The Supreme Court has dismissed a petition filed by Tamil Nadu to review a November 2025 decision that termed the State’s challenge to Karnataka’s proposed Mekedatu Balancing Reservoir cum Drinking Water project as “premature”.

The review petition was dismissed by a Bench of the Chief Justice of India Surya Kant, Justices Vinod K. Chandran and Vipul M. Pancholi via circulation in their chambers on April 15, 2026. The order was only published recently.

“We have carefully gone through the contents of the review petition and the papers appended therewith.  We are satisfied that no case for review of the judgment dated November 13, 2025 is made out. The review petition is, accordingly, dismissed,” the short order said.

On November 13, 2025 the court had said the Detailed Project Report (DPR) on the reservoir, submitted by Karnataka, was only being considered by the experts in the Cauvery Water Management Authority (CWMA) and Cauvery Water Regulation Committee (CWRC).

The Central Water Commission (CWC) had already made it clear that any acceptance of the DPR would be given only after approvals from CWMA and CWRC. The court had said that in case of approval of DPR, the affected parties, including Tamil Nadu, would be free to take measures in accordance with the law. But for now, it was too early, the court had concluded.

The apex court had said, Karnataka, anyway, would be bound to release Cauvery water allotted to lower riparian Tamil Nadu and the Union Territory of Puducherry, which was downstream.

The decision had been based on an application moved by Tamil Nadu seeking a direction to restrain the CWMA from deliberating the proposed reservoir project.

The application had stated that the planning of the Mekedatu project with a capacity of 67.16 TMC ft. (thousand million cubic feet), and generation of a 400 MW project worth ₹9,000 crore was in “gross violation” of the decision of the Cauvery Water Disputes Tribunal of February 5, 2007, which was affirmed by the Supreme Court itself on February 16, 2018.