NEW DELHI: The Centre is carrying out 3D aquifer mapping of every village which will help it take specific water conservation measures at micro level across the country, said Union Jal Shakti minister Gajendra Singh Shekhawat."We have identified some agencies and we are carrying out the 3D mapping of all the villages. This will help us identifying the gradient and how the water flows naturally. No one ever thought about it in all these years. We have undertaken this task. This will help us in water conservation and rainwater harvesting ," Shekhawat told TOI in an interview on Monday.The deficit so identified will help the government to carry out its recharge plan where the treated grey water can also be used. Grey water or 'sullage' is defined as all wastewater generated in households, except from toilets. Sources of grey water include, sinks, showers, baths, clothes washing machines or dish washers. Managing the waste water and solid waste have been identified as the major focus area under Swachh Bharat Mission after achieving 100% toilet coverage in rural areas. He added the focus will be on recycling of the grey water. "Either you use the recycled water for agriculture or for groundwater recharge . Grey water is an asset while everyone thinks it's a liability. Once people find this is an asset, the problem will be over," he said.The ongoing exercise of 3D aquifer (underground layer of water-bearing rock) mapping at micro-level will assist the government in estimating quantity and quality of ground water in a particular village or cluster of villages and help in assessment of sustainable level of ground extraction. The mapping is being undertaken by the Central Ground Water Board on the scale of 1:50,000 in 3D. Currently, 1,034 blocks (ground water assessment units) out of 6,584 are over-exploited, which means withdrawal of ground water is more than recharge in those particular units.934 blocks are in various stages of ground water criticality. Once the government has 3D aquifer map of entire mappable area, it will help in predicting ground water scenario and educating the stakeholders in water use efficiency. The focus to map the natural water flow across villages gains importance considering that an NSSO survey of 2016 had revealed that while 36.7% villages had pakki nali (pucca drain) and 19% villages had katchi nali as drainage arrangement for wastewater coming out of the rural households, 44.4% villages had no drainage arrangement at all.