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For political parties in both states, this remains an issue that can unite public sentiments and sharpen regional identities
Mekedatu is a proposed balancing reservoir and drinking water project planned by Karnataka on the Kaveri River near the Karnataka-Tamil Nadu border. file image
Nearly three decades after it was first proposed, the Mekedatu Balancing Reservoir remains one of India’s most politically controversial infrastructure projects. Every few years, it returns as a topic of discussion, triggering a familiar cycle of political statements, counter-statements, legal arguments and allegations between Karnataka and Tamil Nadu.
Yet, despite successive governments promising to build it and equally determined governments vowing to stop it, the project remains stuck in a maze of litigation, statutory approvals and political compulsions.
The latest trigger is a strongly worded letter Tamil Nadu Chief Minister C Joseph Vijay To Prime Minister Narendra Modi, challenging the Centre’s interpretation of the Supreme Court’s 2018 Cauvery verdict. Vijay’s intervention came a day after the Central government told the Rajya Sabha that Karnataka does not explicitly need to obtain the consent of Tamil Nadu, Kerala or Puducherry before building a structure on the Cauvery river as per the apex court’s decision.
Responding to a question raised by PMK MP Anbumani Ramadoss, Union Minister of State for Jal Shakti Raj Bhushan Choudhary said the February 16, 2018 judgment reiterates Clause XVIII of the Cauvery Water Disputes Tribunal (CWDT) award, which allows a state to regulate the use of water within its limits, unless it is inconsistent with the tribunal’s order. He pointed out that the judgment does not specifically say that Karnataka will have to take the approval of lower riparian states before building structures on the river.
However, Tamil Nadu has strongly objected to that interpretation.
Describing the Centre’s response as “disappointing”, Vijay argued that it ignored the established legal position governing the rights of lower riparian states. In his letter to the Prime Minister, he said that any project on an interstate river with downstream implications cannot be viewed only through the narrow words of a decision. Instead, he argued, it should be examined within the larger legal framework governing interstate rivers and the rights of downstream states.
Why does Karnataka want Mekedatu?
For Karnataka, this logic has remained remarkably consistent over the years, regardless of which party has been in power.
The state emphasizes that Mekedatu is not an irrigation project but a multi-purpose balancing reservoir designed primarily to meet the long-term drinking water needs of Bengaluru. The project, proposed at the confluence of Kaveri and Arkavathy rivers near Kanakapura in Ramanagara district, about 100 km from Bengaluru, is estimated to cost around Rs 9,000 crore.
The reservoir is expected to store about 67 tmcft of water, provide more than 4 tmcft of drinking water to Bengaluru and surrounding areas and generate about 400 MW of hydroelectric power. Karnataka says it is not seeking additional share of Cauvery water, but is proposing to store only the surplus monsoon flow that already falls within its allocated share under the CWDT award and the Supreme Court’s 2018 judgment.
The project has gained greater political importance as Bengaluru grapples with persistent water scarcity, depleting groundwater and rapid urban expansion. The severe drinking water crisis witnessed in parts of the city over the past few years has strengthened the government’s contention that additional storage infrastructure is necessary if Bengaluru is to meet its future water needs.
A rare political consensus in Karnataka
Few issues like Mekedatu unite the political class of Karnataka.
After remaining dormant for years, Congress revived the proposal in 2013. It later turned the project into a major political campaign, organizing the Namma Neeru, Namma Hakku Padayatra in 2022 and accusing the BJP-led central government of delaying the approval despite publicly supporting the project.
Under the leadership of DK Shivakumar, Congress also made Mekedatu a key campaign promise During both the 2023 assembly elections and the 2024 Lok Sabha elections, it was argued that Bengaluru’s future water security depended on it.
BJP has also consistently supported this project. During his tenure as Chief Minister, Basavaraj Bommai announced budgetary allocations and repeatedly expressed confidence that construction would begin soon.
At first, me Interview with News18Bommai had said that he has allocated Rs 1,000 crore for the project in his budget and the work will start after getting the necessary approvals.
Representing the area where the reservoir is proposed, Shivakumar has repeatedly argued that Bengaluru can no longer delay Mekedatu and has repeatedly accused central governments of slowing down the approval process.
So the political competition in Karnataka has never been about whether the project should be built or not. Instead, it focuses on which party deserves credit for moving it forward.
Why is Tamil Nadu continuously opposing it?
Tamil Nadu’s concerns go beyond the project’s stated objective of providing drinking water.
Successive governments in Tamil Nadu have argued that any additional storage structures upstream would give Karnataka greater control over the timing and quantity of water released downstream, especially during low rainfall years. The state fears that such operational controls could impact irrigation in the Cauvery delta, making the project unacceptable unless the concerns of downstream states are fully addressed.
This explains why opposition to Mekedatu remains persistent among political parties in Tamil Nadu. Be it the AIADMK, DMK or now Vijay’s government, the state’s position remains unchanged – that Karnataka cannot go ahead with the project without addressing the concerns of Tamil Nadu and Kerala.
PMK president Anbumani Ramadoss has gone a step further and urged Vijay not to hold talks with Karnataka on Mekedatu. Instead, he has called for an all-party meeting, a joint delegation to meet the Prime Minister and a renewed legal battle before the Supreme Court.
Anbumani said, “We have not accepted the dam at all. There is no reason to go to Karnataka to discuss it.” He alleged that DK Shivakumar’s renewed push for the project was linked to Karnataka’s political calendar.
Why does the Center find itself in a difficult situation?
For the Centre, Mekedatu has always been a political balancing act.
Supporting the project risks infuriating Tamil Nadu, where Cauvery is one of the most sensitive political issues. Declining it or delaying it indefinitely invites criticism in Karnataka, where support for Mekedatu cuts across party lines.
As a result, the project remains stuck in a web of environmental clearance, forest clearance, legal challenges and technical scrutiny. Karnataka submitted its detailed project report to the Center in 2019, but progress has been slow as Tamil Nadu has repeatedly opposed the proposal before various statutory and judicial forums.
The Centre’s latest parliamentary reply has now added another dimension to the debate. Karnataka believes that reinforces its legal argument that the Supreme Court never mandated the consent of downstream states. Tamil Nadu, on the other hand, sees it as an attempt to weaken the long-established rights of the lower riparian states.
more than a dam
Mekedatu is more than just a drinking water project.
For Karnataka, this represents the state’s right to secure Bengaluru’s future water needs. For Tamil Nadu, it symbolizes the need to protect the interests of farmers dependent on the Cauvery and downstream flows. For political parties in both states, this remains an issue that can unite public sentiments and sharpen regional identities.
Perhaps this explains why the project dominates political discussion despite little progress on the ground.
Nearly 30 years after it was first conceived, governments have changed, court battles have come and gone, and elections have been contested over it. But the proposed reservoir remains where it has always been – caught between competing legal interpretations, environmental constraints and political calculations.
The political dilemma remains as to whether the government at the Center has been under the leadership of Congress or BJP.
As new letters are exchanged and the legal situation once again tightens, the fight over Mekedatu is no longer just about water. It has become a test of federalism, competing development priorities and the delicate balance between the rights of an upstream state and the concerns of the downstream.
The two states have interpreted the Centre’s reply in Parliament differently.
Karnataka sees this as strengthening its long-standing argument that the Supreme Court never imposed a mandatory requirement of obtaining the consent of downstream states before building a structure on the river.
Tamil Nadu argues that such a reading ignores the broader legal principles governing interstate rivers and the rights of lower riparian states. It says the absence of an express provision in a decision cannot be interpreted as a blanket approval for upstream projects with downstream consequences.
The important thing is that the Center has not given final approval to this project. Mekedatu still requires a number of clearances, including environmental and forest approvals, in addition to scrutiny by the Central Water Commission and other statutory bodies. Tamil Nadu has consistently challenged the proposal at every available forum, ensuring that the approval process remains slow and controversial.
About the author
Rohini Swamy, Associate Editor, News18, has been a journalist in the television and digital space for almost two decades. She covers South India for News18’s digital platform. She has worked before also…read more
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