¨     India's long-standing inter-state water disputes have once again come into the spotlight, with the Supreme Court intervening in the Pennaiyar River water dispute between Tamil Nadu and Karnataka.

¨     On February 2, 2026, the apex court directed the central government to constitute a dedicated water disputes tribunal within a month to resolve the dispute.
¨     This decision underscores the constitutional framework for resolving inter-state river water disputes and highlights the judiciary's role in upholding cooperative federalism.
Pennaiyar River Water Dispute
¨     The Pennaiyar River flows through Karnataka and Tamil Nadu, making it an inter-state river. The dispute arose when Karnataka constructed check dams and water diversion structures on the river.
¨     Tamil Nadu alleges that these unilateral actions are reducing downstream water flow and violating existing agreements. The river's water is crucial for agriculture and drinking water in several regions of Tamil Nadu, making the dispute economically and socially sensitive.
Why did Tamil Nadu approach the Supreme Court
¨     Tamil Nadu approached the Supreme Court in 2018 through an Original Suit. The state argued that inter-state river water is a national asset and no single state can have exclusive rights over it.
¨     Tamil Nadu also alleged that Karnataka did not share details of the construction works or obtain the consent of the downstream state, which violates federal and legal norms.
Role of the 1892 Agreement
¨     Tamil Nadu cited the 1892 agreement, which governs the use of Pennaiyar River water, in its favor.
¨     The state contends that this agreement is binding on both states and prevents Karnataka from undertaking major water projects without mutual consent.