Darby Creek Restoration Project, PA
Darby Creek drains a largely urbanized watershed adjacent to the City of Philadelphia, Pennsylvania. It is a direct tributary to the Delaware River, and joins with the Delaware near Essington, PA, after passing through the John Heinz National Wildlife Refuge. Early settlement along the Darby relied upon mill dams for economic growth. Today the dams no longer function as originally intended. Instead they contribute to local flooding and block migratory fish passage.
Project overview:
American Rivers is partnering with National Oceanic and Atmospheric Administration and the Pennsylvania Fish & Boat Commission to alleviate localized flooding, improve in-stream habitat, reestablish connectivity for resident and migratory fish (including American shad, hickory shad, alewife, river herring, American eel, bass, shiners, and suckers) , and restore free-flowing conditions along Darby Creek, a direct tributary to the Delaware River. This project will result in unobstructed flows in the lower 9.7 miles of Darby Creek. We seek to accomplish these goals through the removal of three dams and a set of abandoned railroad piers.
Removal of abandoned railroad piers at Colwyn, PA
Description: Removal of two abandoned railroad piers constructed of reinforced concrete. Construction was completed in September 2012.
Benefits of removal: The piers trapped debris and contributed to local overtopping of banks and over-widening of the channel. Removal of the piers is expected to alleviate these impacts.
Removal of Hoffman Park Dam at Lansdowne, PA
Description: The Hoffman Park Dam was a stone masonry dam that was approximately 4 feet high and 40 feet long. The age of the dam is unknown; it appears in the PA DEP Division of Dam Safety records in 1919, but likely dates to the early- or mid-1800s. The dam was previously breached on river right and was owned by the Borough of Lansdowne. Removal of the dam and associated bank stabilization activities were completed in October 2012.
Benefits of removal: Removal of the dam eliminated the direct cause of the backwater condition that negatively impacted in-stream habitat, and allows for the movement of resident and migratory fishes. Removal should also alleviate localized flooding upstream of the former dam location and eliminate a safety hazard.
Removal of Kent Park Dam at Drexel Hill, PA
Description: The Kent Park Dam was a stone dam that was approximately 10 feet high and 90 feet long. The age of the dam is unknown; it appears in the PA DEP Division of Dam Safety records in 1919, but likely dates to the early- or mid-1800s. The dam was previously breached on river left and was owned by Delaware County. Removal of the dam and associated bank stabilization activities were completed in October 2012.
Benefits of removal: Removal of the dam eliminated the direct cause of the backwater condition that negatively impacted in-stream habitat and water quality. It also allows for the movement of resident and migratory fishes, and eliminates a safety hazard.
Removal of Darby Borough Dam & Realignment of Channel at Darby, PA
Description: The Darby Borough Dam was a concrete-capped, stone structure that was approximately 6feet high and 80 feet long. The age of the dam is unknown; it appears in the PA DEP Division of Dam Safety records in 1919, but likely dates to the early- or mid-1800s. It was used as a water source for milling operations, and later, industrial operations, until the early 1900s.The dam was breached approximately 15 to 20 years ago at the river right abutment and the stream completely bypassed the spillway at the time of removal in October 2012. In addition to the removal, approximately 800 feet of stream channel upstream of the former dam is being reconstructed as part of the restoration; all restoration activities will be completed in January 2013. American Rivers staff was on site as Hurricane Sandy approached - see their update here.
Benefits of removal: Removal of the dam is expected to alleviate localized flooding upstream of the former dam location; the dam trapped debris and contributed to local overtopping of banks. During the channel reconstruction, we are extending the length of the channel to reduce the channel slope and energy gradient, and redirect flow away from the most flood prone banks.
This project was funded by the National Fish and Wildlife Foundation (Design/Permitting, $50,000), Pennsylvania Department of Environmental Protection, Growing Greener Program (Design/Permitting, $39,080), and the ATHOS I Oil Spill Natural Resource Damage Settlement (Construction/Oversight/Monitoring, $1,573,287).
Thank you to Delaware County, The Henderson Group, Borough of Colwyn, Lansdowne Borough, Upper Darby Township, Darby Borough, and the Darby Borough Police for their assistance with this project.
For more information, contact Laura Craig with American Rivers at 856-786-9000.
