A treaty phrase, a river reopened: Karnataka signals the Cauvery fight is not settled

CHENNAI: Karnataka has told the court process that the Cauvery settlement itself should be reopened, pointing to the doctrine used in international water law after circumstances fundamentally change. Its response refers to revisiting inter-State allocations by agreement or adjudication when conditions have changed, a principle known as rebus sic stantibus.

For Tamil Nadu's delta farmers, that legal phrase has a simple meaning: a settlement reached after a tribunal award and a Supreme Court judgment may again become negotiable. The tribunal's final award in a normal year was 740 thousand million cubic feet in total, with 404.25 TMC for Tamil Nadu and 284.75 TMC for Karnataka. The Supreme Court largely upheld the sharing arrangement in 2018 and treated the Cauvery as a national asset, after which the Cauvery Water Management Authority was created.

The fresh argument lands only weeks after the Supreme Court refused to entertain a separate plea that sought 70 TMC more for Karnataka from Tamil Nadu's share, saying the two States were already contesting the dispute. In August and September, the management authority directed Karnataka to ensure 9,000 cusecs to Tamil Nadu for a period, with both States telling the court different things about compliance and backlog.

The timing is difficult for the lower riparian State. Tamil Nadu has just recorded its lowest Cauvery realisation in fourteen years, and tail-end fields are again the first to feel a shortfall. A farmer at the end of a canal does not experience a doctrine; she experiences a dry field, a pump bill, and a season decided before the north-east monsoon arrives. Chennai, meanwhile, faces light drizzle and temperatures near 33 degrees Celsius over the coming days, a reminder that city rain does not fill a delta channel.

Karnataka's position, as summarised in its response, is that changed circumstances justify a fresh look. Tamil Nadu's interest is the opposite: a final settlement must mean something, or every dry year becomes a reason to renegotiate. The Justice will follow the filings closely. The question is not only how much water the river holds this season. It is whether a settlement that took decades to reach can be reopened whenever the upper State finds the arithmetic inconvenient.