Groundwater disaster deepens in Karnataka’s arduous rock terrain

Stretching throughout a lot of peninsular India, the Deccan Plateau hides a silent, subterranean battle. Beneath its sunbaked soil lie historical, fractured layers of basalt and granite — arduous rock aquifers that dominate the area’s groundwater story.

In Karnataka, this rocky actuality is almost absolute: about 99% of the State depends on these stubbornly unyielding formations for its water wants. With restricted porosity and a dependence on slim fractures and weathered pockets to retailer and transfer water, these geological formations supply far lower than they promise, in contrast to the beneficiant circulation of sedimentary aquifers.

In a brand new research, researchers from the Water, Surroundings, Land and Livelihoods (WELL) Labs in Chennai examined Aralumallige and Doddathumakuru gram panchayats within the Higher Arkavathy watershed close to Bengaluru, revealing a pointy decline in groundwater ranges pushed by intensive agricultural practices.

These areas provide greens, unique crops, and flowers to Bengaluru, banking on water-intensive farming. Whereas monsoon rains supply seasonal aid, farmers depend upon deep borewells for the remainder of the yr. Borewells drilled into granite bedrock alter the subsurface geology, creating microfractures that fasttrack rainwater deep underground. Because of this, as an alternative of recharging shallow aquifers, water bypasses them fully, disrupting the native hydrology and weakening long-term water retention.

Yearly, the water desk continues to drop. In response to the research, printed not too long ago in PLoS Water, the typical depth of gram panchayat ingesting water borewells dramatically elevated from 183 m throughout 2001-2011 to 321 m in 2011-2021. Thus virtually 55% of all wells drilled within the Aralumallige sub-watershed have failed, with a staggering 70% of ingesting water wells failing inside a decade of their development, primarily resulting from falling water tables.

The research additionally highlighted water high quality points. Whereas nitrate ranges in ingesting water have been typically increased than the prescribed norm of fifty mg/l, folks didn’t abandon their wells. Interviews with gram panchayat officers revealed that solely two of the 79 deserted borewells have been shut resulting from elevated fluoride concentrations.

The findings collectively recommend groundwater high quality points, whereas acknowledged, aren’t the first drivers of borewell abandonment. As a substitute, the overwhelming trigger is the persistent and extreme depletion of the water desk.

Mounting challenges

Electrical energy is free for farmers, however gram panchayats are grappling with a mounting financial disaster. The frequent drilling of deep borewells, which require highly effective pumps, has pushed them into steep electrical debt. Income assortment can’t cowl the ballooning annual energy payments, straight affecting the flexibility of panchayats to keep up rural water infrastructure. Funds meant for growth tasks are being redirected to cowl utility prices, stalling native progress. In the meantime, the State authorities has begun pressuring panchayats to pay excellent taxes regardless of their monetary pressure.

Borewell drilling prices are borne by people. For small farmers, this implies investing ₹4-5 lakh in a single borewell, with no assure of success. Many find yourself leasing their land and migrating to city areas for a steady earnings. Labour, pump set up, and infrastructure bills have hit the agricultural financial system arduous.

Regardless of widespread consciousness of water shortage, there have been few efforts to coach farmers on the results of water-intensive cropping. The area’s terrain limits greywater reuse and youth migrating away additional disrupts sustainable practices.

Whereas Karnataka banned eucalyptus farming because of the species’ high-water use, its long-term impression on groundwater persists.

The brand new research additionally pointed to a broader concern: regardless of widespread groundwater overexploitation, there’s little or no quantitative proof on the dangers to water sustainability on the native stage. This makes it tough to foretell borewell failures or estimate the true prices confronted by ingesting water authorities.

The researchers have argued that poor water useful resource administration is the most important menace to sustained rural ingesting water entry in India. Whereas international ‘water, sanitation, and hygiene’ initiatives deal with technical and monetary infrastructure, they typically overlook the foundational downside: uncared for useful resource administration.

Efforts in movement

Within the research, the researchers used knowledge from the Sujala Challenge, a key groundwater recharge initiative by the Karnataka authorities, to hint depletion traits. In addition they referenced the Jal Jeevan Mission, India’s flagship programme for common piped water entry, which has funded new infrastructure and changed failed borewells. Whereas the research wasn’t straight important of those programmes, it argued that long-term success hinges on addressing the basis disaster: groundwater depletion and the monetary pressure it imposes on native governance.

As Lakshmikantha N.R., one of many research’s authors, put it: “Till and until you modify the farming strategy of over-extraction, no quantity of recharging will change the state of the groundwater” in Aralumallige, Doddathumakuru, and different rural components of the Deccan Plateau. He additionally really useful that gram panchayats start compensating farmers for utilizing much less electrical energy and extracting much less water, encouraging extra sustainable practices whereas decreasing rising electrical energy payments.

“If such an initiative isn’t taken,” he warned, “inside 3-4 years there can be no groundwater left to drink or use.”

Till the Nineteen Seventies, Bengaluru relied on tanks and reservoirs to replenish groundwater. However with the arrival of borewells, which function on shorter timescales, conventional programs have been deserted. In Aralumallige, the native lake, as soon as a key recharge reservoir, has now been encroached upon, its soil dug up, its inexperienced cowl denuded. Earlier than borewells, the lake’s discharge channels helped recharge surrounding areas. In 2022, regardless of heavy rainfall, the lake remained dry.

The findings paint a sobering image: with out pressing shifts in agricultural practices and stronger native governance, groundwater within the Deccan Plateau could slip past restoration. In response to the researchers, sustainable farming, recharge infrastructure, and coverage incentives should work in tandem and never as afterthoughts. The research recommends higher insurance policies and applied sciences to assist rural farmers and governing our bodies use their sources with out inviting a disaster.

Neelanjana Rai is a contract journalist who writes about indigenous group, atmosphere, science and well being.

Printed – July 02, 2025 05:30 am IST