Goa finds itself in an increasingly worrying geopolitical squeeze. Even as the State remains locked in a legal battle with Karnataka in the Supreme Court over the diversion of the Mhadei water, a fresh threat is emerging along its northern boundary. Political leaders and civic representatives in Belagavi have begun pushing to divert water from the Tillari basin to the Markandeya basin to augment drinking water supplies via the Rakaskop reservoir. For Goa, this is a double blow after the Mhadei row, because both threaten long-term water security and the fragile ecological balance.
At the heart of the proposal is a questionable assumption that Tillari has "surplus" water that can be diverted. The question is, how did Karnataka quantify “excess” water? Tillari is an inter-State project jointly conceived by Goa and Maharashtra. Karnataka cannot simply stake a unilateral claim over a shared river basin without scientific assessment and, crucially, without the consent of downstream riparian interests.
Goa is already heavily dependent on the Tillari canal network for drinking water and irrigation. To treat the river's headwaters as an open reservoir ignores the cumulative consequences of reduced downstream flows. Rivers do not recognise political boundaries, and tampering with their natural flow in one part of a basin can have consequences.
The muted response from Goa's Water Resources Department (WRD) comes as a major surprise. Senior engineers have reportedly suggested that a "limited" diversion would not significantly affect the State. In fact, that reassurance is dangerously shortsighted. A diversion in the name of drinking water can become the precedent for much larger inter-basin transfers. Mhadei water diversion was on the premise that 13 towns and villages in Dharwad, Belagavi, Gadag and Bagalkot were not getting adequate water. The State's experience with the Mhadei shows how seemingly incremental interventions can gather momentum while the administration remains caught in procedural delays and political reactions.
The timing of the Tillari proposal should also serve as a wake-up call. August 2026 marks eight years since the Mahadayi Water Disputes Tribunal delivered its Award, yet Goa continues to be fighting for its water. Back then, when the Tribunal announced its decision, the government celebrated it as a victory for Goa, only to realise much later that the Mhadei diversion would impact the State.
Instead of sounding conciliatory to Karnataka’s move, Goa needs to be proactive with a permanent institutional vigilance. The government should immediately review all pending and potential inter-State water disputes and establish a dedicated Legal-Technical Monitoring Cell with hydrological experts, real-time flow monitoring and satellite surveillance. Every proposed intervention upstream should be tracked from its earliest stage. An all-party consensus is equally important so that the protection of Goa's rivers does not change with every election.
Goa cannot afford to sit back while neighbouring upper-riparian states gradually redraw the region's hydrological map. The Tillari proposal may have originated as a local demand in Belagavi, but its implications extend far beyond civic water supply. It raises fundamental questions about inter-State water governance and Goa's own preparedness to defend its interests.
If the State fails to assert its rights, its people may be hit by a water crisis in the years to come. This is a frightening possibility, also because of the rapidly changing weather patterns. We must be ready with science-based action, not loose talk.
