The long-running dispute of Mekedatu dam

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The governments of Karnataka and Tamil Nadu clashed over Mekedatu project, which supplies drinking water to Bengaluru.

Mekedatu is a multipurpose balancing reservoir project at the confluence of the River Cauvery and its tributary River Arkavathi.
The Mekedatu dam project is located in Ramanagaram district (about 100 km south of Bengaluru) close to where the Cauvery enters Tamil Nadu.
The project has been contentious for years between the two states - Tamilnadu and Karnataka.
The dam has a proposed capacity of 48 TMC (thousand million cubic) feet and an estimated cost of Rs 6,000 crore.
The project aims to supply drinking water to Bengaluru and replenish the regional groundwater table.
The Mekedatu dam will be larger than the Krishnaraja Sagar project on the Cauvery.

Tamil Nadu has been opposing it that it would impact the flow of Cauvery river water to the state.
It also argues that the project would affect the interests of the farming community in the state.
The construction of the dam is being done without consent of lower riparian state, in this case Tamilnadu, according to the Inter-State River Water Disputes Act, 1956.

Tamil Nadu witnessed widespread protests against the dam in 2015.
The TN state Assembly passed unanimous resolutions against the project in December 2018 and January 2022.
2007 Tribunal verdict - The Cauvery Water Dispute Tribunal (CWDT) in 2007 awarded Karnataka a share of 270 tmcft of Cauvery water.
2018 SC verdict - The Supreme Court in 2018 delivered its verdict in the decades-old Cauvery water dispute, allocating more water to the state of Karnataka.
According to this verdict, Karnataka’s share is increase by 14.75 tmcft to 284.75 tmcft.
Tamil Nadu will get 404.25 tmcft water per year, which will be 14.75 tmcft less than what was allotted by the tribunal in 2007.

Karnataka has expressed the resolve to build a dam and reservoir on the Cauvery at Mekedatu close to the state’s border with Tamil Nadu.
Tamilnadu is pointing out that the Mekedatu project was not part of the awards of the Cauvery Water Disputes Tribunal (CWDT) or the ruling of the Supreme Court.
Tamilnadu claims that any unauthorised construction across the river could harm Tamil Nadu.
It says it also violates both the 2007 final order of the CWDT and the 2018 verdict of the SC.
The two state governments, run by parties that are southern allies against the BJP, clashed over this project recently.

In August 2021, Tamil Nadu approached the Supreme Court against the project.
Their key argument is that Karnataka is attempting to modify the flow of the river by constructing two reservoirs on it.
Karnataka’s action violates the final award of the CRWT.
This would impound the flow in the intermediate catchment below the Krishnaraja Sagar and Kabini reservoirs, and Billigundulu, along the border of Karnataka and Tamil Nadu.
Tamilnadu’s opposition claimed that under the Inter-State River Water Disputes Act, 1956, Karnataka is legally prohibited from obstructing or altering the natural course of a river.
It also referred to the 2018 judgment, asserting that no irrigation project can start without the lower riparian states’ consent.

Tamilnadu even urged the Prime Minister to stop a feasibility study being conducted for the project in Karnataka.
The Central Water Commission (CWC) cleared the feasibility study for the project in 2018.
The Karnataka government claimed that the project will not come in the way of releasing the stipulated quantum of water to Tamil Nadu, nor will it be used for irrigation purposes.

Cauvery Water Disputes Tribunal (CWDT)

Cauvery is an inter‐State basin having its origin Karnataka and flowing through Tamil Nadu and Puducherry before out falling in Bay of Bengal.
The sharing of waters has been the source of a serious conflict between the two states of Tamil Nadu and Karnataka.
Government of India constituted the Cauvery Water Disputes Tribunal (CWDT) in 1990 in this regard.
It aims to adjudicate the Cauvery water dispute and the river valley thereof among the States of Tamil Nadu, Karnataka, Kerala and Puducherry.
CWDT gave its report and decision under the Inter-State River Water Disputes Act (ISRWD) of 1956 in 2007.