CE-QUAL-W2, a mechanistic, two-dimensional model of hydrodynamics and water quality (Portland State University, 2021), was developed and calibrated for J. Percy Priest Reservoir, Tennessee, a U.S. Army Corps of Engineers (USACE) reservoir on the Stones River, southeast of Nashville, Tennessee. The J. Percy Priest CE-QUAL-W2 model was simulated and calibrated using USACE data collected from January 2012 through May 2019. Constituent loads were developed for the CE-QUAL-W2 model using the LOAD ESTimator (LOADEST; U.S. Geological Survey, 2016) and were based on water-quality data collected by the USACE from January 2005 through May 2019. The calibrated model will be used by the Tennessee Department of Environmental Conservation and others as a water-quality diagnostic and predictive tool for water-resources management. References: Portland State University, 2021, CE-QUAL-W2 Hydrodynamic and Water Quality Model: Water Quality Research Group, accessed October 19, 2021, at http://www.cee.pdx.edu/w2/. U.S. Geological Survey, 2016, Load Estimator (LOADEST): A Program for Estimating Constituent Loads in Streams and Rivers: U.S. Geological Survey website, accessed February 8, 2022 at https://water.usgs.gov/software/loadest/.