What is Rain water harvesting?
The principle of collecting and using precipitation from a catchments surface. An old technology is gaining popularity in a new way. Rain water harvesting is enjoying a renaissance of sorts in the world, but it traces its history to biblical times. Extensive rain water harvesting apparatus existed 4000 years ago in the Palestine and Greece. In ancient Rome, residences were built with individual cisterns and paved courtyards to capture rain water to augment water from city’s aqueducts. As early as the third millennium BC, farming communities in Baluchistan and Kutch impounded rain, water and used it for irrigation dams.
Why Rain water harvesting:
Rain water harvesting is essential because:-Surface water is inadequate to meet our demand and we have to depend on ground water. Due to rapid urbanization, infiltration of rain water into the sub-soil has decreased drastically and recharging of ground water has diminished. As you read this guide, seriously consider conserving water by harvesting and managing this natural resource by artificially recharging the system. The examples covering several dozen installations successfully operating in India constructed and maintained by CGWB, provide an excellent snapshot of current systems.
Rain water harvesting Techniques:
There are two main techniques of rain water harvestings.
← Storage of rainwater on surface for future use.
← Recharge to ground water.
Urbanisation effects on Ground water hydrology:
← Increase in water demand.
← More dependence on ground water use.
← Over exploitation of ground water.
← Increase in run-off, decline in well yields and fall in water levels. ← Reduction in open soil surface area.
← Reduction in infiltration and deterioration in water quality.
Methods of artificial recharge in urban areas:
← Water spreading.
← Recharge through pits,...