Identification of suitable locations for rooftop rainwater harvesting structures

Roof top rainwater collection is one of the solutions for solving or reducing the problem of water availability, where there is inadequate groundwater supply and surface sources are either lacking or insignificant quality. Average annual rainfall in the campus of Jawaharlal Nehru Technological University Hyderabad is 821mm with unutilized non-committed surplus monsoon runoff. Ground water levels are being monitored since 2008 and found to be 25 to 30 m bgl deep in pre-monsoon period and 16 to 19 m bgl in post-monsoon which indicates the ample scope for artificial recharge of rainwater. Present study deals with the geomatic approach by employing GIS, GPS and Remote Sensing techniques for identifying sites for construction of roof top rainwater harvesting structures in the study area by preparing various spatial maps. To meet the deficit water requirement in the campus through artificial recharge and re-use of ground water, three recharge structures each with a capacity of 1,00,000 liters and one reuse structure with a capacity of 2,00,000 liters have been identified using Geomatics.