Beyond Water Sharing: The Geopolitics of the Brahmaputra

The floods that Assam endures every year expose deeper problems in India's water management. As a downstream riparian state, India's ability to predict floods depends on hydrological data from the upper Brahmaputra, which is crucial information for early warning systems, dam safety assessments, and flood-management planning. Yet access to this data depends on cooperation with China, which has control over the upper reaches of the river on the Tibetan Plateau and has built hydropower infrastructure on the Yarlung Tsangpo River.

Illustration by The Geostrata

The Brahmaputra poses a unique geopolitical issue. It rises on the Tibetan Plateau, flows eastward across Tibet as the Yarlung Tsangpo, turns south at the Great Bend around Namcha Barwa, enters India through Arunachal Pradesh as the Siang, and flows on through Assam into Bangladesh.

This geography creates a significant upstream-downstream imbalance. India can track and monitor events that occur once the river flows into its territory, but access to upstream hydrological data from China, regarding developments in terms of water levels and discharge, helps Indian authorities to anticipate changes in river flows and prepare for potential flooding downstream.

As China develops its infrastructure on the Yarlung Tsangpo, such information becomes more important for India in terms of flood forecasting, water availability, irrigation planning, and assessing the impact of upstream projects on downstream facilities.

CHINA'S EDGE IN INFRASTRUCTURE AND INFORMATION 

China has already built substantial hydropower infrastructure on the upper Yarlung Tsangpo, most notably the Zangmu hydropower, commissioned in 2015. Three further run-of-the-river cascade projects lie along the Yarlung Tsangpo's mainstream in Tibet: Jiacha and Dagu are already operational, while Jiexu is still under construction.

Since 2025, China has also begun work on a far larger project on the lower Yarlung Tsangpo near Medog, close to the Great Bend. Besides generating power, such installations carry sensors and gauging systems that measure water levels and discharge.

China is therefore well informed about the water flow conditions in the upper reaches, while India is dependent on information that China chooses to share. This is evident from the Zangmu project, as a run-of-the-river project, its capacity to regulate downstream flow and moderate floods is far lower than that of a large reservoir. Its operations, however, depend on continuous monitoring of river flow.

From India’s perspective, the problem is not only physical capacity to generate power but also asymmetrical access to information on changing hydrological conditions. India has its own systems, such as a network of river gauges, hydrological monitoring stations, satellite observations, and flood-forecasting systems to monitor and predict floods, as maintained by the Central Water Commission of India.

But still, it can't replace the timely information about the upstream regions, given how swiftly the Brahmaputra descends from the Tibetan Plateau through the Himalayas into Arunachal Pradesh and Assam.

The problem, then, is not simply that China may control the river's flow. There is no legally binding agreement on the division of river waters, and China is not a party to the UN Watercourses Convention. It therefore has no treaty obligations to share upstream hydrological information or to consult India on projects that may affect downstream flows. India is left reliant on bilateral coordination and information sharing.

VULNERABILITY OF INDIA'S DOWNSTREAM REGION

India’s vulnerability does not stop at hydroelectric infrastructure. Assam receives extremely heavy monsoon rainfall, compounded by erratic upstream runoff from the Tibetan Plateau, and the region remains prone to regular flooding.

Despite the seasonal nature of Assam’s floods, changes in upstream runoff, rainfall, and river conditions may influence the occurrence and severity of the floods downstream. Thus, timely knowledge of the situation in the upper reaches of the river basin becomes crucial.

India depends on a mix of meteorology, satellite technology, river gauges, and hydrological prediction tools to predict variations in the Brahmaputra. This enables India to generate considerable amounts of information on its own territory, but it cannot fully substitute for timely upstream data. The gap reflects not a lack of Indian capability but the natural information asymmetry of the upstream-downstream relationship.

GAP IN HYDROLOGICAL INFORMATION SHARING 

India and China formalised hydrological information sharing on the Brahmaputra through a Memorandum of Understanding in 2002, under which China committed to share flood-season data from three stations along the Yarlung Tsangpo. This agreement was reaffirmed in 2008, and an Implementation Plan followed in 2010. A further MoU in 2013 extended the sharing period from 15 May to 15 October.

Both countries had already formed an Expert Level Mechanism on transboundary rivers in 2006. Despite these developments, the framework remains narrow, and the Brahmaputra MoU lapsed in 2023 (the Sutlej MoU lapsed in 2020), leaving even this limited arrangement without a formal basis.

The agreements cover specific flood-season data rather than a comprehensive, year-round information-sharing system. They also provide no broad mechanism for sharing information on upstream infrastructure. The result is a widening gap between China's upstream infrastructure development and the institutions meant to govern information sharing. For India, the question is not only whether a data-sharing agreement exists, but whether a seasonal arrangement is adequate for present conditions.

IMPLICATION FOR STRUCTURE

This disparity is structural in nature because of river geography. China will remain upstream, and India will have only limited, seasonal access to information on upper-basin conditions. The decisive factor is going to be the data on hydrological flows across borders. The data gap goes even beyond flood prediction.

In Assam, infrastructure planning needs to accommodate uncertainties at the source end, and any early warning system suffers from the lack of timely data. With the expansion of hydropower in China, accurate data transfer becomes even more crucial, not less. The Brahmaputra case is indicative of one of the basic problems of water governance beyond national borders.

THE INDIAN RESPONSE

The Indian response must combine diplomacy with greater hydrological self-reliance. New Delhi needs to press for an improved data-sharing system with China, covering not only a longer sharing period but also the method of transmission and advanced notice of upstream changes. Cooperation, however, must not be relied upon completely. India should strengthen its own monitoring through satellites, river gauging stations and better hydrological modelling of the Brahmaputra basin.

Rather than treating the river only as a site of competition, the aim should be to reduce vulnerability to information dependence. Institutional engagement combined with independent observation can serve this purpose.

The Brahmaputra is unlikely to become a dispute over water quantity alone, though large upstream projects such as Medog warrant close watching. Its significance lies in the asymmetry between China's position in the upper reaches and India's reliance on upstream information as the lower riparian. Even without any intent to weaponise flows, opacity itself creates strategic uncertainty. India must avoid letting hydrological dependence become strategic dependence.

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BY HEMA PRIYA

TEAM GEOSTRATA

info@thegeostrata.com