The newly completed installation of a green infrastructure project in the Edenwald section of the Bronx will prevent nearly 2 million gallons of stormwater from entering the sewer system each year. The New York City Department of Environmental Protection invested $300,000 in building 22 bioswale curbside gardens designed to collect and absorb rainwater. By managing runoff from roadways, sidewalks and rooftops, the project seeks to improve the health and cleanliness of the Hutchinson River and New York Harbor as well as the surrounding community.
“In order to improve the health of local waterways we have to better manage the stormwater that falls on city streets, sidewalks, parking lots, and rooftops,” said Commissioner Carter Strickland in a press statement. “This green infrastructure installation will collect and absorb stormwater, which will improve the cleanliness of the Hutchinson River, while also greening the neighborhood, providing shade in the summer months, and cleaning the air. The important data we collect will quantify the reduction in pollution and will support our water quality planning efforts.”
Bioswales are relatively large tree pits containing curb cuts nearly five feet in depth that allow the entry and exit of approximately 2,244 gallons of street and sidewalk stormwater runoff. During construction, the pits were backfilled with layers of broken stone and engineered soil to create layers that allow for stormwater storage and promote infiltration. According to the DEP, the addition of hardy plants will further encourage infiltration through root growth and increase the capacity of the bioswale through evapotranspiration. Take a look at how a bioswale absorbs stormwater in this video here.
Over the course of the next year, the DEP will collect post-construction data on the Edenwald bioswale project. Edenwald is only one of three Neighborhood Demonstration Areas developed in order to collect and analyze data on actual combined sewer flow measurements before and after green infrastructure projects were installed. The Department of Parks and Recreation is charged with the task of maintaining all bioswales. Final data collected will be used for modeling future green infrastructure water quality and cost-benefit data on a citywide basis.
Via NYC Gov