The Tamil Nadu government on Monday moved the Supreme Court seeking directions to Karnataka to immediately implement the July 30 decision of the Cauvery Water Management Authority (CWMA) and release 3,500 cusecs of water per day for 15 days from the Krishna Raja Sagara (KRS) and Kabini reservoirs, while also making good the accumulated shortfall in releases at the inter-state border point of Billigundulu.
The application contended that Karnataka had “wilfully” disobeyed the directions issued by the CWMA and the Cauvery Water Regulation Committee (CWRC), despite improved storage levels following recent rainfall in the Cauvery catchment.
Tamil Nadu has sought a direction to the CWMA to ensure Karnataka releases 4.536 TMC of water—equivalent to 3,500 cusecs over 15 days, by August 12. It has further prayed that Karnataka be directed to make good, on a pro-rata basis, the cumulative shortfall in releases from June 1 to August 12 by releasing 26.954 TMC of water forthwith.
The state has also sought directions to the authority to monitor Karnataka’s reservoirs every 10 days and ensure compliance with the stipulated monthly and daily releases at Billigundulu.
The fresh application comes days after the CWMA, in its July 30 meeting, endorsed the recommendation of the CWRC to release 3,500 cusecs from July 29 for 15 days after reviewing the hydrometeorological conditions in the Cauvery basin.
Tamil Nadu told the court that even if Karnataka were to fully comply with the CWMA’s direction, it would receive only 4.536 TMC of water, leaving a backlog of 5.379 TMC even under the distress-sharing formula adopted by the authority.
{{/usCountry}}Tamil Nadu told the court that even if Karnataka were to fully comply with the CWMA’s direction, it would receive only 4.536 TMC of water, leaving a backlog of 5.379 TMC even under the distress-sharing formula adopted by the authority.
{{/usCountry}}According to the state, if the inflows into Karnataka’s four major reservoirs up to August 3 are assessed against the 30-year average, the pro-rata distress ratio works out to 46.34%, under which Karnataka ought to have ensured releases of 26.954 TMC between June 1 and August 12.
“The direction given by the CWRC and CWMA is only 4.536 TMC, which is far less than the quantum of water as per distress proportion,” the application stated.
Tamil Nadu further alleged that Karnataka had not complied even with the limited direction issued by the authority. It pointed out that actual flows recorded at Billigundulu between July 29 and August 2 ranged only between 158 cusecs and 530 cusecs, far below the mandated 3,500 cusecs.
“It is evident that Karnataka has wilfully not complied with the directions of the CWRC/CWMA,” the application said.
The state submitted that as on August 3, Karnataka had gross storage of 77.537 TMC across its four principal reservoirs — 23.078 TMC in KRS, 18.610 TMC in Kabini, 7.827 TMC in Harangi and 28.022 TMC in Hemavathy.
It contended that the increase in storage was due to recent heavy rainfall in the upper catchments of Kabini and KRS and demonstrated that Karnataka had sufficient water to comply with the authority’s directions.
“Thus, Karnataka in spite of having adequate storage has failed to comply with the directions of CWMA,” the plea said.
The application also traced what Tamil Nadu described as Karnataka’s continuing non-compliance with the Cauvery Tribunal’s allocation regime, alleging that the neighbouring state had honoured release obligations only during years of surplus inflows caused by floods.
Referring to rainfall data for the current irrigation year (2026-27), Tamil Nadu said the catchments upstream of KRS, Kabini and the uncontrolled catchment received 488 mm, 676.1 mm and 78.4 mm of rainfall respectively between June 1 and July 27, against normal rainfall of 633.4 mm, 1,160.2 mm and 119.5 mm.
This translated into rainfall deficits of 23%, 42% and 34% respectively, the state said.
Under the final allocation framework, Karnataka is required to ensure monthly releases aggregating 123.14 TMC at Billigundulu between June and September and another 44.11 TMC between October and January, taking the annual release obligation to 167.25 TMC. An additional 10 TMC is earmarked every year towards environmental flows, taking the total annual requirement to 177.25 TMC.