Hydrology of the Reelfoot Lake basin, Obion and Lake counties, northwestern Tennessee
Hydrologic data and analyses and ground-water modeling results are provided to aid in the evaluation of proposed lake management strategies for Reelfoot Lake in northwestern Tennessee. Surface-water and ground-water data collected from May 1 to December 31, 1984, were used to evaluate the Reelfoot Lake hydrologic system. Long-term streamflow, rainfall, evaporation, and lake-level data were used to describe the normal hydrologic conditions at Reelfoot Lake. Estimated monthly water budgets, assuming normal climatic and hydrologic conditions, were derived for Reelfoot Lake in order to determine the time required to refill the lake beginning on November 1, following a proposed mid-summer drawdown of 5.8 feet below normal pool. Additionally, estimates of the time required to fill the lake to 1.0 foot above normal pool were made. Results of these determinations indicate that a normal pool elevation of 282.20 feet above sea level would probably be achieved by mid-January, and a pool elevation of 283.24 feet above sea level by the end of January. A calibrated two-dimensional ground-water flow model was used to simulate groundrater levels following the proposed lake drawdown and refill. Simulation results are presented as ground-water level difference maps which indicate the potential difference in ground-water elevations for the two proposed lake-level extremes. Low lake-level simulation results indicate ground-water levels may decline approximately 5.7 feet below normal in the areas immediately adjacent to the lake. The high lake-level simulation results indicate ground-water-levels may increase approximately 1.0 foot above normal in the areas immediately adjacent to the lake.