Wissahickon Creek was suffering from erosion damage and pollutant overload near the site of Monastery Stables in the Wissahickon Valley Park until 2005, when the Philadelphia Water Department and Fairmount Park Commission intervened and applied for grants to fund projects to mitigate the problem. Runoff from the surrounding fields and structures contributed nonpoint source pollution to the creek, from picking up manure and sediment from the stable paddocks and surrounding areas.
Site improvements were made to capture and infiltrate the water, lessening the sediment, nutrients and bacteria that had been impacting the creek. A grassed waterway and four diversion swales were designed to receive runoff and route it away from the paddock area towards a sediment basin. The basin collects water from the grassed waterway and its diversions, allowing overflow to be stored in a tank. Once filled, the tank releases stored water at a low-flow rate via a perforated manifold pipe into the woods, where it can infiltrate the ground and recharge the groundwater supply.
Other measures taken to prevent sediment pollution were the construction of a stone crossing across the diversions for pedestrian and horse traffic and the excavation of dips in a section of trail between the stables and the creek to reduce erosion on the slope.
Watershed: Wissahickon Creek
Fairmount Park Commission
1515 Arch St., 10th Floor
Philadelphia, PA 19102