The stormwater management demonstration project at Liberty Lands, Northern Liberties’ community-owned and maintained park and garden, has been designed to reduce stormwater runoff and erosion at the site, reduce water use at the park through runoff reuse, and provide a publicly accessible demonstration of best management practices in this rapidly developing neighborhood. The project was designed by the Pennsylvania Horticultural Society, in partnership with the Philadelphia Water Department and the Northern Liberties Neighbors Association.
The Liberty Lands project diverts thousands of gallons of stormwater water from North Third Street into a six-hour detention pond at the park, reducing the load on combined sewers during storms, and subsequently, reducing the likelihood that the past flooding in this area will be repeated. Stormwater flows into the basin on Third Street and is then diverted through a grassy swale into the newly installed rain garden detention pond. After filtering through the rain garden, the water will flow to three in-ground cisterns, where it is stored until it is pumped into an irrigation system. The gray water will be used to irrigate 35 trees planted as part of this project, and the grass area at the heart of this public park.
The grass area, which was sodded as part of the project, will also help to reduce significant erosion problems at the park. With a 17-foot drop from the south to north ends, the park has experienced serious erosion damage. Lack of irrigation made it impossible to establish or maintain a groundcover over the open commons area. The cistern irrigation will ensure that the grass cover can survive Philadelphia summers. A new amphitheater and stage area in front of the rain garden makes the stormwater project a highly noticable element of the park, and the stage will bring thousands of visitors to the project area during the NLNA’s twice-yearly music festivals. In addition to the park visitors who will learn about stormwater management through this project, it will be a featured stop on local and national tours led by groups such as the EPA and the Philadelphia Horticultural Society. Since the park opened ten years ago, Liberty Lands has already served as a demonstration area for brownfield re-use and for park management; this BMP project will add to the educational elements of the park.
Watershed: Delaware River
PA Department of Conservation and Natural Resources
PA Department of Environmental Protection
The Morris Arboretum of the University of Pennsylvania
The Standard Tap
The William Penn Foundation
$340,000 (Estimated cost including design)
700 North 3rd Street
Philadelphia, PA 19123