Groundwater exploitation is silently sinking the ground beneath India’s feet

Agricultural practices in northwest India are heavily dependent on groundwater withdrawal. With limited monsoon rain, the groundwater table is precariously low, show data gathered for years by the Central Ground Water Board (CGWB).

Cracks in buildings and ‘sinking’ land in Joshimath, a hill town in Uttarakhand, made the headlines earlier this year. A similar phenomenon has been playing out for years in the plains of Punjab, Haryana, Delhi and Faridabad. The unlikely culprit is excessive groundwater extraction.

Agricultural practices in northwest India are heavily dependent on groundwater withdrawal. With limited monsoon rain, the groundwater table is precariously low, show data gathered for years by the Central Ground Water Board (CGWB).

In Punjab, for instance, 76% of the groundwater blocks are ‘over exploited’. In Chandigarh it is 64% and about 50% in Delhi. This means that more groundwater than can be recharged is extracted.

“Over time, when the underlying aquifers (deep water channels that are stores of percolated water) aren’t recharged, they run dry and the layers of soil and rock above them start to sink,” Prof. Dheeraj Kumar Jain of the Indian Institute of Technology (Indian School of Mines), Dhanbad, said.

Mr. Jain, whose core research interests lie in mining and minerals, said digging operations that were carried out hundreds of metres below the ground for coal, oil and gas through the years had shown examples of ‘soil settlement,’ or the soil sinking in to fill voids created from mining.

“From here we surmised that if oil and gas extraction cause subduction (sinking), then surely groundwater also ought to be playing some role. We found such instances in several parts of the world and that motivated some of my students to assess the situation in India, particularly the National Capital Territory.”

The CGWB, a subsidiary body of the Jal Shakti Ministry, is tasked with assessing the state of India’s groundwater resources. It has a system of groundwater observation-wells and monitors water levels four times a year. It, however, does not analyse the consequences of ‘over exploitation.’