Tamil Nadu Chief Minister C. Joseph Vijay on Tuesday (May 26, 2026) wrote to Prime Minister Narendra Modi, urging him to instruct the officials concerned in the Ministry of Jal Shakti and the Central Water Commission to reject the detail project report (DPR) submitted by Karnataka for the proposed Mekedatu balancing reservoir across the Cauvery.

He said the DPR went against the final award of the Cauvery Water Disputes Tribunal (CWDT), dated February 5, 2007, and the Supreme Court’s February 2, 2018 judgment.

In his letter, Mr. Vijay said, “I wish to bring to your kind notice that Karnataka, in utter violation of the judgment of the Supreme Court and the final award of the CWDT, has announced the ‘Bhoomi Puja’ of the  Mekedatu reservoir.”

“The public utterances of the Deputy Chief Minister of Karnataka [D.K. Shivakumar] to this effect have caused a lot of concern among the lakhs of farmers of Tamil Nadu who depend on the Cauvery for their livelihood. You may be well aware that a solution to the sensitive  Cauvery water dispute was obtained after a long legal battle, lasting about three decades,” he said.

Mekedatu was not on the list of projects permitted by the CWDT, and this was affirmed by the Supreme Court in its judgment. There was no scope for additional utilisation or creating a new huge storage reservoir, since the Cauvery basin was found to be a deficit basin and the available water at 50% dependability had been allocated to the party States, Mr. Vijay said. Therefore, planning any new project across the Cauvery or its tributaries, other than those permitted by the CWDT  in its final award and affirmed by the Supreme Court, would amount to interfering with the judgment, he said.

Tamil Nadu was of the firm view that by proposing a new project with a storage of 67.16 tmc upstream of the Karnataka-Tamil Nadu border, the Karnataka government was trying to prevent the flows generated in the uncontrolled catchment, one of the three components from which the flows would be ensured to Tamil Nadu, according to the final award as modified by the Supreme Court judgment, he said.

Further, the Supreme Court held that the upper riparian State should not take any action so as to affect the scheduled water deliveries to the lower riparian State. Hence, Karnataka’s proposal for a new reservoir would amount to violation of the judgment, he said. “In this connection, I bring to your kind notice that when Karnataka attempted to obtain Terms of Reference (ToRs) for conducting the EIA [Environmental Impact Assessment], the Expert Appraisal Committee of the Ministry of Environment, Forest and Climate Change opined at its meeting, held on July 19, 2019, that in view of inter-State issues involved, an amicable resolution needs to be arrived at between the States and returned the proposal,” he said.

The Ministry had not issued ToRs for the EIA; therefore, Karnataka’s attempt to proceed with the project was a blatant violation of not only the Supreme Court’s judgment but also the environmental laws, the Chief Minister said. “In this scenario, it is surprising that the Ministry of Jal Shakti and the the Central Water Commission, which are mandated to implement the judgment in letter and spirit, are entertaining Karnataka’s proposal, without considering the plea of the Tamil Nadu government,” Mr. Vijay said.

He also urged the Prime Minister to instruct the officials to advise Karnataka not to take up any new project without getting the concurrence of the co-basin States and not to violate the Supreme Court’s judgment in totality.