Regional Project Profile
Triangle Park  

Category: Implemented Retrofit Design   
Type of BMP: Porous asphalt basketball court, subsurface infiltration bed, rain garden

| Description | Location | Partners | Cost | Other | Contact |
 

The stormwater Best Management Practices (BMPs) at Triangle Park include: 1) Porous asphalt basketball court and underground infiltration facility, and 2) Rain garden. Phase I, consisting of the underground infiltration facility, has been completed.  Phase II will be completed by mid-summer 2008.  These enhancements will improve water quality, provide wildlife habitat, beautify the park, and effectively manage run-off from storm events. 

1) Porous Asphalt Basketball Court and Underground Infiltration Facility
To reduce water run-off flowing on to Rutledge Avenue, the on-site basketball court was resurfaced with porous surface material. Underneath the court, an 85’ x 85’ underground infiltration gallery was constructed and filled with stone or pipe to hold stormwater. This system maximizes the park’s small space and does not interfere with present amenities. Overall, the system allows for adequate storage of surface water during peak flow times and recharge of underlying aquifers. For a porous pavement diagram by Cahill Associates, Inc. click here.

2) Rain Garden
A rain garden, or bioretention basin, will be constructed. The rain garden design incorporates several tiered grades to provide for varied microhabitats for moisture-loving plants. Original topsoil will be replaced upon disturbed earth, native plants shrubs and trees will be planted, and a maintenance plan will be laid out to prevent the growth of invasive species.

The installment of a rain garden at Triangle Park is beneficial to the ecology of the whole watershed region. Nutrient and sediment laden Crum Creek has been listed as an “impaired” body of water under the Clean Water Act. This is due to high impact development and conventional stormwater methods like drains, sod basins, and concrete swales, which simply convey rapid stormwater run-off directly into creeks and rivers. This rain garden will allow sediment to settle and reduce nutrients like fertilizers and oils’ entry into Crum Creek. For a bioretention diagram, click here.

County:         Rutledge Borough, Delaware County
Watershed:   Crum Creek

Triangle Park is on 2.5 acres between Swathmore and Rutledge Avenues in suburban Rutledge Borough. The park, which includes a baseball field, basketball court and playground, is located on the more residential side of the Borough. Parking is located along Swathmore Avenue, which habitually floods along with Rutledge Avenue. There was previously no stormwater infrastructure in place, exacerbating the flooding issue. The flat area of the park and its surrounding streets create huge quantities of run-off, which has been known to sweep away mulch from Triangle Park’s playground. There are no stormwater sewers in the vicinity of the park and water flows straight down the avenues in their gutters. The park’s closest outlet drain is located 500 ft from the park down Swathmore Avenue. Conceptual retrofit design recommendations included building a porous asphalt basketball court, an underground infiltration gallery, and a rain garden. Other recommendations that are not being implemented include a vegetated water quality channel, a diversion berm around the playground, and another subsurface infiltration tank under grassy areas.
 

Rutledge Borough, Delaware County Planning Department, Delaware County Conservation District, Pennsylvania Environmental Council
 

Impervious surface reduction with subsurface infiltration: approx. $24,000-30,000. Subsurface infiltration facility: approx. $75,850-$95,000. Diversion berm: $9,500-12,000. Vegetated water quality channel: $15,800-19,750.
 

The concept design recommendations were prepared by Borton-Lawson through funds provided by the Pennsylvania Department of Environmental Protection (PADEP) and the Pennsylvania Environmental Council’s (PEC’s) Stormwater Retrofit Technical Assistance Program, which is funded through a Pennsylvania DEP Coastal Zone Management Program Grant and through the William Penn Foundation. Catania Engineering is hired under contract by the Borough for the final design project.