About this Project

Bells Mill Run, a tributary of Wissahickon Creek, flows through the Wissahickon Valley, a designated National Natural Landmark. When awarded, this was the largest stream restoration project and the most significant undertaking ever by the Philadelphia Water Department (PWD). The project aimed to stabilize the stream corridor, reduce sediment loads to Wissahickon Creek, and protect adjacent infrastructure, including Bells Mill Road and a parallel sanitary sewer line.

AEG led an extensive watershed study and developed restoration strategies for the PWD and Fairmount Park Commission. The team examined approximately 5,300 linear feet of Bells Mill Run and its tributaries, assessing the soils, geology, stormwater infrastructure, land use, vegetation, and presence of threatened species. Using GIS tools, AEG mapped watershed data and supported hydrologic analysis.

A geomorphic study and detailed hydrologic/hydraulic modeling, calibrated to PWD’s Wissahickon SWMM, enabled AEG to develop accurate flow estimates and restoration strategies tailored to Bells Mill’s unique stream type. Restoration design focused on reconnecting the floodplain, stabilizing streambanks, and enhancing aquatic habitat.

AEG also prepared permitting documents, conducted endangered species surveys, and coordinated with the Pennsylvania Historical and Museum Commission to ensure protection of cultural and environmental resources. The completed restoration reduced sediment loads, improved water quality, and eliminated threats to critical infrastructure.