Tamil Nadu Chief Minister C. Joseph Vijay, on Tuesday (July 28, 2026), wrote to Prime Minister Narendra Modi seeking his intervention to ensure no statutory or administrative approval is granted to the Mekedatu project unless it is demonstrably consistent with the Cauvery Water Disputes Tribunal (CWDT) Award and the judgment of the Supreme Court.

Mr. Vijay also called for withdrawal of the reply given by the Union Minister of State for Jal Shakti Raj Bhushan Choudhary in Rajya Sabha on July 27 with regard to the Mekedatu project. The Minister had said the judgment of the Supreme Court on February 16, 2018, does not expressly stipulate that Karnataka should obtain the consent of the lower riparian States before constructing a structure across the Cauvery. Mr Vijay said the Minister's reply was made without referring to the settled law and legal principles in inter-State water issues.

In his letter, the Chief Minister said, “This disappointing reply from the Union Minister of State for Jal Shakti seems to have been made without taking into consideration the prevailing legal position and settled law with regard to the consent of the lower riparian States.”

He said the Constitution Bench of the Supreme Court, in the Alamatti case between the States of Karnataka and Andhra Pradesh, ruled that the consent of the lower riparian State is absolutely necessary. Mr. Vijay also quoted the relevant paragraph from the judgment, which said: “Nor can Karnataka State be permitted to construct up to that height without the consent of all other riparian States as well as without the approval of the Central Government…”

As far as the Cauvery Tribunal Award is concerned, the Supreme Court expressly affirmed Clause XVIII of the Tribunal Award, which preserves the power of each State to regulate waters within its territory only “in a manner not inconsistent with the order of the Tribunal.” Thus, any project that has the potential to affect the regulated flow regime established under the Award necessarily requires scrutiny for consistency with the Award, Mr. Vijay said.

The Tribunal itself has laid down important guiding principles. In the case of Kerala’s Pambar Hydro-electric Project, involving only 0.1 TMC of consumptive use, it directed that Kerala and Tamil Nadu should jointly agree upon the schedule of releases so that downstream irrigation is not adversely affected. This demonstrates the Tribunal attached paramount importance not merely to annual quantities but also to the coordinated regulation of releases affecting lower riparian interests, the Chief Minister said.

Further, Clause XI of the Award specifically prohibits any upper riparian State from taking action affecting scheduled deliveries to downstream States except through mutual agreement and consultation with the regulatory authority. Clause XX similarly recognises that modifications to the Award can only be achieved through agreement among the party States, Mr. Vijay pointed out.

“Tamil Nadu is therefore of the considered opinion that the proposed Mekedatu Project cannot be evaluated merely as an engineering proposal. Its legal permissibility must first be examined in the context of the Final Award of the Cauvery Water Disputes Tribunal, the judgment of the Supreme Court on February 16, 2018, and the rights of the lower riparian States,” he said.

It is pertinent that the Detailed Project Report submitted by Karnataka in 2019 was returned by the Central Water Commission for revision to ensure compliance with the Tribunal Award and applicable guidelines. This itself demonstrates that compliance with the Award remains an indispensable precondition, Mr. Vijay pointed out.

He urged the Union government to ensure the rights of the lower riparian States in relation to both the quantum and the regulated pattern of releases are fully protected. Any future consideration of the project shall be undertaken only after a comprehensive technical and legal examination, taking into account the concerns of all lower riparian States, he said.

The Cauvery is not merely a source of water but the lifeline of millions of farmers and citizens across south India. Protecting the integrity of the Tribunal Award and the judgment of the Supreme Court is essential for maintaining confidence in the constitutional mechanism governing inter-State rivers, Mr. Vijay added.

Published - July 28, 2026 02:52 pm IST