The study compared three models to see how well they predict water and soil processes in a small watershed. The newer version of SWAT, called SWAT+, performed better than the older version and matched the performance of APEX after calibration. All models initially overestimated soil and phosphorous loss, but after calibration, they accurately predicted water yield. SWAT+ is a useful tool for understanding water quality in small watersheds due to its improvements over the older version.