What’s the Cauvery dispute and how does the Mekedatu dam feature in it?

The sharing of interstate river waters is a complex issue in Indian federalism governed by Article 262 of the Constitution, which empowers Parliament to adjudicate such disputes. Under this provision, Parliament enacted the Inter-State River Water Disputes Act, 1956, allowing the central government to constitute a tribunal when states cannot resolve a water dispute through negotiations. The Cauvery Water Disputes Tribunal (CWDT) was established under this Act in 1990. The 2018 Supreme Court judgment is significant because the court asserted its jurisdiction to hear appeals against the tribunal's final award under Article 136 (Special Leave Petition), establishing that tribunal awards have the same force as a Supreme Court decree. The ongoing friction over the Mekedatu Dam illustrates the limitations of judicial and tribunal mechanisms in enforcing compliance, particularly regarding 'distress sharing formulas' during years of weak monsoons. The Cauvery Water Regulation Committee (CWRC) serves as the technical body monitoring water releases, highlighting the need for institutionalized, data-driven dispute management rather than ad-hoc political interventions.

The Cauvery River basin spans Karnataka, Tamil Nadu, Kerala, and Puducherry, making it a crucial resource for millions. The dispute centers on the geographical reality of upstream-downstream dynamics. Karnataka, as the upper riparian state, controls the headwaters and has constructed reservoirs to harness water for irrigation and drinking, including the proposed Mekedatu Dam, intended primarily as a balancing reservoir and for Bengaluru's drinking water needs. Tamil Nadu, the lower riparian state, historically utilized the majority of the river's yield and relies heavily on scheduled flows from upstream to sustain agricultural activities, particularly in the fertile Cauvery delta. The core geographical challenge is managing a deficit river basin where water demand exceeds supply. The tribunal's allocation—404.25 TMC to Tamil Nadu, 284.75 TMC to Karnataka, 30 TMC to Kerala, and 7 TMC to Puducherry—attempts to balance historical usage rights with developmental needs. The Supreme Court's modification, placing 'drinking water requirements' on a higher pedestal, reflects a critical geographical prioritization in resource allocation.

The controversy surrounding the Mekedatu Dam underscores the governance challenges of managing shared water resources. Tamil Nadu invokes Clause XI of the CWDT Award, arguing that the project cannot be evaluated 'merely as an engineering proposal' and that upper riparian states must not alter scheduled water deliveries. This highlights a critical governance principle: upstream infrastructure development must not jeopardize downstream water security without mutual agreement. Karnataka's counter-argument, that the project is for drinking water and hydropower and won't affect total allocations, points to the need for robust, independent impact assessments for major water projects. The dispute exposes the weakness of current interstate consultation mechanisms and the often-politicized nature of water management. Effective governance requires moving beyond zero-sum legal battles towards integrated basin-level management, emphasizing water conservation, efficient irrigation practices, and the development of mutually agreed-upon distress-sharing protocols to manage droughts, rather than relying solely on post-facto adjudication.