Recession of hydrograph gives a significant contribution to estimation of baseflow using rainfall-runoff models and baseflowseparation methods, because recession affects baseflow. This study attempted to enhance the accuracy of streamflow predictionsusing a Soil and Water Assessment Tool (SWAT) model and to separate baseflow from the predicted streamflow. For this, thisstudy used two scenarios: 1) to calibrate eleven parameters using an auto-calibration tool with the alpha factor obtained fromRECESS (S1); and 2) to calibrate twelve SWAT parameters including alpha factor (one of SWAT parameters) using anauto-calibration tool (S2). Then, baseflow spearation from the predicted streamflow was conducted by using Web-basedHydrograph Analysis Tool (WHAT). The results show that there is no significant difference between Nash-Sutcliffe efficiency(NSE) values of S1 and S2 for calibrations to streamflow. However, calibrations to baseflow showed that NSEs are 0.777 forS1 and 0.844 for S2, which means a significant difference. Quantitatively compared to the observed streamflow, relative errorswere 20.78 % for S1 and 6.59 % for S2. Finally, this study showed the importance of recession in baseflow separated fromthe predicted streamflow using a rainfall-runoff model.