A contrast in Cauvery water realisation

Cauvery dispute: SW monsoon saw TN realise 10% of what it got in '22; NE monsoon saw 12.85 tmc ft vs. 121 tmc ft in Oct '22. Cumulative realisation till Oct end was 58 tmc ft vs. 143.4 tmc ft in normal year. CWMA modified water release schedule from mid-Aug. Storage in Mettur dam 19.7 tmc ft; prospects of bumper harvest of samba crop look bleak.

The crux of the Cauvery dispute can be best illustrated by the contrast in water realisation this year with that of the previous year. This year’s southwest monsoon (June-September) saw Tamil Nadu realising a mere 10% of what it received during the corresponding period in 2022. In those four months last year, the State got around 452 thousand million cubic feet (tmc ft). This year, it was just 45 tmc ft.

October, the first month of the three-month northeast monsoon, saw a similar contrast. The State registered around 12.85 tmc ft last month as against nearly 121 tmc ft in October 2022. Till the end of October, the cumulative realisation was approximately 58 tmc ft. In a normal year, the State should have realised around 143.4 tmc ft. As the Cauvery catchments in Karnataka and Kerala are unlikely to have heavy rainfall in the coming months, the chances of a relatively higher realisation appear dim. Only many spells of rain in the intermediate catchments (downstream of the Krishnaraja Sagar and Kabini dams in Karnataka and upstream of the Mettur reservoir) can change the situation.

When it became evident by the end of July and early August that the Cauvery catchments in Karnataka and Kerala had been recording low rainfall, the Cauvery Water Management Authority (CWMA), assisted by the Cauvery Water Regulation Committee, began to modify the water release schedule from mid-August by stipulating now and then the quantum of water to be released by Karnataka to Tamil Nadu. It is for the first time since it was established in June 2018 that the CWMA had to resort to the modification.

The present storage (around 19.7 tmc ft) in the Mettur dam is the outcome of the Water Resources Department’s decision of suspending water release since October 11. Yet, the authorities were letting out a bare minimum quantum. The prospects of a bumper harvest of the samba crop look bleak this year.