Change in water hydrology is caused by climate change. This study evaluates the response of stream flow to climate change. A study of the impact of climate change on streamflow and direct runoff in the Gumera watershed was carried out using the hydrologic model HEC-HMS. Climate change impact analysis was performed using a down scaled Regional Climate Model (RCM) called the Hadley Center Earth System Model (Had GEM-ES). In this model, bias correction was done for 365 days using power transformation for rainfall correction. The study showed that for the RCP2.6 scenario, streamflow decreases annually by 0.001% in the 2050’s. It decreases annually with change of 0.01% for RCP4.5. The RCP8.5 scenario reveals an annual decrease in streamflow of 0.002%. The study provides a broad perspective on probable hydrologic alterations in the region, and the results provide useful input for sustainable water resource development.