CHENNAI: Water storage in Tamil Nadu’s reservoirs has dropped to a critical level, with 63 of the state’s 90 reservoirs holding less than 25% of their capacity on Friday. Another 17 reservoirs have storage between 26% and 50%, leaving the state with little buffer as it enters the northeast monsoon. None of the reservoirs has reached full capacity, mainly due to the southwest monsoon’s failure.
According to water resources department (WRD) data accessed by TNIE, the combined storage in the 90 reservoirs stood at 74.412 tmcft, or just 33.17%, against their total capacity of 224.343 tmcft. The storage was significantly higher at 181.591 tmcft (80.94%) during the corresponding period last year and 134.712 tmcft (60.06%) in 2024.
The sharp fall in storage, attributed mainly to the rainfall deficit, has raised concerns over water availability for drinking and irrigation during the coming months. “With water availability remaining low, the state is now largely dependent on the northeast monsoon to meet drinking water needs and summer requirements,” a senior WRD official told TNIE.
The official also referred to a recent Central Water Commission warning that reservoir storage levels across the country had fallen below the 10-year average due to El Niño conditions.
The situation is particularly worrying in western Tamil Nadu. Of the 24 reservoirs in the Coimbatore region, including Sholayar, Aliyar, Bhavanisagar, and Amaravathy, none has water level above 40%, except Parambikulam in Palakkad, which has 73.76% storage, another official said.
In the Tiruchy region, Mettur reservoir remains the major source of hope. It has 40.37% storage; the other five reservoirs in the region have less than 17% storage, the official said.
The situation is also worrying in the Chennai and Madurai regions, where reservoir storage has remained particularly low.
Officials said the poor storage could put pressure on drinking water supplies, irrigation and hydropower generation in the coming months. With the southwest monsoon failing to replenish reservoirs adequately, the state will now have to rely heavily on the northeast monsoon to improve storage and meet its water requirements.