Baseline Channel Characterization of the Lower Bushkill Creek in Easton, Pa, Prior to the Removal of Three Low-Head Dams

Funds have been allocated through a Consent Order and Agreement by the Pennsylvania Department of Environmental Protection (PADEP) to be administered by the Delaware River Basin Commission (DRBC) to remove the first three run-of-river dams on the Bushkill Creek. Dam 1, the lowermost dam, is owned by Lafayette College and is 1.8 m high and 21.3 m long, dam 2 is 2.4 m high and 39.6 m long, and dam 3 is 1.5 m high and 33.5 m long. The dams will be removed with the goal of restoring the lower Bushkill to a more natural, free-flowing condition and to improve ecosystem function. We are collecting baseline background data on channel morphology and channel bed sedimentology immediately downstream and upstream of each dam. These data will be used to help develop a model of channel response to dam removal and also as the baseline for continued monitoring the channel response to dam removal. We measured multiple channel cross-profiles upstream and downstream of the two upstream dams, and more thoroughly surveyed the channel upstream and downstream of dam 1 near the confluence of the Bushkill Creek and the Delaware River. We are also collecting grain size data at each cross-profile to characterize the channel bed prior to dam removal. During the summer 2017 we mapped approximately 5.7 km of the Bushkill Creek from the mouth of the creek at it’s confluence with the Delaware upstream to the bridge at Edgewood Ave in Easton PA. The stream was separated based on physical characteristics into runs, riffles, pools, and dam pools formed. Other characteristics that were mapped include both natural and man-made features such as islands, rip-rap, bridges, significant storm drainage pipes, and retaining walls along the riparian corridor. The proposed dam removals afford a unique opportunity close to our campus to study channel bed dynamics and hydrologic impacts of dam removal at relatively short timescales as well over the long term.