Darby Creek Dam Removal and River Restoration

Princeton Hydro was contracted to investigate, analyze, and design the removal of obstructions and restore natural stream function on Darby Creek. With funding from the National Fish and Wildlife Foundation and Pennsylvania Growing Greener program, the objective of the project was to remove remnant bridge piers in Colwyn and Sharon Hill Boroughs, a failed dam in Darby Borough, a mill dam in Landsdowne and Clifton Heights Boroughs, and a dam in Upper Darby Township and Clifton Heights Borough.

Princeton Hydro prepared hydrologic and hydraulic analyses, assessed fluvial geomorphic characteristics, determined infrastructure impacts, inventoried natural resources, including wetland delineations and invasive species, and assessed impounded sediment. Design plan sets were prepared, public presentations completed, and permit applications submitted to the Pennsylvania Department of Environmental Protection, U.S. Army Corps of Engineers, and the Delaware County Soil Conservation District.

The innovative design for this project included the relocation of 800 feet of stream in Darby Borough from a dammed, channelized, and incised river reach to a sinuous section of stream that reconnected the channel with its floodplain. This portion of the project included the reuse of harvested trees as toe-wood with root wads and locked limbs throughout the reach, use of biodegradable reinforced soil lifts, and the installation of over 700 woody native plants and several hundred pounds of herbaceous seed.

Princeton Hydro provided construction observation and administration to ensure the implementation met the stakeholders’ expectations and design intent. This project was funded by the PADEP Growing Greener Grant program, the National Fish and Wildlife Foundation, and a NOAA settlement fund from the 2004 Athos I oil spill on the Delaware River.