Kabini Surplus Reaches Mettur Dam: Cauvery Inflow Rises

Fresh inflow from the Cauvery river system has brought some relief to Tamil Nadu's Mettur Dam, as surplus water released from the Kabini reservoir in Karnataka reached the Stanley reservoir in Salem district on Tuesday.

The release was necessitated by heavy downpour in the catchment areas of the Kabini river in Karnataka, which has brought the reservoir nearly to its full capacity. Water was let out from the dam on Saturday, and it took three days to traverse the downstream reaches of the Cauvery before arriving at Mettur.

Water Resources Department officials said the inflow into Mettur steadily increased after the water first arrived in the afternoon. The discharge from the Kabini reservoir is being maintained at 25,000 cusecs, and officials expect the inflow at Mettur to correspondingly rise to that level in the next couple of days. Meanwhile, the inflow measured at Hogenakkal, further upstream on the Cauvery, touched 18,000 cusecs on Tuesday.

Officials noted that if the dam receives a sustained 25,000 cusecs for a full day, the water level could rise by about four feet. This would augment storage in the reservoir, which has been below-average this season.

At 8 p.m. on Tuesday, the water level at Mettur stood at 73.18 feet against its full reservoir level of 120 feet. The live storage was 35.49 TMC (thousand million cubic feet), against the full capacity of 93.47 TMC. The inflow into the dam had surged to 4,923 cusecs, up from a meagre 68 cusecs earlier, reflecting the arrival of the Kabini waters.

The Mettur dam authorities have continued to release 1,500 cusecs downstream for drinking water needs. This is part of the normal operation for supplying water to towns and villages along the Cauvery delta.

Mettur Dam, also known as Stanley Reservoir, is one of the largest reservoirs in Tamil Nadu and is vital for irrigation across the delta districts. The Cauvery river water sharing between Karnataka and Tamil Nadu is governed by a tribunal award and subsequent Supreme Court orders. The present release is described as 'surplus water' arising from heavy rainfall in Karnataka, rather than a distress-sharing situation.

The increase in inflow is being closely monitored by farmers in the delta region, who rely on releases from Mettur for the ongoing samba cultivation season. While the current storage is still only about a third of the full capacity, the fresh influx provides some hope for better water availability.

The Water Resources Department has said it will continue to track the inflows and adjust downstream releases accordingly. Officials also cautioned that the situation depends on further monsoon spells in the catchment areas of Karnataka.