Project Update: Forbidden Drive Streambank Stabilization Complete

Current Projects // October 31, 2019

Friends of the Wissahickon is excited to announce the completion of its extraordinary Forbidden Drive Streambank Stabilization Project.

The RiverLogic Solutions and Applied Ecological Services (AES) crews have hauled their equipment off site, removed all barriers, replaced all split rail fencing, and planted each location, leaving the three collapse site locations stable and ready to face the future

Each of the once-eroded streambank sites – approximately 1,000 feet downstream from Valley Green Inn, the Mt. Airy Ave. pedestrian bridge, and immediately downstream from the Kitchen’s Lane Bridge – is a great example of FOW’s conservation-driven construction practices. They were all stabilized using soil lifts (similar to terraces) and materials that will integrate into the natural view scape. The AES crew populated the completed soil lifts with native seeds, small young trees and shrubs. Over time, these plantings will become established growth, support the engineering techniques, and naturalize the streambank.

Although all three locations have much in common, the Kitchens Lane project site has two distinct features to ensure that future erosion is limited. The first one, known as rock armoring, connects to the second feature, a stormwater drainage channel leading to the creek. A dip in the trail was dug out and large stone was laid flat to create the first feature. Rock armoring allows water to quickly be moved from the trail while trapping sediment between the stones and keeping it from entering waterways. It also inhibits gullies from forming and gouging the trail as water flows downhill to the creek. With this improvement, the water is directed across Forbidden Drive, over the rock armor dip, to a stormwater management drainage channel made of cascading stone to the Wissahickon Creek, which allows for optimum water quality and overall creek health by removing sediment and adding oxygen.

FOW would like to thank RiverLogic Solutions and AES for their expertise, hard work, and dedication to this project; and Philadelphia Parks & Recreation and the Philadelphia Water Department for their support and guidance. We also appreciate our park users’ patience during the construction process. Finally, we are indebted to the private donors, and funders whose generous support made this important work possible, including the Community Conservation Partnership Program, Pennsylvania Department of Conservation and Natural Resources, Bureau of Recreation and Conservation, Pennsylvania Department of Community and Economic Development, and Pennsylvania Commonwealth Financing Authority.