86 taluks contaminated, Bengaluru over-exploited: Groundwater report

Bengaluru: While Karnataka has seen an overall decline in groundwater extraction, the entire Bengaluru area remains ‘over-exploited’ and sub-surface water in 86 taluks is contaminated, a government report released Wednesday said.

Overall groundwater extraction has reduced from 68.44% in 2024 to 66.49%, the Dynamic Ground Water Resources of Karnataka 2025 report said.

The annual groundwater recharge capacity has marginally risen from 18.74 billion cubic metres (BCM) in 2024 to 19.28 BCM in 2025. Also, annual extractable groundwater resources rose from 16.88 BCM to 17.41 BCM.

“These gains are the result of good rainfall, focussed policy interventions and large-scale water conservation initiatives,” Minor Irrigation Minister NS Boseraju said after releasing the report.

However, all taluks in the Bengaluru Urban district remain in the ‘over-exploited’ category.

The groundwater status in 11 taluks -- Athani (Belagavi), Channapatna (Bengaluru South), Chamarajanagar, Molkalmur (Chitradurga), Davangere, Ron (Gadag), Channarayapatna (Hassan), Ranebennur, Savanur, Shiggaon (all Haveri) and Afzalpur (Kalaburagi) -- have improved.

In six taluks, the situation has deteriorated: Magadi (Bengaluru South), Kamalanagar (Bidar), Laxmeshwar (Gadag), Aland (Kalaburagi), Chadchan and Indi (both Vijayapura).

Groundwater extraction ranges from 5.91% in Madikeri (Kodagu) to a staggering 378.85% in Bengaluru East, the report shows. District-wise extraction ranges from 25.44% in Ballari to 184.43% in Kolar.

The report also notes a small decline in groundwater extraction for domestic use thanks to the Jal Jeevan Mission (JJM).

Contamination

Nitrate is the highest contaminant of groundwater in 41 taluks, which includes Bengaluru North and Yelahanka, the report shows. There is high salinity in 17 taluks, fluoride in 15 taluks and uranium in 13 taluks.

AI-based surveillance

Boseraju said the government will soon initiate AI-based satellite surveillance for real-time data for continuous groundwater monitoring. This will be under the Digital Water Stack (DWS) initiative, the minister said.

“Instead of depending solely on the 120-day monsoon, we’re ensuring water availability across all 365 days through scientific management. This has strengthened long-term water security for both farmers and urban residents," he claimed.