China has greenlit the construction of what is set to become the world’s largest hydropower dam. This ambitious project, located on the eastern rim of the Tibetan plateau, has sparked concerns among neighboring countries India and Bangladesh due to its potential downstream impact.
The dam will be built on the lower reaches of the Yarlung Zangbo River and is projected to generate an impressive 300 billion kilowatt-hours of electricity annually, according to estimates by the Power Construction Corp of China in 2020. This output is more than three times the designed capacity of the Three Gorges Dam, currently the world’s largest hydropower facility in central China, with an 88.2 billion kWh capacity.
The official Xinhua News Agency reported that the project aligns with China’s carbon neutrality and carbon peaking targets. Additionally, it is expected to stimulate related industries, create jobs in Tibet, and significantly contribute to the country’s green energy ambitions.
Engineering challenges abound, as the Yarlung Zangbo experiences a dramatic 2,000-meter (6,561 feet) drop within a 50-kilometer (31-mile) span, offering immense hydropower potential. However, these challenges also entail significant costs. The dam’s construction expenses, including engineering work, are likely to surpass those of the Three Gorges Dam, which cost 254.2 billion yuan ($34.83 billion). The Three Gorges project displaced 1.4 million people, and its final cost was over four times the initial estimate of 57 billion yuan.
Authorities have yet to disclose how many people the new project in Tibet will displace or its full impact on the local ecosystem—one of the richest and most diverse on the plateau. Despite these uncertainties, Chinese officials assert that hydropower developments in Tibet, which holds over a third of the nation’s hydroelectric potential, will have minimal environmental impact and negligible effects on downstream water supplies.
Nevertheless, India and Bangladesh have expressed apprehension over the dam’s potential repercussions. The project could alter the river’s flow and ecology downstream. The Yarlung Zangbo transforms into the Brahmaputra River as it flows into India’s Arunachal Pradesh and Assam states before entering Bangladesh, making its course and volume critical for millions of people living in these regions.
China has already started hydropower generation along the upper reaches of the Yarlung Zangbo and plans further upstream developments, heightening concerns among its southern neighbors.
