The Tamil Nadu government headed by Chief Minister C. Joseph Vijay moved the Supreme Court on Monday (August 3, 2026) for a direction to the State of Karnataka to implement a Central Water Management Authority (CWMA) decision of July 30 to ensure the release of 3,500 cusecs for 15 days from its two reservoirs at Kabini and Krishna Raja Sagara.

Editorial | Distress and dispute: On Karnataka, Tamil Nadu and the Cauvery

Tamil Nadu’s approach to the Supreme Court for the release of 4.536 TMC (at the rate of 3,500 cusecs for 15 days) on or before August 12 has come even as Karnataka Chief Minister D.K. Shivakumar said the water situation has become “slightly better” while urging Kannada organisations to withdraw their State-wide bandh plan on August 13.

The Tamil Nadu application, finalised by senior advocates C.S. Vaidyanathan and G. Umapathy, and drafted by Tushar Nair, was filed by advocate-on-record B. Karunakaran. The State urged the Court to direct the CWMA to issue an appropriate direction to Karnataka to make good, on a pro-rata basis, the shortfall at the inter-State point of Billigundulu for the period from June 1 to August 12, and in this regard release 26.954 TMC of water forthwith.

It further sought an order to the CWMA to monitor the flows in the reservoirs of Karnataka every 10 days and ensure stipulated monthly/daily releases at Billigundulu.

The Tamil Nadu government said Karnataka had continued to defy the orders of the Cauvery Tribunal for allocation of water to its neighbour except a few times when there were inevitable surpluses in the reservoirs on account of floods.

The State said the had reviewed the hydrometeorological condition in Cauvery basin on July 30 and endorsed the July 28 recommendations of the Cauvery Water Regulations Committee (CWRC) to release waters from Krishna Raja Sagara (KRS) and Kabini reservoir at the rate of 3,500 cusecs from July 29 for 15 days.

Comment | A gamble on the Cauvery issue

“Even if Karnataka ensured flows of 3,500 cusecs for 15 days, it would get only 4.536 TMC leaving a backlog of 5.379 TMC even as per the pro rata assessment of distress as on July 28... 28.07.2026. If the inflows into the 4 major reservoirs of Karnataka against 30 years average up to August 3, 2026 is considered, the pro-rata ratio works out to 46.34%. Based on this pro-rata ratio, the flows due from June 1, 2026 to August 12, 2026 works out to 26.95 TMC. The direction given by the CWRC and CWMA is only 4.536 TMC, which is far less than the quantum of water as per distress proportion,” the Tamil Nadu application said.

The State argued that despite the CWRC/CWMA interventions, total flows realised at Billigundulu from July 29 to August 2 were only in the range of 158 cusecs to 530 cusecs.

“Thus, it is evident that Karnataka has willfully not complied with the directions of CWRC/CWMA. It is stated that as on August 3, Karnataka is having 23.078 TMC in KRS, 18.610 TMC in Kabini, 7.827 TMC in Harangi and 28.022 TMC in Hemavathy, totally 77.537 TMC of gross storage... This increase in the live storage is on account of recent heavy rainfall in the catchments upstream of Kabini and KRS. Thus, Karnataka in spite of having adequate storage has failed to comply with the directions of CWMA,” Tamil Nadu contended.

During the current irrigation year of 2026-2027, Tamil Nadu said the catchments upstream of KRS, Kabini and the uncontrolled catchment during the period from June 1 to July 27 received a total rainfall of 488.0 mm, 676.1 mm, and 78.4 mm, respectively, against the normal rainfall of 633.4 mm, 1160.2 mm and 119.5 mm, respectively.

“The rainfall deficit in the catchment upstream of KRS, Kabini and in the uncontrolled catchment was 23%, 42% and 34%, respectively,” the application said.

Tamil Nadu said the monthly stipulated flows to be ensured by Karnataka during June to September at Billigundulu were 123.14 TMC, and from October to January was 44.11 TMC, comprising a total of 167.25 TMC every year. In addition, 10 TMC was allocated for meeting the environmental flows during every year making a total of 177.25 TMC.