The Salvation Army’s Ray and Joan Kroc Corps Community Center is one of the most comprehensive sustainable landscape approaches in the City of Philadelphia. The Center is a highly diversified headquarters offering recreational facilities, job training, and educational and spiritual programs for the adjacent neighborhoods. The site is a 12.43-acre contaminated brownfield, formerly used to manufacture pulleys and then as a city impound parking lot. The richly programmed landscape creates a hierarchy of activities arrayed around a central green, including sports fields, picnic area, play zone, formal gardens, and an urban agriculture zone. The site design responds to the city’s most stringent stormwater codes by using cost-effective strategies, including rain gardens, bioswales, porous asphalt, porous unit pavement and rainwater cisterns. The stormwater management is made visible with a set of decorative runnels that make artful expression of rainwater.
The stormwater management system captures the first one inch of stormwater runoff from the site and building and infiltrates or uses it onsite. When compared to predevelopment conditions, the project has reduced the rate of stormwater runoff by 98%, 97%, and 64% for the 2-, 10-, and 100-year storms, respectively. The redevelopment project reduced impervious surfaces on the site by 43%, from 9.26 acres to 5.30 acres. The first inch of stormwater runoff from the site and building is captured, reused, and infiltrated on site using a combination of cisterns, rain gardens, porous pavements, and engineered soil mixes. A series of four rain gardens filter and infiltrate stormwater runoff from the building and porous parking lot. One lined rain garden is located on the street side of the building; the other three are unlined. The rain gardens are designed as wet plant communities. Carved granite runnels capture air conditioner condensate and carry it to cisterns and rain gardens.
The landscape design utilizes native plant communities, creating upland, lowland and wet habitats. Dragonflies, bees, other insects and some bird species have been observed on the site post-planting. A small urban farm dedicates a third of an acre to growing produce and has an outdoor classroom for educational programs. These amenities have increased the ecological quality by 34 times that of the former site, as measured by the Plant Stewardship Index, an assessment of native biodiversity based on a site’s plant list. The 562 new trees and shrubs planted onsite also sequester 15,293 lbs. of carbon dioxide annually.
The landscape architect chose to strive for a zero net waste approach to site construction. Nearly all of the site’s existing pavements were recycled and reused on-site. The design buried specific contaminated soils deeply on the site through a creative and complex grading scheme. Regulations required that some toxic soil be disposed of off-site. All existing pavement on the site was crushed and reused as a sub-base below paved areas and for bulk aggregate fill. The site contained approximately 2,700 cubic yards of asphalt, 2,410 cu yd of concrete, 7,020 cu yd of aggregate stone sub-base, and 370 cu yd of railroad ballast. These materials were recycled and integrated into the construction of the parking areas, synthetic turf base, lawn base, paths, and structural fill. By determining the equivalent performance capabilities of the type of aggregate debris, each could be specified for maximum benefit at the site. This effort saved $575,000 in disposal fees and prevented 12,500 cubic yards (17,500 tons) of material from entering landfills.
Contaminated sites require import of specialized soil. It is important to ensure that the imported soil meets the specifications by conducting on-site testing during landscape construction.
Technologies such as cisterns and approaches to landscape (i.e. native plant communities), require client and staff education to ensure proper operation and maintenance. Landscape designs intended to act as living systems and to perform stormwater mitigation require attention in their early years. The project landscape architect provided regular assistance to the Salvation Army on a pro bono basis in order to ensure that irrigation and cisterns were functioning properly, that rain gardens were being cared for properly, and that the landscape was being managed organically. This also ensured that the client understood how to use the site systems to reduce costs and improve sustainability.
Sustainable landscapes need comprehensive management plans and regular post occupancy attention to ensure that the ecological integrity of the site is maintained over time. The current Plant Stewardship Index number indicates high ecological quality a year after the project was completed, but this is subject to change. Invasive species will come in from other sites and from the adjacent railroad corridor. Maintaining native plant communities requires diligence and field knowledge from both the landscape architect and landscape crews.
When installing systems to be maintained by the client, such as irrigation, useful and accurate operation manuals should be required. At the time construction is completed, these systems should be tested and demonstrated with the contractor, landscape architect, and client in attendance. Collaboration between the system designer and the landscape architect is encouraged to facilitate ease of operation, observation, and maintenance. Irrigation systems require fine tuning and monitoring for success and must be designed to facilitate these activities.
Watershed: Schuylkill River
The Ray and Joan Kroc Corps Community Center is located in the Tioga-Nicetown neighborhood in the city of Philadelphia in the Lower Schuylkill River Watershed.
Architect: MGA Partners, Inc.
Civil Engineer: Duffield Associates, Inc.
Structural Engineer: CVM Engineers
Cost Estimator: Becker & Frondorf
Total project $54,155,263
Andropogon Associates Ltd, Principal
10 Shurs Lane
Philadelphia, PA 19127