Let's Protect the Mugar Wetlands

Policy Statement of the Mystic River Watershed Association

Regarding Development of the Mugar Property in Arlington, Massachusetts

August 11, 2015

MyRWA Mission
The Mystic River Watershed Association (MyRWA) is a non-profit organization dedicated to the preservation and enhancement of the Mystic River Watershed. The mission of MyRWA is to protect and restore the Mystic River, its tributaries, and watershed lands for the benefit of present and future generations and to celebrate the value, importance, and great beauty of these natural resources. This includes working to improve the water quality in the Mystic River and all of its tributaries.

Statement of Policy
MyRWA has a history of successful collaboration on developments that benefit the community and contribute to the health of the watershed. However, the housing project proposed by Oaktree Development for the Mugar property in East Arlington would significantly degrade the ecological and hydrologic value of the site and would further stress an already impaired watershed. For these reasons, MyRWA strongly opposes the proposed development and supports efforts to preserve the property as open space, as outlined in the Town of Arlington’s newly adopted Master Plan.

The Mugar property is located within the sub-watershed for Alewife Brook, an impaired tributary to the Mystic River. Alewife Brook drains approximately 4,500 highly urbanized acres, made up of 47 percent impervious cover in Arlington, Belmont, Cambridge, and Somerville.1 The Brook recently received a grade of D from the U.S. Environmental Protection Agency for its chronically poor water quality.2 Despite many challenges, MyRWA and its partners remain committed to improving the quality of the waterway and its surrounding floodplains, wetlands, and uplands. The disposition of the Mugar property will have substantial impact on these efforts.

The 17.7-acre Mugar property plays an important role in Arlington and the greater Mystic River Watershed by providing floodwater storage in the naturally pervious land and wetlands within its boundaries. Wetlands and floodplains such as those located on the Mugar property serve as natural sponges that not only store floodwater, but also filter pollutants and recharge groundwater, providing a slow release of groundwater to streams during dry weather. These functions are particularly important in this vulnerable, low-lying section of East Arlington, which already experiences flooding during storms.

The proposed development would set aside 10.5 acres of unbuildable floodway and wetlands for preservation. The developer has not, though, shown how construction on the remaining 7 acres could be accomplished without degrading the watershed. The proposed development would convert 3.7 acres of pervious land (mainly forested) to impervious buildings and pavement. Additional vegetated area would be cleared and graded. Some of the proposed construction would occur within the FEMA 100-year flood zone and all of it would fall within the 500-year flood zone. The proposed change in land cover would significantly diminish the ability of the land to slow, store, filter, and infiltrate rainwater and floodwater.

As one of the last undeveloped parcels in the impaired Alewife Brook sub-watershed, the Mugar property provides vital ecological services to the neighboring community and the Mystic River Watershed.

MyRWA strongly recommends that every effort is made to preserve and protect in its natural state this extremely valuable natural resource, and supports every effort to purchase the property for that purpose.

1 Horsley Witten Group (2012) Technical Analysis Upper Alewife Brook Basin Impact Study

2 U.S. EPA, Mystic River Watershed Report Cards: www.epa.gov/mysticriver/reportcards.html