2010-04-05-ATM-CPC-rpt - Laserfiche WebLink

Browse Search

ARTICLE 8 (b) Project: Stormwater Mitigation Old Res./Marrett Road CPA Category: Recreational Use Amount Requested: $190,047 Amount Recommended: $190,047 CPC Vote: (9-0) Project Description: In 2007,the Town hired the Louis Berger Group to do a water quality study at the Old Reservoir on Marrett Road.The Old Reservoir is located in the watershed of the Vine Brook, which is part of the watershed for the Shawsheen River.The objective of the study was to analyze and understand the relationship between bacteria concentrations in the Old Reservoir and potential bacteria sources. The results of the study show that the main source of bacteria entering the reservoir is stormwater. Stormwater enters the reservoir via four outfalls along Marrett Road. Two of these outfalls go directly into the reservoir and the other two first enter a detention basin. In FY 2010, $569,000 of CPA Funds was appropriated to address Phase I of the stormwater mitigation on Marrett Road by the Old Reservoir. Phase I will improve the water quality of storm runoff from the drainage areas entering the Old Reservoir via three outfalls along Marrett Road by expanding the existing retention area,constructing a spillway and constructing a new water quality structure. This work is scheduled for the spring/summer of 2010.The Phase II request for FY 2011 is$190,047. This work will include creating a second water quality structure to capture water in the southwest corner of the facility from the single remaining outfall along Marrett Road. The Town applied for State DEP 319 funding for this work, but was unsuccessful. Project Goals and Objectives: • Preserve the Old Reservoir and its surrounding recreational and open space areas to enhance both passive and active uses. • Mitigate stormwater runoff before it enters the Old Reservoir. • Improve the water quality of the Old Reservoir. Reduce number of days the swimming area must be closed due to elevated bacteria count. Project Benefit: Originally built as the water supply to the Town of Lexington,the Old Reservoir is now used for both active and passive recreation. The Old Reservoir is an important recreational resource, one that is used during the summer for swimming, and year round for walking and fishing. During the school year, teachers from the Bridge School use the 0ld Reservoir as part of the school science curriculum, and children use the paths to get to and from school.Mitigating the stormwater runoff is instrumental in preserving the Old Reservoir as a natural resource and an important recreational area.Improved water quality will also help the Shawsheen Watershed. Funding Request: The Town received an engineer's estimate from the Louis Berger Group based on the plan approved by the Department of Environmental Protection. The FY 2011 request for this Phase 11 project is$190,047. 7