The water budget is an important phenomenon driving all other processes in a watershed. Climate is the main driver responsible for regulating the water budget process and planning of water resources. Soil and Water Assessment Tool (SWAT) is a widely used hydrological model, which has been used in the study to understand the role of climate parameters on water budget components. The water budget of the baseline period (1990-2004) was calculated .Model was simulated for three global SRES precipitation and temperature scenarios (A2, B1 and A1B) for three different time periods (2010-2024; 2046-2060; 2082-2096). Water budget components analysis done for projected values shows rise in water yield as well as rise in evapotranspiration amount for all three time periods under all the scenarios. In case of south Asia, there is also rise in water yield amount. Change in water yield is more in case of south Asia as compared to global for all three periods.