In 14 years (2001-02 to 2014-15), net irrigation in India increased just 20 per cent, with an alarming trend of massive groundwater extraction. Per data from the Ministry of Statistics and Programme Implementation, while 41 per cent of the net irrigated area in India got water from tube wells in 2001-02, tubewell irrigation increased to 46 per cent in 2014-15. Interestingly, during the same period, irrigation based on canal systems came down to 24 per cent from 27 per cent and well irrigation declined to 17 per cent from 21 per cent. Not surprisingly, groundwater schemes are increasing, but surface water schemes are declining across India.

Other sources of irrigation have increased from 8 per cent to 11 per cent while use of tank irrigation has witnessed a minor decline (from 4 per cent to 3 per cent).

Per a report by the Committee on Restructuring of Central Water Commission and the Central Ground Water Board, when the annual withdrawal rate of groundwater is compared with the annual recharge of groundwater the picture that emerges is “not very rosy”.

The withdrawal rate expressed as a percentage of the net ground water available per year (termed level of Ground water development) exceeds 100 per cent in some states and is far from satisfactory in other States. “A major contributor to this rapid depletion in water tables is the overwhelming dependence on deep drilling of groundwater through tube wells,” the report adds.

Low water mark danger

If the current pattern of demand continues, about half of the demand for water will be unmet by 2030. The work based on data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites, reveals significant rates of non-renewable depletion of groundwater levels over large areas. The declines were at an alarming rate of as much as one foot per year over the past decade.

During the study period of August 2002 to October 2008, groundwater depletion in Rajasthan, Punjab, Haryana and Delhi was equivalent to a net loss of 109 cubic km of water, which is double the capacity of India’s largest surface-water reservoir.

As water bodies continue to vanish from the urban landscape and the groundwater table in rural areas depletes rapidly, the water situation looks severe considering that over 60-70 per cent of India is vulnerable to drought. One-third of the country’s districts have faced more than four droughts in the past decade and the number of drought- prone areas has increased by 57 per cent since 1997.

Many of India’s peninsular rivers are facing a serious crisis of postmonsoon flows and water tables are falling in most parts of India with fluoride, arsenic, mercury, even uranium found in groundwater. Not surprisingly, per the government data the average annual per capita water availability in the years 2001 and 2011 was assessed as 1,820 cubic meters and 1,545 cubic meters respectively, which may reduce further to 1,341 and 1,140 in the years 2025 and 2050, respectively, it said.