PMK chief S Ramadoss and MDMK general secretary Vaiko requested the Centre to trash the Detailed Project Report (DPR) submitted by Karnataka to the Central Water Commission (CWC) on June 7 for constructing a dam at Mekedatu.
The PMK leader alleged that Karnataka had sought the nod for the project by submitting "false details".
In a statement issued here, Ramadoss said Karnataka had told the Centre in its DPR that it could release water for Tamil Nadu, in accordance with the Cauvery Water Disputes Tribunal's (CWDT) award, only if the proposed dam was built.
"All these assurances were given to deceive the CWC and the Tamil Nadu government and they cannot be believed," said Ramadoss.
More From This Section
He recalled that in the past, Karnataka had stopped releasing water for Tamil Nadu citing low levels in its dams.
Since the DPR did not have the concurrence letter from Tamil Nadu and Puducherry, it should be sent back to Karnataka, he said, adding, "The Centre should not be deceived by the sweet words of Karnataka and the Tamil Nadu government should be vigilant."
Accusing Karnataka of "acting against the final award of the CWDT", he said if the new dams were built, Tamil Nadu would not get "even a drop of Cauvery water".
"Twelve lakh hectares of land in the Cauvery basin will become barren if the new dams are built," he alleged.
The MDMK chief urged the Centre not to sanction the project, which he said, would affect the rights of Tamil Nadu over the Cauvery waters.
"The Centre should immediately set up the Cauvery Management Board and a regulatory authority," he said.