In 2016, the U.S. Geological Survey (USGS) carried out a hydraulic study within the upper Delaware River Basin for the purpose of determining the time of travel for water releases from the Brookfield Renewable U.S. hydroelectric plant at Lake Wallenpaupack, Pennsylvania, to reach the USGS streamgage located on the Delaware River at Montague, New Jersey (site number 01438500). From September 19 to October 14, 2016, Brookfield Renewable initiated repeated releases of approximately 650 cubic feet per second (ft3/s) and 1,440 ft3/s. Hydraulic signals from the releases were tracked at nine key locations between Lake Wallenpaupack and the USGS streamgage at Montague, New Jersey (01438500). Gage height data were recorded at streamgages at major confluences of the Lackawaxen and Delaware Rivers, Mongaup and Delaware Rivers, and the Neversink and Delaware Rivers. The time of travel to the USGS streamgage at Montague, New Jersey, was determined to be 1,185 minutes during the approximately 650 ft3/s releases and 960 minutes during the approximately 1,440 ft3/s releases. Elevated streamflow between Lake Wallenpaupack and the Montague streamgage from runoff events prior to the dam releases was found to decrease calculated time of travel identified during the study. The results from this study can be used as a guide to estimate time of travel while considering the water level of downstream streamflow, the volume of water being released, and other outside influences, such as precipitation and snowmelt.
