The Tamil Nadu government has moved the Supreme Court seeking to restrain Karnataka from proceeding with any activity regarding the proposed construction of a reservoir at Mekedatu across the inter-state Cauvery river.
The Tamil Nadu government in its plea stated that the planning of the Mekedatu project by Karnataka with a capacity of 67.16 TMC ft. and generation of 400 MW power at a cost of about Rs 9000 crores is in gross violation of the decision of Cauvery Water Disputes Tribunal.
The petition said that the entire object and intendment of the final decision of the tribunal as modified by the top court is to ensure that the pattern of the release of water to the downstream state to meet the irrigation interests are not jeopardised.
The state of Karnataka unilaterally and contrary to the judgment of this court, sent a feasibility report of the Mekedatu project to Central Water Commission (CWC), the petition said adding that the CWC, which is the implementing agency, is bound to honour the judgement, but instead proceeded to entertain the proposal.
"The proposed construction by Karnataka would have a cascading effect on the daily and monthly inflows during the crucial months of June to September as stipulated in the Final Order of the Tribunal as affirmed by this Court resulting in prejudicing the livelihood of lakhs of inhabitants of Tamil Nadu depending on the flows from the upstream in Karnataka," the plea said.
It said that any new scheme contemplated should be taken up only with the consent of the other basin states as they are vitally affected by the unilateral action of the upper riparian state.
The plea has sought directions to the Central Water Commission to reject and return the Detailed Project Report for the proposed Mekedatu Balancing Reservoir cum Drinking Water Project filed by Karnataka.
It has also sought to restrain the ministry of environment & forests and its agencies from entertaining any application for clearance relating to the Mekedatu project.
According to the plea, the proposed reservoir would result in impounding the flows generated in Cauvery river from the uncontrolled catchment of Kabini sub-basin downstream of Kabini reservoir, the catchment of Cauvery river downstream of Krishna Raja Sagara dam, uncontrolled flows from Shimsha, Arkavathy and Suvarnavathy sub-basins and various other small streams, which are the sources to ensure 177.25 TMC at Billigundlu.
The petition stated that the proposed project would affect the flow of the river Cauvery considerably and will severely affect the irrigation in Cauvery basin of Tamil Nadu.
If any new storage structure is permitted to be constructed by Karnataka, the applicant state will not be able to get its due share of water as per monthly schedule even in normal years and more so in deficit years, the plea said.
"Karnataka will appropriate the waters to the maximum extent using the additional storage thereby, depriving the lower riparian state of its due share, which is the past experience of Tamil Nadu." the plea said.
The state government claimed that in spite of a series of correspondence with the ministry of Jal Shakti, Karnataka and the prime minister, the Centre has not issued any instructions to Karnataka and its instrumentality not to proceed with the project.
The top court in 2018 had directed the Karnataka government to release 177.25 tmcft of Cauvery water to Tamil Nadu from its inter-state Billigundlu dam.
The judgement clarified that Karnataka will now have an enhanced share of 14.75 tmcft water per year while Tamil Nadu will get 404.25 tmcft, which will be 14.75 tmcft less than what was allotted by the tribunal in 2007.
Earlier, in accordance with the 2007 award of the Cauvery Water Dispute Tribunal (CWDT), Karnataka had a share of 270 tmcft of Cauvery water. This will now increase to 284.75 tmcft.
