The process of accumulation and storage of rain water into a catchment area for further use is known as Rain Water Harvesting. This water can be used for irrigation, cleaning, gardening, indoor heating for houses and other domestic use, it is not suitable for drinking without proper water treatment.
With the increase in pace of construction the water table is falling rapidly resulting in drought conditions and the lakes have been replaced with landfill dumps. This is creating a very scary situation of scarcity of water which is one of the most essential natural resources that are required for survival.
Areas that face regular water shortage can combat their problems to some extent by rain water harvesting. In ancient India the dry states like Gujarat and Rajasthan used step wells to store water whenever there was shortage. Hence it a process of going back to the roots and conserving water by restoring the water balance.
The most simple and common method of rain water harvesting is accumulating water from the roof. In this method the rain water is transferred from the roof top through gutters and pipes into a catchment area or reservoir for further use.