Bengaluru East Taluka is pulling 378% of what its aquifer can sustainably replace

There is a number in Karnataka's groundwater reporting that deserves more attention than it gets. Across the state, extraction in 2025 reached 66 per cent of what the aquifer can sustainably replace. In Bengaluru East Taluka it reached 378 per cent. The difference between those two figures is the entire water story of the city in one ratio.

Sustainably extractable volume is a specific measure: the withdrawal rate at which the aquifer would be depleted. It is not a measure of how much water is left. A figure above 100 per cent does not mean Bengaluru East has emptied its groundwater; it means that at the current rate of withdrawal, replacement cannot keep pace — which is a slower and harder problem than running out.

The physical explanation is local. Bengaluru sits on crystalline rock that stores little water and recharges slowly. Demand concentrates where population density and per-capita use are highest, which is to say tech parks and apartment complexes, and the paved surfaces those require suppress the percolation that would have recharged the rock. As The Hindu's editorial put it on April 14, the city treats supply as if it were infinitely expandable when it is not.

1. 1.378 per cent — Bengaluru East Taluka's 2025 extraction against sustainable yield, against 66 per cent for Karnataka as a whole.
2. 2.308.4 MCM — annual groundwater extraction attributed to Bengaluru in the 2025 assessment.
3. 3.15,731 — Sanchari Cauvery tanker orders fulfilled in the first quarter of 2026, worth Rs 1.7 crore, against 11,681 orders and Rs 1.2 crore in the October-December 2025 quarter.
4. 4.220 tankers and 90-plus filling stations — BWSSB's declared capacity for the service.
5. 5.65 wards — where an Indian Institute of Science study found declining groundwater levels.

What the tanker data shows

BWSSB's Sanchari Cauvery service, launched in May 2025 to undercut private tanker operators, has become a measure of the problem rather than a solution to it. Demand rose 20-25 per cent in the weeks to April 21. Of the orders fulfilled in 2026, 5,819 were bulk requests from apartments and industry, worth Rs 70.9 lakh — commercial users, not just households, are now queueing. Registrations for the service reached 14,419 since launch, with 3,810 recorded between January and early April alone, more than double the previous quarter.

The crisis has also moved. A weak monsoon in 2024 left close to half of Bengaluru's 14,000 borewells dry, and the tankers went to the villages at the city's edge. A 2026 study reported in The Hindu found the problem had shifted to Koramangala and Hebbal. Beyond the city, the rural water supply department recorded 210 villages on tanker supply and 125 more on hired private borewells, with Ramanagara district the worst affected at 55 villages, ahead of Raichur at 41.