The Cauvery water-sharing issue dates back to 1892 when the princely state of Mysore and the Madras Presidency signed an agreement on sharing Cauvery water. In 1924, a definitive agreement was reached allocating fixed water shares to both regions for 50 years.

However, the formation of new states—Andhra Pradesh, Karnataka, and Kerala—in 1956 necessitated modifications to the water-sharing agreement. When the 1924 agreement expired in 1974, the states were unable to reach a fresh consensus.

In 1986, Tamil Nadu approached the Supreme Court, seeking the establishment of a tribunal to resolve the long-standing water-sharing dispute. Four years later, in 1990, the Supreme Court established the Cauvery Water Disputes Tribunal (CWDT). The CWDT issued an interim order a year after its formation, directing Karnataka to release 205 tmcft (thousand million cubic feet) of water to Tamil Nadu annually.

After years of legal battles, the tribunal issued its final award in 2007, allocating 41.92% of the water to the lower riparian state, Tamil Nadu, 27.36% to Karnataka, 12% to Kerala, and 7.68% to Puducherry. However, in 2012, Karnataka challenged the CWDT’s allocation in the Supreme Court due to severe rainfall deficit.

In 2018, the Supreme Court declared the Cauvery River a national resource and upheld the water-sharing arrangements determined by the CWDT. Additionally, the Central Government was directed to formalise the Cauvery Management Scheme.


The most recent controversy emerged as Karnataka refused to adhere to previously agreed-upon water release quantities.

Tamil Nadu demanded a release of 10,000 cusecs of water over a 15-day period, while Karnataka has proposed a lower water release of 8,000 cusecs for the same 15-day span.

Karnataka cites insufficient inflow due to decreased rainfall in the Cauvery catchment, which includes the origin point of Kodagu.

The Cauvery Water Regulation Committee, based on the deliberations of a meeting held on Tuesday, recommended Karnataka to release 3000 cusecs at Biligundlu starting from September 28th up to October 15th.