The project on a river that runs through Tibet and India downstream could dwarf the Three Gorges Dam when completed.
China has started building a mega-dam on the Yarlung Zangbo River in Tibet, which could become the world’s largest source of hydroelectric power when completed, according to Chinese officials.
The mega-project in the foothills of the Himalayas will include five hydropower stations on the river, which is also known as the Brahmaputra, further downstream in India, and the Jamuna River in Bangladesh.
China’s Xinhua state news agency reported that Premier Li Qiang attended a commencement ceremony for the dam on Saturday.
Beijing had planned the project for several years, and approval was given in December last year, linking the development to the country’s carbon neutrality targets and economic goals in the Tibet region.
“The electricity generated will be primarily transmitted to other regions for consumption, while also meeting local power needs in Tibet,” Xinhua reported after the groundbreaking ceremony in southeastern Tibet’s city of Nyingchi.
The project is expected to cost an estimated 1.2 trillion yuan ($167.1bn), Xinhua said.
India said in January that it had raised concerns with China about the project, saying it would “monitor and take necessary measures to protect our interests”.
India’s Ministry of External Affairs said at the time that China “has been urged to ensure that the interests of the downstream states of the Brahmaputra are not harmed by activities in upstream areas”.
In December, Beijing’s Ministry of Foreign Affairs said the project would not have any “negative impact” downstream, adding that China “will also maintain communication with countries at the lower reaches” of the river.
China annexed Tibet in 1950, and has built several dams on the region’s rivers, prompting concerns from Tibetans about the potential impacts on the unique ecosystems of the Tibetan Plateau.
Tibet’s vast glaciers and major rivers provide fresh water to 1.3 billion people in 10 countries, according to Yale’s E360 environmental magazine.
The Yarlung Tsangpo is the world’s highest river, reaching some 5,000 metres (16,404 feet) above sea level, and is considered sacred to Tibetans.
The new dam is also being built just 30km (18 miles) from China’s vast border with India, much of which is disputed, with tens of thousands of soldiers posted on either side.
Once built, the dam could provide as much as three times as much energy as the Three Gorges Dam on the Yangtze River in central China.
The Three Gorges Dam, which was completed in 2003, controversially displaced some 1.4 million people.
Tibet is much more sparsely populated, with some 2,000 people displaced for the construction of the Yagen Hydropower Station in 2015, according to local media reports.