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 late-1690s. 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. American Rivers staff was on site as Hurricane Sandy approached – see their update here. In addition to the removal, approximately 800 feet of stream channel upstream of the former dam was reconstructed as part of the restoration; all restoration activities were completed in June 2013.
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 extended the length of the channel to reduce the channel slope and energy gradient, and redirect flow away from the most flood prone banks.