The Soil and Water Assessment Tool (SWAT) model was used to study the Maquoketa River watershed in Iowa. Data from weather stations and streamflow measurements were used to analyze how different factors affect surface runoff and baseflow. The model showed that curve number, evaporation compensation factor, and soil available water capacity are crucial parameters for watershed hydrology. The model was calibrated and validated for accuracy, explaining over 86% of streamflow variability during calibration and 69% during validation. This study lays the groundwork for future water quality analyses in the Maquoketa River watershed using SWAT.