Water consumption is likely to increase substantially in the future on account of rising population, economic growth, and social development. Rapid urbanization and population growth of Allahabad city, has necessitated thinking about the declination in ground water level as well as supply of sufficient quantity of water for future either for drinking purpose or industrial use. In the present study, rainfall recharge of Allahabad city has been computed on GIS platform (ArcInfo). Groundwater recharge potential zones of Allahabad city have also been found out using GIS. Case study of recharge of ground water through roof top rainwater harvesting at Vikas Bhawan (a multistoryed building), Allahabad is discussed. An implementation of this analysis and decision making software is expected to work for sustainable water management.