Damn the Chinese Dam

China’s mammoth hydropower project on the Brahmaputra is rattling its southern neighbours and the river itself.

China has long sought to master its rivers. Its latest and most audacious attempt is unfolding on the Yarlung Tsangpo, the upper stretch of the Brahmaputra River that flows from Tibet into India and then on to Bangladesh. In the Nyingchi region of southeastern Tibet, close to the Line of Actual Control (LAC) with India, Beijing has begun construction of what it claims will be the world’s largest hydroelectric dam. This colossal project, which is expected to generate 60,000 megawatts or thrice the output of the Three Gorges Dam, has triggered alarm across the region.

India and Bangladesh couldn't care less that the dam represents an engineering marvel. For them, it raises serious environmental, economic and strategic concerns. The Brahmaputra, originating from the Chemayungdung Glacier near the holy Kailash range, is one of Asia’s great river systems. Known variously as the Yarlung Tsangpo in Tibet, the Siang or Dihang in Arunachal Pradesh, the Brahmaputra in Assam, and the Jamuna in Bangladesh, the river is the lifeblood of millions. Its braided channels nourish some of the most fertile lands in the subcontinent. Altering its flow could have profound consequences downstream.

China’s project, located at the ‘Great Bend’ of the river (where the Yarlung Tsangpo curves sharply before entering India) is to include five cascade hydropower stations. With an investment of 1.2 trillion yuan (roughly $167 billion), the scale is staggering. Though official material estimates are unavailable, the Three Gorges Dam used over 27 million cubic metres of concrete and half a million tonnes of steel. This project will almost certainly surpass those figures.

Environmentalists are already raising red flags. The region is seismically active and ecologically fragile. Building such a massive dam here could increase the risk of floods, landslides, and even potential dam failure. The river’s natural flow of silt which is critical for agriculture in Assam and Bangladesh risks being disrupted, while aquatic life downstream could suffer from altered water temperatures and seasonal flow patterns.

But it is the geopolitics of water and not just its ecology that makes India especially nervous. For one, China’s dam sits just a few kilometres north of Arunachal Pradesh, which Beijing claims as its own. The possibility of China manipulating river flow during times of conflict, either by withholding water or releasing excess volumes, adds a sharp strategic edge. In a region already prone to water stress and climate unpredictability, India views the dam as a potential instrument of ‘hydro hegemony.’

New Delhi fears that even without malicious intent, the dam could still cause water shortages during dry seasons in Assam and Arunachal Pradesh. India’s foreign ministry has publicly expressed concern, though cautiously, emphasising the need for “transparency and consultation.” Behind the scenes, Indian officials have stepped up diplomatic engagement with Beijing, seeking details about the project’s scope and environmental safeguards.

Bangladesh, too, watches warily. With much of its agriculture dependent on the Brahmaputra-Jamuna system, Dhaka worries about reduced water availability and silt deposition. Unlike India, Bangladesh has less geopolitical leverage over China. But it may find common cause with Delhi to demand a more collaborative basin-wide framework for river management.

Yet hopes for regional cooperation are tempered by Beijing’s track record. Though it occasionally shares hydrological data with India and Bangladesh, its overall approach to transboundary rivers remains opaque. Chinese officials insist the project lies within sovereign territory and claim it will not adversely affect downstream countries. But given China’s history of disregarding international norms - from the South China Sea to the Himalayas - neighbours are understandably sceptical.

India’s options are limited but not negligible. Domestically, it must invest in better water management, reduce dependency on the Brahmaputra, and create contingency plans for downstream states. Diplomatically, India could push for a joint environmental impact assessment, as per international best practices, and consider elevating the matter to multilateral platforms, including the UN. There is also merit in engaging Bangladesh more closely, both to amplify shared concerns and to explore the possibility of a regional water-sharing accord that includes all riparian states.

Above all, India will need to approach the issue with the long game in mind. Beijing may not be swayed by diplomatic niceties, but it may respond to sustained multilateral pressure, especially when the reputational costs grow too high. China is already facing international criticism for its Belt and Road-related environmental impacts. Adding a potentially destabilising mega-dam on one of Asia’s most important rivers will only deepen concerns about its role as an unreliable neighbour.

Water, like oil and data, is fast becoming a geopolitical asset. As climate change exacerbates scarcity, rivers that cross borders like the Brahmaputra will become theatres of both cooperation and conflict. China’s audacious bid to tame the Yarlung Tsangpo may be technologically impressive, but its political and ecological fallout could ripple far beyond the Himalayas.

India, and indeed the world, would do well to remember that rivers respect no boundaries. Neither, it seems, does Beijing.

(The writer is a retired naval aviation officer and defence and geopolitical analyst. Views personal.)