Karnataka-Tamil Nadu Cauvery Dispute: Why It Keeps Recurring
UPSC / SSC current affairs note · Polity
Why in news
The Cauvery water dispute has flared up again in July 2026, with the Cauvery Water Management Authority (CWMA) rejecting Karnataka's appeal against a release order. Tamil Nadu is planning to move the Supreme Court, and pro-Kannada groups have protested in Karnataka. This recurring conflict highlights the inadequacy of a fixed water-sharing formula in the face of changing river flows.
Background
The Cauvery water dispute is a long-standing inter-state river water sharing conflict between Karnataka and Tamil Nadu. The 2018 final award by the Cauvery Water Disputes Tribunal, as modified by the Supreme Court, allocated water based on a 740 tmcft annual flow assumption. The Cauvery Water Management Authority (CWMA) and Cauvery Water Regulation Committee (CWRC) were constituted to implement the award.
Key facts
In July 2025, Mettur reservoir in Tamil Nadu reached full capacity seven times, and Tamil Nadu received 317.28 tmcft of water at Biligundlu by December, exceeding its annual entitlement of 177.25 tmcft.
On July 28, 2026, the CWRC ordered Karnataka to release 3,500 cusecs per day for 15 days (about 4 tmcft) to Tamil Nadu.
Tamil Nadu had requested 9.94 tmcft (7,670 cusecs per day), more than double the CWRC order.
Karnataka refused the CWRC order and appealed to the CWMA, which rejected the appeal this week.
Karnataka CM DK Shivakumar reported that KRS reservoir was at 36% capacity, Kabini at 83%, Harangi at 95%, and Hemavathi at 67%.
Combined inflows into Karnataka's four main Cauvery reservoirs were around 25,000 cusecs.
Officials estimate Karnataka may need to release 6,000-7,000 cusecs from KRS and Kabini for 3,500 cusecs to reach Biligundlu due to dry riverbed absorption.
Karnataka had released about 3.5 tmcft by end of July 2026.
The 2018 division formula assumed the river carried 740 tmcft in a typical year, but actual flows vary significantly.
Pro-Kannada groups have marched in Bengaluru, Mysuru, and Mandya in protest.
Prelims pointers
- Cauvery Water Disputes Tribunal (CWDT) - final award 2007, modified by Supreme Court in 2018.
- Cauvery Water Management Authority (CWMA) - constituted under Section 6 of the Inter-State River Water Disputes Act, 1956 (as amended).
- Cauvery Water Regulation Committee (CWRC) - operational arm of CWMA.
- Mettur Reservoir (Stanley Reservoir) - Tamil Nadu, on Cauvery.
- Krishnaraja Sagar (KRS) Dam - Karnataka, opened in 1932.
- Kabini, Harangi, Hemavathi - other major reservoirs in Karnataka.
- Biligundlu - inter-state gauge station on Karnataka-Tamil Nadu border.
- tmcft (thousand million cubic feet) - unit of water measurement.
- cusec (cubic feet per second) - unit of flow rate.
- Article 262 of the Constitution - adjudication of inter-state water disputes.
Mains angles
- Discuss the reasons for recurring Cauvery water disputes despite a tribunal award and Supreme Court judgment.
- Critically examine the efficacy of the Cauvery Water Management Authority in resolving inter-state water conflicts.
- Analyze the impact of climate change and variability on inter-state river water sharing agreements.
- Evaluate the role of federal institutions in managing inter-state river disputes in India.