Karnataka Says It Will Go Ahead With the Mekedatu Reservoir: The Cauvery Dispute Explained
The Karnataka government said it will go ahead with the Mekedatu balancing reservoir-cum-drinking water project on the Cauvery river.
Karnataka's position is that the Supreme Court has allowed it to build the project, as long as it keeps releasing Tamil Nadu's share of water. That share is 177.25 tmc ft a year, fixed by the Supreme Court in 2018.
In November 2025, the Supreme Court refused to hear Tamil Nadu's objections to the project, calling them premature, because expert bodies were still examining Karnataka's Detailed Project Report (DPR). The court also warned that Karnataka must keep obeying the water-release orders. In May 2026, the court rejected Tamil Nadu's review petition against that order.
The Tamil Nadu government has asked the Centre not to give any approval for the project without the consent of all the states in the Cauvery basin.
The project still needs several approvals, including from the Cauvery Water Management Authority (CWMA), the Central Water Commission (CWC) and the environment ministry.
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, close to the Tamil Nadu border. "Mekedatu" means "goat's leap", after a narrow rocky gorge on the river there. Karnataka says the main aim is drinking water for Bengaluru and some electricity. Tamil Nadu, which lies downstream, fears it will reduce the water reaching it.
Karnataka reads the Supreme Court's November 2025 order as clearing the way for the project. Tamil Nadu's appeal to the Centre is aimed at the next stage: the approvals from the CWMA, CWC and environment ministry that the project still needs.
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 river. The river rises in Karnataka but much of its farmland lies in Tamil Nadu's delta. A tribunal and then the Supreme Court have fixed each state's share. Since 2018, a central body called the Cauvery Water Management Authority makes sure the shares are followed.
The 177.25 tmc ft that Karnataka must release is the figure fixed in the 2018 judgment. Karnataka argues Mekedatu will not change this obligation. Tamil Nadu argues a big new dam upstream would give Karnataka more control over the flow, which is why it wants basin-wide consent before any approval.
Article 262 and the Inter-State River Water Disputes Act, 1956
When a river flows through two or more states, they often fight over how much water each should get. Article 262 of the Constitution lets Parliament make a special system to settle such fights. Under this, Parliament passed the Inter-State River Water Disputes Act, 1956. The Act lets the Centre set up a tribunal (a special court) whose award all states must obey.
The Supreme Court did not decide the Mekedatu question itself; it called Tamil Nadu's challenge premature while expert bodies study the project. This fits the Article 262 design, where water sharing is settled through the tribunal, its award and the bodies that implement it, rather than through fresh court cases.
- Tamil Nadu's annual share at Biligundlu: 177.25 tmc ft (Supreme Court, 16 February 2018; earlier 192 tmc ft under the 2007 tribunal award)
- Mekedatu: about 67.16 tmc ft storage, about 4.75 tmc ft drinking water for Bengaluru, about 400 MW power
- DPR submitted to the Central Water Commission in January 2019
- Supreme Court called Tamil Nadu's challenge premature in November 2025; review petition rejected in May 2026
- CWMA and CWRC set up in 2018 under the Inter-State River Water Disputes Act, 1956
- Article 262: Parliament may exclude courts from inter-state water disputes; done through Section 11 of the 1956 Act