New Delhi, Nov 22 (UNI) The methodology for estimation of groundwater sources in the country is periodically changed to get a fair estimation of availability of groundwater even as the country is currently undergoing an estimation in 2007-08.
The country has estimated replenishable groundwater resources of 433 billion cubic metres (BCM) with a net annual availability of 399 BCM. Out of 5,723 assessment units, 4078 units were categorised as 'safe' and 550 units were 'semi-critical' and 226 units were 'critical'. About 839 units were listed as 'over exploited', while the rest of the blocks were in the category of saline groundwater.
He said the latest estimate was done in 2004 and the methodology involved for annual recharge of groundwater through various sources like rainfall, canal seepage, return flow of irrigation, seepage from tanks and ponds. There is also estimation of annual groundwater draft for different uses -- domestic, industrial use and irrigation.
The latest Groundwater Resources Estimation Committee consisted of various academic institutions like Central Ground Water Board, NABARD, National Institue of Hydrology, Rourkee, Indian Institute of Science, Bangalore, IIT Rourkee and Centre for Water Resources Kozhikode and various state groundwater departments.
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