What is it?

• According to a sample assessment in 2011, groundwater in 19 of India’s 71 districts were exploited, meaning that nearly as much or more water was being pulled out than their reservoirs’ natural rechargeability.
• Groundwater is exploited unequally. The maximum overdraft is in the northwestern States of Rajasthan, Punjab and Haryana.
• The latter two are key wheat granaries and, despite developed canal-networks, rely extensively on groundwater.
• The overall contribution of rainfall to the country’s annual groundwater resource is 68%, and the share of other resources, such as canal seepage, return flow from irrigation, recharge from tanks, ponds and water conservation structures, taken together is 32%.
• Moreover, the population increase has meant that the national per capita annual availability of water has reduced from 1,816 cubic meters in 2001 to 1,544 cubic metre in 2011, a 15% reduction.

How has this come about?

• Over the last two decades, an overall decline in the quantum of pre-monsoon rainfall has increased dependence on groundwater.
• The immediate signs of deficit are visible in water storage.
• According to figures from the Central Water Commission, India’s key reservoirs are, as of this week, 10% short of their decadal average for this time of the year.

Why does this matter?

• Other than groundwater being a reserve to be used judiciously, over-exploitation poses health risks.
• West Bengal, Odisha, Uttar Pradesh, Bihar and Jharkhand face severe problems of arsenic contamination, and one of the causes is drawing water from increasingly greater depths.
• Punjab and Haryana have for years reported a spike in cancer cases owing to chemical fertilisers leaching into the soil.

What lies ahead?

• There have been several attempts to get the States to use groundwater more responsibly.
• The Centre has a ‘model’ groundwater Bill that is not binding on the States.
• However, 11 States and four Union Territories have adopted it.
• But the legislation has had limited impact on groundwater exploitation.
• Currently, the owner of a piece of land is deemed the owner of the groundwater below it.
• This Bill attempts to put the State as the custodian of the groundwater.

Source:TH