Tamil Nadu has said Karnataka's proposal to construct a reservoir across river Cauvery at Mekedatu was "untenable and ought to be rejected outright" and urged the Centre against giving its nod for the project following a fresh appeal by the upper riparian state.
Tamil Nadu is opposed to Karnataka's proposal to construct a balancing reservoir at Mekedatu in that state, saying it will be affected if the project takes shape.
Chief Minister K Palaniswami wrote to Union Jal Shakti Minister Gajendra Singh Shekhawat and his Environment Ministry counterpart Prakash Javadekar, reminding them of pending court cases in this matter.
The letters dated October 9 were released by the state government on Thursday.
He told them the Cauvery Water Disputes Tribunal and the Supreme Court "have found that the existing storage facilities available in the Cauvery Basin are adequate for storing and distributing water to the lower riparian states as per the monthly schedule prescribed by it."
"Therefore, the proposal of Karnataka to build a reservoir is ex-facie untenable and ought to be rejected outright," he said.
Further, the concurrence of Tamil Nadu and that of other co-basin states has not been obtained for the project, he added.
The chief minister recalled that an Expert Appraisal Committee (EAC) for River Valley and Hydro-electric Projects of the Environment Ministry in its July meeting had "deferred the proposal of Karnataka's Mekedatu project."
It has come to Tamil Nadu's notice Karnataka has again approached the said committee seeking approval of the Terms of Reference (ToR) for the reservoir, he said.
"The Government of Tamil Nadu once again reiterates its strong objections to the project proposal of Karnataka, as it has no right to construct any reservoir on an inter-state river without the consent of the lower riparian state i.e. Tamil Nadu," he asserted.
In his letter to Javadekar, Palaniswami recalled he had earlier written to him in July requesting the union minister to reject and return Karnataka's proposal as it was against the final order of the Tribunal and the February 2018 apex court judgment.
He told Shekhawat he had written a letter to him in July this year, requesting that the Jal Shakti ministry should not accord any clearance to the Mekedatu project.
Palaniswami urged Javadekar to instruct the Environment Ministry to issue instructions to the EAC "not to entertain"
Karnataka's proposal and reject its detailed project report seeking grant of ToR to conduct environmental impact assessment (EIA) and environment management plans (EMP)."
He urged Shekhawat to take up the matter with the Environment ministry.