Cobbs Creek Gully and Slope Repair


A stormwater outfall pipe sited on a forested slope formed an eroding gully up to 12 feet deep and was contributing excess sediment to Cobbs Creek. An adjacent hillside was denuded and heavily compacted by illegal ATV usage, with resulting slope erosion. The eroding gully was filled and permanently stabilized using naturalistic construction methods. 1100 tons of large rock was used to construct a series of cascading stone step pools over a distance of 360 feet.

The denuded and compacted hillside was stabilized with erosion control fabric. A stormwater infiltration trench was installed on the flat area near the top of the slope. 896 trees, 1114 shrubs and 3935 herbaceous plants were installed along the repaired gully, on the repaired slope and on the adjacent floodplain. A gate and guide rail was installed to prevent future unauthorized access.

Downed woody material was placed along the access path to maintain the trail width and further preclude ATV access to the repaired hillside.


County: Philadelphia
Watershed: Darby-Cobbs Creek


PA Department of Environmental Protection
U.S. Environmental Protection Agency
William Penn Foundation


$205,000 (all construction)


Philadelphia Parks and Recreation

Leave a Reply