Wissahickon Charter School’s Harmony Garden was created by converting an asphalt playground into a stormwater catchment system. The majority of the site, including a 645,000 square foot roof, is impervious cover, contributing a vast amount of runoff to the city’s combined sewer system. The project is designed to collect runoff from the parking lot and roof and deliver the runoff to three infiltration basins, which will allow it to seep into the ground, rather than into the sewer system. Two cisterns are in place to collect roof runoff for storage and future use for watering plants during dry weather. Grasscrete turf pavers provide additional pervious surface area, and help prevent runoff from leaving the site.
The project also serves as an educational tool, in addition to the school’s other environmental curriculum, including its Earth Day FreeCycle event, a solar panel roof demonstration site, and community garden.
Watershed: Schuylkill River
$110,000 provided by a PA Department of Environmental Protection Growing Greener grant
Julie Stapleton Carroll
Wissahickon Charter School
4700 Wissahickon Avenue
Philadelphia, PA 19144