RES was awarded a Greened Acre Retrofit Program (GARP) grant to implement the Darien Crossing Regional Stormwater Retrofit (Darien Project) on a parcel managed by the Philadelphia Industrial Development Corporation (PIDC). The GARP program is a component of the Philadelphia Water Department’s (PWD) innovative Green City, Clean Waters Program, which was adopted in 2011 as Philadelphia’s plan to use green infrastructure to reduce the volume of stormwater entering the combined sewer system, limiting overflows (CSOs), and preventing sewer pollution from entering Philadelphia’s waterways.

The Darien Project, located within the very active stadium district in South Philadelphia, provides Philadelphia Water Department (PWD) a large-scale green stormwater project at a high-profile, highly visible, impervious-dominated part of the City. This provided a unique opportunity for RES to develop an innovative solution that addressed PWD’s programmatic goals while maintaining the preferred land use of PIDC and the surrounding stakeholders.

Design and permitting, along with demolition for the project was completed in 2019 with construction in Spring 2020. Excavation of the site was completed in phases due to the size constraints of the parcel. The Stormwater Management Pond (SMP) was installed and the finished work (curbing/paving/landscaping) was completed in Fall 2020. RES executed a long-term lease agreement with PIDC to operate and maintain the facility for a 45-years post-construction. PIDC, the Philadelphia Phillies, and other project stakeholders will benefit from significantly reduced stormwater fees after the implementation of the project.

Client Benefits
• Largest Greened Acre retrofit project to date within Philadelphia
• Removed portion of vacant warehouse to install stormwater management practices
• Situating parking facilities on top of retrofit allows for beneficial use of parcel, in conjunction with stormwater storage
• Long-term lease for operations and maintenance of the facility