Pennaiyar Water Dispute: SC Seeks Karnataka, Tamil Nadu's Response on Centre's Plea to Refer Matter to Mahadayi Tribunal

The Supreme Court has sought responses from Karnataka and Tamil Nadu on the Centre's plea seeking modification or clarification of its February 2, 2026 order, so that the Pennaiyar water dispute can be referred to the existing Mahadayi Water Disputes Tribunal instead of setting up a fresh tribunal.

A Bench of Justices Vikram Nath and Sandeep Mehta granted two weeks' time to senior advocates Shyam Divan and G Umapathy, appearing for Karnataka and Tamil Nadu respectively, to file their responses to the Union government's application.

Attorney General R Venkataramani and Additional Solicitor General Aishwarya Bhati appeared for the Centre.

Why does the Centre want the Pennaiyar dispute referred to the Mahadayi Tribunal?

The Centre argued that the Pennaiyar dispute could be resolved more quickly and economically by referring it to the already existing Mahadayi Water Disputes Tribunal, instead of constituting a fresh tribunal exclusively for the dispute.

According to the application, setting up a new tribunal would involve avoidable delays and duplication of institutional infrastructure, whereas the Mahadayi Tribunal is already in place and can take up the matter without additional administrative effort.

The Mahadayi Water Disputes Tribunal, constituted under the Inter-State Water Disputes Act, submitted its Report-cum-Award under Section 5(2) of the Act on August 14, 2018. The award was published in the Gazette of India on February 27, 2020 pursuant to the Supreme Court's order dated February 20, 2020.

The Centre pointed out that the references pending before the tribunal under Section 5(3) of the Act were adjourned sine die on June 16, 2020 on the joint request of the concerned states. No hearings have taken place since then, although the tribunal's tenure has been extended until August 15, 2027.

It submitted that the tribunal continues to exist with its registry, secretariat, premises, technical assessors and data systems fully in place, while not being engaged in active hearings.

"Referring the Pennaiyar dispute to such an existing tribunal would materially advance the object underlying the direction of February 2, 2026, would obviate the avoidable delay and expenditure inherent in raising a fresh institutional apparatus de novo, and would ensure the optimal utilisation of the judicial and administrative resources of the Union," the Centre stated.

The application further said the Supreme Court has ample powers under Article 142 of the Constitution to pass such an order.

Alternatively, if the Court concludes that a fresh tribunal must still be constituted, the Centre has sought more time than the six months granted by the Supreme Court on May 8, 2026 to establish it.

Karnataka was also represented by Advocate General Shashi Kiran Shetty, senior advocate Mohan V. Katarki and advocate Nishanth Patil.

What is the Pennaiyar water dispute?

Pennar, also known as Pennaiyar, is an inter-state river, with Karnataka being the upper riparian state and Tamil Nadu the lower riparian state.

Tamil Nadu invoked Section 3 of the Inter-State Water Disputes Act, 1956, alleging that projects undertaken by Karnataka across the main Pennaiyar River and its tributary, the Markendeya Nadhi, have prejudicially affected, or are likely to affect, the interests of the downstream state and its inhabitants.

Karnataka, however, has opposed the claim, contending that out of the total 11.77 TMC of water available in its catchment area, it plans to utilise only 9.77 TMC while leaving 2 TMC, along with surplus flows, for Tamil Nadu, which it says is sufficient to meet the latter's requirements.

Earlier, on May 8, 2026, the Supreme Court granted the Union government six months to comply with its February 2, 2026 judgment directing it to constitute an inter-state water disputes tribunal to adjudicate the Pennaiyar dispute.

Case Title: The State of Tamil Nadu Vs The State of Karnataka & Anr

Bench: Justices Vikram Nath and Sandeep Mehta 

Date of hearing: July 24, 2026