The federal government in India is accelerating measures to boost rainwater harvesting in the country.
The ministry of Water Resources has requested other central ministries including the departments of Railways, Defence, Posts, Telecommunications, Central Public Works Department and National Highways Authority of India to provide roof top rainwater harvesting structures in the buildings under their control.
Already to promote roof top rainwater harvesting in rural areas, the ministry is implementing a demonstrative scheme through Non-Government Organizations under which funding is provided for construction of roof top rainwater harvesting structures for collection of rain water for drinking and also for use in toilets constructed for girls in all-girls schools.
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 rainwater and used it for irrigation, historians say.
While surface water is inadequate to meet the increasing demand for water everywhere, thanks to rapid urbanization, percolation of rain water into the sub-soil has decreased drastically. Consequently recharging of ground water too has diminished.
The groundwater table is below eight metres below the surface in many places in and around the national capital New Delhi.
It is in these circumstances rain water harvesting has become more and more popular.
is the collection and storage of rain from roofs or from a surface catchment for future use. The water is generally stored in rainwater tanks or directed into mechanisms which recharge groundwater.
This is appropriate in many parts of the world, such as western Britain, China, Brazil, Thailand, Sri Lanka, Germany, Australia and India, where there is enough rain for collection and conventional water resources either do not exist or are at risk of being over-used to supply a large population, experts say.
Rainwater harvesting can provide lifeline water for human consumption, reduce water bills and the need to build reservoirs which may require the use of valuable land, experts note.
As part of its recent initiatives, The Central Ground Water Authority (CGWA) of India has now issued directions to Group Housing Societies, Industries, Farm Houses, and the like in the nation's capital region to adopt the rain water harvesting system.
It has also directed state governments to take all necessary measures to adopt artificially recharge ground water and promote rainwater harvesting in all over-exploited areas.
The CGWA itself regularly conducts mass awareness and training programmes throughout the country on rainwater harvesting.