The statement comes after Southern Bench of the National Green Tribunal formed a four-member committee to check if there are any construction activities in the site.

Tamil Nadu Water Resources Minister S Durai Murugan
news Controversy Thursday, May 27, 2021 - 08:51
Tamil Nadu Water Resources Minister S Durai Murugan on Wednesday said that the state will not allow Karnataka to build a dam across River Cauvery at Mekedatu, which is near the inter-state border. In a statement, Durai Murugan said, "Tamil Nadu will never allow the construction of Mekedatu dam planned by the Karnataka government across the Cauvery river." 
Recalling that the state government has approached the Supreme Court, the Minister said, the state government would consult legal counsels on this matter and take appropriate action. The state government had filed a petition in the Supreme Court in November 2018 seeking a stay on the permission granted by the Central Water Commission to the Karnataka government to go ahead and prepare a detailed project report (DPR).

Accordingly, the Minister’s statement also comes after the Southern Bench of the National Green Tribunal formed a four-member committee based on news reports to check whether there were any construction activities undertaken at the site without obtaining the required permission from Forest Department as well as from the Ministry of Environment, Forests and Climate Change under the Forest Conservation Act and EIA Notification, 2006.
The NGT’s committee with constituents including the Union Environment Ministry, Cauvery Water Management Authority, Cauvery Neeravi Nigam Limited and the Forest Department of Karnataka government will conduct an inspection of the concerned area and submit a factual report and an action taken report, if any violations are found. The NGT has directed the panel to submit its report on or before July 5.
"If the project is to be implemented without conducting any environmental assessment study and without obtaining necessary clearance if any required, then it will be an unauthorised act affecting the environment," the tribunal said.

The reservoir project is an extension of the tussle between the two states over sharing the Cauvery water.
(With IANS inputs)