Small changes from norm can have big impacts
By Summit Voice
FRISCO — An in-depth U.S. Geological Survey study in the Tennessee River basin may help quantify how streamflow alteration changes aquatic ecosystems.
The research is based on community data collected by the Tennessee Valley Authority, and predictions of streamflow characteristics at more than 600 locations — and the findings indicate that even small deviations from natural streamflows can reduce fish diversity.
The study highlights the importance of the timing, magnitude, and variability of low streamflows and the frequency and magnitude of high streamflows as key characteristics critical to assessing how fish communities change in response to streamflow alteration.
“Managing river flows to meet the needs of our growing communities and economies will become increasingly challenging in the future”, said Sally Palmer, director of science for The Nature Conservancy in Tennessee. “Maintaining our rivers to support an abundance of natural wildlife, including our native fish, is an important goal as well. Studies like these give us better information to make management decisions which more effectively balance all the demands placed on our river resources.”
The Tennessee River basin is one of the richest areas of aquatic diversity in the country, if not the world. However, expanding urban development, more than 600 privately held small dams on medium to small streams, and withdrawal of more than 700 million gallons of water each day threaten this diversity. Understanding the effect of streamflow alteration on aquatic ecology is increasingly important as change in land use and human population are projected.
The National Park Service, responsible for the protection and management of Big South Fork National River and Recreation Area and the Obed Wild and Scenic River in Tennessee, has a need to assess potential impacts to the resources they are charged with protecting.
“This research enhances our ability to respond to current development pressures and serves as the foundation to develop a decision support tool to address future water resource issues” said Jeff Hughes, hydrologist with the NPS.
Additional information regarding environmental flows research in the Tennessee River basin can be found online. This work was completed as part of the USGS Cooperative Water Program in collaboration with the Tennessee Wildlife Resources Agency, Tennessee Department of Environment and Conservation, and The Nature Conservancy.