The ecological consequences of drawing heavily on groundwater are grave. Deep aquifers are a vital link in the hydrological cycle because they release water slowly into rivers, lakes and wetlands in the dry season and soak up water to prevent flooding during the wet. Drawn critically, it would result in dried wetlands and river. Studies indicate that by 2050, more than 50 per cent of the Indian population may shift to cities, with water stress increasing manifold.
Collecting rain however can provide the crucial link. Restricting wasteful runoff from rooftops and using it to recharge the aquifer or storing for future use is a simple doable concept. By opting for harvest of rain water, we promote self sufficiency and help foster an appreciation for this precious resource. Collecting rain water is not only water conserving, it is also energy conserving since the energy input required to operate a water system designed to pump water over a vast service area is bypassed. Rainwater harvesting also reduces erosion and flooding caused by runoff.
A compelling advantage of rain water over other water sources is that it is one of the purest sources of water available. Indeed, the quality of rainwater is an overriding incentive for people to choose rainwater as their primary water source. Rain water quality almost always exceeds that of ground or surface water: it does not come into contact with soil and rocks where it dissolves salts and minerals, and it is not subject to many of the pollutants that often are discharged into surface waters such as rivers, and which can contaminate groundwater. However, rainwater quality can be influenced by where it falls, since localised industrial emissions affect its purity. Field tested information, education and communication should be implemented to create awareness among the people to adopt and propagate rain harvesting measures.