Rain Water Harvesting
RAIN WATER HARVESTING AND ARTIFICIAL RECHARGE TO GROUND WATER
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.
ARTIFICAL RECHARGE TO GROUND WATER :
Artificial recharge to ground water is a process by which the ground water reservoir is augmented at a rate exceeding that obtaining under natural conditions or replenishment. Any man-made scheme or facility that adds water to an aquifer may be considered to be an artificial recharge system.
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.
The storage of rain water on surface is a traditional techniques and structures used were underground tanks, ponds, check dams, weirs etc. Recharge to ground water is a new concept of rain water harvesting and the structures generally used are :-
DIVERSION OF RUN OFF INTO EXISTING SURFACE WATER BODIES
Construction activity in and around the city is resulting in the drying up of water bodies and reclamation of these tanks for conversion into plots for houses.
Free flow of storm run off into these tanks and water bodies must be ensured. The storm run off may be diverted into the nearest tanks or depression, which will create additional recharge.
Urbanisation effects on Groundwater Hydrology :
Methods of artificial recharge in urban areas :
Computation of artificial recharge from Roof top rainwater collection :
Factors taken for computation :
Benefits of Artificial Recharge in Urban Areas :
HARVESTING RAINWATER HARNESSING LIFE :
A NOBLE GOAL - A COMMON RESPONSIBILITY
Ground water exploitation is inevitable is Urban areas. But the groundwater potential is getting reduced due to urbanisation resulting in over exploitation. Hence, a strategy to implement the groundwater recharge, in a major way need to be launched with concerted efforts by various Governmental and Non-Governmental Agencies and Public at large to build up the water table and make the groundwater resource, a reliable and sustainable source for supplementing water supply needs of the urban dwellers.
Recharge of groundwater through storm run off and roof top water collection, diversion and collection of run off into dry tanks, play grounds, parks and other vacant places are to be implemented by Special Village Panchayats/ Municipalities /Municipal Corporations and other Government Establishments with special efforts.
The Special Village Panchayats /Municipalities/Municipal Corporations will help the citizens and builders to adopt suitable recharge method in one's own house or building through demonstration and offering subsidies for materials and incentives, if possible.
ATTRIBUTES OF GROUNDWATER :