One-size-fits-all method for groundwater recharge may not work in India: experts

A one-size-fits-all solution to charge aquifers is unlikely to work for a country where even states in the Indus-Ganga-Brahmaputra groundwater basin, the planet's richest groundwater reservoir, are at risk of long spells of drought, say experts.

With the threat of many Indian cities running out of groundwater by 2020 looming large and not just traditionally dry areas facing a parched future, hydrologists, geologists and other experts said a multi-pronged approach is imperative.

Estimates show that India consists of only two per cent of the world's total land area, but supports 19 per cent of the global population, making it inherently stressed for natural resources for its citizens.

A NITI Aayog report in June estimated that many Indian cities will run out of groundwater by 2020 -- a bleak scenario for a country where 75 per cent of the domestic water sectors and 80 per cent of agriculture irrigation are reliant on groundwater.

"India is living beyond its available water resources. Initially, it was thought that only traditionally water-scarce, western India and parts of southern India are getting parched. However, in last couple of summers, unprecedented water worries are showing up even in the maps of eastern India, which have been historically known to be water affluent, and host some of the largest groundwater basins in the world, said Abhijit Mukherjee, associate professor of hydrogeology at the Indian Institute of Technology (IIT) Kharagpur.

Widespread occurrences of natural groundwater contaminants along with emerging pollutants, increasing food demand associated with growing population, and effects of climate change have further compounded the problem, Mukherjee told PTI in an email interview.

The government, he said, has taken stock, and plans to supply piped drinking water to every household by 2024.

"A nationwide effort to artificially recharge the groundwater has started under MNREGA programme and parched water harvesting structures across the country is getting reviewed," Mukherjee added.

He added that the propositions are in good spirit and intent but have not kept in mind the scientific principles that govern groundwater recharge.

Water resource availability is extremely heterogeneous and largely dependent on the topography, geological -- soft sediment or hard rock -- and climatic setup (mostly as rainfall) for an area, along with human usage, mostly for food production through irrigated agriculture.

Groundwater storage is influenced primarily by a very delicate balance of certain factors, which needs a detailed scientific evaluation and understanding.

Explaining these factors, Mukherjee said, Every year, the groundwater of an area is typically recharged by rainfall, particularly during the monsoon."