India’s Climate Diplomacy Begins at Its Rivers

Image: Rainer Lesniewski / Shutterstock

This December, the Ganga Treaty, which for thirty years has guaranteed Bangladesh a share of dry-season flows, comes up for renewal at a difficult moment for Indian water diplomacy. The Indus Water Treaty sits in abeyance; other smaller agreements with Bangladesh and Nepal are stalled or unfulfilled. And on the Brahmaputra there is no treaty at all, even as Beijing is initiating mega-dam construction without transparency. A transboundary water treaty exists to turn a contested, seemingly zero-sum resource into a governed one. It guarantees downstream states a defined share of the flow and obliges upstream states to share data and by making each side’s rights and duties predictable, it reduces the risk of confrontation.

The stakes of treaties failing are not abstract. India holds just four percent of the world’s freshwater but 18 percent of its population. Nearly 600 million Indians already face high-to-extreme water stress and this demand is projected to reach twice the available supply by 2030. NITI Aayog warns the shortfall could cost India up to six percent of GDP. But behind those percentages are the farmers of eastern Uttar Pradesh and Bihar whose winter wheat depends on that dry-season flow and the floodplain villages of Assam that live or lose by an upstream warning. We have seen what such dependencies cost when cooperation collapses. In 2017, during the Dokhlam standoff, China suspended Brahmaputra flow and the same year floods swept through Assam, causing scores of deaths and affecting more than three million of its residents.

Water is emerging as a non-traditional security challenge for India and New Delhi has already treated it as one. When India placed the Indus Waters Treaty in dormancy last year and declared that “blood and water cannot flow together”, New Delhi securitised water without saying so outright. But using water as a strategic lever is not the same as having a strategy. Without a strategy, when treaties fail, floods arrive without warning and dry seasons bring shortages that no system is ready to absorb. And the burden of all these falls on people and their livelihoods. This is security in the human sense, as it determines the lives of hundreds of millions of people. What India lacks is not evidence or instinct but a stated doctrine. This gap is also an opportunity. A declared position would cost little: it commits India to no new allocations and concedes nothing. Yet it would do two things at once. It would align India with the vocabulary of its neighbours Nepal, Sri Lanka and Bangladesh on climate related insecurities, where India remains the holdout. And by committing India to anticipate water risk rather than merely react to it, it would begin to reduce the enormous money the country spends on flood recovery, by effective pre-disaster preparedness.

The regional workaround

The Indus Waters Treaty has been suspended since the 2025 Pahalgam attack, a violent militant assault on April 22 in which 26 civilians were killed in the Indian-administered Kashmir. The Indian government described the attack as Pakistan’s support for cross-border terrorism. As a result, the Permanent Indus Commission has gone dormant and hydrological data-sharing has stopped.  Re-engagement seems difficult for now, but the IWT freeze need not slow cooperation elsewhere. With SAARC being non-functional, the Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation, (BIMSTEC) offers a different opportunity. BIMSTEC is quiet and functional. Its advantage for India is that it excludes Pakistan while bringing together the major riparians of the Ganga-Brahmaputra system and it cooperates on exchanging power, forecasts and data rather than on allocation, the issue that deadlocks every water negotiation. The instruments already exist. In November 2024, Nepal sold power to Bangladesh through the Indian grid for the first time. This was only 40 MW, but it was the first instance of Himalayan water crossing two borders as electricity under a framework that India had brokered. India also has separately committed to importing 10,000 MW of Nepal’s hydropower over a decade, while the BIMSTEC Grid Interconnection Master Plan is under discussion and the BIMSTEC Centre for Weather and Climate in Noida, India, already issues forecasts to all seven members. Taken together, these are not just projects but are early stages of a basin-scale adaptation architecture for the Ganga-Brahmaputra system, built without ever convening a water negotiation. India’s policy choice therefore is simple: scale these functioning instruments deliberately or let them remain episodic. Water sharing may stay off the table, but water diplomacy in terms of sharing data and forecasts, is already underway through BIMSTEC.

India already exchanges river data with nearly every neighbour, but only in fragments. The policy option therefore is not to reinvent data-sharing but to upgrade and upscale it, from bilateral and seasonal to year-round, basin-scale and pooled, with the Noida centre as the repository that already exists. None of this means sidelining China; any Himalayan water order will ultimately need Beijing on board, which is hard to get but not impossible. In 2020, on the Mekong issue, Beijing conceded year-round data-sharing only when organised downstream states, who were equipped with satellite evidence, asked collectively. The Brahmaputra’s riparians have never made that collective ask, because no platform exists to make it. Building the coalition with other states is how India makes the conversation with China possible in the near future and worth Beijing’s while to join.

India cannot dam or drill its way out of a crisis whose headwaters lie beyond its borders. The recent series of flash floods in Nepal exposed a Himalayan fragility that crosses borders and therefore demands transboundary governance.  For New Delhi, the elements of that governance already exist and they can use it for some strategic decisions. First, India can publish a national doctrine that names water as a human security issue, closing the gap between securitised practice and absent policy. Second, declare the BIMSTEC energy, forecasting and data instruments to be what they already are: water diplomacy. India should name it, fund it and lead it. Third, use the Ganga Treaty renewal this December to do what a treaty written for a stationary climate never could: embed year-round, basin-scale data-sharing, turning an agreement India will sign anyway into the template for the basin’s next arrangement. India can arrive at that table as a defensive state clinging to expiring paper or as the architect of that arrangement in South Asia. December will tell which.

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