Cauvery water dispute: In SC, Tamil Nadu claims 20 TMC deficit as Karnataka says many districts face drought

The Supreme Court on Thursday (September 24, 2026) sought Karnataka’s response to a Tamil Nadu plea that it is suffering a shortfall of 20 thousand million cubic (TMC) feet of Cauvery river water.

Karnataka, in turn, submitted in the top court that it was facing a “terrible drought situation”, and has complied to the best its responsibilities towards Tamil Nadu as an upper riparian State.

Appearing before a Bench headed by Justice Vikram Nath, both State governments, however, concurred on the point that the Cauvery water was a “very sensitive” issue for them.

“Karnataka is usurping all the water, depriving us of our own,” senior advocate C.S. Vaidyanathan submitted for Tamil Nadu.

Senior advocate Shyam Divan, for Karnataka, said entire districts in the State have been declared as drought-prone. “Yet, we have taken it on the chin and done our best to comply,” he submitted.

The court gave Karnataka a week to file its response while scheduling the next hearing on October 12.

Mr. Vaidyanathan, accompanied by senior advocate G. Umapathy, complained that both the Cauvery Water Regulation Committee (CWRC) and the Cauvery Water Management Authority (CWMA) have not addressed the deficit of Cauvery water due to Tamil Nadu from Karnataka.

“They are directing the release of only low quantities. Karnataka has a sizeable quantity,” Mr. Vaidyanathan submitted. He said Tamil Nadu’s kharif crop had been affected.

He said Karnataka had realised 112. 729 TMC between June 1 and September 9. “They have also drawn 19.349 TMC through the canals in the four reservoirs; 3.9 TMC through Anaicut channels; and 3.962 TMC through diversion in Kabini dam. The total yield in Karnataka is 140 TMC... I should have got at least 57% of the 97.408 TMC Tamil Nadu is usually entitled to receive in normal conditions. That would come to 59.191 TMC. But we have realised only 35 TMC. There is a deficit of 20.969 TMC,” Mr Vaidyanathan submitted.

He said the monsoon has receded. There may not be any further rainfall.

“They [Karnataka] have water in their reservoirs. Why is my shortfall not being made good?” Mr. Vaidyanathan said.

Mr. Divan, along with senior advocate Mohan Katarki, submitted that the CWMA, an expert body, was monitoring the situation on a regular basis.

“The CWRC/CWMA are monitoring. They have discussed everything in detail, including the live storage position of the designated reservoirs in Karnataka and Tamil Nadu, the declining trend in the gross inflows into the four reservoirs of Karnataka, data, the rainfall activity in the next fortnight, drinking water flow, industrial and environmental flow, El Nino… Every factor is being considered,” Mr. Divan said.

He said that while there was minimal likelihood of further rainfall in Karnataka, the State of Tamil Nadu could take advantage of the fast-approaching northeast monsoon.

The Bench informed that the meeting of the Cauvery authority was scheduled on September 24..

Justice Sandeep Mehta, on the Bench, said the rights of both States to be heard before the CWMA has not been denied. The parties could voice their grievances before the authorities.