The dispute over sharing Cauvery River water has intensified because of deficient rainfall and drought conditions in the river basin. Tamil Nadu has demanded that Karnataka make up for the shortfall in water releases. However, the Supreme Court of India has questioned how Karnataka can clear the backlog when it is also facing water scarcity.

Why in the News?

On October 12, 2026, the Supreme Court of India questioned Tamil Nadu’s demand for Karnataka to make up the shortfall in Cauvery water releases. The Court reserved its order on Tamil Nadu’s application, which claimed a shortfall of around 11.7 thousand million cubic feet (tmc ft) as of October 6 at Biligundulu, the inter-State water measurement point.

1. Reasons Behind the Current Dispute

Deficient rainfall during the southwest monsoon (June-September) has reduced water availability in the Cauvery basin. This has increased tensions between Karnataka, the upper riparian State, and Tamil Nadu, the lower riparian State.

 

●        Between June 1 and October 7, the Cauvery catchments recorded a 30% rainfall deficit compared with normal levels.

●        The deficit reached 43% in the catchment downstream of the Krishnaraja Sagara (KRS) and Kabini reservoirs up to Biligundulu.

●        Against the expected release of 57.568 tmc ft, the relevant period recorded only 45.849 tmc ft.

●        The figures were calculated by the Cauvery Water Regulation Committee (CWRC), which assists the Cauvery Water Management Authority (CWMA).

●        At the CWMA meeting on October 8, Tamil Nadu demanded that Karnataka make up a backlog of 15.02 tmc ft.

 

The difference between Tamil Nadu’s claimed shortfall of 11.7 tmc ft and its demand for a backlog of 15.02 tmc ft reflects the figures cited at different stages of the dispute.

2. Karnataka’s Position

Karnataka has argued that drought conditions and reduced reservoir inflows make it difficult to meet Tamil Nadu’s demand. It has also stressed the need to reserve water for essential uses.

 

●        The State reported a 54% deficit in cumulative inflows into its four Cauvery basin reservoirs.

●        It said around 45 tmc ft would be needed to meet drinking water requirements and maintain environmental flows.

●        Karnataka stated that it was complying with the CWMA’s direction to release 3,000 cubic feet per second (cusecs) for 15 days from October 9.

●        It argued that the approaching northeast monsoon (October-December) could replenish Tamil Nadu’s reservoirs.

3. Tamil Nadu’s Position

Tamil Nadu considers the prescribed release inadequate to address the accumulated shortfall. It has also raised concerns about the impact of reduced water flows on agriculture and farmers’ livelihoods.

 

●        Tamil Nadu argued that the release of 3,000 cusecs would not clear the existing backlog.

●        It maintained that the pro-rata flow required at Biligundulu in October should be around 3,500 cusecs.

●        Reduced water availability could affect the Samba paddy cultivation season and the livelihoods of farmers in the Cauvery delta.

●        Tamil Nadu also questioned reliance on the northeast monsoon, which is highly variable across locations and over time.

4. Supreme Court’s Response

A Division Bench headed by Justice Vikram Nath questioned whether Karnataka could reasonably be expected to clear the backlog while facing water scarcity itself. The Court observed that a backlog could be recovered only when excess water was available. It indicated that if Karnataka had excess water but failed to release it, Tamil Nadu’s demand for recovery would have a stronger basis. The Court reserved its order on the application.

5. Institutional Framework for Cauvery Water Management

The Cauvery water-sharing arrangement is implemented through institutions established following the final award of the Cauvery Water Disputes Tribunal, as modified by the Supreme Court.

 

●        Cauvery Water Management Authority (CWMA): Oversees implementation of the water-sharing arrangement.

●        Cauvery Water Regulation Committee (CWRC): Assists the CWMA in regulating and monitoring water releases.

●        The final award was modified by the Supreme Court in February 2018.

●        The existing water allocation arrangement is stated to remain valid until 2033.

 

The present institutions primarily focus on implementing the existing award. A broader river-basin framework could help the States coordinate water use and agricultural planning.

6. Way Forward

Recurring rainfall deficits and the risk of extreme weather make cooperation between Karnataka and Tamil Nadu increasingly important.

 

●        Coordinated agricultural planning: Both States should coordinate cropping patterns and agricultural operations according to water availability.

●        River Basin Organisation: The Union government should work towards establishing a dedicated organisation for the Cauvery basin to support integrated planning and management.

●        Drought preparedness: Water-use planning should account for uncertain monsoon rainfall and changing weather conditions.

●        Long-term cooperation: Both States need mechanisms to balance drinking water needs, environmental flows, irrigation requirements and equitable water sharing.

 

The World Meteorological Organization (WMO) has cautioned that El Niño may increase the risk of extreme weather in 2027, adding to concerns about future water availability.

Conclusion

The Cauvery dispute highlights the challenges of sharing river water during periods of drought. While Tamil Nadu seeks compensation for the shortfall in releases, Karnataka faces competing demands on limited water resources. Coordinated agricultural planning and integrated river-basin management can help the States manage water scarcity and reduce recurring disputes.

Article Resource- The Hindu