Lower Mill Creek Garden Stormwater Management Techniques

Description

Before the establishment of Lower Mill Creek Garden, the lot was abandoned and in disrepair with fractured sidewalks and the concrete remnants of an apartment building. Because most of the surface of the parcel was impervious, the property was contributing to the area’s recurrent combined sewer system overflow problem.

Though originally conceived by University of the Sciences of Philadelphia (USP) to be an adjacent niche park complementary to Clark Park, the institution began to envision more than just the reclamation of a vacant urban lot. University of the Sciences of Philadelphia and partners implemented stormwater best management practices (BMPs) as they reclaimed the half-acre site. By using these stormwater management techniques, a type of low impact development, costly and technically complicated underground storage tanks were avoided.  The detention and infiltration of stormwater is collected from approximately 1,200 square feet of roof area, diverting the water from the overflow sewer system.

By using grading techniques at the lowest portion of the site a 3-4 foot wide and 44 foot long swale, or infiltration trench, was constructed to direct stormwater into a bioretention basin. Native plants including grasses, perennials, trees and shrubs were planted within the basin, which is 2.5 feet deep and measures 600 square feet in area. For a list of native plants, click here. Native plant species help block and absorb stormwater runoff while they also remove pollutants, absorbing them before they are able to enter ground water. The wetland is constructed to detain water long enough to divert it from the sewer system.

Despite a city ordinance requiring brick paving to be underlain with cement, a permeable sidewalk was constructed as an exception with government approval in order for rainwater to effectively infiltrate the ground. Gravel and woodchip paths meandering through the garden also allow for the permeability of stormwater. Rain barrels were also installed to store stormwater on site, and irrigation is conducted using conserved water. For a site plan, click here.

The grand opening of Lower Mill Creek Garden occurred on May 11, 2006. The park has wetland, meadow, and wooded areas, which are introduced to the visitor by interpretive signs. The educational component of this project is supported by the addition of an outdoor classroom within the garden. University of the Sciences’ students in Science Teacher Certification as well as students in the biological sciences program developed educational materials focusing on the education of pre-teens. Educational activity instructions were prepared for teachers, including field guides on wildflowers, tree and shrubs, wildlife certification, stormwater management, and information on watersheds. USP is planning on applying to get National Wildlife Certification as a “Backyard Habitat.”

Location

County: Philadelphia
Watershed: Schuylkill River

Lower Mill Creek Garden is found within the Mill Creek Watershed, the focus of an overarching plan involving local community groups and educational institutions aimed at creating a greenway in West Philadelphia. The Historic Mill Creek Trail Project, spearheaded by the Philadelphia Water Department, consists of about a dozen West Philadelphia projects, and includes Lower Mill Creek Garden. The parcel was purchased back in 2001 by University of the Sciences of Philadelphia (USP) and is located just north of the campus across the street from Clark Park at the intersection of 43rd Street and Chester Avenue in West Philadelphia.

Partners

University of the Sciences (USP) 
Philadelphia Water Department 
University City (UC) Green 
Baltimore Avenue in Bloom

Cost

Total Project Cost: $113,000

Wright-Cook Foundation: $10,000
League of Women Voters of Pennsylvania Citizen’s Education Fund: $3,800
Wal-Mart: $500
USP contributions for sidewalk & fence installation, landscape grading, signage, labor & other miscellaneous items total approximately $60,000.
Pennsylvania Department of Environmental Protection Growing Greener Grant: $38,800

Contact

Mary Kate McGinty (administrator)
Assistant Vice President
Executive Affairs
University of the Sciences in Philadelphia
600 South 43rd Street
Philadelphia, PA 19104
215-596-8719

Stephen McCoubrey (landscape designer)
Landscape Design
229 S. 42nd Street
Philadelphia, PA
215-387-0454
smccou@verizon.net

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