Phosphorus retention models for Tennessee Valley Authority reservoirs

Abstract

Data for the 18 largest Tennessee Valley Authority (TVA) reservoirs are compared with previously developed models for predicting steady state phosphorus concentrations in lakes. A plug flow model is presented for lakes and reservoirs which have significant longitudinal variation in phosphorus concentration. The results indicate that phosphorus sedimentation and retention coefficients developed for natural lakes are not directly applicable to TVA reservoirs. The apparent settling velocity of phosphorus in TVA reservoirs was substantially higher than previously reported values for natural lakes. Application of the plug flow model to Cherokee Reservoir showed good agreement with measured in‐lake phosphorus concentrations.