Author(s): Benjamin Dye; Jonathan Czuba

Linked Author(s): Jonathan Czuba

Keywords: No keywords

Abstract: Dam releases can result in hydropeaking events, most noticeable during the low-flow summer months of July and August. These events can disrupt low flow periods that are critical to the life cycles of benthic species (Shacheri et al., 2025). The various life stages of brown trout (Salmo trutta) are impacted by hydropeaking events. They require low flow periods to spawn and nest. If dam releases are too rapid, this could result in negative impacts on brown trout populations. Negative impacts primarily affect reproductive phases in the trout life cycle. Eggs are deposited in a redd that is buried in a gravel stream bed for months until they hatch. While they are buried, rapid flow increases can scour the redd and wash away the eggs. Additionally, rapid rises and decreases in the flow can injure trout in the fry or juvenile stage (Maryland Department of Natural Resources). Controlling dam releases to reduce hydropeaking events reduces the risk young stages of trout face in river systems. The Sustainable Rivers Program is a partnership between the U.S. Army Corps of Engineers (USACE) and The Nature Conservancy (TNC) to improve downstream river ecosystem health by adjusting dam operations (Bahabib et al., 2025). The USACE and TNC are interested in determining if the controlled dam releases at Jennings Randolph Dam are too rapid and are negatively affecting recruitment of brown trout in the North Branch Potomac River on the border of Maryland and West Virginia, USA. It is hypothesized that flow changes due to the release of the dam are much more rapid than natural flow changes. The extension of the hypothesis is that the unnatural increases in flow rate influence the biota of the North Branch Potomac River. The purpose of this study is to compare the flow recorded at the USGS gage downstream of Jennings Randolph Dam with other gages on the North Branch of the Potomac River with natural flows will give insight into whether Jennings Randolph Dam causes hydropeaking events that could influence trout populations. Releases from this dam can be identified by comparing data from U.S. Geological Survey (USGS) 15-minute streamflow data from several nearby gages. Gage 01595500 Kitzmiller, is upstream of Jennings Randolph Dam and is not affected by hydropeaking, and gage 01595800 Barnum, is downstream of the dam ; both on the North Branch Potomac River. Additionally, gage 01596500 Barton, is upstream of Savage Dam on the Savage River, a tributary to the North Branch Potomac River. Barton is also not affected by hydropeaking. The 15-minute instantaneous streamflow data were analyzed for all three gages. RStudio was utilized to download the data from the USGS servers, and organize, analyze, and plot the data. First , the change in flow between subsequent 15-minute intervals was calculated, and we refer to this as the change in flow or flow difference. This indicates how much the flow change d every 15 minutes. The change in flow was plotted with

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.197

Year: 2026