80% of the Gross Floor Area excluding the Gross Floor Area of garages and other structured parking. 2. The maximum height of buildings and structures shall be determined in accordance with the Zoning Bylaw, with the exception of the following: Structures erected on a building and not used for human occupancy, such as but not limited to air and exhaust equipment, chimneys, heating- ventilating or air- conditioning equipment, solar or photovoltaic panels, elevator housings, antennas, skylights, cupolas, spires, mechanical and acoustical screening and the like ( "rooftop structures "), may exceed the maximum height of a building in feet provided, except as otherwise stated below, no part of the rooftop structure(s) is more than twenty five (25) feet higher than the maximum permitted height of the building and the total horizontal coverage of such rooftop structures on the building does not exceed sixty (60) percent of the total roof area. Notwithstanding the foregoing: (a) an aggregate area not to exceed three (3) percent of the total roof area may contain rooftop structures that extend up to thirty five (35) feet above the roof line (these structures shall be included in the calculation of the horizontal coverage limit set forth above), and (b) none of the aforementioned rooftop structures may exceed 20' above the roof line on a parking garage structure. The [Town Planning Board] [NOTE: need to confirm this is now PB] may grant a special permit to exceed the maximum height in feet or the percentage of horizontal coverage of structures erected on a building allowed by Section 7 Dimensional Standards or these PSDUP provisions provided it makes a determination that the structure is compatible with the scale of the neighborhood and does not negatively impact the solar access of any adjoining lot. 10. OTHER ZONING PROVISIONS. 10.1. Landscaping, Transition and Screening. The Landscape Planting Plan, submitted as part of the Regulatory Plans, [supplements the previously approved landscaping plans for 45, 55 and 65 Hayden Avenue on file with the Planning Office in depicting the detailed landscaping for the Site.] [NOTE: We are looking into whether we can provide an updated landscaping plan that shows the whole site (including existing landscaping), which may be able to supersede all prior landscaping plans.] For this Planned Development District, the standards of § 5.3 of the Zoning Bylaw, Landscaping, Transition and Screening, shall not apply except for the following: 1. The objectives of § 5.3.1 apply. 2. The requirements of § 5.3.3 pertaining to the landscaping plan apply. 3. The provisions of § 5.3.11 Maintenance, and § 5.3.12, Landscaping, to be completed prior to issuance of certificate of occupancy, apply. 8975196 4. The provisions of § 5.3.13, Screening of Other Uses within the Lots, apply. 10.2. Traffic. This Planned Development District is subject to the Transportation Demand Management Plan and Memorandum of Understanding referenced in the Special Conditions below. The provisions of § 5.5 of the Zoning Bylaw, Traffic Standards, do not apply to this Planned Development District. 10.3. Off -Street Parking and Loading. For this Planned Development District, the standards of § 5.1 of the Zoning Bylaw, Off - street Parking and Loading, shall not apply except for the following: 1. The objectives of § 5.1.1 apply. 2. The provisions of § 5.1.3, Parking Plan; § 5.1.7, Preferential Rideshare Parking; § 5.1.8, Bicycle Parking Facilities; § 5.1.10 Driveways; § 5.1.12, Screening for Parking; and §5.1.14, Special Permit, shall apply. 3. Calculation of required off - street parking spaces and calculation of required loading bays in this Planned Development District shall be provided in compliance with § 5.1.4, § 5.1.5 and § 5.1.6, with the exception of the following requirements: 8975196 PARKING FACTOR TYPE OF USE (ihJn' iMuM nu nbef of par*ing , spaces ,to be pr6vided) , INSTITUTIONAL, EDUCATIONAL & RECREATIONAL USES College, technical school As Needed Day -care center, school age child care program, nursery school, kindergarten 1 per 500 s.f. Lodge, community service center As Needed Gymnasium, stadium, field house 1 per each 6 seats Parks, athletic fields, tennis and pool facilities, golf As Needed courses, recreation centers, other institutional uses OFFICE USES All permitted Office uses (except as otherwise 1 per 333 s.f. classified) Medical office, out - patient clinic 1 per 200 s.f. PERSONAL BUSINESS USE Personal services, bank, business services, retail 1 per 250 s.f. sales, and rental uses MANUFACTURING, RESEARCH USES Manufacturing, research laboratory 1 per 500 s.f. 8975196 Construction, storage, distribution and industrial 1 per 1,000 s.f. service users Total Lot Area All other permitted uses As needed 4. Shared Parking Spaces. Parking for all uses (both existing and proposed) within the PD -2 District shall be permitted to be located in common parking lots as of right subject to the recording of any necessary easements with the Middlesex South County Registry of Deeds. 5. Reserve Spaces. The developer may petition the [SPGA for a modification of Special Permit] that parking on the Site can be accommodated with a parking ratio which is less than the minimum as required above. [NOTE: need to confirm if SPGA is Planning Board and the ideal process.] As part of this petition, the Developer shall be required to identify the ability to fully construct the minimum number of required spaces per the ratios above, the legal right to use such spaces, and shall further identify those spaces being held in "reserve" for construction at a future date. Reserve Spaces may include future spaces to be constructed in a parking garage or surface parking. 10.4. Signs. This Planned Development District is subject to the Regulatory Plans submitted herewith and the previously submitted and approved plans on file with the Planning Office. For this Planned Development District, the standards of § 5.2 of the Zoning Bylaw, Signs, shall not apply except for the following: 1. The objectives of § 5.2.1 apply. 2. The General Regulations of § 5.2.4 apply. 3. The provisions of § 5.2.5, Prohibited Signs, apply. 4. The provisions of § 5.2.10, Special Permit, apply. 5. [NOTE: we will need to build in flexibility for another monument sign identifying the new building.] In addition, any wall sign, free standing sign or other legally permitted sign presently in existence on the Site as of the submission date of this PSDUP may be retained and relocated within the Site, so long as it is not enlarged unless permitted by the Zoning Bylaw. 10.5. Illumination. This Planned Development District is subject to the Regulatory Plans submitted herewith and the previously submitted and approved plans on file with the Planning Office. The provisions of § 5.4 of the Zoning Bylaw, Outdoor Lighting, apply. 11. TABLE OF DEVELOPMENT DATA. The following table describes what is currently on site and what is proposed to be added. The application for site plan review must substantially conform to the proposal described below. In the event of conflict or inconsistency between the Table of Development Data and the Regulatory Plans, the Regulatory Plans control. 8975196 Existing Proposed Total Lot Area 1,628,227 square feet 1,628,227 square feet Building Coverage 9.75% 15.73% Floor Area Ratio 0.254 0.41 8975196 Wetland Area 462,489 square feet [462,489 square feet] Developable Site Area 1,165,738 square feet [1,165,738 square feet] Gross Floor Area 370,225 square feet (occupied bdgs) 203,000 square feet (garages) 573,225 square feet (total) 596,669 square feet (occupied bdgs) 563,883 square feet (garages) 1,160,552 square feet (total) Net Floor Area 296,181 square feet 477,335 square feet Impervious Area 478,746 square feet 448,355 square feet Off - street Parking Areas 1,066 spaces 1,624 spaces Off - street Loading Docks 4 docks 7 docks 12. SPECIAL CONDITIONS. This Planned Development District is subject to the following special conditions: 12.1 Traffic Mitigation and Traffic Demand Management The developer of the Site shall, as a condition of receiving a certificate of occupancy for the building located at [75] Hayden Avenue, provide for the traffic mitigation and traffic demand management measures as described in the Transportation Demand Management Plan incorporated herein and attached hereto as Appendix . 12.2 Memorandum of Understanding Certain obligations related to further development of the Site are memorialized in a Memorandum of Understanding, dated October _, 2017, between the developer and the Town of Lexington through its Board of Selectmen ( "MOU "). The MOU is incorporated by reference herein and attached hereto as Appendix _. 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Ronchetti 2020 Vision Committee Voting Member Ms. Johnson Metropolitan Planning Organization Voting Member Mr. Canale Battle Road Scenic Byway Committee Voting Member Mr. Canale (Mr. Henry) Center Streetscape Liaison Ms. Corcoran - Ronchetti Net Zero Energy Task Force Liaison Mr. Creech Metropolitan Area Planning Council Voting Member Mr. Canale (Mr. Henry) IPlannhng Board p po ii IrJ brn IrJ L, Board /Committee Role Planning Board Designee MAGIC (MAPC Subregion) irneed a vote Voting Member Ill ir, III-Ieun!j Hanscom Area Towns Committee Voting Member Ms. Corcoran - Ronchetti Community Preservation Committee Voting Member Mr. Hornig Economic Development Advisory Committee Liaison Mr. Hornig Energy Conservation Committee Liaison Mr. Creech Transportation Advisory Committee Liaison Mr. Creech Bicycle Advisory Committee Liaison Mr. Canale Sustainable Lexington Committee Liaison Ms. Johnson Greenways Corridor Committee Liaison Ms. Johnson Lexington Center Committee Liaison Mr. Hornig Turning Mill NCD Voting Member Mr. Canale Lockwood — Bryon Road Voting Member Mr. Canale Design Advisory Committee Liaison Mr. Creech Comprehensive Plan Advisory Committee Liaisons (2) Mr. Canale /Ms. Johnson IPlaininhng Board lb Ir v ii In Board /Committee Role Planning Board Designee �„ �„ �„ �„ �„ �„ �„ �„ � „� „� „� „� „� „� „� „� „� „� „� „� „� „�,,. Tree Committee M s., Johnson, Historic Districts Commission Mr. Canale Historic Commission Mr. Canale Conservation Commission Ms. Johnson Zoning Board of Appeals FAI....I....Y: CAIVAI....E = 9 Cl.)R l.)RAN Rl. NC IF.:-M ®k CRF.:ECH = 4 I Il. RNIG ®k JOHNSON = 6 C: \Program Files ( x86 ) \neevia.com \docConverterPro\ temp \NVDC \79E199DO- 66D3- 48D7 -B5FE- 5 DE 180F94COC\ Lexington. 2889.1. PB_Cmte__ Liasons _List_(rev_2017- 08- 02).docx