Chennai, Aug 18: Tamil Nadu is facing mounting water concerns as the combined storage in its 90 reservoirs has fallen to just over 37 per cent of total capacity, with inadequate southwest monsoon rainfall failing to provide sufficient inflows to replenish key water sources.
The decline is raising concerns among farmers and water managers, particularly as the state moves towards the crucial northeast monsoon season. The latest figures show that the reservoirs together hold around 83.1 thousand million cubic feet (tmcft) of water against a total capacity of 224.3 tmcft. At the same point last year, the combined storage was considerably higher at around 189.5 tmcft.
The distribution of water across the reservoirs is also uneven. As many as 58 of the 90 reservoirs are holding less than a quarter of their capacity, while only two have crossed the 80 per cent mark. The low levels are particularly significant for reservoirs that support both irrigation and drinking-water requirements.
Mettur, one of the state’s most important reservoirs and a key source of irrigation for the Cauvery delta, is holding around 43.3 tmcft, or roughly 46 per cent of its capacity. This is significantly lower than the more than 91 tmcft recorded at the same time last year.
The latest state data also puts Mettur’s storage at around 43.8 tmcft, while Bhavanisagar has about 6.4 tmcft and Vaigai only around 0.65 tmcft.
For farmers, declining reservoir levels mean greater uncertainty over irrigation. If inflows remain weak, authorities could have less flexibility in releasing water for crops, potentially affecting sowing decisions and agricultural output in water-dependent regions.
The situation is also important for drinking-water security. While supplies are currently being managed, a prolonged dry spell could place greater pressure on reservoirs, particularly in towns and cities that depend heavily on surface water.
The Cauvery basin remains another key factor. Water availability in Tamil Nadu is influenced not only by rainfall within the state but also by inflows from upstream areas. The condition of reservoirs in Karnataka and the timing and volume of downstream water flows will therefore remain important to Tamil Nadu’s water outlook.
With the southwest monsoon providing limited relief, attention is increasingly turning to the northeast monsoon, which is crucial to Tamil Nadu’s annual water balance. A strong and well-distributed northeast monsoon could replenish reservoirs, improve groundwater levels and ease pressure on agriculture and drinking-water supplies.
However, continued dry conditions would leave the state with a much smaller water buffer. Farmers could face tighter irrigation schedules, while urban areas may have to rely more heavily on alternative sources and groundwater.
The current numbers do not necessarily indicate an immediate statewide water crisis, but they underline the vulnerability created by low reservoir storage. With substantially less water available than a year ago, Tamil Nadu has less protection against another prolonged period of below-normal rainfall.
For now, the state’s water outlook will depend heavily on the weather over the coming months. A strong spell of rainfall could significantly improve the situation, while continued weakness in the monsoon could increase pressure on reservoirs, agriculture and drinking-water supplies.