Tamil Nadu moves Supreme Court over Cauvery water release dispute with Karnataka

The Tamil Nadu government on Monday approached the Supreme Court seeking directions to Karnataka to release the state's due share of Cauvery water, accusing the neighbouring state of ignoring orders passed by the Cauvery Water Management Authority (CWMA) and the Cauvery Water Regulation Committee (CWRC).

Chief Minister C. Joseph Vijay directed the state government to move the apex court after Karnataka failed to comply with the water release schedule fixed by the two regulatory bodies, according to an official release.

At its 139th meeting on July 28, the CWRC reviewed hydrological and rainfall data in the Cauvery basin and directed Karnataka to release 3,500 cusecs of water at Biligundlu between July 29 and August 12, drawing from the Krishna Raja Sagar (KRS) and Kabini reservoirs. The CWMA ratified this direction at its 54th emergency meeting on July 30.

Tamil Nadu said the actual inflow at Biligundlu between July 29 and August 2 stayed between just 158 and 550 cusecs, well short of the mandated quantity.

The state also flagged Karnataka's current reservoir levels, which it said leave no room for the shortfall to be explained away. As of early August, KRS held 23.078 TMC, Kabini 18.610 TMC, Harangi 7.827 TMC and Hemavathi 28.022 TMC, taking combined storage across the four reservoirs to 77.537 TMC, with 67.517 TMC of it usable.

Tamil Nadu further argued that heavier than usual rainfall in the KRS and Kabini catchment areas this year entitles it to 26.954 TMC at Biligundlu on a proportionate basis, nearly six times the 4.536 TMC fixed by the CWMA for the period.

On the advice of senior legal counsel, the state filed its petition before the Supreme Court on August 3, seeking directions to enforce compliance and ensure Tamil Nadu gets its rightful share within the stipulated window.

The Cauvery water sharing dispute between the two states dates back decades, with the Cauvery Water Disputes Tribunal's 2007 award later modified by the Supreme Court in 2018. Karnataka, as the upper riparian state, has repeatedly cited deficient storage and drought conditions in past years to justify shortfalls in release, a defence Tamil Nadu's latest petition seeks to pre-empt by pointing to this year's above-normal storage levels.