Cauvery Water Oversight: The Data Behind the CWRC’s 3,500 Cusec Mandate

On July 28, 2026, the Cauvery Water Regulation Committee (CWRC) moved to address the escalating water tension between Karnataka and Tamil Nadu by directing a release of 3,500 cubic feet per second (cusecs) to the lower riparian state. This 15-day mandate, effective from July 29, aims to deliver approximately 4.5 thousand million cubic feet (tmc ft) of water. The decision emerges during a period of severe climatic stress, with the CWRC scheduled to reconvene on August 11 to evaluate compliance and updated flow data.

The Mechanics of Distribution and Deficit

Operating as the technical arm of the Cauvery Water Management Authority (CWMA), the CWRC is tasked with enforcing the 2007 tribunal award as modified by the 2018 Supreme Court ruling. Led by Vineet Gupta, the committee synthesizes data from the India Meteorological Department, the Central Water Commission, and agricultural experts to monitor eight critical reservoirs across Karnataka, Tamil Nadu, and Kerala.

• Reservoir Health: Current storage in Karnataka’s four primary reservoirs stands at 64.15 tmc ft, significantly below the 114.57 tmc ft capacity.
• Inflow Shortfalls: Historical 30-year averages reveal a 60% deficit in net inflows for the current season.
• Biligundulu Gauging: Flow realizations at the Biligundulu station show a staggering 90% shortfall, reflecting a grim reality for downstream supply.

The committee’s mandate includes tracking daily levels at Hemavathy, Harangi, Krishnarajasagara, and Kabini in Karnataka, alongside Mettur, Bhavanisagar, and Amaravathy in Tamil Nadu, and Kerala’s Banasurasagar. By analyzing the intermediate catchment between KRS-Kabini and Mettur, the CWRC determined that despite the bleak outlook, the 3,500 cusec figure represented a manageable threshold for Karnataka.

Political Friction and the Search for a Formula

Response to the directive has been icy in both state capitals. Karnataka Water Resources Minister K. Ramalinga Reddy indicated the government may contest the order before the CWMA, as the state has yet to begin irrigation releases due to rain scarcity. Concurrently, farmer organizations in Karnataka are lobbying for a "distress formula" to mitigate the impact on local growers.

Tamil Nadu officials find the quantum inadequate. With the Mettur reservoir holding only 36 tmc ft—of which 10 tmc ft is reserved for dead storage and drinking needs—the state faces a steep climb to meet the 100 tmc ft required for the kuruvai crop season. Critics in Chennai argue the CWRC should have mandated the full 9.8 tmc ft deficit immediately.

Diplomatic Path and Technical Solutions

The absence of a standardized distress-sharing mechanism remains a structural vulnerability in Cauvery management. Vineet Gupta emphasized that both states must prioritize evolving this formula to handle low-rainfall years. High-level diplomacy may offer a breakthrough, as Tamil Nadu Chief Minister C. Joseph Vijay prepares for discussions in Bengaluru to negotiate water shares directly. The CWMA is expected to meet shortly to deliberate on these systemic issues before the CWRC’s next technical review.

Source: The Hindu — National