China's Brahmaputra dam flurry is India's worry

India Today

6 days ago

(NOTE: This article was originally published in the India Today issue dated April 7, 2025)Originating from the icy grip of the Angsi Glacier, near the northern slopes of the Himalayas, close to Lake Manasarovar in western Tibet, the Yarlung Tsangpo—known as Siang in Arunachal Pradesh and the Brahmaputra in Assam—embarks on a long and winding 2,900 km journey. It flows eastward across the Tibetan Plateau, a seemingly calm giant, until it reaches the easternmost edge of the Himalayas. And then, it encounters an obstacle—a towering 7,782-metre peak called the Namcha Barwa. But the river does not stop. In one of nature's most breathtaking feats, it takes a dramatic U-turn around the mountain—the Great Bend, one of the sharpest and most spectacular river bends on Earth.advertisementWhat follows is pure fury. The river plunges into the Yarlung Tsangpo Grand Canyon, a monstrous 500km-long chasm with depths exceeding 5,000 metres—nearly five times the height of Dubai's Burj Khalifa, the tallest structure in the world. It is one of the deepest and most treacherous canyons on the planet, where the river transforms into a roaring beast, its waters churning with an unstoppable force. This is where China wants to step in. The steep gradient at the Great Bend holds unparalleled hydroelectric potential that Beijing is determined to exploit. The plan? A colossal hydropower project embedded deep into the unforgiving terrain of Medog County, Tibet—one of the last unexplored and most geologically unstable regions on Earth. It is a project of staggering proportions, a testament to human ambition and engineering audacity.With an estimated cost of $137 billion (Rs 11.9 lakh crore), this is poised to become the most powerful hydropower facility ever attempted, generating a jaw-dropping 60 GW of electricity annually—three times the output of China's own Three Gorges Dam, the current world record-holder, and surpassing the UK's entire annual energy consumption. Expected to be completed by 2033, the scale of the project is mind-boggling. To divert nearly half of the river's flow, Chinese engineers plan to drill tunnels up to 12.5 miles long through the Namcha Barwa mountain, rerouting 2,000 cubic metres of water per second—enough to fill three Olympic-sized swimming pools every second.
INDIA'S GREAT WORRYWhile China presents the project as a step toward achieving carbon neutrality by 2060, for India and Bangladesh, it signals a looming disaster. The dam's location, barely 30 km from Arunachal Pradesh, places it alarmingly close to India's border, raising security concerns in New Delhi. Worst-case scenarios throw up a nightmarish picture: if the dam were to fail—due to engineering flaws, an earthquake or even sabotage—the consequences would be catastrophic. A towering surge of water could rip through Arunachal Pradesh and Assam, wiping out entire towns within minutes. 'This Chinese project isn't just a tease,' says Michael Kugelman, director of the Washington-based South Asia Institute. 'China has the capacity to mobilise capital quickly and build out large-scale infrastructure projects without delays, thanks to its centralised economy and undemocratic politics. This means New Delhi needs to start thinking now about how to mitigate the possible deleterious implications—especially for water security, the environment and geopolitics.'advertisementThe Brahmaputra is a vital artery that sustains millions across four countries—China (50.5 per cent), India (33.6), Bangladesh (8.1) and Bhutan (7.8). More than just a waterway, it sustains agriculture, drinking water and energy needs, making any disruption to its flow a serious concern. For India, the primary worry is China's ability to control the Brahmaputra's flow. If Beijing releases excess water during monsoons, devastating floods could ravage India's northeastern states, particularly Assam and Arunachal Pradesh, where nearly 40 per cent of the land is already flood-prone. The fallout—mass displacement, infrastructure collapse and economic devastation—would be severe.Conversely, restricting water flow during dry months could cripple agriculture, hydropower generation and drinking water supplies. Given that the Brahmaputra accounts for nearly 30 per cent of India's freshwater resources, any interference poses a strategic threat. 'The proposed hydropower project has the potential to alter the flow dynamics of the Yarlung Tsangpo-Brahmaputra, affecting water availability, by influencing both groundwater and surface water levels,' warns Genevieve Donnellon-May, a researcher at the Oxford Global Society.advertisement
For Assam, the implications for agriculture are particularly alarming. The river's nutrient-rich sediments sustain rice, tea and jute cultivation. Any disruption—excessive flooding or drought—could slash crop yields, threaten food security and financially cripple thousands of farmers. If upstream damming reduces sediment flow, it could accelerate riverbank erosion, degrade soil fertility and leave lasting ecological scars.advertisementIndia's concerns over China's hydropower ambitions are well founded. In 2000, severe flooding in Arunachal Pradesh's Pasighat was linked to a dam collapse on Tibet's Yigong River. In 2012, the Siang River mysteriously ran dry, prompting then chief minister advisor Tako Dabi to blame China's dams. In 2016, China blocked the Xiabuqu River near India's border for the Lalho hydropower project, further raising suspicions. A year later, the Siang's waters turned black, igniting accusations against China. While Beijing dismissed the claims, satellite images later revealed that earthquakes on the Tibetan Plateau had triggered landslides, sending sediment downstream. 'Storing water in a region with extensive mineral extraction—Tibet is home to over 100 exploited minerals—leads to contamination as mining runoff mixes with the water, forming black soot. Arunachal Pradesh has already seen instances of blackened water,' says Srikanth Kondapalli, professor of Chinese Studies at Jawaharlal Nehru University. Adding to the uncertainty, open-source data from the Tibetan Autonomous Region suggests irregular river flow patterns in 2024, deviating from the trends of the past 25 years.advertisementWhat raises even deeper concerns is China's broader ambition—to divert the Yarlung Tsangpo to its arid Xinjiang province. Gopal Dhawan, founder and chairman of the Dr Dhawan Academy of Geologists, and former CMD, Mineral Exploration and Consultancy Ltd and NHPC, warns that if China stores and redirects water through an inter-basin transfer scheme, 'any projects we develop will face water shortages and be adversely affected.' Though several experts rule out any such possibility, doubts persist. 'The Medog dam appears to be a hydroelectric project rather than a water storage and diversion initiative. But given China's track record of undertaking large-scale infrastructure projects, such a possibility cannot be ruled out,' says A.K. Bajaj, former chairman of the Central Water Commission. Amid these uncertainties, New Delhi has made its apprehensions clear to Beijing. 'We have consistently raised concerns over China's mega river projects,' says foreign ministry spokesperson Randhir Jaiswal, asserting India's lower riparian rights. He states that India will continue pressing China to safeguard downstream interests and 'take necessary measures to protect our interests'.
CHINA'S WATER HEGEMONYThe Tibetan Plateau feeds 10 major river systems sustaining over a dozen Asian nations. Among them, two stand out for their geopolitical weight: the Mekong, which courses through Southeast Asia, and the Brahmaputra. China's aggressive dam-building along these rivers has triggered alarm over its push for hydro-hegemony, particularly given its refusal to sign water-sharing treaties. China's treatment of the Mekong offers a stark warning for India and Bangladesh. Over two decades, Beijing has constructed 12 massive dams along the river's upper reaches, disrupting natural flows and worsening environmental stress downstream. In 2019, despite above-average rainfall, China's upstream dams hoarded record amounts of water, triggering droughts in Thailand, Cambodia and Vietnam. In 2021, it slashed the Mekong's flow by 50 per cent for three weeks—citing power-line maintenance—without prior notice, leaving millions struggling for irrigation, fisheries and drinking water. These unilateral actions stoke fears that Beijing could deploy similar tactics on the Brahmaputra.The Medog dam isn't an isolated project but part of a grand strategy. Sayanangshu Modak, a doctoral researcher at the University of Arizona's School of Geography, Development and Environment, says the Yarlung Tsangpo stretch was marked for hydropower as early as 2003. Since the 2010s, China has steadily expanded its hydropower footprint on the Brahmaputra's upper reaches. The Zangmu dam, completed in 2015, set the stage for further projects at Dagu, Jiacha and Jiexu. Satellite imagery now reveals nearly 20 dams—large and small—along the river, signalling Beijing's long-term water ambitions. 'The new move appears to be the latest step by Beijing to maintain an upper hand in the region's water geography,' says Kugelman.India is also wary of the timing of the Medog dam approval, which came just as New Delhi and Beijing resumed talks after a prolonged diplomatic freeze post-Doklam (2017) and Galwan (2020). Many analysts see it as a calculated move to pressure India in border negotiations. By intertwining territorial disputes with transboundary rivers, Beijing is likely angling for strategic concessions.
A HIMALAYAN BLUNDER?As debate rages over the potential impact of the Medog Dam on India and Bangladesh, one fact is undisputed: its construction poses irreversible ecological risks to the fragile Himalayan region. Dams can trigger tremors, a phenomenon known as reservoir-induced seismicity—when the immense weight of impounded water destabilises fault lines of the Earth. 'The sheer weight of a vast reservoir could induce small earthquakes by exerting pressure on the Earth's crust. In an already hyper-seismic zone, the consequences of such stress remain dangerously unpredictable,' warn Robert Wasson, adjunct professor, College of Science and Engineering, James Cook University, Australia, and emeritus professor, Fenner School of Environment and Society Australian National University, and Shukla Acharjee, assistant professor, Centre for Studies in Geography, Dibrugarh University.Beyond seismic threats, the dam's sheer scale demands mass deforestation, stripping the region of its green cover and natural stabilisers. Without tree roots anchoring the soil, heavy monsoon rains could trigger deadly mudslides, raising the risk of dam failure.The Himalayas, already crumbling under climate stress, have seen a surge in Glacial Lake Outburst Floods, avalanches and landslides. 'On March 22, 2021, a massive glacier collapsed in the Sedongpu River basin, on the left bank of the Grand Canyon of the Yarlung Tsangpo and blocked the river and caused water levels to rise by 10 metres,' says Modak. Wasson and Acharjee note that the Tsangpo Gorge is one of the most geologically dynamic—and possibly the most active—regions on Earth. 'It experiences extreme floods, with peak flows reaching up to a million cubic metres per second. A single such flood can erode as much of the gorge as 4,000 years' worth of annual flow,' they add.The region's volatile geo-morphology also makes dam stability a growing concern. Earthquakes, heavy siltation and landslides will shorten the dams' lifespan. After the January 7 earthquake, inspections of 14 hydropower dams in Tibet found structural cracks in five, forcing three to be emptied. 'This region is the most sediment-rich and sediment-producing area on Earth. As a result, dams here degrade faster, increasing the risk for downstream populations,' says Ruth Gamble, deputy director (research), La Trobe Asia, La Trobe University, Australia, who specialises in the environmental, cultural and climate history of Tibet, the Himalayas and Asia.On its part, China insists the Medog project is a clean energy game-changer, not a geopolitical weapon. Wang Lei, charg d'affaires at the Chinese Embassy in India, dismisses concerns about adverse impacts on India and Bangladesh, framing the project as a climate-friendly solution that will power 300 million people while curbing fossil fuel use. Backing this stance, Chinese foreign ministry spokesperson Guo Jiakun says the project underwent rigorous scientific evaluation and poses no risk to downstream ecosystems, geological stability or water rights. Instead, Beijing argues it will help mitigate floods and aid climate adaptation in India and Bangladesh. However, China's assurances on the Medog Dam ring hollow, given its track record of secrecy, unilateralism and broken commitments on transboundary rivers. Independent researcher Gabriel Lafitte has highlighted that past Chinese project announcements have been long on statistics but short on execution details.
WAITING TO BE DAMMED: The Siang River near Along in Arunachal Pradesh. (Photo: Alamy)
INDIA'S COUNTERA decade ago, India embarked on a defensive hydropower strategy to counter China's upstream dam-building spree on the Brahmaputra. Rooted in the international legal principle of 'prior appropriation'—which grants water rights to the first user—India's plan aims to pre-emptively secure control over the river's flow. 'India can still challenge Beijing by constructing its own dams near the border, keeping China on edge. This would give New Delhi some leverage in potential water negotiations with Beijing,' says Kugelman.After Beijing announced the Medog Dam, India has accelerated plans for the Siang Upper Multipurpose Project (SUMP)—a colossal hydropower dam in Arunachal Pradesh intended to counter China's influence over the river. With a proposed capacity of 11,000 MW, SUMP's reservoir would hold 9.2 billion cubic metres (bcm) of water, compared to Medog's 5.5 bcm. Estimated at $17 billion (Rs 1.5 lakh crore), it will be India's most powerful hydroelectric project, designed to regulate water flow, mitigate seasonal droughts and serve as a safeguard against sudden surges from Chinese dams. While feasibility surveys areUnderway in Parong, a remote hamlet in Siang district, SUMP has faced resistance since its proposal by NITI Aayog in 2017. The project threatens to submerge over 30 villages, putting thousands at risk of displacement.Experts also warn against escalating the dam race, as it could prompt China to fast-track its own projects, capitalising on its superior execution speed to shift the balance further in its favour. Such a move might also strain relations with Bangladesh, a crucial downstream stakeholder in any future Brahmaputra basin management framework. 'The concerns we've raised about China's projects are equally relevant to Bangladesh,' notes Prof. B.R. Deepak of the Centre for Chinese & Southeast Asian Studies at JNU.Rather than pursuing a spree of dam construction, experts urge India to strengthen its northeastern water management systems. This includes enhancing independent river flow monitoring from China using advanced satellite technology, refining flood risk assessments and upgrading telemetry stations. Gamble points out that India lags behind China in studying Himalayan ecology and river systems. 'India has yet to thoroughly analyse the flow data China has provided on the Yarlung Tsangpo. Instead of issuing threats over dam construction, India must invest in a deeper understanding of the region's hydrology and risks. Armed with this knowledge, it can engage China in informed negotiations, presenting concrete evidence on the downstream impacts,' she asserts.India and China share several major rivers, including the Brahmaputra, Sutlej and Indus. However, water-sharing remains a contentious issue, in the absence of a formal treaty. Despite China's upper riparian advantage, India can push for stronger data-sharing commitments under international conventions like the UN Watercourses Convention, which mandates that no country can take actions significantly harming another. However, neither India nor China is a signatory, and no Brahmaputra basin nation has ratified the 2014 UN Convention on Non-Navigational Water Uses, rendering first-user rights unenforceable.In the Brahmaputra's turbulent waters, survival will depend not on the might of dams but on the foresight of nations.—with India Today NE BureauSubscribe to India Today Magazine- EndsMust Watch