Pennaiyar River Dispute: Supreme Court to hear suit on water sharing issues between Tamil Nadu, Karnataka

The Supreme Court has agreed to hear on September 23, 2025 the water sharing issues between Tamil Nadu and Karnataka in relation to the Pennaiyar River.

A bench of Justices Vikram Nath and Sandeep Mehta was told yesterday that the Pennaiyar Water Dispute Tribunal had still not been constituted by the Central government.

In November last year, the Supreme Court was told that although an effort by Central Government for mediation was attempted between the State of Karnataka and the State of Tamil Nadu and discussions were held on multiple dates, the mediation process had not succeeded. Earlier in July 2024, court had been informed that active negotiation was going on between the states and five meetings had taken place and the parties together also visited the concerned area.

Centre had in July 2023 informed the Supreme Court that a proposal to set up the Pennaiyar Water Dispute Tribunal, to resolve water sharing issues between Tamil Nadu and Karnataka had been sent to Cabinet Secretariat and was awaiting final decision by the Union Cabinet.

In an affidavit, the Water Resources department of Jal Shakti Ministry had stated, "in order to constitute a Tribunal, a proposal for formation of Pennaiyar Water Dispute Tribunal under the relevant section of the Inter State Water Dispute Act, 1956 has been submitted to Cabinet Secretariat for consideration and approval of Union Cabinet. It is submitted that the Union Cabinet is yet to take a final decision in the matter."

Hearing an original suit filed by Tamil Nadu, the top court had on May 2, 2023 granted the Union government one month's further time for setting up the tribunal and issuance of a gazette notification for it. In its plea filed under Article 131 of the Constitution, Tamil Nadu had claimed plaintiff and defendant (State of Karnataka) are the two riparian States among the three basin States and the Union Territory of Puducherry in which the Inter-State River Pennaiyar flows.

As a riparian State, top court was told that the plaintiff is entitled to and has been using the waters of the river Pennaiyar and its tributaries/rivulets, etc, except for the reasonable beneficial use of Karnataka. The extent of the rights of the Party States, in the use, control and distribution of waters of the Inter State River, is recognised in an agreement of 1892 entered into between the then State of Madras and Mysore, the predecessor States of Tamil Nadu and Mysore / Karnataka respectively.

However, its rights and interest in river Pennaiyar and its tributaries have been prejudicially affected by the executive action of Karnataka by its various works, and in violation of 1892 and 1933 agreements, Tamil Nadu asserted.

It alleged that Karnataka has taken up construction of a reservoir across Markandeyanadhi, a tributary of Pennaiyar, diversion of surplus waters of Varathur tank, implementation of lift irrigation scheme at Yellamallappa Chetty tank, pumping of water at Belahalli, besides a scheme to pump the waters of Pennariyar from Thattanur village to distribute to 160 tanks.

On November 14, 2019, the Supreme Court permitted the Tamil Nadu government to invoke the powers of the Union government in terms of the provisions of the Inter-State Water Disputes Act and seek the constitution of a tribunal on the dispute over sharing of water.

Case Title: The State of Tamil Nadu vs. State of Karnataka & Anr.

Hearing Date: September 8, 2025

Bench: Justices Nath and Mehta