How has the Odisha-Chhattisgarh Mahanadi water dispute evolved? Explained
The Chief Minister of Odisha wrote to the Chief Minister of Chhattisgarh on 25 July 2025, proposing an amicable, negotiated settlement of the long-running Mahanadi river water-sharing dispute.
The Chief Minister of Chhattisgarh replied on 1 August 2025, stating that the proposal for settling the dispute was under consideration.
This exchange represents an attempt to resolve the dispute through direct inter-state negotiation, running parallel to the ongoing adjudication before the Mahanadi Water Disputes Tribunal.
The tribunal, which has been unable to secure a jointly agreed water-sharing formula from the two states, has indicated it may proceed to a final ruling in the absence of a settlement.
Article 262 and the Inter-State River Water Disputes Act, 1956
Article 262 of the Constitution empowers Parliament to legislate for the adjudication of disputes over waters of inter-state rivers or river valleys, and permits Parliament to bar the jurisdiction of the Supreme Court and other courts over such disputes. Parliament exercised this power through the Inter-State River Water Disputes (ISRWD) Act, 1956, under which tribunals are constituted to adjudicate specific disputes referred by the Centre.
Key Details
- Article 262(2) allows Parliament to exclude the Supreme Court's and other courts' jurisdiction in respect of a referred inter-state river dispute
- The ISRWD Act, 1956 provides the machinery for setting up ad hoc tribunals once a state government's request is accepted by the Centre
- The Inter-State River Water Disputes (Amendment) Act, 2019 replaced multiple ad hoc tribunals with a single, permanent tribunal having multiple benches, and introduced statutory timelines for adjudication to reduce delays
The Mahanadi dispute is being adjudicated under this constitutional-cum-statutory mechanism; the parallel Chief Minister-level correspondence is an attempt at a negotiated resolution that would pre-empt or supplement the tribunal's award.
Mahanadi Water Disputes Tribunal
The Mahanadi Water Disputes Tribunal was constituted after Odisha approached the Supreme Court in 2016, alleging that upstream barrages and anicuts built by Chhattisgarh were reducing downstream flow, particularly in the non-monsoon season, threatening irrigation, drinking water, and fisheries in Odisha. Following the Supreme Court's direction, the Centre notified the tribunal on 12 March 2018 under the ISRWD Act, 1956.
Key Details
- Originally chaired by a retired Supreme Court judge; the chairmanship changed after the first chairperson's resignation in March 2024, with a sitting Supreme Court judge subsequently heading the tribunal
- Central dispute: absence of a formal water-sharing agreement between the upper riparian state (Chhattisgarh) and the lower riparian state (Odisha), compounded by a lack of mutually accepted hydrological data
- The tribunal has signalled it may deliver a final water-sharing formula if the states fail to reach a negotiated settlement
The 2025 Chief Minister-level correspondence is the latest bilateral effort to reach a settlement before or alongside the tribunal's prospective final award.
Riparian Principles and Comparable Inter-State Disputes
Inter-state river disputes in India typically pit an upper riparian state's claim to utilise water within its territory against a lower riparian state's claim to an equitable share of flow reaching it. India does not follow a single codified doctrine (such as absolute territorial sovereignty or absolute river integrity) but applies the principle of "equitable apportionment," similar to the approach used in other major disputes.
Key Details
- Comparable disputes: Cauvery (Karnataka-Tamil Nadu-Kerala-Puducherry, adjudicated by the Cauvery Water Disputes Tribunal, with the Cauvery Water Management Authority now administering the award), Krishna and Godavari (multi-state tribunals)
- Post-award administration is typically entrusted to a management authority or board, distinct from the adjudicating tribunal itself (e.g., the Cauvery Water Management Authority, set up in 2018 following the Supreme Court's 2018 judgment)
- The Mahanadi basin's principal riparian states are Chhattisgarh (upper riparian, larger catchment share) and Odisha (lower riparian)
The Mahanadi case follows the familiar upper-lower riparian contest seen in Cauvery and Krishna, but is distinctive in that both states are attempting a negotiated political settlement before the tribunal issues a final award, rather than relying solely on adjudication.
- Mahanadi Water Disputes Tribunal notified: 12 March 2018, under the Inter-State River Water Disputes Act, 1956
- Trigger for tribunal formation: Odisha's 2016 Supreme Court petition against Chhattisgarh's upstream barrages/anicuts
- ISRWD (Amendment) Act, 2019: introduced a single permanent tribunal with multiple benches and fixed adjudication timelines
- Odisha CM's settlement letter: 25 July 2025; Chhattisgarh CM's reply: 1 August 2025
- Constitutional basis: Article 262, empowering Parliament to legislate on inter-state river water disputes and exclude court jurisdiction over them