Alewife Reservation Stormwater Wetland

William Brewster, the 19th-century naturalist, once referred to the 120-acre Alewife Reservation as part of the Great Swamp. This conservation land near Cambridge, Massachusetts, was at risk from surrounding urban development and a flooding-combined sewer system that threatened the community’s potable water reservoir. The city needed to take action. Our role? Engineer a multi-purpose sewer separation project that manages storm water, eliminates combined sewer overflows, and repairs the environment. 

Commissioned in 1998, the sewer separation project featured an engineered storm water wetland designed to manage storm runoff and act as an ecological filter with physical and biological treatment. Debris, nutrients, and pollutants are removed as storm water journeys through the wetland features. The resulting 3.5-acre facility treats urban runoff, optimizes storm water levels and flow rates, restores lost environmental habitat, encourages biodiversity, and reduces our environmental footprint.

The wetland was completed as part of a $117 million investment in ongoing construction that will reduce sewer overflows by 43.6 million gallons each year. The Alewife Reservation is now a showpiece of 21^st-century green technology and a benchmark for sustainable integration of storm water infrastructure within the natural environment.