China to build world's largest hydropower dam in Tibet

China has approved the construction of the world's largest hydroelectric dam, raising concerns about the displacement of communities in Tibet and the environmental impact downstream in India and Bangladesh.

The dam, located on the lower reaches of the Yarlung Tsangpo River, can produce three times more energy than the Three Gorges Dam, currently the world's largest hydroelectric power plant.

Chinese state media has described the development as "a safe project that prioritizes environmental protection", saying it will boost local prosperity and contribute to Beijing's goal of climate neutrality.

But human rights groups and experts have raised concerns about the development's impact.

Among them are fears that the dam, first announced in late 2020, could displace local communities, as well as significantly alter the natural landscape and damage the local ecosystem, which is one of the richest and most diverse on the Tibetan Plateau.

China has built several dams in Tibet - a contentious issue in the region, which has been tightly controlled by Beijing since it was annexed in the 1950s.

Activists have previously told the BBC that the dams are the latest example of Beijing's exploitation of Tibetans and their land. The predominantly Buddhist Tibet region has seen years of repression, with thousands believed to have been killed.

Earlier this year, the Chinese government detained hundreds of Tibetans protesting against another hydroelectric dam.

They had been opposing plans to build the Gangtuo Dam and hydroelectric power station, which would displace several villages and submerge ancient monasteries with sacred relics. But Beijing says it has relocated and compensated locals and has moved ancient wall paintings to safety.

In the case of the Yarlung Tsangpo Dam, Chinese authorities have insisted the project will not have a major environmental impact - but they have not specified how many people it will displace. The Three Gorges Dam required the resettlement of 1.4 million people.

The report indicated that the massive project would require digging four tunnels at least 20 kilometers long through the Namcha Barwa Mountains, diverting the flow of the Yarlung Tsangpo, Tibet's longest river.

Experts and officials have expressed concern that the dam would enable China to control or divert the flow of the border river, which flows south into India's Arunachal Pradesh and Assam states and then into Bangladesh.

A 2020 report published by the Australia-based think tank Lowy Institute noted that "control over these rivers [on the Tibetan Plateau] effectively puts China under pressure on India's economy".

Shortly after China announced plans for the Yarlung Tsangpo Dam project in 2020, a senior Indian government official told Reuters that the Indian government was seeking to develop a large hydroelectric dam and reservoir to "mitigate the adverse impacts of the Chinese dam project".

In response to India's concerns about the proposed dam, China's Foreign Ministry said in 2020 that China has the "legitimate right" to dam the river and has considered the impact of the downstream.

China has built a series of hydroelectric power plants on the Yarlung Tsangpo River over the past decade, aiming to harness the river's power as a source of renewable energy. Part of the river, which flows through the world's deepest gorge, drops 2,000 meters in just 50 kilometers, offering huge potential for hydroelectric power generation.

However, the river's dramatic topography also poses major engineering challenges - and this latest dam is China's largest and most ambitious to date.

The construction site is located along an earthquake-prone tectonic plate boundary. Chinese researchers have previously expressed concerns that such extensive excavation and construction in the steep and narrow gorge will increase the frequency of landslides.

"Landslides and mudflows caused by earthquakes often become uncontrolled and will also pose a huge threat to the project," a senior engineer from the Sichuan Provincial Geological Bureau said in 2022. The project could cost up to one trillion yuan ($127 billion; £109.3 billion), according to estimates from the Chongyi Water Resources Bureau.