‘Even rains don’t help’: Groundwater crisis acute in Karnataka

As rainwater harvesting expert Devaraj Reddy points out, Karnataka has used 70% of its extractable groundwater resources.

In Agumbe, known as the ‘Cherrapunji of the South’, stands one of the oldest houses in the region — Doddamane. Part of the famed television series ‘Malgudi Days’ was shot in this house and later, it hosted a number of tourists every summer.

This season, its owner G K Ravikumar Pai (61), was hesitant to entertain guests as the 35 ft well, a major attraction, had just two ft of water left in it.

“For the first time in 145 years the water level was so low,” says Ravikumar.

Also Read: Scanty rainfall leaves borewells dry in Bengaluru's peripheral areas

Not just this well, nearly 80 per cent of the open wells in Agumbe, were all but empty this summer.

Credit: DH Graphic

Like many others, Ravikumar believes that the region is witnessing a water crisis in the last three to four years because of a rainfall deficit.

As against the 7,565 mm annual rainfall, Agumbe received just 3,695 mm of rainfall in 2020 (a 51 per cent deficit). In 2021, the region had a 45 per cent deficit of rainfall and in 2022, a 38 per cent deficit.

Experts believe that rainfall deficit is just one of many reasons behind the depletion of groundwater levels in Malnad and Coastal Karnataka, where water was easily available in the past. Deforestation, concretisation, over-exploitation of groundwater for agriculture and poor rainwater harvesting systems are equal culprits. As a result, even places which have seen an increase in rainfall are also facing a water crisis.

As rainwater harvesting expert Shree Padre points out, good rainfall does not always ensure the replenishment of groundwater tables. “Good rainfall does not necessarily ensure replenishment of groundwater table. It is the extent of percolation into the earth that matters. It is like a bank operation. Unless we deposit, we cannot withdraw, and now we are overdrawing. We have already started receiving notices,” he explains

While people are using groundwater for agriculture, domestic and industrial purposes, there is little understanding about using the resource judiciously. Ideally, only 50 per cent of groundwater resources should be extracted.

Experts advise against using up the quantum of recharged groundwater due to ecological constraints.

But as rainwater harvesting expert Devaraj Reddy points out, Karnataka has used 70 per cent of its extractable groundwater resources.

As per ‘Dynamic Groundwater Resource of Karnataka’, a 2023 study by the Central Groundwater Board (CGWB) and other institutions, Bengaluru, Chamarajanagar, Chikkaballapur, Chitradurga and Kolar have extracted more than 100 per cent of the recharged groundwater.

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Davangere, Ramanagar, Tumakuru and Vijayanagara have extraction between 90 per cent and 100 per cent of water.

Such indiscriminate withdrawal of limited groundwater resources is not without consequence.

These districts, located in the central, southern and eastern drylands of Karnataka, are increasingly dependent on groundwater, owing to limited surface water availability.

Cropping patterns

The report reveals an interesting pattern of extraction — 89 per cent of extracted groundwater is used for irrigation purposes, 10 per cent is used for domestic purposes and 1 per cent for industrial use.

The lack of surface water and poor irrigation systems contribute to a majority of farmers using borewells.

Despite the presence of two major rivers, the Krishna and the Malaprabha, most farmers in Belagavi still depend on borewells to irrigate their land. The district had more than 88,885 functioning borewells in 2022, according to the CGWB report. Most of the water thus supplied is used to cultivate sugarcane— a water-guzzling crop.

During the green revolution, farmers particularly experienced the need for water. This caused an indiscriminate number of borewells to pop up. “People overlooked the culture of rejuvenating the open wells and maintaining lakes and tanks the traditional way resulting in poor recharge of the water table,” says Pramod Hanamgond, a professor from Belagavi.

Wrong cropping patterns and an errant supply of electricity are other reasons for the excess drawing of groundwater.

This is a situation that needs immediate intervention according to Padre. The priority should be ‘more crop per drop’, he explains.

“Forests are our first line of defence against drought. The more organic matter in the soil, the greater the percolation of water. With deforestation, we are creating more run-offs for the rainwater and reducing the water-holding capacity of the earth,” he adds.

Also Read: K'taka reservoir levels plummet; drinking water shortage follows

The effects of deforestation are clear in Malnad and coastal Karnataka where the land has lost capacity to retain water. Environmentalist Nagesh Hegde explains that even surface water evaporates quickly due to global warming and percolation of water into the ground takes a longer period due to silt accumulation in water bodies.

An increase in cropping area and the shift in focus to water-guzzling crops resulted in the indiscriminate installation of borewells, most of which were dug below permissible levels. This has also led to water contamination and a deterioration in quality.

According to the quality tests conducted across 1,245 borewells and 700 Atal BhooJal units in the state by the CGWB, samples from Ballari, Chitradurga, Davangere, Kalaburagi, Raichur, Kolar and Vijayanagara contained fluoride. Salinity was noticed in samples from Chitradurga and Koppal.

In 13 taluks, including Gadag, Chikkaballapur, Chitradurga, Vijayapura and Yadgir, nitrate contamination was found.

Drinking water

Traces of uranium, a nuclear substance, were also found in borewells that were used to supply drinking water to homes in Kolar and surrounding areas, says a 2020 report from the Indian Institute of Science. This is a matter of concern as the nuclear substance is a possible carcinogen.

Water contamination has proved fatal in many regions. At least eight people died, and several others were admitted to the hospital in a span of one year, in Koppal and Raichur, according to reports. They complained of diarrhoea and other health issues after consuming contaminated groundwater.

Two villages where such incidents were reported received the Har Ghar Jal certificate. “We have tap connections but water has not flown in them till now. So, even to this day, we rely on water from a hand pump,” says Raghavendra Nayak, of Raichur’s Rekalmaradi village, who lost his one-year-old nephew to contaminated water.

Under the programme, every house in the panchayat has a drinking water pipeline connection.

“Unluckily, sewage water percolated into the groundwater and mixed with the water that we drew from the hand pump,” recalls Nayak.

Chemical contamination

Extracting groundwater 25-30 m below ground level can be harmful as chances of chemical contamination increase.

“Groundwater (from the hard-rock regions of India) generally hosts shallow aquifers up to depths of 25-30 mts below ground level. Extracting from deeper levels is not sustainable as deeper aquifers take longer to recharge, have lower unit storages and may have higher dissolved solids,” says hydrogeologist Himanshu Kulkarni, Advanced Centre for Water Resource Development and Management, Pune.

Unfortunately, due to poor management, most water bodies have either become defunct or are contaminated.

Kulkarni explains that there is no silver bullet solution as the problem is diversified. To start with, India should strictly adhere to the internationally-accepted ‘managed aquifer recharge’ (MAR) techniques that help recharge an aquifer using surface or underground recharge techniques.

Failure to follow through on these guidelines can also prove devastating. In Kolar and Chintamani, the state government has taken the initiative to fill lakes and other water bodies, in an effort to replenish groundwater.

“Replenishing groundwater seems like a good step. But the state government is filling lakes and other water bodies with second-level sewage-treated water instead of tertiary potable water. This is causing more damage,” says Anjaneya Reddy, a Kolar-based activist.

A report from the Indian Institute of Science warns that this water could potentially be a health hazard through direct and indirect consumption.

In addition, according to Anjaneya, the government did not conduct an environmental, health and social impact study after discharging half-treated sewage water through the Koramangala-Challaghatta (KC) and Hebbal-Nagawara (HN) valley projects.

Balasubramanya B, Minor Irrigation Department Deputy Secretary, says currently they were ‘pumping’ secondary treated water from KC and HN Valley to Kolar and Chintamani taluks. “Tertiary treatment, which improves the water quality to potable, is a costly affair. The Bangalore Water Supply and Sewerage Board is supposed to provide us with tertiary-treated water. However, it is not being done,” he says.

He also adds that a dedicated staff has been appointed to test the quality of the water and based on the recommendation and quality suggestion by the Indian Institute of Science, Bengaluru, water was being supplied to the region.

These efforts have resulted in an improvement of groundwater level from 1,000 ft to 100 to 200 ft, according to the official. However, he did not respond to questions on the quality of water that was available.

“Government has to take necessary steps to ensure that tertiary treated water is supplied,” he says.

Percolation in cities

The dependence on groundwater, despite the potential for contamination, persists in even a metropolitan city like Bengaluru — about 50 per cent of the city is dependent on groundwater.

“Water scarcity is not prevalent in central Bengaluru where there are more open spaces. However, the ‘new’ Bengaluru that has plinth-to-plinth buildings built upon ‘encroached’ lakes is facing a water crisis as there is no space for water to percolate,” says Veena Srinivasan, a researcher with Ashoka Trust for Research in Ecology and Environment.

She says that the government has no control over the number of borewells. This has worsened the situation. At least 20-30 per cent of wastewater should be allowed to seep into the earth, she adds.

Rainwater harvesting

The city’s water needs could be met by utilising rainwater, says S Vishwanath, urban developer and ‘A Million Recharge Wells’ project initiator.

“There is no need for us to draw 1,450 million litres of water per day from the Kaveri. A Kaveri flows right beneath us. Even if we harvest 50 per cent of the total rain that Bengaluru receives annually, we can get 1,500 million litres of water per day for 365 days.”

Even though urban bodies claim that 85 per cent of the city harvests rainwater, Devaraj Reddy says the reality comes to light every monsoon in the form of waterlogging. Unless rainwater harvesting norms are strictly implemented, as the late Jayalalithaa government did in Chennai in 2001, Bengaluru will continue to face drinking water and waterlogging problems.

Officials in the Groundwater Directorate say that measures have been put in place to replenish the groundwater table through tank and lake filling projects. Over the last three years, groundwater levels and quality have improved, says Ramachandraiah, director of the Groundwater Directorate.

However, he acknowledges that some taluks are in need of special attention. He faults the concretisation of urban areas for the poor replenishment of groundwater. “A strict norm should be put in place to restrict drilling borewells,” he says.

Some experts suggest a master plan of linking water bodies should be developed. In the absence of such a network, even though surface water is available, people will continue to depend on groundwater.