Cauvery dispute: How Tamil Nadu and Karnataka are pulling Congress in two directions

NEW DELHI: 2026 has been a year of Congress' re-emergence in southern India. The party won comfortably in the Kerala assembly elections, entered the Tamil Nadu government by supporting Vijay's TVK, and also solved the three-year-long tussle over the chief ministerial post in Karnataka.But, just as it seemed that everything was going Congress's way, regional tensions appear to have taken over the party line. Tamil Nadu and Karnataka have locked horns over the proposed foundation stone ceremony announced by Karnataka for the Mekedatu dam project across the Cauvery River, exposing a sharp interstate fault line..Incidentally, as Congress is in power in Tamil Nadu and Karnataka, it finds itself caught between a rock and a hard place — forced to balance electoral gains against a combustible local dispute.What is the Cauvery water dispute?The Cauvery water dispute is one of India's longest-running inter-state river water conflicts. It centres on the sharing of waters of the Cauvery river, a crucial source of irrigation, drinking water and livelihood for millions of people in southern India.The roots of the conflict go back more than 150 years to agreements signed in 1892 and 1924 between the erstwhile Madras Presidency and the princely state of Mysore. These agreements established the principle that the upper riparian state (Mysore, now Karnataka) must obtain the consent of the lower riparian state (Madras, now largely Tamil Nadu) before undertaking major construction projects on the river.Tensions intensified after 1974 when Karnataka began diverting water into newly built reservoirs without Tamil Nadu's consent. Tamil Nadu argued that these actions reduced water availability downstream, particularly for its farmers who depend heavily on the Cauvery for irrigation.To resolve the dispute, the Central government constituted the Cauvery Water Disputes Tribunal (CWDT) in 1990 under the Inter-State River Water Disputes Act, 1956.After 17 years of deliberations, the tribunal delivered its final award in 2007, laying down a formula for sharing Cauvery waters among Karnataka, Tamil Nadu, Kerala and Puducherry.The award was notified by the Centre in 2013 and subsequently challenged before the Supreme Court. In its landmark 2018 judgment, the apex court largely upheld the tribunal's water-sharing framework while making certain modifications.The court described the Cauvery as a national asset and allocated water among the riparian states, directing the Centre to establish an institutional mechanism to implement the decision.Following the verdict, the Centre created the Cauvery Water Management Authority (CWMA) and the Cauvery Water Regulation Committee (CWRC) to oversee water releases and ensure compliance with the sharing arrangement.However, conflict resurfaces almost every year, particularly during periods of deficient rainfall. Karnataka argues that it needs adequate water to meet the drinking and irrigation requirements of its population, while Tamil Nadu insists on timely releases as mandated by the tribunal and Supreme Court orders.Disagreements are especially intense during drought years when water availability falls below normal levels. Questions over how shortages should be shared between states often trigger political and legal confrontations.The latest flashpoint is Karnataka's proposed Mekedatu Reservoir Project, which is intended to provide drinking water to Bengaluru and generate around 400 MW of electricity.Karnataka Vs Tamil NaduThe controversy was triggered by Karnataka's then deputy chief minister DK Shivakumar after he said that the Detailed Project Report (DPR) for the Mekedatu project will be submitted to the Centre soon, and the groundbreaking ceremony will be held after obtaining Union government approval."The DPR for the Mekedatu project has been prepared, and a project office has been opened. We are identifying alternate land to compensate for the forest area that will be submerged. The DPR will be submitted to the Centre shortly. Once the Centre grants approval, we will perform the bhoomi puja for the project," DKS said."There is a clear order to release 177 TMC of water to Tamil Nadu. We will discuss how to resolve this in the coming days. The Supreme Court has ruled that Tamil Nadu has no right to object to the Mekedatu project and that the Central Water Commission must take a decision on it," he added.In what could be seen as retaliation, Tamil Nadu's newly appointed Chief Minister Vijay conducted detailed consultations with Cauvery water experts and legal experts in order to uphold the state's rights and safeguard the welfare of farmers.Taking into account the details of the Supreme Court judgment and detailed legal consultation, CM Vijay advised that immediate follow-up legal measures should be undertaken without delay.He also met Prime Minister Narendra Modi in Delhi and urged him to advise the Jal Shakti ministry and the central water resources tribunal not to permit the project without the consent of all states involved in the dispute."The Mekedatu dam is not on the list of projects permitted by the Tribunal which has been affirmed by the Supreme Court," Vijay has earlier said in a letter to the Prime Minister."There is no scope for additional utilisation or for creating a huge storage reservoir, since the Cauvery basin is found to be a deficit basin and the available water at 50 per cent dependability has already been allocated to the party states... Hence the act of proposing to construct a new reservoir by Karnataka would amount to clear violation of the said judgment," the letter read.Why Congress is in a whirlpoolAmid the controversy, Congress finds itself in the unusual position of having to cater to two opposing stands. The party has become the centre of a conflict that has transformed from a bilateral state dispute into an internal political challenge, with its units in Karnataka and Tamil Nadu backing contrasting positions on the Mekedatu project.The fault lines have already become visible. Congress MP Manickam Tagore chose to skip Karnataka CM DK Shivakumar's swearing-in ceremony on June 4, 2026, citing the Mekedatu dispute. TN Congress vice-president SM Hidayathullah also backed legal action against the project and stated that there should be no dam across the river, placing the Tamil Nadu unit at odds with the Karnataka government's position.In Karnataka, support for Mekedatu is closely tied to the interests of farmers in the Cauvery basin, particularly the influential Vokkaliga community that forms a key support base for chief minister DK Shivakumar.In Tamil Nadu, however, the focus remains on protecting the state's share of Cauvery waters and ensuring compliance with the existing water-sharing framework. Congress is also part of the ruling coalition in the state, where opposition to the project has been a consistent position. The party's alliance equations have gained added significance after TVK backed Congress leader Praveen Chakravarty for a Rajya Sabha seat.