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HomeMy WebLinkAbout1930-05-19-STM-MIN 376 in CD TOWN MEETING MAY 19 , 1930 The meeting was called to order by the Moderator , Robert H . Holt at 8 : 07 P . M . Art . 2 . Mr . Theodore A . Custance moved that article 2 be taken up . Under this article Mr . Robert P . Trask offered the following motion : " Voted : That the following amounts be appropriated for the following accounts for the ensuing year . Granolithic sidewalks 612000 . Forest Fires 1000 . Waltham Street Damages 199 . Street Signs 300 . Fire Department 2450 . Lowering Brooks 500 . Town Clerk 200 . Police Department 700 . Mr . George M . Ross , Chairman of the Appropriation Committee , reported that this committee approved the appropriations as offered by Mr . Trask . Art . 3 . Under this article , Dr . Clarence Shannon offered the following motion which was passed unanimously : " Voted : That the report of the Planning Board and Selectmen on the drainage and development of the Vine Brook Water Shed be accepted and placed on file . " Drainage of VINE BROOK WATERSHED in South Central Portion of Lexington Reports of the SELECTMEN AND PLANNING BOARD and copy of the Report of METCALF & EDDY , ENGINEERS . Report of the Planning Board. April 15 , 1930 . The Selectmen , Town Offices , Lexington , Mass . Gentlemen : Pursuant to vote of the adjourned Town Meeting of March 31 , 1930 , the Planning Board submits herewith copy of the principal part of the report of the Engineers , Messrs . Metcalf & Eddy , under date of September 29 , 1928 , upon the subject of drainage of the Vine Brook area . The copy lacks a reproduction of the plan giving the soundings taken throughout the drainage area because the data on • said plan is so small it would not reproduce satisfactorily . 377 Bound with the report is a copy of the plan prepared by A . A . Shurtleff of street layout to harmonize with the drainage channels . This street layout has already been changed somewhat and will be subject to further changes as the detail work of development proceeds , but it affords a good idea of the plan of through ways and principal connecting streets as they will eventually be built if present plans are carried out . Except as above , the copy of the Metcalf & Eddy report is complete . That report discusses present conditions ; outlines a system for draining the area south of Massachusetts Avenue to reclaim the present low and unusable portions thereof ; lays down a system of through highways to fit in with the proposed drainage channels ; gives plans for installing sewers to serve the territory and finally presents a careful analysis as a guide to the assessment of betterments upon the benefited areas . The drainage system suggested covers both the North Branch and South Branch areas , respectively at opposite sides of Waltham Street , also the trunk line section Which extends beneath Vine Brook Road , Massachusetts Avenue and the railroad . These areas aggregate some 900 acres . While the entire project could be carried out as a unit with large savings in cost , and while the entire plan, if executed as a single undertaking , would undoubtedly simplify the problem of assessment of betterments and would probably permit the Town to recover most of the cost , if not the entire cost of construction by assessment of betterments , the Planning Board feels that the entire project would involve so much money that the Town would hesitate to undertake it all at once . Furthermore , the entire project , if executed at once , would also possibly throw into the market more land for residential building than could be well digested in a period of time that would make it profitable . Therefore , the Planning Board feels that it would be wiser to undertake a part only of the work at this time , leaving the balance to be executed at a later date when the need therefor shall have become more immediately imperative .p The Town should , however , immediately make such layouts and takings as will make possible eventual accomplishment of the entire project . The trunk line section extending from a point just above Vine Brook Road to and under Massachusetts Avenue and the railroad to an outlet point some thousand feet below the railroad , being located almost in the heart of the business section of the Town, is the key to the entire situation . The capacity of this section must be increased in the immediate future to take care of the surface drainage from the center of the Town without considering the problem of conducting away the waters received from the areas beyond . This trunk section must be lowered some eight feet before the South Branch area above can be properly drained for building ; the North Branch area will require a lowering of not more than six and one- half feet . The Planning Board has felt that this trunk line section should be deepened and constructed by the Town as a Town project and at the expense of the Town ; its location in the very heart of the Town ; the fact that it drains the entire business center as well as the area surrounding the center ; the fact that the entire Town would benefit from this improvement just as the entire Town benefits from &ny improvement in the center of the Town; mad the complications that accompany any effort to assess better- ments in respect to that particular section of the brook would seem to make it more properly a Town proposition than one relating to bordering properties only . It would seem that every municipality is under obligation to maintain drainage structures , adequate for the normal growth of the a 2 7 S )0 p town . Furthermore , the Planning Board believes that the enhanced values of property throughout the center of the Town and the area drained eventually into this trunk section of the brook would in a comparatively few years return to the Town in taxes more than the reconstruction of this particular section would cost . The trouble with the General Betterment Act has been that the entire cost of any improvement must necessarily be assessed as betterments , - - it is not possible to divide the cost ; and these betterments can not be assessed until after the work is completed. If any error lb found to have occurred in method of assessment or in the apportionment among the properties especially benefited , the entire assessment can be thrown out and the cost of the completed work would then fall back upon the Town. In June last a new Betterment Act was passed, Acts of 1929 , Chapter 380 , evidently with the purpose of removing some of the objections to the earlier act . This recent act makes possible , among other things , the assessment of a part of the construction cost only instead of the whole cost , where the situation justifies , and provides aleo for outlining a plan and taking the matter before the court for approval or disapproval before any costs of construction are incurred . If the court approves , then the work may be carried out with comparative certainty that the betterments assessed according to the approved plan may be collected , and if , after the court has considered the proposed plan , it appears to the Town that the cost is likely to be heavier than it anticipated, the Town may abandon the entire project , reimbursing land owners for any expense they may have been put to in opposing the plan before the court . Apparently many of our citizens feel that any work of this sort should be constructed under a betterment Act , and if a majority of the Town Meeting members entertain that view , this new Betterment Act above referred to would appear to furnish the most desirable plan upon which to proceed , for it would not , like the earlier act , require the entire cost of the trunk section to be borne by the properties especially benefited along its line and and along the North and. South Branch areas , to the exclusion of the Town as a whole . Just what betterments would, under this act , be assessable along the trunk line cannot yet be stated at this time , but this new act would make possible the assessment of only so much of the entire cost as would appear to be just and fair . As the sentiment of the Town appears to have developed , it would seem to be wise to undertake at once not only the deepening and improvement of the trunk section, but , in addition, what is known as the South Branch section extending to Marrett Road . There can be no question but what the South Branch section should be constructed under one of the Betterment Acts . ROADS . We suggest that the roads be omitted from consideration at this time except that the Town should adopt a definite plan and make any necessary layouts , and takings where necessary , to assure that such roads as eventually may be built , shall be built in accordance with that approved layout . As such roads are found necessary , they may be built like other roads in newly developed areas in the Town, the cost of the same to be charged back against the abutting lands . This cost at the present time averages from $7 . 00 to $10 . 00 per lineal foot of road . In the present instance , some of the roads should be built to serve as through roads , to relieve Massachusetts Avenue and the center of the Town of as much traffic as possible . To that end such roads should be built as indicated on the Shurtleff plan, wider than would be necessary for purely local needs and , as a consequence , the Town, and possibly the State , should bear a proper part of the construction cost . SEWERS . Sewers also , so far as necessary to accommodate the areas under development , should be built under cur present act , and therefore form no necessary part of the present drainage problem except that such sewer as must extend from Vine Brook tio .ad to junction with the present sewer trunk line in the vicinity of Sheridan Street , estimated to cost 08 , 000 , must be built at the expense of the Town because the locality through which that section must extend is already served by and * has been assessed for the present sewer system . COSTS . Messrs . Metcalf & Eddy estimate the cost of the trunk line drainage section , extending from its outlet near the junction of Sheridan and. Grant otreets to Vine Brook Road , and including necessary engineering , at : $88 , 000 From Vine Brook Road to the new junction point a short distance beyond the proposed extension of Winthrop Road : 15 , 000 From the new junction point to Marrett Road : 17 , 000 A total of : $120 , 000 The cost from Vine Brook Road to the new junction point : $15 , 000 Thence to Marrett Road : 17 , 000 A total of : $32 , 000 • should in any event be assessed under the Betterment Act upon the land specially benefited . There are 166 acres of unusable land in the South Branch area . Deducting 20 acres for land which, when drained, may still be found unsuited for building , and good for parks only , leaves 146 acres of unusable lands to be reclaimed ; at 43 , 560 feet per acre , this would mean a total of 6 , 359 , 760 square feet . A betterment assessment of one -half cent per square foot upon this area alone-- $218 per acre - - would bring a total of $31 , 798 . 80 , or approximately the cost of the drainage channel from Vine Brook Road to Marrett Road . This does not take into account additional betterments that may be assessed upon higher lands , fronting upon the unusable areas and now inaccessible because of the same . It would seem, therefore , wise to take in the entire South Branch area with the initial construction of the trunk line under Massachusetts Avenue and the railroad. To make this possible , another meeting must be called, the warrant for which shall contain an article of broader scope than- Article 34 of the warrant for the present meeting . The Engineers , following a further examination, confirm the report originally made to the Planning Board, that for the present there will be no appreciable damage to the areas below Grant Street from such increased rate of flow as may result from the deepening of the brook throughout the trunk and South Branch sections under consideration; - 1 380 that such increase as may result will be accommodated by enlarging the culvert under Hayes Lane , which is included in the scheme already proposed, and by substitut- ing two culvert pipes each of about five feet in diameter for the single culvert under East Street now existing and cleaning the brooks , at an additional cost estimated by the engineers at something less than a thousand dollars . Later it may be found desirable to improve the lands below Grant Street as much as is now proposed for the North and South Branch areas; thereby to remove danger from increased flow from above Vine Brook Road as building in that locality proceeds , and at the same time render the lands south of Grant Street available for building just as the upper areas will be made available by the proposed drainage scheme . The engineers also report that in their opinion there will be little liability from damage claims arising from shifting the locations of brooks in the North and South Branch areas - - at most a relatively small liability . The matter of connecting necessary or desired laterals with the main drainage chamnels would appear to invlove no serious difficulty . she engineers advise that , in general , these laterals should be constructed by the property owners to drain their several properties into the main channels to whatever extent necessary to adapt the properties to desired uses . Most of the large individual properties in the South Branch area adjoin one or both sides of the proposed South Branch channel and can with little difficulty be drained thereinto . If it is desired to convert these properties into residential developments , laterals would probably be necessary, but in general such laterals should follow the streets laid out and approved by the Board of Survey for residential development ; they would ordinarily take the form of drains or pipes underlying the streets and would be constructed at the time the streets are constructed . Obviously it is impracticable to lay down those laterals in advance of the detail plans for residential development because the laying out of streets and lots necessarily constitute parts of a single problem- -neither should be Paid out independently or in advance of the other . There are some small properties in the South Branch area that will not be directly reached by the proposed main drainage channel but such properties can easily be accommodated , when necessary or desired , over the la : outs for some one or more of the projected streets . In the nature of the case many details must be left until the work is entered upon but we are convinced the project involves no insurmountable nor unduly expensive problems . The plan of betterment assessments suggested by Messrs . Metcalf & Eddy is probably more extensive than would be practicable for the Town to adopt ; but will be exceedingly helpful in estimating any betterment plan that may be proposed . By undertaking the work under consideration, the Planning Board feels that the Town will protect itsel against any undesirable development within this large . Rage and will invite and assure itself the kind of development that will be in every way to the best interest of the Town. Respectfully submitted, F . L . Emery , Chairman. 381 ( Insert map of Town of Lexington , Plan of Proposed Highways in South Central portion of Town . Arthur A . Shurtleff , 11 Beacon Street , Landscape Architect , Boston , Mass . , October 4 , 1926 . Revised to October 29 , 1926 . Revised to December 17 , 1926 . Revised to December 30 , 1926 . Revised to April 22 , 1927 . Revised to April 27 , 1927 . ) REPORTSOF THE SELECTMEN . THE MAJORITY REPORT . May 6 , 1930 . To the Town Meeting Members , Lexington , Massachusetts : The subject of drainage as it is related to the Vine Brook area now under consideration and which the Town Meeting mem !. ers will be asked to consider at a meeting May 19 , 1930 , has been discussed from many points of view . While it has been studied by a number of out townspeople , we ask that you study the enclosed report of Metcalf & Eddy , : Engineers , under date of September 29 , 1928 to the Planning Board, mad the report of the Planning Board to the Selectmen under date of April 15 , 1930 . While we as a Board have been giving a great deal of study to this project for a number of years , we have studied it more intensely in the last few plonths . The report of Metcalf & Eddy , Engineers , which is submitted herewith, shows us very cont lusiyely what must be done to make this drainage possible . she Planning Board has made an exhaustive study of this report and has made specific recommendations concerning its adoption. Your Selectmen have also made a careful study of the report of Metcalf & Eddy , have conferred with the Planning Board, have held several informal meetings with interested groups and made independent investigations , and we are of the opinion that the Town should adopt the plan as a whole and proceed at once with that part of the project which includes the trunk system and the south branch . While it is not possible to anticipate how rapidly this land will develop once it is drained , Winthrop Road is already being extended to Waltham Street by private enterprise , and it seems reasonable to expect that more streets will be laid out in the near future . Even if all the area is not immediately developed , its value is obviously greatly enhanced by changing it to a well drained piece of property in close proximity to the center of the. Town. It must be conceded that no amount of money spent on clearing the present channel of Vine Brook and rebuilding walls will be of any avail as long as that part of the trunk line section which runs under Massachusetts Avenue is eight feet higher than the point to which the water table must be lowered to make this land available for building purposes . In view of the fact that many citizens are of the opinion that this entire project should be authorized under the Betterment Act , aid since most of the property owners in the south branch area have expressed a willingness to agree to a reasonable betterment assessment , we now recommend this procedure in order that the Town may have immediate returns on its investment . We have secured definite estimates on this work by different contractors based on the specifications of the 382 C Town Engineer . These firms have had experience in this type of work , andwe are confident that a substantial saving can be made over the estimated submitted by the Engineers , so that it seems probable that the entire south branch area can be drained for only a little more than the amount estimated by them to construct the trunk line alone . This lay out is in line with the studies we have had of the proposed through highways that will be of great value to the Town. It seems wise to us to encourage the land owners to lay out and drain their property along the lines suggested so that when the Town is ready to take over the street , under the Betterment Act , it will not be necessary for any drainage to be done at that time . It should be remembered that the Board of Survey laid out a street from Massachusetts Avenue to Vine Brook Road in 1918 over Vine Brook . This matter has been held in abeyance until the drainage of Vine Brook has been done . This , when constructed , will form an entrance to that territory between Massachusetts Avenue and Marrett Road , and is an important link of highway which will later lead to Cambridge by way of Belmont . This is the only portion in which the Town will encounter damages of any consequence . In tbis section the Town will have to take 29 , 920 square feet of land and one house , and this should be done before the land becomes more valuable . We respectfully urge every Town Meeting Member to study with great care the entire report of Metcalf & Eddy and the recommendations of the Planning Board . We further urge a personal inspection of that portion of the drainage area that is easily accessible , so that the fullest possible knowledge may be obtained of this important improvement . Respectfully submitted, Theodore A . Custance Robert P . Trask Clarence Shannon Hallie C . Blake Selectmen. THE MINORITY REPORT My reasons for a minority report on Vine Brook drainage are as follows : I do not believe that the closed drain proposed from Vine Brook road to Sheridan Street will take care of the drainage in the area between these two streets . This is to be a tight cement pipe , and I cannot see any way for the ground water to enter . It will only take care of the street water thrcnksh catch basins . Also , no borings have been made so far to determine the nature of the soil through which this drain must pass . If it should be quicksand ( the same as encountered when the Cary Memori al , Bui l di ng was built and the sewers in Massachusetts Avenue constructed ) it will add very much to the cost of construction. I think this information should be in the hands of the voters before they are asked to vote on this project . So far as the South Branch is concerned , lowering the brook only will not take care of lowering the water table any great distance back from the brook itself . In order to accomplish this , laterals must be put in close enough to each other to take care of the water in the ground in the areas removed from the main brook . If these laterals are not provided and the water in these back areas taken care of , I do not think the Town can collect betterments on the areas not drained. No plans for these laterals have been presented , and no money 383 provided for their construction in the figures presented to the Town . In regard to the question of betterments , this drainage project , when carried out , benefits the owners of the area involved so that they receive a very distinct improvement . It seems to me that they should be willing to make a definite agreement with the Town as to what extent they are willing to stand betterment assessments , thus relieving the Town at some future time of probable litigation or the alternative of abating them . Respectfully yours , Albert H . Burnham Selectman . Copy of the REPORT of METCALF & EDDY Engineers . Table of Contents . Page . No . Letter of transmittal 14 Report Outline of Problem 17 Basis of Design . 18 Types of Channels 21 Soil Conditions 22 Sewerage 23 Drainage Projects Studied 24 Proposed Drainage Project . 25 Open Channels . 25 Portions of Channels to be covered 25 Old Lexington Reservoir 26 Soundings 26 Location of Channels 27 Area Tributary to Channels 27 Estimates of Cost of Proposed Drainage Project . . 28 Proposed Through Highways 29 Vine Brook Betterments 31 Drainage Benefits 31 Park Benefits 34 Through Highway Benefits 35 LIST OF TABLES . No . Page No . 1 Maximum Average Intensities of Rainfall at Chestnut Hill Arranged in Order of Magnitude Based on Records from 1879 to 1916 , inclusive 20 2 Computations of Design . . . Opposite 32 384 '1- wd 710 ►•1 11 LIST OF FIGURES Opposite Page No . 1 Rainfall and Runoff Curves for Use in Design of Drains for Vine Brook District 22 2 Map of Vine Brook Drainage District . . 25 3 Preliminary Development Map 28 4 Typical Sections of Open Channels . . . . 28 5 . Profile of Proposed Re .ocated North Branch Channel of Vine Brook 28 6 Profile of Proposed South Branch and Main Channels of Vine Brook 28 7 Map Showing Proposed Through Highways 30 8 Drainage Benefit Map 36 9 Park Benefit Map 36 10 Through Highway Benefit Map 36 LETTER OF TRANSMITTAL Town Planning Board Lexington , Mass . Gentlemen : We transmit herewith our report upon " Drainage of Vine Brook Watershed in South Central Portion of Lexington . " This report may be summarized as follows : The drainage area of Vine Brook south of Massachusetts Avenue , comprises about 900 acres much of which is close to the center of the Town and unsuitable for residences because of its low swampy nature . Considerable portions of these areas can be made available for residences by the construction of suitable drainage channels and conduits . Other portions have firm bottom so deep that it will be best to reserve them for use as parks or playgrounds , because foundations would be too expensive to warrant development into house lots . It is advisable for the Town to adopt a plan for the drainage and development of this district , in order to control the development and forestall difficult drainage and sewerage problems which would probably result from uncontrolled development . For the brook channels , it is economical to build portions of open earth channels and portions of closed masonry conduits and to so locate them th(-Yt they can be constructed in firm ground where deep foundations of piles or masonry will not be required. We have designed the main brook channels and conduits to care for the ran- off from a two-year frequency rainfall gage at the Chestnut Hill Reservoir of the Metropolitan Water Works . Occasionally , very heavy storms will occur , which will cause .Poore flooding of streets and cellars in the low areas . The soil in the swampy areas consists of a soft muck overlying sand, gravel , rock or clay . After the ground water level has been lowered in these areas by the construction of the proposed channels and conduits , a subsidence of the surface of a foot or more will take place because of decomposition and compression. This fact has been taken into consideration in our design of the drainage channels . Cesspools will be impracticable of operation in the swampy areas , because the soil will be very slow to drain. Therefore , sewers must be provided before development can be made in the low portions . A submain sewer can be built 385 to serve the North Branch district and discharge into an existing sewer near Waltham Street at the present brook culvert . Portions of the South Branch Districts are so low that a satisfactory sewer to serve the area cannot discharge into the existing main sewer near the junction of the present North and South Branches . It will , therefore , be necessary to build a new sewer substantially parallel to the existing main sewer from the junction of the existing North and South Branches to a location near Grant and Sheridan Streets where it will discharge into the existing main sewer . The proposed drainage project involves an open brook channel for the South Branch of Vine Brook following near the easterly border of the swamp from la point 700 to 800 ft . north of Marrett Road to the junction with the proposed channel for the North Branch. The channel of the North Branch will be relocated following the easterly and southerly shore of the swamp , thus diverting the flow from the present brook channel which is parallel to the park road west of Waltham Street . From the junction of the North and South Branches , . an open channel will extend north to a point near the southerly line of Massachusetts Avenue ; thence the channel will be a covered conduit to the end of the steep drop several hundred feet north of Sheridan Street with a relativdly short open channel to connect with the present brook channdl . If preferred , the covered conduit can be extended from Massachusetts Avenue to Vine Brook Road. The estimates of cost of the main drainage channels and conduits are as follows : North Branch 871 , 000 South Branch 17 , 000 Main channel from junction of North & South Branches to Massac-'usetts Avenue 30 , 000 Main channel east of Mass . Ave . 67 , 000 Total $185 , 000 The estimated cost of the through highways required to provided access to the areas within the district is $241 , 000 . This estimate is based a upon gravel surfaced p roadway 24 ft . wide . When permanent paved surfaces are required for these highways , an additional expenditure of about $163 , 000 will be required . We have studied the problem of assessment of betterments upon the areas within the district , to cover the cost of drainage and through highways . We recommend that the cost of constructing the drainage channels and conduits be assessed uniformly upon the drainage area for the reasons given in the report . We recommend that the cost of through highways be assessed in accordance with the principles described in the report and illustrated by the through highway benefit map ( No . 10 , opposite page 36 . ) . The construction of the drainage channels and conduits will make possible the development into parks or playgrounds of considerable areas which will not be suitable for residences . Certain adjacent areas will be benefitted by these parks , and we recommend that such areas be assessed the cost of the construction of main drainage channels which would otherwise be assessable to the park ares . We recommend that these assessments be made in accordance with the principles described in the report and illustrated by the park benefit map ( No . 9 , opposite page 36 ) . We have worked out assessment units for the three different types of benefits . It is probable that some modification will be made in the relative assessments , but we bqlieve the principles upon which the proposed assessments have been based are sound and equitable . For the park and highway benefits , the district should probably be divided into smaller zones so as to make smaller differences in the benefit ratios . Such a method would involve a large amount of work Which does not appear to us to be justified at this time . 386 geNOC By the methods which we have used , the maximum assessment on any given area for the drainage , through highway andpark benefits combined would be .*0 . 03137 per sq . ft . The share of the cost of the improvements to be borne by the Town would be $52 , 900 . The proposed drainage project can be carried out in sections in accordance with any financial program which the Town may see fit to adopt . Considerable saving in expense can-be realized if the drainage channels , sewers and through highways for contiguous portions of the project are constructed under one contract . Out estimates have been based upon such a program . Before any portion of the construction work is undertaken , plans and specifications will have to be prepared . Very truly yours , METCALF & EFFY By Almon L . Fales REPORT . Sept : 29 , 1928 . Town Planning Board Lexington , Mass . Gentlemen : As authorized by the Lexington Board of Selectmen, we have completed out studies for the drainage of the Vine Brook watershed in the south central portion of Lexington and present the following report thereon. OUTLINE OF PROBLEM The drainage area of Vine Brook south of Massachusetts Avenue comprisea bout 900 acres , including extensive . areas of nearly level swamp lands which are subject to flooding during rainy seasons and are for the most part unstitable even for agricultural purposes . Portions of the high sloping firm land surrounding the swamp areas , particularly those adjacent to the swamps , are inaccessible for dwellings and are available only for agricultural uses . A preliminary investigation indicated that it would be feasible to carry off the storm water and to lower the ground water level in the low areas sufficiently to permit of their development for residential purposes , by the construction of channels for the main brook and the north and south branches beginning near Sheridan Street where there is a rapid fall in the brook of several feet . The greater part of the swamp lands and inaccessible higher areas adjacent thereto is situated within one mile of the center of Lexington , and practically all of the available swamp areas had already peen developed with streets and residences . The recent rapid growth of the towns of Arlington and Belmont as well as some developments in Lexington , indicate that the demand for land for residential purposes in Lexington will be far greater in the near future than it has been in the past . There has already been considerable development of the higher lands of the district and some lateral drains have been constructed which convey the runoff from 387 the streets to ditches of brooks . Some lots south of Massachusetts Avenue and cellars along Vine Brook Road have been subject to flooding . With continued • development of the higher lands of the district , more frequent and more widespread flooding will occur unless adequate main channels and conduits are provided for Vine Brook and its branches . If the large areas of swamp lands and inaccessible higher lands in the Vine Brook watershed remain un- improved and uncontrolled by the Town, it is probable that a low grade of development will start in these areas and that serious sewerage and drainage problems will arise in the future . It is advisable to adopt a plan for drainage and improvement of these lands whereby those portions which can be made economically suitable for a good class of residences will be so developed and those which are suitable only for parks will not be encroached upon. The Town Engineer has furnished us with maps of the Vine Brook district and with other available information bearing on the problem of drainage including the Report on Lowering Brooks by McClintock and Woodfall in 1913 . W e have supplemented the data furnished us by some check surveys and by many rod soundings in the swampy areas . We have consulted with Mr . Shurtleff in regard to locations for the required brook channels slid he has furnished us with plans of proposed highway layouts ; Our Mr . Raymond has attended several conferences of your Planning Board and one conference of your Board with the Selectmen . Our report deals with the basis of design o'D` the brook channels , types of channels , soil conditions , drainage plans considered and recommended plan of drainage with estimates of cost . At the request of your Chairman , we have also estimated the cost of proposed main highways through the drainage district and have suggested a method of assessing betterments . BASIS OF DESIGN . Under existing conditions , high flows in Vine Brook ordinarily occur during the spring . However , considerable areas of land are subject to flooding from any long- continued heavy rain . The higher rates of runoff through the brook channels under present conditions are much less than will occur when the drainage area has become developed with paved streets and the lots have been built upon . Further- more , the building of streets with catch basins and drains will cause the runoff to pass into the channels rapidly , thus resulting in a higher maximum rate of discharge . The problem of determining the carrying capacity which should be provided in the design of channels to convey the runoff resulting from storms is not a simple matter of computation . It involves the determination of the tributary area and the slope available for the channel , an estimate of the probable future character of development , a study of the intensity , duration and frequency of rainfalls which are to be expected and a consideration of the relative benefits which would be derived from the construction of channels having different capacities . On rare occasions , very severe and intense storms occur which produce rates of run- off so high that it is uneco- nomical to build channels large enough to prevent flooding at such times . After the districts have been developed, some portions will be subject to more frequent flooding than others . If covered channels were used throughout for the main drains , a more liberal capacity would be required than if open channels were used, because an increased depth of flow in the open channels would result in a greater discharge capacity , whereas no material increase in capacity would be obtained from sur- charging of long covered channels . 388 e . ow It is our judgment that if open channels be provided for the main brook andthe principal branches , and about 3 ft . of freeboard allowed between the water surface and the tops of the banks of the channel , provision should be made for a rainfall rate which may be expected to be equalled or exceeded about once in two years on the average . We have examined the records of the rain gage at the Chestnut Hill pumping station of the Metropolitan Water Works as published in the Journal of the Boston Society of Civil Engineers , 1920 , Vol 7 , p . 47 , and have constructed a curve which represents those fre - quencies of rainfall which may be expected to be equalled or exceeded once in two years on the average . Table 1 shows the intensities of precipitation in inches depth per hour , the order of magnitude , the frequency and the duration in minutes for the records from 1879 to 1916 , inclusive . ( Insert Table 1 , Maximum Average Intensities of Rainfall at Chestnut Hill Arranged in Order of Magnitude based on Records from 1879 to 1916 , inclusive . ) The proportion of the rainfall which runs off immediately and during a storm depends upon the character of the sub- soil , the slope of the ground surface and. its condition , that is , whether of sandy or clayey nature and whether covered with vegetation , buildings , pavement or sidewalks . The soil of the greater part of the district is of a sandy nature . The slopes of the land adjacent and surrounding the swamps are rather steep . It is expected that the development will result in relatively large lots , and that considerable areas of the swamp lands impracticable of development for residential purposes will be used for parks or playgrounds , so that the district as a whole will have a fairly low percentage of total impervious area . Consequently , drains of less capacity will sufficethan would be required were the soil of a clayey nature and the percentage of total impervious area high as is found in the centers of large cities . We have estimated that the average proportion of impervious surface in the whole area will be about 25 per cent . The diagram , Fig . 1 , shows the two- year rainfall curve together with the runoff curve used as the basis of design for determining the required capacity of channels . CInsert Figure 1 . Lexington , Mass . Rainfall and Run-Off Curves for use in Design of Drains for Vine Brook District . August 9 , 1928 . Metcalf & Eddy , Engineers , Boston , Mass . ) TYPES OF CHANNELS To make the low areas suitable for developments for residences and parks will /inquire main drainage channels in which the water surface will be well below the adjacent ground sufface most of the time to insure a low ground water level and with sufficient capacity to prevent frequent flooding of streets and yards during heavy rains . Two types of ppen channels have been considered , -- one with masonry walls on timber foundation , for use where it w .. s contemplatedto locate the brook channel across swampy areas where a hard bottom is at considerable depth below the swamp surface , and the other a channel without masonry or timber foundation to be constructed in firm soil , with slopinf2. side surfaces which can be grassed and thus present an appearance in harmony with attractive main thoroughfares bordered by planted strips . Such a channel can he used effectively with double -barreled highways , the brook channel to be located between the two highway lanes . Covered masonry channels or conduits throughout have been considered in one project studied, and in another project covered channels for the upper ends of both the north and south branches of Vine Brook and that portion of the main channel north of Massachusetts Avenue with 389 open earth channels for the remainder , except where the channels will cross under Waltham Street and Vine Brook Road . Flat concrete arch construction has been figured on for these crossings . In determining the required size of channels , we have computed the velocity by the Chezy formula , usin: the Kutter formula for determining the value of C , taking as 0 . 025 for open channels and 0 . 013 for covered channels upon the assumption that the covered channels will be of concrete with smooth interior surfaces . The open channels have been designed with side slopes of 1 vertical on 3 horizontal below the level of the proposed water surface for the run- off from a rainfall of two -year frequency with slopes of 1 vertical to 1 horizontal above that level . SOIL CONDITIONS Much of the present low areas along both the north and south branches will have the water level lowered several feet after the drainage ixn ).rovements have been made . The soil consists of a b]. ack peaty muck for the most part overlying sand , . gravel or rock . When the wat3r level is lowered in these areas , a considerable subsidence of the soil will result , over a period of years , as the muck contains considerable amounts of organic matter which , when exposed to the atmosphere by the lowering of the water level , will shrink due to dec - imposition and compression . In many places , it may be expected that a subsidence of as much as a foot may occur because of shrinkage . In pli ces a greater amount of subsidence will take place if the surface is covered with filling material for grading lots and streets . In view of the probability that considerable areas will be subject to subsidence and to provide a somewhat gretter capacity for excessive storms , we have designed the open channels with the water surface for the runoff from a two -year frequency rainfall at about 3 ft . below the present general swamp level . In considering the soli_ conditions of the swamp areas , reference perhaps should be made to the type of construction required for satisfactory permanent highways across locations where the soil consists of muck . Ex - perience has demonstrated that a satisfactory highly cannot be constructed upon such soil and that it is usually necessary to remove the muck to practically firm bottom and substitute a fill of good material upon which to build the hi ;hway . There is an example in Lexington where the nark road follows along the north branch of Vine Brook between Waltham Street and the p1aypround where at some locations it has been necessary to add filling materials because of subsidence . Since the ground water level in many places will be only 5 or 6 ft . or pe rHaps less below the surface and as the muck is naturally very slow to drain , it will be practically impossible to provide sewerage facilities in the low areas by means of cesspools , and therefore , sewers will be required before any considerable develo )meat of such low areas can take place . SEWERAGE A sub-main sewer can be cons tr 1c ted , to serve the North Branch District , from the existing sewer at Waltham Street near the present brook culvert , thence across low land west of Waltham Street to a location near the proposed open channel and thence southwesterly along, and substantially parallel with , the proposed brook channel . The existing sewer near the present junction of the north and south branches of Vine Brook is too high to receive the sewerage flow from a sewer which will be low enough to serve the South Branch District . The most economical means of providing an outlet for the sewerage of the South Branch District appears to be the construction of a sewer in the same trench with the covered conduit and open channel for Vine Brook north of Vine Brook Road to a point near Grant and Sheridan Streets where such a sewer 7 . 9 900 can discharge its flow into the existing main sewer . If a sewer is provided as described above , 731.7 a sub -main sewer can be constructed to serve the South Branch District from near Vine Brook Road along the proposed channel to Marrett Road . If the above sewers are cons tr!icted at the same time as the main gook channels and. conduits , a considerable saving in cost can be realized . Our estimates of cost of these sewers so constructed are as follows : North Branch District sib -main sewer $16 , 000 South Branch District sub-main sewer 12 , 000 Sewer from junction of present North and South Branches of Vine Brook to point near Grant add Sheridan Streets 8, 000 Total $36 , 000 . If these sewers are not included in the contracts with the corresponding portions of the main brook channels and conduits but are constructed independently , their cost will probably be much greater , perhaps two or even three times the above estimates . DRAINAGE PROJECTS STUDIED . Consideration has been given to several plans for the principal drainage channels . A preliminary study was made with the pr fled channels substantially in the location of the existing brook channels . These extend through portions of the swamp areas where the muck is of considerable depth . A brook channel in such a location would be quite expensive , requiring pile foundations and to he permanent should probably be constructed of masonry , at least those portions which would lie abo e the ground water level . Such a channel would not harmonize With the plan for parks and boulevards which your Board has in mind . Consequently final estimates for this project we ~' e not prepared . A plan of devel op,:;ent consisting of a single roadway boulevard with the brook channel enclosed in a covered masonry conduit located beneath the roadway was studied . Such a project woul ' ref-Nine less arna of land for the main h ghways and brook channels and probably would result in some saving in the cost of highways when compared with the double - barreled highway scheme . The cost of the brook chan : el itself, however , woad be quite expensive even if constructed in firm ground . Furthermore , such a channel would have no excess capacity above the desiin capacity , for the runoff from storms greater than that estimated for a two -year frequency storm, and more objectionable flooding would result than with an open channel . At the suggestion of Mr . Shurtleff , a study was made of open channels constricted in firm ground along the edges of the swamp . This plan wou1 .3 permit o {' economical construction of double -barreled highways for the main throughfares with an open brook channel between the two traffic lanes in accordance with the plan of development which your Board ' contemplates . Our studies indicate that open channels for the most part , but with certain portions covered , will be the best plan to adopt . PROPOSED DRAINAG PROJECT . The l ayo at of the proposed drainage project is shown in Fig . 2 . The computations o f design are given in Table 2 in the Ap u endix . :tee pg . 434 . ( Insert Fig . 2 , Lexington , Mass . , Map of Vine Brook Drainage District . , Nov . 15, 1927 . ) It is proposed to provide brook channel crossings under existing hi7hways , by means of concrete masonry arches . Open Channels . The open type of channel can be used advantageously south of the southerly line of Massa- ehus etts Avenue , since the ground surface is flat and a reasonably shallow channel will suffice . North of Massachusetts Avenue its use would result in so deep and wide a ditch that it would be very expensive and undesirable 391 excepting just northeast of Sheridan Street where a relatively short open channel can be built , to connect with the existing brook channel . The open channels , excepting; that portion just northeast of. Sheridan Street , have been designed with sir, e slopes of 1 vertical on 3 horizontal for the portions of the slopes beneath the water surface and with slopes of 1 vertical to 1 horizontal above the water surface . The open channel just northeast of Sheridan Street has been designed with side slopes of 1 on 1 . The depth of water will vary from 2 to 3 ft . when carrying the runoff to be expected firm the rainfall of two -year frequency after development to the extent assumed . Some of the typical earth ch Innels used as the basis of our estimates are s own in Fir . 4 . Portions of Channels to be Covered . Near the northerly end of the olr1 race track , which is located between the old Lexington reservoir. and Lincoln Street , the present brook bed of the North Branch of Vine Brook falls about 8 ft . in a distance of about 800 ft . By making use of this steep drop , a covered channel can be built through the old race track location at an elevation low enough to permit of the development of nearly all the ar a within the race track with only a nominal amount of filling . A shallow open channel could be built through this location at a saving of about $15 , 000 but there would be about 6 acres on swamp which would be unsuitable for residences unless filled extensively . Therefore a covered channel is proposed for the North Branch of Vine Brook upstream of the location of the steep drop . This will be a circular conduit 42 and 48 in . in diameter . Along the main channel between Sherman Street and Hayes Lane , the bed of the brook falls about 13 ft . in about 700 ft . By making use of this steep drop , a relatively steep covered channel can be built from near the southerly line of Massachusetts Avenue to near the northerly terminus of the steep portion of the brook and considerable economy effected by the construction of a conduit of moderate size which will be suitable to carry the flood flows of the area after development . This conduit will be 75 in . in diameter . Old Lexington Reservoir . In our preliminary studies which have been discussed in considerable detail in conferences with your Board , it was assumed that that ccrtion of the area of the North Branch District tributary to the old water works reservoir near Marrett Road wo>> ld continue to remain so . Thus it wts permissible to design the brook channel leading from the reservoir , of somewhi t smaller capacity than would be reouire d were the reservoir not used. Such use of the reservoir would probably result in muddy water much of the time , and a rather rapid filling up of the bottom by the deposition oP material brought in by the storm water . After cons iderint' this matter , your Board directed us to cesi ; gin the channels upon the assumption that the storm flows would not discharge into the reservoir . We have , therefo ^e , prepared our designs and estimates herein upon the latter assumption . This requ res somewhat larger sizes f - r both the open and covered channels than were used in preparin the estimates given in our letter of October 21 , 1927 . Soundings . Many bar soundings have been made to determine a location where it would be feasible to construct open channels in firm ground . The locations together with the data Indicating the material and depth are shown upon the map accompanying thiwreport . The figures on the map indicate the depth , etc ; for example , 151 indicates that a sounding 5 ft . was made 15 ft . deep and material was soft at that depth . Similarly Sd indicates sand, H indicates hard , R indicates rock , etc . Where there are figures above and below the line , such as ( 205 . 5 ) the figure above the line indicates the elevation ( 6 ' Hd . ) of the surface of the ground and that below the line the depth of the sounding . The soundings indicate that there are considerable 292 areas where suitable hard bottom is at such a depth that it will be expensive to build houses , streets , sewers and gas and water mains , as they would require deep foundations . Such areas probably will be sufficiently improved by the general lowering of the ground water level so that with a moderate amount of fillintr they may be used for park or playground purposes . The development plan accompanying this report indicates such areas . Location of Channels . The proposed project involves an open brook channel for the South Branch of Vine Brook following near the easterly border of the swamp from a point 700 to 800 ft . north of Marrett Road to the ,junction with a proposed channel for the North Branch . The channel of the North Branch will be relocated following the easterly and southerly shore of the swamp , thus div e cling the flow from the present brook channel which is parallel to the Park Road west of Waltham Street . This will rc_sult in a very small flow in the present channel and it may become advisable to provide a closed conduit in this location to serve the needs of local drainage . From the junction of the north and south branches an open channel will extend northerly to a poitt near the so ztherly line of Massachusetts Avenue ; thence the channel will be a covered conduit to the end of the steep drop several hundred feet north of Sherman Street with a relatively short open channel to connect with the present brook channel . If preferred, the covered conduit can be extended fram Massachusetts Avenue to Vine Brook Road . Profiles of the proposed north and south branch channels and the main channel are shown in Figs . 5 and 6 , respectively . Sete Pg . 404 ( Insert Fig . 3 , Preliminary Development Map ; Fig . 4 , Main Channel North of Sheridan St . , Fig . 5 , Proposed Relocated North Branch Channel of Vine Brook ; Fig . 6 . Profile of Proposed South Branch and Main Channels of Vine Brook . ) Areas Tributary to Channels . In Fig . 2 are shown the approximate limits of the drainer e area the existing streets and brook channels and those areas which will require drainage before they can be developed . The total area of the district tributary to the main channel ( south of Massachusetts Avenue ) will be about 984 acres . This area may be subdivided as follows : Area tributary to proposed North 3ranch. channel about 455 acres Area tributary to proposed South Branch channel about 240 acres Area tributary to main channel between the junction of the proposed North and South Branches and Massachusetts Avenue about 206 acres Area tributary to main channel north of Massachusetts . Avenue about 83 acres The total area requiring drainage before development is about 312 acres . After the proposed plan shall have been completed including roadways , there will he approximately 185 acres of low land or at present inaccessible lands which will become suitable for dwellings . There will remain aboug 215 acres of low land unsuitable for dwellings and all of this except the portion required for the brook channels and highways will be reservations or parks . Fig . 3 is a preliminary development map showing the general arrangment of the proposed brook channels , highways and parks and the existing aljacent streets . ESTIMATES OF COST OF PROPOSED DRAINAGE PROJECT . It is estimated that the construction of the proposed main drainaf;e channels will cost about $185 , 000 . The detailed estimates are appended to this report . A summary is given in the following tabulation : 393 Summary of. Estimated Costs of Main Draina : e Channels for Vine Brook . North Branch $54 , 080 Allowance for rock - 10% 5 , 408 $59 , 488 Engineering & Contingencies , 201 11 , 897 Total S71 , 385 . South Branch $11 , 405 Allowance for rock - 20% 2, 281 $13 , 686 Engineering & Contingencies , 20% 2 , 737 Total $16 , 423 Main Channel from Junction of North and South Branches to Massachusetts Avenue . $22 , 435 Allowance for rock - 10% 2 , 244 $24 , 679 Engineering & Contingencies , 20% , 4 , 936 Total $29 , 615 Main Channel East of Massa - chusetts Avenue $46 , 685 Allowance for rock - 20% 9 , 337 $56 , 022 Engineering & Contingencies , 20%, 11 , 204 Total $670226 Grand Total . $184 , 649 The above estimates do not include allowances for future road crossings of the open channels but do include allowances for the crossings at Waltham Street and Vine Brook Road . The following unit prices have been used in preparing these estimates of cost and are believed to be sufficient to co ‘ er the cost of all work . Clearing location , one - third of area $100 per acre Excavation for open than ' els in- cluding disposal of and spreading on swamp and low ground 65 ¢ per cu . yd . Loaming , grassing and seeding channel slopes ( assuming loam on site 500 per sq . yd . Excavation for arches at Waltham Street and Vine Brook Road $2 . 50 per cu . yd. Concrete in arches 30 . 00 per cu . yd . The covered conduits have been estimated upon the assumption that they will be constructed of pre - cast re - inforced concrete pipe . The unit prices for different sections of these conduits will be found in the detailed estimates . PROPOSED THROU ^H HIGHWAYS In order to make accessible those areas which will became available through drainage and to provide connecting links through the district with existing and contemplated trunk highways , it will be necessary to construct about 42 miles of thrauc:h highways . Such highways are indicated on Fig. 7 . This arrange - ment will provide a hieThway from Massachusetts Avenue near Grant Street to Marrett Road at a location where it will be feasible in the future to extend it southerly to the Beaver Brock Parkway . A connecting link will be provided from Massachusetts Avenue near its junction with Lincoln Street cq4 00 Os to the above mentioned location at Marrett Road . The point where the through highway will meet Massachusetts Avenue is such that it may be extended in the future to Bedford Street some distance north of Lexington Green . A through highway is provided from a po -i :A a short distance southwest of Vine Brook Road ; thence westerly parallel with the existing North Branch of Vine Brook to Muzzey Street ; thence southwesterly along Muzzey Street if extended, to a proposed double barreled highway along the proposed relocated North Branch open chann el ; thence northwesterly and south- westerly curving throu : h proposed park lands and westerly throu -rh lands proposed to he developed as residences and now occupied by the old race track to Marrett Road . It is estimated that about 4 miles of these through hi P,hways will be constructed upon firm ground and about a mile across soft ground . We have made estimates of cost of the construction work required to provide roadways 24 ft . wide with . ravelled surfaces . A minimum of about 4 culvert eros s in :s of the proposed open brook channels will be required by the construction of the throu .:rh highways . We have estimated that these culverts will be of the flat arch masonry type . The estimates cost of the throupth hi . rhways are as follows : 4 miles of hi rhw Sys in firm ;-:round at $ 34 , 000 S136 , 000 2 mile higiway in soft ground at 96 , 000 48 , 000 Contingencies and engineering - 15% 28 , 000 Total cost of throu �'h hi;rhways , exclusive of cilverts , land & pavement . $212 , 000 4 arch culverts at 86 , 000 $24 , 000 Contingencies & engineering - 20% ___54000 29 , 000 Total cost of throufm highways excluding land and pavement . $241 , 000 . If a bituminous macadam pavement is provided for the throuh highways , it is estimated that the additional cost would be about $ 163, 000 . Such pave - ments for the throui7h highways can probably be post - poned for some years and their cost need not be in- cluded in the present program of assessments . In the event that the throu :h highwa between Massachusetts Avenue near Grant Street and Mar2ett Road is extended to the Lexin - ton - Belmont line , its cost , exclusive of land and ' avement , will Le about ($110 , 000 . Such an extension obviously is not a part of the proposed improvement of the Vine Brook district . The following unit prices have been used in the estimates of cost of through highways : Excavation for roadway in firm ground 50j per cu . yd . Excavation for ro _ic3way in soft ground 65 $' per cu . yd . Gravel fill for roadways hailed from open charnel excavations 25 $' per cu . yd . Rolling road surfaces $2 . 00 per lin . ft . Bituminous madadam pavement . . 2per 2 5 sq . yd . See Pg . 404 ( Insert Fig . 7 . Proposed Through Highways ) VINE BROOK BETTERMENTS . The improvement of the Vine Brook district eon- templated by your Board will probably be carried out under authority of Chanter 263 of the Acts of 1926 . Section 4 of this act states that -:assessments for the improvement shall be made acc nrdin -r; to Chapter 30 of the General Laws . Under Chapter 30 , assessments may be made by either frontage or area , or both , but no assessment an exceed the amount o f the benefit ; thus the problem is to ap oortion the assessments in ac - cordance with the benefit to each individual parcel of land . Drain, age Benefits The entire area within the drainagelimit , as shown on the map , develop- ment p , will receive a certain amount of benefit fran the construction of the main drainage channels 3 9 5 and ccn_ duits . The character of the benefit differs materially for areas in different locations . These areas may be sub-divided into several classes , as follows : Class 1 areas which will receive cam I ete benefit from the construotion of the main drainage channels and conduits . This class consists of such areas as are located adjacent to the cc'hanne1s or conduits with their ground surfaces at such elevation that they will not be subject to inconvenience from occasional flooding , and because of their elevation and proximity to the main drains , will not rev ire systems of lateral drains . Class 2 areas which will have nearly complete benefit from the constriction of main drainage channels and conduits . Thi. s class consists of areas located adjacent to the channels and conduits , so that they will not require systems of lateral drains , but with their surface elevation such that the streets will be s .ib j ect to occasional flo ding and probably some inconvenience will be experienced from water entering cellars . Class 3 areas which will have partial benefit , consisting of areas located one half block or more away frum the main drainage channels and conduits , thus requiring systems o f lateral drainage , and with their surface elevations such that they will be subject to occasional flooding of streets and the possibility of water entering cellars , but to a less extent than in the case of Class 2 areas . Class 4 areas which will have partial benefit , • consisting of those areas which will require or are now provided with lateral draina :e systems , but will not : e subject to any material inconvenience from floodi n ; . Class 1 areas consist of small , widely separated sections , but for the most part adjacent to areas in Classes 2 and 3 . While Class 1 areas will not be subject to flooding , because of the proximity to areas of Classes 2 and 3 and the inconvenience caused by flooding of neighboring highways , the increase in market value of lots in Class 1 areas will probably be no ,treater than in the case of Classes 2 and 3 . We have included in Class 1 certain areas which are adjacent to the existing open brook channel east of Massachusetts Avenue , where , under present conditions , little , if any , floodin r is experien ed , but incon - venience results from the maintenance of foot and driveway bridges across the brook channel to private yards . In this location , it is proposed to construct a closed conduit which will permit the abandonment of bridles and the utilization , for yard and driveway purposes , of the areas now occupied by the brook channel . Class 2 areas being adjacent to the main channels will not require lateral drains , but the frequency and duration of flood periods will he greater than will be experienced by Class 3 areas , which will reuire lateral drainage . Class 4 arras will be the most desirable for residences becaase of elevation and general freedom from flooding . Also , a considerable proportion , say 25% or more , can be developed with streets and houses before lateral and main drainage systems are required , whereas scarcely any development can 1) e made of Class 3 areas before the installation of lateral and main drainage systems . Probably the highest class of development within the district will take place in the Class 4 areas . In view of certain developments within the town of Lexington, and one which has already taken place within the Vine Brook district ( Highland Avenue ) , lateral drainage in the form of underground conduits to convey storm water from street surfaces , sidewalks and yards , and to prevent flooding of cellars and small (? epressions , will eventually ' .e required for the Class 4 areas . The development of the district with paved streets , graded lots , and houses will result in a larger proportion of the rainfall running off and a lerjs er pro 'portion entering roe e soit and being absorbed or evaporated than in the case at pres nt . After such development , it is likely CD that there will be found small depress ions which woild be subject to periodic flooding in the absence of lateral draina ; e . The development of the area into streets and blocks , and the subsequent layout and donstr .xction of lateral drainage systems will in many cases chant, e the limits of the sub- drainage areas and the locations of the points of discharge from those limits and locations fixed by nature . Legally, areas high in elevation may have the right to discharge storm water on to lower lying areas as long as the oath of the water is not changed from its natural course , and the owners of such land may have a legal right to do anything to their land whether or not it increases the amount or rate of runoff . It is practically impossible , however , to lay out streets with suitable surfaces , gutters and sidewalks , mike suitable street intersections and grade house lots , so that they meet the needs of tenants , without changing the limits of areas tributary to natural water courses or ch • i.nging the locations of the water courses . The development of the hi. h lands may result in three or more times the rate of discharge and amount of water which would be discharged from these lands under natural conditions . Such development of the high lands as well as of the low lands regaires more costly brook channels and conduits . Considering the actual benefits without regard to legal rights , insdfar as main drainage channels and conduits are concerned , we think all areas -Within the drainage limit should share proportionately in the cost . The required capacity of such channels and conduits is directly proportional to the area served , dis - regarding minor variations in local co = nditions such as character of soil , steepness of slope , etc , ; thus , 3 acres of high land require about 1 cu . ft . per second of capacity in the main channels and conduits , which is the provision made for 3 acres of log land . The total draina 397 It is largely a matter of judgment ato s/ the proportions of benefits received by the throe clams . Without going into en elaborate stugy to determine the benefit according to a progress ion for each 100 ft . zone , or p ' chaps less , we think it is reasonable to fix the average ratios of betterment between the three classes as follows : Average Benefit Ratio Area Acnes Class 1 ( adjacent areas ) 3 66 . 5 Class 2 ( 1 , 1: 00 ft . zone ) 2 Class 3 ( 2 , 000 ft . zone ) 1 53 . 4 553 . Multiplying each area by its correspondin average benefit ratio , the total cost of park drainage is to be divided into 1491 . 3 units . The estimated amount of the drainage cost attributable to the nark areas , $22 , 500 , divided by 1491 . 3 ;rives $15 . 10 as the average amount of one unit of assessment . This amount is the aver are assessment per acre for Class3 areas , twice this amount or ' 30 . 20 is the average assessment for Class 2 areas and three times 515 . 10 or $45 . 30 is the average assessment per acre for Class 1 arras . These averare assessments reduced to the sq . ft . basis are as follows : Class 1 areas $0 . 001040 Class 2 areas 0 . 000693 Class 3 areas 0 . 000347 ( Insert Table 2 Computations for Drains or Combined See Pg . 404 Sewers ) Through Highway Benefits . The benefits which will be derived from the construction of through highways in the Vine Brook District will differ widely . The areas within the district may be sub- divided into three general classes , as follows : Class 1 - areaa which will receive complete benefit consisting of lands abutting on the through highways and not now accessible from present hiiways . Class 2 - areas which will receive nearly complete benefit , consisting of areas made accessible by the through highways , but which will require sub- division roads . Class 3 - areas which will receive only partial benefit , consisting of those aneas which are now or can be made accessible frau existing roads and may or may not require sub - division roads , but mill be made more easily accessible by the conte s t ruc ti on of the through highways . It is very difficult to fix upon equitable definite ratios for the benefits frau through highways . It is very evident that Classes 1 and 2 receive a Very substantial benefit . Likewise , it is evident that areas outside of these classes receive some benefit from the construction of the throe'h hi -;hways . The Town as a whole also will receive a corisi ijerable benefit from these hi -thways . It is our judgment that the average benefit ratios of the three classes should be about as follows : Class 1 - areas abutting Average Benefit Ratio Area Acres on through highways . 10 69 . Class 2 - araas made accessible by. through Highways 7 Class 3 - areaseasily made more46 . 9 accessible by thro Lgh highways 3 247 . It is doss ible that the benefit should he extended to a larger area , but it seems to us that for the purpose of this roport , it will be satisfactory to assume that the additional benefits outside of the for r e classes described above will be borne by the Town . It is our judgment that the Town ' s share of the cost of through highways should be about 20% . The estimated cost of construction of through highway gravelled roads is $241 , 000 . The Town ' s share of this cost ( 20% ) would be $48 , 200 , leaving $192 , 800 to be assessed upon Classes 1 , 2 , and 3 . 393tee. .17.) -� a Multiplying the areas of the individual classes by the con espondinc average benefit ratio gives 1 , 759 . 3 assessment units . Dividing the 4192 , 800 800 by 1 , 759 . 3 rives $109 . 50 as the amount of one assessment unit . Class 1 areas would be assessed 10 units per acre or 31 . 095 . Class 2 areas would be assessed. 7 units per acre of $766 . 50 . Class 3 areas would be assessed 3 units per acre or $328 . 50 . These assessments reduced to the sq . rt . bnsis are as follows : Class 1 areas 1;0 . 02513 Class 2 areas 0 . 01760 Class 3 areas 0 . 00754 The maximum assessment on any single p .. reel of land for draina : :e , parks and through highways wo ild he $0 . 03137 per sq . ft . This assessment wog .lcl apply only on those relatively small areas abutting on the proposed throuc h h i ;hway s . The mans , Figs . 8 , 9 and 10 , show the different classes of areas for each benefit as outlined above . _ • . In order to determine what the approximate assessment per square foot would be on any given piece of land within the district , it is only necessary to consult the individual maps and ddd the proposed assessments for the area under consideration . Obviously , the assessments must be levied on the bases of the actual cost . Before any asses :-ments are levied , it will be necessary to make accurate surveys to determine the limits of the drainage area and of the different classes ' f areas beiefitted . The Town will have to acquire the lands to be used for brook than , els , streets and public parks . No allowances have been male in the estimates of cost for the purchase nf such lands . It seems reasonable to expect that for the most part these lands will be donated to the Town . Any lands which do not became the . property of the Town for Dark purposes , highways or brook channels should be assessed their proportionate shares for the benefits . Respectfully submitted ed METCALF & EDDY JTNR : CH . By Almon L . Pales . See Pg . 404 ( Insert . fig . Drainage Benefit Map ) ( Insert , fig . 9 . Park Benefit Map ) ( Insert , fig . 10 . Through Highway Benefit Eap ) Estimate of Construction Cost of North Branch Channel . W . end track to E . end track 1300 ft . of 48 in . pipe at $12 . 40 $16 , 100 1 - 7 . 5 M . H . 100 E . end track to S . end swamp 500 ft . of 42 in . pipe at $14 . 80 7 , 400 1 - 10 . 5 ' M . H . 130 450 ft . of 48 in . Pipe at $12 . 10 5 , 440 1 - 9 / M . H . 115 . Sta . 43 + 0 to 41 + 0 200 ft . open channel 697 cu . yd . excavation at $0 . 65 450 471 sq . yd slopes at 0 . 50 235 Sta . 411- 0 to 30 4- 50 1050 ft . open channel 8 , 880 cu . yd . excavation at $0 . 65 5 , 725 399 3 , 720 sq . yd . slopes at :30 . 50 $1 , 860 Sta . 30 + 50 to 17 + 0 1350 ft . open than ; el 7 , 285 cu . yd . excavation at 10 . 65 4 , 740 3 , 600 sq . yd slopes at p0 . 50 1 , 800 Sta . 17 -+' 0 to 7 -t- 40 960 ft . oven channel 3, 090 cu . yd excavation at 10/65 2 , 010 1 , 920 sq . yd . slopes at $0 . 50 960 Sta . 71- 40 to 64- 80 60 f t . Waltham 7, t . culvert 560 ca . yd excavation at $2 . 50 1 , 400 111 ct . yd . concrete at 30 . 00 3 , 330 Paving invert 60 ' at $5 . 00 per lin . ft . ' 300 Sta . 61- 80 to 2 .11-50 430 ft . open channel 1 , 300 cu . yd , excavation at $0 . 65 845 836 sq . yd slopes at . 0 . 50 420 420 Sta . 21- 50 to 0i- 0 250 ft . oen chan-Iel 572 cu . yd . excavation at $0 . 65 372 417 s q . yd . slopes at 30 . 50 208 Clearing 1 . 4 acres at 100 per acre 140 $54 , 080 Estimate of Construction Cost of South Branch Channel Middle St . to Sta . 48 + 00 700 ft . of 21 in . pipe ay . c .t 3 . 0 at $4 . 20 $2 , 940 Sta . 481- 0to 401- 80 720 ft . of open channel 1 , 680 cu . yd . excavati n at $0 . 65 1 090 1 , 250 s : . yd slopes at $0 . 50 ' 625 Sta . 40 * 80 to 30 + 50 1030 ft . of open channel 3 , 030 cu . yd excavat i .-n at $0 . 65 1970 1 , 820 sq . yd slopes at $0 . 50 ' 910 Sta . 30 -1-- 50 to 22 ± 80 770 ft . open channel 2 , 845 cu . yd excavation at $0 . 65 1 850 1 , 575 sq . yd slopes at $0 . 50 ' 790 Sta . 22 -+- 80 to 20 + 80 200 ft . open channel 417 cu . yd excavation at 30 . 65 270 358 s q . yd slopes at $0 . 50 180 Clearing 7 . 8 acres at 3100 780 $11 , 405 Estimate of Construction Cost of Main Channel Sta . 20 -*-80 to 71- 00 1380 ft . open channel 7 , 725 cu . yd excavati <m at $0 . 655 020 2 , 990 sq . yd slopes at $0 . 50 $ , 1 , 495 Sta 7 + 0 to 01-- 0 700 ft . open chan : el 4 , 760 cu . yd excavation at $0 . 65 3 , 100 1 , 663 sq . yd slopes at $0 . 50 830 400 O Sta . 0 -r0 to S . L . Massachusetts Avenue ( 60 lin_ . ft .. for culvert not included ) 490 ft . open channel 5 , 440 cu . yd excavation at 80 . 65 $3 , 540 1 , 510 sq . yd slopes at 30 . 50 755 Vine Brook Road culvert 60 ft . long 765 cu . yd excavation at 2 . 50 1 , 910 183 c,t . yd . concrete at 30 . 00 5 , 485 Paving invert 601 at 5 . 00 per lin. ft . 300 S . L . Massach i.s et t. s Aven ze to Headwall 1270 ft . of 75 in . pipe ay . cut 13 . 5 ft . at $35 . 40 44 , 850 Headwall - 330 ft . open channel 822 cu . yd excavation at $0 . 65 535 430 sq . yd slopes at 1,0 . 50 215 - to Hayes Lane 400 ft . open channel 1 , 330 cu . yd excavation at 10 . 65 865 300 sq . yr? . slopes at 0 . 50 150 Clearing 0 . 7 acre at 1100 per acre 70 $ 69 , 120 April 9 , 1930 Town Planning Board Lexington , Mass . Attention : Mr . F . L . Emery, Chairman Gentlemen : On April 2 , Mr . Raymond , in cam puny with Mr. Cosgrove , examined the channel of Vire Brook in Lexington downstream from Sheridan Street to ascertain the extent to which flooding conditions would be aggravated as a result of the construction of the proposed Brook conduit between Hayes Lane and Vine Brook Road . There has been periodic flooding of low lands along the brook between Hayes Lane and East Street due to the sl i T.ht fall , the small size of the brook channel and the limited capacity of the East Str et culvert . No appreciable damage results from flooding under present conditions as the land subject to flooding is unimproved . Flooding as a result of the proposed construction would not be measurably increased and would at worst be a matter of only a few inches in height greater and a few hours longer duration . Probably any increase can he compensated for by substituting two Calvert pipes about 5 ft . in size beneath East Street in place of the present stone culvert and keeping the brook channel free from bushes and debris by annual clearing . Very truly yours , METCALF & EDDY By Almon L . Fales 401 • .. April 15 , 1930 Town Planning Board Lexington , Mass . Attention : Mr . F . L . Emery , Chairman Gentlemen : Regarding flooding along lower Vine Brook c1ownstre . tm from Sheridan Street as a result of the cons trzc tion of the propos ed conduit between Hayes Lane and Vine Brook Road and the channels for the main brook and the South Branch we are of the opinion that the increase in flooding will be very slight . Construction of the main channel south of Vine Brook Road and the South Branch channel will not measurably increase the flood runoff and conditions on lower Vine Brook will be as stated in our letter of April 9 , 1930 , to wit : Flooding as a result of the construction o :f the proposed main brook conduit andopen channel and the South Branch channel will not be measurably increased , at worst being a matter of a few inches greater height and a few hours longer' duration . Such increase can be compensated for by install ing two culvert pipes about 5 ft . in size beneath East Street in place of the present culvert and by keeping the brook channel free from bushes and debris by annual clea:^ing . Very truly yours , METCALF & EDDY, By Almon L . Fales . It was then voted that article 3 be laid upon the table . Art . 7 . Under this article Dr . Clarence Shannon o 'f erod the following motion : "Voted : That the sum of $ 650 be appropriated and assessed to cover the expense of printing and publishing the report of Vine Brook drainage and the Engineering services obtained in connection therewith " . Mr . Albert H . Burnham stated that he understood the cost of the Engineering services would come out of the Engineering Department and offered a motion to amend this motion , substituting the sum of $300 . for the sum of 8650 . The meeting voted to pass the amendment of Mr . Burnham , substituting the sum of $300 for $650 . so that the motion passed read as follows : " Voted : That the sum of $300 be a Tipropriated and assessed to cover the expense of printing and publishing the report of Vine Brook drainage . " Art . 3 , 4 and 5 . On motion of Mr . Theodore A . Custance it was voted to take up articles 3, 4 , an" 5 . Mr . Albert H . Burnham having made a minority report , Mr . Fred H . Moulton asked to hear fr m him to get his ideas on the subject of Vine Brook drainage . Mr . Burnham stated that he did not want to oppose the project with the idea of defeating it , but he did 402 Cl not feel that sufficient study had been given to - ' this project to warrant the Town makinre an expenditure of money until they are certain that this closed drain would drain the land , and he also felt that unless laterals were constructed , the water could not ~ et out of the land into the culvert , and in Metcalf & Eddy ' s report , they did not provide for laterals . Mr . Burnham also stated that as he figured it the betterments to be paid by Mr . Ryder would amount to 822 , 454 . He also felt that when the spring freshets come , he did not believe that this uipe would readily take all the water . Mr . Fred H . Moulton made remarks regarding the cost to the Town and suggested that the Town might start at East Street et and do a certain portion of the brook each year , and eventually the project would be completed . Remarks were also made by Messrs . William Roger Greeley , Elwyn G . Preston , Harold Lamont , Allen Chamberlain , William J . Marshall , Eugene G . Kraetzer , George E . Foster , Edgar F . Scheibe and Robert H . Eldride . Mr . Edward W . Taylor surges to d that the rate of betterment of one half a cent per foot might be increased to a cent a foot . Mr . Robert L . Ryder stated that his brother owns the property in question where the Vine Brook drainage was to be extended, and paid taxes on it for the past seven or eight years . They have on this property sixty- two lots of land on Winthrop Road extension , andthey have put restrictions on the to 1-.s for the ' 5enefi_ t of the property owners , and have agreed to refund their money if the restrictions are not carried out . They have built a road and taken out five or six feet more of earth that the Town Engineer required , and they have ma ' e a thirty -two foot set back when only a twenty foot set back is required by the Town . They al =; o have one hundred and three acres in this territory to develop and when developed in the fashion that they propose , it will be one of the finest developments th & t the Town has ever had and the Town will receive the return in taxation . It depended upon the town , however , to help make this kind of a development by draining the land . Dr . James J . Walsh asked whether or not Mr . Ryder would be willing to place the restrictions on the ?--hole area and whether or not he has placed the plan on file at the Registry . Mr . Ryder stated that he had placed the plan on file with the Planning Board and the Board of Survey had already approved the plan of Winthrop Road extension , and wouldprobably approve the whole plan at a later date , but have approved the plan generally . He did not propose to put it on file at the Resist ry of Deeds until the plan was approved . A rising vote was taken on the motions orfered under articles , 3 , 4 , and 5 , by Mr. Theodore A . Custance , which read Ps follows : 4Q3 Art . 3 . Voted : That the Board of Jelectmen be and they hereby are authorizedand directed to proceed. under Statute 1926 , Chapter 263 , for the purpose of surface drainage , to construct a culvert for Vine Brook from about Vine Brook Road to about Sheridan Street , approximately in accordance with the report of Metcalf & Eddy , Civil Engineers , dated September 29 , 1928 and to deepen , widen , relocate and clear of obstructions Vine Brook in the area between Vine lirook Road , '?laltham Street and I\Iarrett Road with any necessary culverts approximately in accordance with said report and to construct such lateral ditches in said area , if any , as they may deem advisable , and to make necessary takings therefor by eminent domain and in their order for such improvement to state that betterments are to be assessed therefor . Further Voted : That for the purpose of paying for the imbrovement authorized under the preceding vote the sum of ninety thousand ( $90 , 000 ) doa. lara be raised and appropriated of which twenty thousand. ( S20 , 000 ) dollars shall be assessed and to meet the remainder of said appropriation the Treasurer with the approval of the electmen be andhe hereby is authorized to borrow not exceeding seventy thousand ( $70 , 000 ) dollars under the authority of and in accordance with the provisions of General Laws , Chapter 44 , section 7 and acts in amendment thereof and in addition thereto , and to issue bonds or notes of the town therefor payable in not more than thirty years from the date of issue or at such earlier date as the Treasurer and Selectmen may determine . Art . 4 . Voted : That the sum of $2500 be appropriated and assessed for deepening , widening , relocating and clearing of obstructions Vine Brook below Sheridan Street , including the alteration and reconstruction of the present culvert for the said brook under East Street . Art . 5 . Voted : That the Board of Selectmen be authorized to construct a sewer in Winthrop Road extension from the present end of Winthrop Road to Waltham Street , a distance of approximately 1 , 450 feet ; also from a point in Winthrop Xoadextension near the present south branch of Vine Brook across private lands to Vine Brook Road , a distance of wnirtzteigsS9iRgki 4}8R ox apE°O �� & 8sssstoe rai� roa • 'from to rairo�aa across P privatd lands to Sherman Street ; from Sherman Street across private lands to Sheridan Street ; thence along Sheridan L> treet to a point in Grant Street ; the total distance from Vine Brook Road to Grant Street , as above described , beim; approximately 2 , 000 feet and that bonds or notes be issued in the sum of $10 , 000 . in accordance with the law . Seventy- six voted in the affirmative and eighty - seven in the negative . The motions were declared lost . The meeting adjourned at 10 : 57 P . M . to June 9 , 1930 at 8 P . M . A true record , Attest : • , Town Clerk . 404CD Pg . 390 . Fig . 2. g g "Map of Vine Brook Drainage District , Scale 800 ft . to 1 in . ( approx . ) Nov. 15 , 1927 , Revised Sept . 26 , 1928 , Metcalf & Eddy , Engineers , Boston , Mass . " Pg . 392 . Fig . 3 . " Preliminary Development Map , Scale in feet ( approx . ) + August 9 , 1928 . Revised 000 2000 Sept . 25 , 1928 . Metcalf & Eddy , Engineers , Boston , Mass . " Pg . 392 . Fig . 4. "Main Charnel North of Sherican St . , Lexington , Mass . Vine Brook District . Typical Sections of Open Channels , Scale 5 ft . to 1 in . August 3 , 1928 , Metcalf & Eddy , Engineers , Boston, Mass . " Pg . 392 . Fig . 5 . " Profile of Proposed Relocated North Branch Charnel of Vine Brook , Scales - Hor . 200 ft . to 1 in . Vert . 5 ft . to 1 in . , July 1928 . Metcalf & Eddy , Engineers , Boston , Mass . " Pg . 392 . Fig . 6 . " Profile of Proposed South Branch and Main Channels of Vine Brook . Scales Hor . 200 ft . to 1 in . Vert . 5 ft . to 1 in . July , 1928 , Revised Sept . 28 , 1928 . Metcalf & Eddy , Engineers , Boston , Mass . " Pg . 394 . Fig . 7 . " Proposed Through Highways , Scale in feet ( approx . ) , September 1928 Metcalf & 0 1006 2000 Eddy , Engineers , Boston, Mass . " Pg . 397 . Table 2 . " Computations for Drains or Combined Sewers , March 21 , 1927 revised September 25 , 1928 , Metcalf & Eddy , Consulting Engineers , Boston, Mass . " Pg . 398 . Fig . 8 . " Drainage Benefit Map , Scale in feet ( appy . ) Sept , 1928 , Metcalf & Eddy , 000 2000 Engineers , Bostoffi, Mass . " Pg . 398 . Fig . 9 . " Park Benefit Map , Scale in feet ( approx . ) 0 1000 2000 Sener Sent . 1928 , Metcalf & Eddy , Engines , Boston , Mass . " Pg . 398 . Fig. 10 . "Through Highway Benefit Map , Scale September 1928 , Metcalf & Eddy , Engineers , 6 1000 2000 Boston, Mass . "