Failure of monsoon makes the situation worse. As surface water sources fail to meet the ever- increasing demands, ground water reserves are tapped, often to unsustainable levels. Also, the fast rate of urbanisation reduces the availability of open spaces for natural re-change of rain water. Unplanned and uncontrolled extraction of ground water would disturb the hydrological balance along the coastal areas which results in possible sea water intrusion. Hence, it is necessary to take up measures to conserve and increase the renewable water resources in all possible ways.
Water crisis occurs in the absence of effective collection and storage of rain water.
If only we save every drop of water and recharge the underground aquifer, we can rescue ourselves from this perpetual problem of water scarcity. The potential of rain to meet water demand is tremendous. In scientific terms, water harvesting broadly refers to collection and storage of rain water and also other activities such as harvesting surface water, extracting ground water, prevention of losses through evaporation and seepage. In general, water harvesting is the activity of direct collection of rain water. The fast rate of urbanisation reduces the availability of open surfaces which would enhance the recharge of ground water.