Cauvery Water Management Authority: Tamil Nadu Considers Stronger Enforcement Powers on BBMB Model

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Tamil Nadu is considering approaching the Supreme Court to seek stronger enforcement powers for the Cauvery Water Management Authority (CWMA), a senior government official said on November 11, 2026. The State wants the Authority to be modelled on the Bhakra Beas Management Board (BBMB), which owns, operates and regulates the Bhakra Nangal and Beas projects. The Cauvery Water Disputes Tribunal had referred to the BBMB model in Volume V of its report.

Tamil Nadu has complained that Karnataka, the upper riparian State, has not complied with mandated water releases in five of the seven 15-day spells ordered by the CWMA since July 29. Although cumulative realisation measured at Biligundulu on the inter-State border was about 5,000 cusecs higher than the total ordered figure of 5.71 lakh cusecs, the State estimates a backlog of nearly 17 thousand million cubic feet (tmc ft). The CWMA has not directed Karnataka to clear the backlog, the official said. The four Karnataka reservoirs — Krishnaraja Sagara, Kabini, Hemavathi and Harangi — recorded a net cumulative inflow of about 132 tmc ft from June 1 to November 4, a shortfall of around 54% against the 30-year average of 288 tmc ft. Biligundulu received 53.43 tmc ft in the same period, against an estimated 67 tmc ft if the same shortfall were applied.

What was the Cauvery Water Disputes Tribunal and its final award?

The Cauvery Water Disputes Tribunal was constituted by the Union government in June 1990 under the Inter-State River Water Disputes Act, 1956 to adjudicate the water-sharing dispute among the basin states of Karnataka, Tamil Nadu, Kerala and Puducherry. The Tribunal gave its final order in February 2007, allocating 419 thousand million cubic feet (tmc ft) to Tamil Nadu, 270 tmc ft to Karnataka, 30 tmc ft to Kerala and 7 tmc ft to Puducherry in a normal year. The Supreme Court upheld the Tribunal's award in its February 2018 judgment, modifying the allocation slightly by reducing Tamil Nadu's share by 14.75 tmc ft and increasing Karnataka's share by the same amount. The Cauvery Water Management Authority was created by the Centre in June 2018 on the direction of the Supreme Court to implement the award, replacing the earlier Cauvery Supervisory Committee.

What is the Bhakra Beas Management Board model?

Established in October 1967, the BBMB regulates the supply of water and electricity from the Bhakra Nangal and Beas projects to Punjab, Haryana, Rajasthan, Himachal Pradesh, Delhi and Chandigarh. Its chairperson is appointed by the Union government. The Board jointly decides how much water is to be given and what the scheduling will be, and it owns, operates and manages the projects, CWMA chairperson Saumitra Kumar Haldar had explained in August.

What has the CWMA achieved and missed?

The CWMA has ordered water releases in 15-day spells since July 29, and cumulative realisation at Biligundulu has exceeded the total ordered figure. However, Karnataka did not comply with mandated releases in five of the seven spells. Tamil Nadu says the Authority has not enforced its directions or asked Karnataka to clear the estimated backlog of nearly 17 tmc ft. The State had earlier approached the Supreme Court, which told it to go to the Authority, but the CWMA's orders were not implemented properly, a senior official said.