Mekedatu Dam: Tamil Nadu Objects to Central Officials' Site Inspection of Karnataka's Cauvery Project
On 7 November 2026, the Tamil Nadu government wrote to the Prime Minister raising concerns over a reported site inspection by Union government officials at the proposed Mekedatu dam site in Karnataka.
Tamil Nadu asked that no statutory or administrative approval be given to the project without the consent of the co-basin States (all states that share the Cauvery basin).
Tamil Nadu said the proposed reservoir, with a capacity of 67.16 TMC (thousand million cubic feet), sits just upstream of the Karnataka-Tamil Nadu border. It argued that the dam would affect the monthly water deliveries fixed by the Supreme Court in the Cauvery dispute.
It pointed out that 2026-27 is a deficit water year in the Cauvery basin, and that Cauvery delta farmers are already anxious.
The State also recalled that its Legislative Assembly passed a unanimous resolution on 19 June 2026 against the project. It has a writ petition pending in the Supreme Court asking for withdrawal of Ministry of Jal Shakti guidelines of December 2025 on preparing Detailed Project Reports (DPRs) for irrigation and multipurpose projects, as applied to the Cauvery basin.
Karnataka resubmitted the project's DPR, with a compliance report, to the Central Water Commission (CWC) on 13 August 2026 for appraisal.
Mekedatu Balancing Reservoir-cum-Drinking Water Project
The Mekedatu project is a large dam and reservoir that Karnataka wants to build on the Cauvery river at Mekedatu, near Kanakapura in Karnataka, close to the border with Tamil Nadu. Karnataka calls it a "balancing reservoir-cum-drinking water project": it says the dam will store water to supply drinking water to Bengaluru, generate about 400 MW of electricity, and help it release water to Tamil Nadu in a steady way. Tamil Nadu, the downstream state, strongly opposes it because it fears the dam will reduce or control the water that reaches its farmers.
The reported visit of Union officials to the Mekedatu site came after Karnataka resubmitted the project's DPR in August 2026. Tamil Nadu sees any central inspection as a sign that appraisal is moving forward, which is why it has asked the Centre not to give any approval without the consent of all co-basin states.
Cauvery Water Dispute and the Cauvery Water Management Authority
The Cauvery Water Dispute is a long fight between Karnataka and Tamil Nadu (with Kerala and Puducherry also involved) over how to share the water of the Cauvery (Kaveri). The river rises at Talakaveri in Kodagu district of Karnataka and flows through Tamil Nadu into the Bay of Bengal. The final allocation was settled by the Supreme Court in February 2018, and a permanent body, the Cauvery Water Management Authority (CWMA), now implements it.
Tamil Nadu's main argument against Mekedatu is that the monthly deliveries fixed by the 2018 judgment must stay fully protected. The Supreme Court has also said that the CWMA and CWRC must be heard before any decision on the project.
Article 262 and the Inter-State River Water Disputes Act, 1956
When a river flows through two or more states, they often fight over sharing its water. Article 262 of the Constitution lets Parliament make a law to settle such disputes, and also to bar the Supreme Court and other courts from hearing them. Using this power, Parliament passed the Inter-State River Water Disputes Act, 1956, under which the Centre sets up a tribunal to decide each dispute. The tribunal's award is final and binding.
The Mekedatu row shows how a dispute "settled" by a tribunal and the Supreme Court can still flare up when one state proposes a new project. Tamil Nadu's demand for co-basin consent rests on the award and judgment produced through this constitutional system.
- Tamil Nadu letter to the Prime Minister: 7 November 2026; earlier letter: 28 July 2026
- Tamil Nadu Assembly unanimous resolution against Mekedatu: 19 June 2026
- Project capacity cited by Tamil Nadu: 67.16 TMC; site just upstream of the inter-state border
- Ministry of Jal Shakti DPR guidelines (December 2025): challenged by Tamil Nadu in the Supreme Court, as applied to the Cauvery basin
- Tribunal held the Cauvery a deficit basin (final award, February 2007)
- Revised Mekedatu DPR submitted to the CWC: 13 August 2026
- Supreme Court on Mekedatu (13 November 2025): Tamil Nadu's challenge premature
- Biligundlu release: 177.25 TMC a year (Supreme Court, 16 February 2018)