Water Availability Is One of the Major Issues That Needs Attention from the Present Generation Across the Whole World to Attain Sustainability. Spatial Variation of Water Resources and Further Climatic Changes Are Main Reasons For Extremes Like Droughts and Floods. This Urges For the Quantification and Forecasting of Availability of the Basic Need of Life. at the River Basin Level, Stream Flow Is Considered As the Most Crucial Parameter to Assess Water Availability, Which Can Be Estimated By Simulation or Modelling Approaches. This Article Presents About the Hydrological Modeling Using a Semi-Distributed Model Namely Swat (Soil and Water Assessment Tool), Applied to Seonath River Basin, Chhattisgarh, India. the Cfsr (Climate Forecasting System Reanalysis) Meteorological Data For the Period of 1979-2014 (35 Years) Is Used and the Runoff Is Generated, Which Is Calibrated Using the Observed Flow at the Basin Outlet. the Results Reveal the Observed Flow and Modeled Flow to Be Very Poorly Correlated. the Major Causes of Such Mismatch Are Identified and Possible Improvement Options Are Discussed.