Central Delaware Trail Extension
Philadelphia recently adopted a plan to transform a six-mile stretch along the Central Delaware River into a waterfront that will revitalize and redevelop that section of the city. A key feature of the plan is changing the decayed urban industrial infrastructure into an inviting space that encourages public access and use of the waterfront.
Biohabitats was commissioned to extend an existing trail and provide better access to Washington Avenue Green, a new public space created by Biohabitats as a design-build project on the Delaware in 2010. The extension was on a challenging parcel: a narrow strip of constricted, mostly paved area threading between private parcels and the river. The first step in the design was to remove much of the existing concrete. This reduced the impervious surface while increasing permeable retention zones to capture stormwater runoff. Biohabitats’ plan replaced concrete slabs with a mixture of soil media, interspersed amongst repurposed concrete rubble, paying homage to the site’s industrial history with these “rubble meadows” that flank the trail (shown at top left, before before planting and growth of native vegetation).
In addition to concrete removal, the construction contractor cleared additional debris and regraded existing soil mounds fringed by weedy invasive vegetation. Implemented efforts removed the invasive species that dominated the site, predominantly Japanese knotweed, and repopulated the site with native trees, shrubs, grasses, and wildflower plantings. The space now serves as a more appealing and creative transitional zone to Washington Avenue Green and reconnects the northern gateway to the future Delaware River Wetland Park Trail.