Models for Stormwater Management on Reclaiming Vacant Land

Description

A partnership between The Pennsylvania Horticultural Society (PHS) and The Philadelphia Water Department (PWD) led to the formation of a plan in 2005 to incorporate stormwater management techniques into the Greenway Project, which sought to stabilize abandoned inner city lots. The new pilot program incorporates stormwater management techniques to assuage the citywide problems of flooding, combined sewer overflow into waterways, and nonpoint pollution. By detaining and infiltrating stormwater running off nearby streets and sidewalks with the use of basins and native plants, the overloaded neighborhood stormwater system is spared. A native plant list can be found here. The stormwater is diverted from the system by mimicking natural processes with landscaping solutions rather than with infrastructure solutions.

The five lots in the pilot program were excavated and cleared of debris and (except the 3rd Street & North Bodine Street site) were graded to a 2% slope. Soil berms were built up to create retention areas 6 inches deep located at least 25 feet from existing buildings.  Click on the following links for grading plans:  N. 3rd & N. Bodine (2323 N. 3rd St.)N. 3rd & W. NorrisN. 8th & W. BerksN. 8th & W. Norris, and N. 9th & W. Norris. Four inches of topsoil, amended with leaf compost, was re-deposited in the basins. Elsewhere on the lots the surface soil was loosened by tillage to a depth of 3 to 4 inches and 3 inches of amended soil was then added. The design at the 3rd Street & North Bodine Street site graded two-thirds of the site to a slope. This approach left the remaining third of the land graded flat, acting as a retention basin. The water has been infiltrating successfully during storm events.

A year after planting was completed, Temple University’s department of Landscape Architecture and Horticulture conducted field surveys in order to record the status of vegetation and soil profiles. Data was collected for the purpose of running stormwater modeling techniques.  Using a penetrometer, the compaction of soils was analyzed and a DEP-approved device called a Turf-ric double ring infiltration meter was used to measure field stormwater infiltration rates. Soil samples were taken using an ASTM soil auger, and a composite was made and texture, bulk density, soil porosity and volumetric water content were analyzed.

As calculated by Temple University’s Department of Landscape Architecture and Horticulture, accumulated runoff decreased by 90,934 gallons on these sites between June 2005 and May 2006. These results were simulated using a SWMM 5.0 model.

The City’s thousands of fragmented vacant parcels provide a land management challenge. This project is the first step in developing a model for integrating vacant land parcels and stormwater management in an urban redevelopment framework. Future technological advances will need to be addressed to ameliorate cost-effective design to further maximize runoff collection. The maintenance of these sites is important so that they are perceived as important community assets. PHS’s partnership with city government will help ensure the oversight and stewardship of these demonstration sites.

The completed converted area for these 5 sites was 86,392 square feet. The project was completed from October 2004 through December 2006. This pilot program is also a demonstration program to educate the public about the use of stormwater best management practices (BMPs). Signage in English and Spanish is posted onsite at each of 5 sites, as well as along various vacant sites along N 3rd St. and Berks Street corridor.

Location

County: Philadelphia
Watershed: Delaware River

The Pennsylvania Horticultural Society’s Clean and Green Program is a component of the “Green City Strategy,” aimed at 6 target areas in Philadelphia. One of these target areas consist of 5 lots located on N. 9th Street, Norris Street and Berks Street, where stormwater management techniques have been implemented on cleared and clean vacant parcels.

Partners

Philadelphia Water Department provided engineering support.
Philadelphia’s Neighborhood Transformation Initiative (NTI) provided the protective fencing.
The Asociacion de Puertorriquenos en Marcha (Association of Puerto Ricans on the March) helped establish the Greenway Plan for the entire length of North 3rd Street from Berks to Lehigh.
Temple University Department of Landscape Architecture and Horticulture documented the project’s construction and completed studies for recommendations on future improvements. Professors Mary Myers and Jun Yang guided the research and were aided by field assistants Annmarie Rambo and Joshua Roberts.

Cost

Site Installation Cost ($) Maintenance Cost ($) Total Cost ($)
3rd & N. Bodine 47,990 1,700 49,690
3rd & W. Norris 9,885 1,300 11,185
8th & N. Berks 1,300 1,300 12,652
8th & W. Norris 25,045 3,160 28,205
9th & W. Norris 18,657 3,160 21,817

Pennsylvania DEP Growing Greener Grant for $200,000
Matching contributions came from city partnerships.
Cost savings resulted in interpretive signage.

Contact

Joy Lawrence
Project Manager
Pennsylvania Horticultural Society
100 N. 20th St.
Philadelphia, PA 19130
215-988-8898
jlawrence@pennhort.org

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