Green Infrastructure Pilot Studies in the Jamaica Bay Watershed.

The New York City Department of Environmental Protection (DEP) installed various green infrastructure demonstration pilots as part of its 2007 Jamaica Bay Watershed Protection Plan, Nitrogen Consent Order and Combined Sewer Overflow (CSO) Consent Order Environmental Benefit Projects with the New York State Department of Environmental Conservation (NYSDEC), the City’s 2008 Sustainable Stormwater Management Plan and the September 2010 Green Infrastructure Plan. These pilots include five Streetside Infiltration Swales (SSIS), five Enhanced Tree Pits (ETP), one Wet Meadow, one Green Roof, one Blue Roof, and four rain gardens on parking lots. For Enhanced Tree Pits, stormchamber, crushed stone and recycled glass were employed and compared. The 15 pilots were built at 11 locations in Brooklyn, Queens and Far Rockaway, and on three different landforms. Five of the systems are in parking lots, whereas ten are on street sidewalk. These demonstration studies are used to help identify effective measures to reduce stormwater flows to the City’s sewer system during storm events. The soils at each site also function to retain part of the stormwater to sustain healthier plant growth, thereby establish a dynamic mico ecosystem to better the local urban environment and for carbon storage. Tree and plant roots and microbial activities in turn promote a functioning rhizosphere that helps to improve and maintain good infiltration rates. The soils also serve as natural filters to remove and breakdown contaminants and excess nutrients from runoff. Stormwater capture volume and efficiency, storage, as well as the quality of runoff water and sediments/soils, have been monitored to evaluate the pros and cons of each design, implementation cost, benefits and identify specific maintenance requirements.