The Water Erosion Prediction Project (WEPP) watershed scale model was developed by the USDA for
purposes of erosion assessment and conservation planning. The purpose of this study was to evaluate the WEPP
watershed model applicability and prediction accuracy for small watersheds (0.34-5.14 ha) under different climate,
topography, soil, and management regimes. No calibration was conducted to obtain the results. Only default model
parameters were used. Data from 15 watersheds in six U.S. locations were compared to runoff and sediment yield
estimates using WEPP95. The r2 values between measured and predicted total runoff and sediment yield for the
15 watersheds were 0.86 and 0.91, respectively. The r2 between measured and predicted event data for individual
watersheds ranged from 0.01 to 0.85 for runoff and from 0.02 to 0.90 for sediment. Cumulative frequency distributions for
predicted values of event runoff and sediment matched those for measured values with some exceptions. Improvements in
the WEPP model are suggested where limitations were observed.