Supreme Court to Hear Tamil Nadu’s Suit Against Karnataka Over Pennaiyar River Dispute on September 23

The long-standing inter-State water dispute between Tamil Nadu and Karnataka over the Pennaiyar river is set to return to the spotlight before the Supreme Court of India on September 23, 2025. The matter, which has been pending since 2018, involves critical issues of water-sharing rights, federal negotiation mechanisms, and the constitutional powers of the Union government under the Inter-State River Water Disputes Act, 1956.

The hearing will be conducted by a Bench comprising Justice Vikram Nath and Justice Sandeep Mehta, following a mention made by counsel for Tamil Nadu highlighting the prolonged delay in the constitution of a Tribunal despite statutory mandates.

Background of the Pennaiyar River Dispute

The Pennaiyar river, also known as the South Pennar, originates in Karnataka and flows into Tamil Nadu before emptying into the Bay of Bengal. The dispute over its waters has persisted for decades, with Tamil Nadu alleging that Karnataka has been diverting and obstructing the natural flow of the river through dam constructions and irrigation projects without prior consultation or consent.

In 2018, the State of Tamil Nadu invoked Article 131 of the Constitution of India and filed an Original Suit before the Supreme Court titled State of Tamil Nadu v. State of Karnataka and Anr., O.S. No. 1 of 2018. Tamil Nadu’s core grievance was that Karnataka had embarked upon new water resource projects without approval, thereby reducing the flow of water to Tamil Nadu, adversely affecting agriculture and drinking water availability.

Procedural History Before the Supreme Court

During earlier hearings, the Court had suggested that the Union Government explore the possibility of constituting a Tribunal under the Inter-State River Water Disputes Act, 1956 (ISRWDA) since bilateral negotiations between the two States had failed to yield a solution.

However, in 2023, the Government of Karnataka sought more time, arguing that its newly elected government had not had an opportunity to negotiate directly with Tamil Nadu. Karnataka requested that further negotiations be attempted before proceeding with the Tribunal.

Tamil Nadu strongly objected, pointing out that the Union had already initiated the process for Tribunal constitution but later backtracked. The State argued that this delay was causing grave prejudice to its farmers and citizens who rely on the Pennaiyar waters.

In January 2024, the Supreme Court directed the formation of a Negotiation Committee under Section 4 of the ISRWDA, clarifying that a Tribunal can be constituted only if the Central Government forms the opinion that the dispute cannot be resolved by negotiations. Importantly, the Court noted that the Act prescribes a one-year time limit for the negotiation process.

By November 2024, the mediation process was officially declared a failure, leaving Tribunal constitution as the only statutory recourse.

Legal Framework: Inter-State River Water Disputes Act, 1956

The ISRWDA, 1956, enacted under Article 262 of the Constitution, governs disputes relating to inter-State river waters. Key provisions include:

• Section 4: A Tribunal may be constituted if the Central Government is satisfied that negotiations have failed.
• Time Limit: Negotiation attempts cannot extend beyond one year.
• Binding Nature of Tribunal Awards: Once constituted, the Tribunal’s decision is binding on the States.

In the present case, Tamil Nadu argues that the Centre has failed in its statutory duty by delaying Tribunal formation despite failed negotiations. Karnataka, on the other hand, continues to emphasize political settlement over adjudication.

Tamil Nadu’s Position

Tamil Nadu has maintained that:

1. Karnataka’s unilateral constructions on the Pennaiyar river are illegal and unconstitutional.
2. The Centre’s delay in constituting a Tribunal is a violation of the ISRWDA and amounts to denial of justice.
3. The 2018 suit under Article 131 must be adjudicated urgently as millions of farmers and residents in Northern Tamil Nadu depend on Pennaiyar waters for irrigation and drinking purposes.
4. Past precedents such as the Cauvery Water Dispute demonstrate that prolonged negotiations without binding adjudication are ineffective.

Karnataka’s Position

Karnataka has countered by arguing that:

1. The newly elected government (2023) has not had sufficient opportunity to negotiate with Tamil Nadu.
2. The Union Government has the discretion to determine when negotiations have conclusively failed.
3. Tribunal constitution should be a last resort, not the first step, as adjudication often deepens inter-State tensions.
4. The projects undertaken are within Karnataka’s territorial rights and meant to ensure equitable use of the Pennaiyar river resources.

Supreme Court’s Observations So Far

The Apex Court has:

• Emphasized that Tribunal constitution is conditional on the Centre’s satisfaction that negotiations cannot succeed.
• Noted that the negotiation process must conclude within one year under Section 4.
• Directed the formation of a Negotiation Committee in January 2024, while keeping the Original Suit pending.

With the failure of mediation reported in November 2024, the September 23, 2025 hearing is expected to clarify whether the Centre must now move ahead with Tribunal constitution.

Broader Implications

The outcome of this case carries wider implications for federalism, cooperative governance, and environmental justice in India:

1. Federal Balance: The case will test the extent of the Centre’s discretion under ISRWDA vis-à-vis the Supreme Court’s supervisory role.
2. Agricultural Sustainability: Tamil Nadu’s agrarian economy is heavily dependent on river water flows; continued scarcity could fuel unrest and migration.
3. Inter-State Dispute Resolution Mechanism: The judgment may influence how swiftly future disputes—such as those over Cauvery, Krishna, or Godavari rivers—are referred to Tribunals.
4. Environmental Management: Over-extraction and damming of rivers raise concerns about ecological impacts, including groundwater depletion and loss of biodiversity.

Conclusion

The Pennaiyar river dispute highlights the persistent challenges of inter-State water sharing in India. Despite constitutional safeguards and statutory mechanisms, delays in dispute resolution often exacerbate tensions and hardships for ordinary citizens.

As the Supreme Court prepares to hear the matter on September 23, 2025, all eyes will be on whether it directs the Union Government to finally constitute a Tribunal or grants Karnataka’s request for renewed negotiations. Either way, the case underscores the urgent need for efficient, transparent, and time-bound resolution of water disputes to ensure equity, justice, and sustainability in India’s federal framework.

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