Cliveden Park is a unique “urban oasis” which showcases the natural topography of the Mt. Airy neighborhood in northwest Philadelphia. Two city blocks of street runoff are captured and directed into the city-owned and operated park, where the natural topography helps to detain stormwater before it flows into the combined sewer system. Small upland depressions provide water quality treatment and some infiltration of stormwater, and a modified outlet structure allows water to pond in the existing wetland before it is slowly released. The BMP system was designed to maximize environmental benefits for storage and treatment of street runoff while respecting the historic and natural features of the park. The system features a series of constructed step pools, which direct flow from an adjacent street down a steep slope, and into a central rain garden. The system reduces stormwater volume and velocity contributed to the combined sewer system through evapotranspiration and infiltration, especially during the small, frequent storms that cause the majority of combined sewer overflows. An ephemeral stream that captures overland flow from the park provides seasonal flow into the rain garden. In addition to meeting stormwater management objectives, the project enhances the existing wetland in the park, and is an amenity for the park community.
The project was designed by Pennsylvania Horticultural Society in partnership with Philadelphia Department of Recreation and the Friends of Cliveden Park. Operation and ownership is coordinated through the City of Philadelphia’s Department of Recreation. The design team worked closely with Friends of Cliveden Park to refine the design within the project constraints, which included budget limitations, permitting restrictions, community design considerations, historic and cultural landscape considerations and existing park conditions. In addition to design funds from Philadelphia Water Department and implementation funds from the Pennsylvania Department of Environmental Protection, Friends of Cliveden Park received a grant from Bank of America that was used to install a new pedestrian access and overlook to the project site.
Watershed: Tacony-Frankford Creek
Bank of America
Friends of Cliveden Park
Philadelphia Department of Recreation
Pennsylvania Department of Conservation of Natural Resources
Pennsylvania Horticultural Society
Philadelphia Water Department
The William Penn Foundation
Philadelphia Horticultural Society
100 North 20th Street
Philadelphia, PA 19103