Riverbend Environmental Education Center, a non-profit organization, is a valuable community resource since it serves to educate the public, especially children, about environmental processes. The Center is found in an environmentally precarious location since the Center’s building and its protected acreage are found at the bottom of a steep valley many miles below disturbed riparian acreage. The velocity and volume of runoff worsens each year and causes damage in Lower Merion Township and to the Center’s property, where a flood took out a bridge in 2004.
In 2004, the Center underwent a master planning process in order to outline areas of program growth and habitat restoration initiatives. The planning process identified Best Management Practices (BMPs) to reduce water volumes and erosion and improve the quality of outflow into Saw Mill Run, including a Porous Asphalt Parking Lot and Bioswale. These BMPs were installed during October 2006.
Porous Asphalt Parking Lot
The replacement of the Center’s parking lot was a top priority because oils, road salts, and other nutrients were unloading into adjacent Saw Mill Run during storm events. The old asphalt parking area was also due to be replaced, so the timing corresponded well.
The recharge bed underlying the porous asphalt stores water and allows it to percolate into the ground. During construction, soil below the storage bed was loosened at the natural substrate level to allow for greater infiltration and aquifer recharge. This has improved water table levels and calmed water velocity in the vicinity.
This stormwater BMP has had a positive effect on Saw Mill Run. Erosion has subdued and aquatic diversity is improving. Pollution (e.g. nutrients and heavy metals), trash and sediments are filtered by the porous asphalt, and thus are prevented from entering Saw Mill Run. Spring Mill Road was re-contoured on one side to capture runoff as well.
Additional water running off the porous asphalt is discharged into a bioswale, which acts as a second line of defense before pollutants and nutrients can reach Saw Mill Run. This vegetated swale uses soil and native plants to infiltrate stormwater, trap pollutants, calm water velocity, regulate water temperature, facilitate evapotranspiration, and recharge the water table.
The bioswale plant list (including shrubs, trees, and seed mixes) and planting sequence are available here.
Watershed: Schuylkill River
Riverbend Environmental Education Center is located at 1950 Spring Mill Road in Gladwyne. Located at the confluence of Saw Mill Run into the Schuylkill River, the Center is a natural haven amidst heavy development in the Philadelphia metropolitan area.
Riverbend Environmental Education Center
Montgomery County Conservation District
Partnership for the Delaware Estuary (Schuylkill Watershed Initiative Grant-SWIG)
The Ed and Christine Snider Foundation
Lower Merion Township
Cahill Associates, Inc. (engineering)