Chennai, 28 July

Tamil Nadu Chief Minister C Joseph Vijay on Tuesday told Prime Minister Narendra Modi that the Centre's reply in the Rajya Sabha that Supreme Court verdict does not stipulate that Karnataka should get riparian states' consent vis-a-vis the proposed Mekedatu dam was "disappointing."

Hence, that reply given by the Minister of State for Jal Shakti (Unstarred Question No 876 in Rajya Sabha) dated July 27, 2026 without referring to the settled law and legal principles in interstate water issues may be withdrawn, Vijay urged Modi in a letter.

In the Karnataka-Andhra Pradesh Alamatti case, the apex court has ruled that consent of lower riparian state is absolutely necessary, he underscored. Vijay urged the Prime Minister to ensure that no statutory or administrative approval is granted to the Mekedatu dam project unless it is consistent with the Cauvery Water Disputes Tribunal (CWDT) Award and the Supreme Court judgement.

The CM said the minister stated in the Upper House of Parliament that the judgment of the Supreme Court dated 16 February 2018 does not expressly stipulate that Karnataka should obtain the consent of the lower riparian states before constructing a structure across the river Cauvery.

"This disappointing reply from the 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," Vijay said.

As far as the Cauvery Tribunal Award is concerned, the apex 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.

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 that the Tribunal attached paramount importance not merely to annual quantities but also to coordinated regulation of releases affecting lower riparian interests. 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 of the Award can only be achieved through agreement among the party states. 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 and the judgment of the Supreme Court dated 16 February 2018.

Also, the rights of the lower riparian states must be factored in and 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," Vijau underlined.

Against this background, the CM demanded that the reply of the Union Miniser in the Parliament be withdrawn. Further, the CM urged Modi to ensure that the rights of the lower riparian states in relation to both quantum and regulated pattern of releases are fully protected.

Any future consideration of the project shall be undertaken only after comprehensive technical and legal examination, taking into account the concerns of all lower riparian states.

"The river Cauvery is not merely a source of water but the lifeline of millions of farmers and citizens across southern 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," Vijay added.

The union minister's reply comes against the background of expectations of a meeting between the Tamil Nadu CM and his Karnataka counterpart DKShivakumar over the Cauvery issue.

Meanwhile, farmers organisations and leaders of parties have opposed such a meeting and parleys over Cauvery arguing it would not help establish Tamil Nadu's rights on the issue.