Mekedatu Row:  Balancing Bengaluru's Thirst And Tamil Nadu's Anxiety 

“The Cauvery issue is a highly sensitive matter between Tamil Nadu and Karnataka. Therefore, this August House urges the Union government to advise the Karnataka government not to undertake the construction of a dam or any new water storage project at Mekedatu, or elsewhere in the Cauvery basin, without the concurrence of the other basin states and the approval of the Union government.”

The resolution passed by the Tamil Nadu Assembly against Karnataka’s proposed Mekedatu dam near Bengaluru is the latest chapter in the decades-long dispute between the two states over sharing the waters of the Cauvery river. The project, which Karnataka says is essential to meet Bengaluru’s growing drinking water needs, has been strongly opposed by Tamil Nadu, which fears it could affect downstream water flows.

The Karnataka government is preparing a Detailed Project Report (DPR) for the proposed Mekedatu dam, a move that gained momentum after the Supreme Court dismissed Tamil Nadu's challenge to the project as "premature".

Karnataka plans to build the dam about 100 km from Bengaluru, with a storage capacity of 67.16 thousand million cubic feet (TMC) and an estimated cost of Rs 9,000 crore. The project also includes a hydroelectric component.

Officials in Tamil Nadu's Water Resources Department argue that the project is against the interests of the lower riparian state and that no new reservoir should be constructed without the consent of the other basin states. Citing the Assembly resolution, an official said Tamil Nadu's opposition is rooted in the view that both the Cauvery Water Disputes Tribunal and the Supreme Court have recognised the Cauvery as a deficit basin whose available waters have already been apportioned among the basin states."So there is no question of a new reservoir being built," the official said on condition of anonymity.

Environmental cost

The proposed project also carries significant environmental costs. The dam would require the submergence of 4,996 hectares of land, including nearly 4,800 hectares of forest and wildlife habitat. Environmental groups have raised concerns over the potential impact on biodiversity and protected ecosystems in the region.

Meaning "goat's leap" in Kannada, Mekedatu is a narrow gorge within the Cauvery Wildlife Sanctuary, located about three kilometres downstream of Sangama, where the Arkavathy river joins the Cauvery. Environmentalists say the proposed reservoir would submerge ecologically sensitive forest land that is home to several species of wildlife, including the grizzled giant squirrel, which is listed as 'near threatened' by the International Union for Conservation of Nature (IUCN). They argue that the project could have a significant impact on the sanctuary's fragile ecosystem. Activists also contend that the project would displace several tribal communities living in villages likely to be submerged, including Bommasundra, Galebore, Makivala, Kogge Doddi, Nelluru Doddi and Sampatagere Doddi. They argue that the dam would not only result in the loss of forest land but also disrupt the livelihoods, culture and traditional way of life of these indigenous communities.

Karnataka, however, maintains that the project is essential to utilise the 4.75 TMC of Cauvery water allocated to the state by the Supreme Court. The government argues that the Mekedatu reservoir will not affect Tamil Nadu's share of river water but will enable Bengaluru to meet its growing drinking water needs while also generating hydropower. According to the state, the project offers a long-term solution to the city's recurring water shortages.

"The water crisis in Bengaluru becomes severe every summer. We are forced to depend on private water tankers, which charge exorbitant rates during periods of peak demand," said Adith K.K., an IT professional. "While environmental concerns are important, they should not overshadow the urgent need to ensure a reliable supply of drinking water for millions of people."

Depleting ground water

A study by the Indian Institute of Science (IISc) found that unplanned urbanisation and a sharp decline in the extent of water bodies in and around Bengaluru have led to severe groundwater depletion. The study warns that the city's rapid expansion, coupled with the loss of lakes and wetlands, has significantly reduced groundwater recharge, exacerbating water scarcity and increasing dependence on external sources to meet its growing drinking water needs.

Against this backdrop, the Karnataka government and political parties across the political spectrum have rallied behind the Mekedatu project, arguing that it offers a long-term solution to Bengaluru's recurring water crisis.

"We do not want even a single drop more than what has been allocated to Karnataka. We only want the water that has been allocated to us," Karnataka Water Resources Minister Ramalinga Reddy said, reiterating the state's position that the project would not infringe on Tamil Nadu's share of Cauvery waters. He argued that the reservoir would, in fact, benefit the downstream state as well.

"If the Mekedatu dam had already been built, and if there had been water stored there, we could have released water to Tamil Nadu even during periods of poor rainfall. That would have helped us meet drinking water requirements while ensuring the monthly allocations due to Tamil Nadu, benefiting its farmers as well," he said.

Echoing this position, Karnataka Chief Minister D.K. Shivakumar had said that  his government is prepared to hold talks with Tamil Nadu to "dispel misunderstandings" surrounding the project and build consensus.

Emotional issue

The Cauvery water-sharing dispute has long been an emotionally charged issue between Karnataka and Tamil Nadu, with its origins dating back to agreements signed during the colonial era. To resolve the conflict, the Cauvery Water Disputes Tribunal was constituted in 1990. After nearly 17 years of studying river flows and hearing the claims of the basin states, the tribunal delivered its final award in 2007, allocating the river's waters among Karnataka, Tamil Nadu, Kerala and Puducherry. The Supreme Court later largely upheld the tribunal's award, with minor modifications to the allocation.

Over the decades, disagreements over the implementation of the award have repeatedly triggered political confrontations and violent protests in both Karnataka and Tamil Nadu, particularly during years of poor rainfall.

Tamil Nadu maintains that Karnataka is misinterpreting the Supreme Court's recent observations as a green signal for the Mekedatu project. "The state is examining all legal options to challenge Karnataka's move, as the proposed dam will have serious consequences for Tamil Nadu's farmers," said C.T.R. Nirmal Kumar, without elaborating on the legal strategy being considered.

The state is hopeful that the Supreme Court's earlier observations—that no new dam or major water storage project in the Cauvery basin should proceed without the consent of the co-basin states and the approval of the Union government—will weigh in its favour when the issue returns before the apex court.

Beyond the legal battle, however, the Mekedatu project encapsulates the competing demands that define India's inter-state river disputes. Bengaluru's worsening drinking water crisis has strengthened Karnataka's case for a new reservoir, while Tamil Nadu fears any upstream storage could jeopardise water availability for its farmers. At the same time, environmentalists warn of the submergence of ecologically sensitive forests and wildlife habitats, while activists highlight the displacement of tribal communities living in the project area. Balancing these competing claims—water security for a rapidly expanding metropolis, the rights of downstream farmers, the livelihoods of indigenous communities and the ecological cost of the project—will be central to any lasting resolution of the Mekedatu dispute.