New Delhi : The long-running Cauvery water dispute between Karnataka and Tamil Nadu has returned to the Supreme Court, with the two States differing over whether Karnataka has released enough water to meet Tamil Nadu’s share.

During Monday’s hearing, Karnataka told the Supreme Court that it was complying with the Cauvery Water Management Authority (CWMA) direction to ensure a flow of 9,000 cusecs to Tamil Nadu. Karnataka’s counsel said the State had actually released more than the prescribed quantity at Biligundlu, the monitoring point on the Karnataka-Tamil Nadu border.

Tamil Nadu, however, argued that the current release does not address the water deficit accumulated during earlier months.

The State has sought the release of 17.604 TMC ft of Cauvery water, which it says was the balance due as of August 27 under the pro-rata formula.

Karnataka says it is already releasing water

Senior advocate Shyam Divan, appearing for Karnataka, told the Supreme Court that the State had released 9,888 cusecs at Biligundlu on August 30, exceeding the 9,000-cusec requirement.

He further told the Bench that the flow had crossed 11,000 cusecs by 8 am on August 31 and said Karnataka would endeavour to maintain the required 9,000-cusec flow.

Karnataka’s position is therefore that it is complying with the latest CWMA direction.

The authority had upheld the Cauvery Water Regulation Committee’s recommendation that Karnataka ensure a flow of 9,000 cusecs for 15 days, from August 25 to September 8.

From Karnataka’s perspective, the immediate question is whether the State is meeting the current direction.

Tamil Nadu, however, is looking at the larger accumulated deficit.

Tamil Nadu says the old shortfall still matters

Tamil Nadu’s argument is that simply releasing 9,000 cusecs now does not automatically erase the shortage that built up earlier in the year.

In its supplementary affidavit, Tamil Nadu asked the Supreme Court to direct Karnataka to release 17.604 TMC ft, calculated as the balance due under the pro-rata formula as of August 27.

The State has also sought enforcement of the current 9,000-cusec direction and compensation for any shortfall in the flows recorded at Biligundlu during the relevant period.

Tamil Nadu says the accumulated deficit must be considered when determining how much water Karnataka should release.

Why the 17.604 TMC figure is important

The dispute is not simply about one day’s flow.

Water sharing under the Cauvery arrangement is based on an annual allocation and a schedule of releases, with adjustments required when actual flows differ from expectations.

Tamil Nadu says that by August 27, the pro-rata calculation showed a 17.604 TMC ft backlog.

It had earlier raised the issue before the CWRC and subsequently before the CWMA, arguing that the 9,000-cusec release ordered for the 15-day period did not adequately address the accumulated shortage.

Tamil Nadu had initially sought a much higher release, asking for about 22,000 cusecs for 15 days, or roughly 1.9 TMC per day, to help address its water requirements and accumulated deficit.

The CWRC, however, recommended the lower 9,000-cusec flow.

Farmers are at the centre of Tamil Nadu’s argument

Tamil Nadu has highlighted the impact of the water shortage on farmers in the Cauvery Delta.

The State told the Supreme Court that a significant area of agricultural land depends on Cauvery water. It has argued that the shortage has affected cultivation, particularly during the Kuruvai season, while concerns have also emerged over the next crop cycle.

Tamil Nadu has also pointed to the fact that the Mettur reservoir could not be opened for irrigation as expected because of inadequate storage.

For farmers in the Delta, the timing of water releases can be as important as the total quantity eventually received.

A delay can affect sowing and crop growth even if water arrives later.

Tamil Nadu also questions water use within Karnataka

Another part of Tamil Nadu’s argument concerns Karnataka’s own use of Cauvery water.

Tamil Nadu has told the authorities that Karnataka had already drawn more than 20 TMC through canals, anicuts and lift irrigation systems for agricultural purposes.

It argues that this must be considered when assessing the balance available for downstream release.

Karnataka, however, has repeatedly maintained that it is facing its own hydrological difficulties and must also protect the drinking-water and agricultural requirements of its people.

This tension between upstream and downstream needs is at the heart of the annual Cauvery dispute.

The Supreme Court has already stepped in

The latest hearing is part of a broader legal process that has continued for years.

The Supreme Court had earlier directed Karnataka to comply with the directions of the CWMA when Tamil Nadu approached it over the release of Cauvery water. In August, the court sought status information from the authority while continuing to hear Tamil Nadu’s plea.

The court has also previously emphasised the role of the CWMA and CWRC in implementing the Cauvery water-sharing framework established following the Supreme Court’s 2018 judgment.

The current dispute therefore involves not only the two States but also the question of how effectively the regulatory authorities are implementing the established water-sharing mechanism.

What happens to the backlog now?

This is the key question before the court.

Karnataka says it is complying with the latest direction and has even released more than the prescribed daily flow.

Tamil Nadu says that compliance with the current order is not enough because a significant quantity remains outstanding from earlier periods.

The Supreme Court will therefore have to consider whether the claimed 17.604 TMC ft backlog should be separately addressed and, if so, how and when it should be released.

The court has also asked the Cauvery authorities to consider Tamil Nadu’s concerns.

One river, two urgent needs

The dispute is difficult because both States have genuine demands for the same resource.

For Karnataka, reservoir storage, rainfall, drinking water and the needs of farmers remain important considerations.

For Tamil Nadu, the timing and quantity of water reaching the Cauvery Delta are crucial for agriculture and the livelihoods of farmers.

In a year affected by water stress, every additional demand becomes more politically and economically sensitive.

The legal framework provides a mechanism for resolving these differences, but implementing it on the ground can still lead to disputes when actual rainfall and reservoir conditions differ from expectations.

The issue is bigger than 9,000 cusecs

The latest Supreme Court proceedings show why the Cauvery dispute cannot be understood simply by looking at the daily release figure.

Karnataka points to the water it is releasing now.

Tamil Nadu points to the water it says it should have received earlier.

Both figures can therefore be true within the context of their respective arguments.

The immediate legal question is whether Karnataka’s current compliance satisfies the CWMA’s direction. The larger question is whether Tamil Nadu’s claimed accumulated deficit must also be cleared.

For farmers on both sides of the border, however, the issue is much more immediate than legal calculations.

It is about water reaching fields at the right time.

As the Supreme Court and the Cauvery authorities examine the competing claims, the focus will remain on finding a balance between legal entitlement, available water and the needs of farmers and communities in both States.

The Cauvery may flow across State boundaries, but every decision over its water continues to carry consequences far beyond the river itself.