Tamil Nadu has, yet again, realised a higher quantity of Cauvery water in the just-concluded water year (2025-26) than what was stipulated for the State.

During June 2025 to May 2026, the State recorded, at Billigundulu on the border of Karnataka and Tamil Nadu, about 330 thousand million cubic feet (tmc ft.) against 177.25 tmc ft. prescribed in the Cauvery Water Disputes Tribunal’s final award of 2007 that was amended by the Supreme Court in its 2018 judgment. The Central Water Commission (CWC) monitors the flow at Billigundulu.  

This was for the seventh time that Tamil Nadu received more than the prescribed amount. Also, it was for second occasion that the State’s annual realisation was in the range of 300 tmc ft. to 400 tmc ft. Of the total quantity of around 330 tmc ft. during the previous year, approximately 292 tmc ft. was realised in the first five months (June to October), an uncommon event.  

Rain shortfall likely

However, the current water year, beginning on June 1 (Monday), does not appear rosy. Going by the latest forecast of the Meteorological department, there is likely to be a shortfall in rainfall during the Southwest monsoon. Besides, the storage of reservoirs in the Cauvery basin of Karnataka and the Mettur dam in Tamil Nadu is not as much as it was about a year ago. On Wednesday (June 3, 2026), the storage of Mettur was 41.72 tmc ft. whereas it was 82.32 tmc ft. on the corresponding day last year. Likewise, the combined storage of four Karnataka reservoirs was 33.62 tmc ft. against 74.5 tmc ft. 

Notwithstanding the actual storage position, the coverage of paddy during the Kuruvai cultivation season in Tamil Nadu’s Cauvery delta is about 30,000 acres higher now than what it was a year ago. As on June 1, the coverage was around 2.1 lakh acres. An official says the coverage essentially reflects those areas where filter points, drawing groundwater, are available. He expects the figure to reach the mark of 2.5 lakh acres. In view of increase in coverage in recent years, the normal area for the delta has been revised to 4.4 lakh acres. If the monsoon plays truant, the coverage is not likely to go up.