Flood alert sounded as Tamil Nadu's Mettur Dam nears full capacity

Chennai: As rains pound the catchment areas of Cauvery river in Karnataka leading to huge outflow from dams, the inflow into the Stanley Reservoir in Mettur in Tamil Nadu increased to 81,000 cusecs which is likely to result in the dam reaching its Full Reservoir Level (FRL) of 120 feet in the next couple of days.

As a result, the Public Works Department (PWD) on Saturday issued a flood alert warning to Erode, Namakkal, Karur, Ariyalur, Trichy, Thanjavur, Thiruvarur, Mayiladuthurai, Nagapattinam, and Cuddalore.

“The Mettur Dam water level reached a depth of 117.390 feet today (28.06.2025) at 12.00 noon. In anticipation of heavy inflow, Mettur dam would reach its full capacity (120 feet) soon.

"There is a likelihood of releasing surplus water to Cauvery river from 50000 cusecs to 75000 cusecs and this may be increased at any moment,” the advisory said.

People living on the banks of Cauvery and low lying areas have been asked to move to safer places and take precautionary measures for safety and security of their lives and properties.

At 4 pm on Saturday, the water level at the dam stood at 117.930 feet, with the storage level standing at 90,206 mcft. The inflow stood at 80,984 cusecs while the outflow into the river was 26,000 cusecs.

This will be the first time that the 91-year-old Stanley Reservoir will achieve FRL in this year. The sluices of the Mettur Dam was opened on June 12 for irrigation of kuruvai (short-term) crops in the fertile Cauvery Delta region.

In 2024, the dam was not opened on June 12 due to non-availability of adequate water with Tamil Nadu blaming Karnataka, the upper riparian state, for not adhering to the monthly release of water due to it as mandated by the Supreme Court in its February 2018 order.

However, the dam was reopened on July 28, 2024, after the southeast monsoon intensified in the second week of the month.

The dam, built in 1934 during the British regime, is usually opened on June 12 for cultivation of kuruvai but it has missed the deadline many times in the past. It was opened on June 12 in 2020 and 2021 and the DMK government in 2022 advanced the release of water to May 24 as there was enough water in the dam. In 2023, the dam was opened on June 12.