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The dam, situated in the Yarlung Tsangpo canyon—reputedly the world’s largest and deepest on land—carries an estimated cost of 1.2 trillion yuan (£125 billion). Chinese authorities claim the project will prioritise ecological protection and boost prosperity in the region, with electricity primarily transmitted to eastern China under the "xidiandongsong" policy, or "sending western electricity eastwards."
However, the project has sparked alarm in downstream nations. The Yarlung Tsangpo flows into India’s Arunachal Pradesh and Assam states, where it becomes the Siang and Brahmaputra rivers, and continues into Bangladesh as the Jamuna. Experts warn that the dam could give China significant control over these trans-border rivers, potentially disrupting water flow to millions. A 2020 Lowy Institute report suggested that China’s control over Tibetan rivers could give it a "chokehold" on India’s economy.
Arunachal Pradesh Chief Minister Pema Khandu recently told PTI that the dam could "dry up" the Siang and Brahmaputra rivers, posing an "existential threat" to local tribes, particularly the Adi community. He warned of a potential "water bomb" scenario, where sudden water releases could devastate lives, property, and land in the Siang belt.
India’s Ministry of External Affairs has urged China to ensure transparency and protect the interests of downstream states. In response, India is planning its own hydropower dam on the Siang river to mitigate flooding risks from sudden water releases. Bangladesh has also raised concerns, with officials requesting more information from Beijing earlier this year.
China’s foreign ministry has defended its "legitimate right" to dam the river, asserting that downstream impacts have been considered. The project involves drilling 20km-long tunnels through the Namcha Barwa mountain to divert water and constructing five cascading power stations, according to state media.
Environmental and human rights concerns are mounting. The dam’s location in a seismically active region with rich biodiversity raises fears of ecological damage, while activists argue it represents further exploitation of Tibetan land and communities. Last year, protests against another dam in Tibet led to arrests and violent crackdowns, according to verified reports.
As construction progresses, the project underscores the delicate balance of regional geopolitics, environmental sustainability, and the livelihoods of millions downstream.
