Bioengineering Group Project Featured in November-December 2010 issue of Stormwater Magazine

Located within the 100-year floodplain in Alewife Reservation, an urban wild, the site serves as habitat for diverse wildlife and provides opportunities for restoration and education. The challenge was to design a constructed wetland basin that met the technical requirements for stormwater detention and treatment while simultaneously meeting the habitat and recreational functions envisioned for the area in the Massachusetts Department of Conservation and Recreation Master Plan for Alewife Reservation. Bioengineering Group designed this multifunctional stormwater management facility to serve the objectives of combined sewer overflow compliance, wildlife habitat enhancement, and recreation/education. The system is based on natural systems and processes as opposed to the traditional engineering approach. It incorporates both conventional and bioengineered structures that won praise from stakeholder groups and saved public agencies millions of dollars compared to more structural alternatives. Read the full article here

 

Earthen levees and spillway structures interface with trails, boardwalks, overlooks, an amphitheater, and native plants (trees, shrubs, and wetlands)

The Cambridge Stormwater Wetland system: • Is located on a15-acre site adjacent to Alewife T station and made up of 6.5 acres of existing wetland
• Provides 10.3 acre-feet of stormwater runoff storage
• Reduces CSO discharges into Alewife Brook and ultimately Boston Harbor by 87 percent (43.6 million   gallons eliminated annually)
• Separates sewage from stormwater in a 420-acre area
• Includes high quality habitat (deep marsh, shallow marsh, open water, upland islands)
• Is self-sustaining with low maintenance requirements (e.g. mowing)
• Creates a sustainable hydrology that mimics national conditions
• Restores ecosystem structure and function by replacing invasive species with native species

Benefits:
• Create 3.4 acres of new, high-quality wetland
• 90 percent removal of TSS
• 95 percent removal of bacteria
• Preservation and enhancement of wildlife habitat
• Improved site amenities and esthetics
• Provides educational and recreational opportunities

Features:
• New entrance/gateway
• Boardwalk and scenic overlooks
• Amphitheater/outdoor classroom
• Bike paths
• Interpretive signage
• Invasive control
• Enhanced habitat

Pollutant Removal Pathways:
• Sedimentation
• Adsorption to sediments
• Physical filtration
• Microbial breakdown
• Plant uptake
• Detention