Quantification of available surface water is one among the most important aspects of Water budgeting in the rapid changing climate and erratic rainfall conditions prevailing in India amidst the rapid human developmental activities. Though conventional methods are being employed for periodical estimation of existing surface water from water bodies, there is no standard Geospatial technology based simple methodology available for anytime-use by the planners and administrators. This research paper presents one such simple and accurate methodology for quantification of surface water from reservoirs and tanks using Remote Sensing and GIS techniques. The results obtained in this study have been evaluated with the published data. Thus, it forms a basic model to further strengthen and make it useful for the administrators in water resource budgeting and proper distribution of it for sustainable development of the society.