The Mekedatu Dam is a proposed multi-purpose infrastructure project by the Government of Karnataka, not an act, institution, or judgment. It is planned as a balancing reservoir across the Cauvery River, near the confluence with its tributary, the Arkavathi, in the Ramanagara district, approximately 90 km from Bengaluru. The project's origin dates back to investigations in 1948 when the area was part of the Madras Presidency, with the Karnataka Power Corporation Limited (KPCL) preparing a project report in 1996.
The primary problem it aims to solve is securing an additional 4.75 TMC (Thousand Million Cubic feet) of drinking water for the Bengaluru Metropolitan Region, with a secondary objective of generating 400 MW of hydroelectric power. The proposed reservoir capacity is 67.16 TMC.
The project's mechanism is to store surplus monsoon flood water and regulate the flow to ensure Karnataka meets its downstream commitment to Tamil Nadu, as mandated by the Supreme Court's judgment of February 16, 2018. This judgment modified the Cauvery Water Disputes Tribunal (CWDT) award, increasing Karnataka's share to 284.75 TMC.
The Mekedatu project is inextricably connected to the larger Cauvery Water Dispute between the upper riparian state, Karnataka, and the lower riparian state, Tamil Nadu. Tamil Nadu opposes the project, arguing it will reduce the natural flow of water and violate the CWDT award and subsequent Supreme Court judgments, while Karnataka maintains it will only store surplus water and not affect the allocated share. The project requires approval from central authorities like the Cauvery Water Management Authority (CWMA) and the Central Water Commission (CWC). Recently, the Supreme Court termed Tamil Nadu's challenge to the project as "premature" since the Detailed Project Report (DPR) had not yet been officially approved, clearing the way for Karnataka to submit a revised DPR.