In recent times there is a continuous influence by climate change and human activities on the environment giving rise to hydrological focus research. Hydrologic modeling tools are employed to examine various practical issues arising from planning, design, operation, and management of water resources systems. These include physical, empirical, stochastic, distributed models and open-source watershed models such as Info Works River Simulation (IWRS), Stormwater Management Model (XP-SWMM), Soil and Water Assessment Tool (SWAT), Kinematic Runoff and Erosion Model Software (KINEROS), Long-Term Hydrologic Impact Analysis (L-THIA) and River Analysis System (HEC-RAS). From the models mentioned, SWAT is a typical distributed model widely used in analyzing and forecasting several complex hydrologic variables. This paper is aimed at providing an overview of SWAT and its applicability in hydrological modeling.