INCOH/SAR-27/2006-Manual for roof top rain water harvesting using cisterns or storage tanks for individual households community and institutions

Abstract

Roof Top Rain Water Harvesting is an important rain water harvesting process of capturing and storing rainfall utilizing the roof tops of the residential, industrial and other housing complex, thereby preventing run off, evaporation and seepage of rainfall; for efficient conservation and utilization. Roof Top Rainwater Harvesting is mainly used for drinking water supply. For many parts of India, Roof Top Rainwater is the cheapest form of water supply due to the availability of substantial rain-water. Roof Top Rain Water Harvesting techniques have an edge over other alternatives especially in hilly areas, islands, coastal and saline areas because of difficulties in construction of water supply schemes. The planning and designing of Roof Top Rain Water Harvesting system is guided by the volume of water that could be captured by the rooftop and subsequently stored. The extent and distribution of rainfall decides the volume of water available from the rooftops. Since the area of rooftops is by and large a fixed entity, the extent of rainfall and related climatic conditions decide the quantity of rainwater, which could be harvested and stored.