Water constitutes one of the sensitive environmental parameters of the hydrological processes. Therefore, the study of water resources exploitation sustainable to the environment is important. This is not an easy task for practice and cannot be effective, until the evaluation of the resources are made, scope for further development are assessed and the potential zones are delineated. Therefore, for the best practice of water resources development, a knowledge based GIS model for targeting water resources in a regional scale covering Peninsular India, has been developed by processing the hydrogeological database in a coherent and logical structure supported by a GIS (Geographic Information System) environment.