When Wen visited the Yarlung Tsangpo Grand Canyon in the spring of 2025, the independent Chinese ecologist saw numerous heavy trucks loaded with construction materials along Medog county in the southeastern part of the Tibet Autonomous Region. Only a single, narrow road connected the county seat and townships, and locals believed the roads were being paved just as the central government was ramping up plans to build a hydropower plant.
It wasn’t just a hydropower project, though. Chinese Premier Li Qiang called it a “project of the century,” as he stood alongside high-ranking officials to announce the construction of the 1.2 trillion yuan (about $168 billion) infrastructure project along the lower reaches of the Yarlung Tsangpo river in July. The state-run Xinhua News Agency hailed the world’s biggest planned hydropower dam as a “low-carbon development … a safe project that prioritizes ecological protection.”
But the sheer scale of the dam carries immediate and long-lasting consequences for planetary health. Environmentalists say the Yarlung Tsangpo creates unique hydrothermal conditions when it collides with the eastern Himalayas, resulting in the world’s northernmost tropical rainforest, home to diverse large cats and ungulates, as well as some of Asia’s largest and ancient trees. Many new species are still being discovered in the area, including the white-cheeked macaque, found around 2014.
“The ecological and environmental impact of this project is my primary concern,” said Wen, who asked to use a pseudonym due to the sensitive nature of the project. “All the specific plans for the project are confidential. We cannot assess the project’s exact impacts—which habitats may be flooded or fragmented and … changes in the river’s flow rate, water temperature—[nor] do we know how to mitigate these impacts.”
While China’s environmental impact assessment laws and regulations contain several provisions for public disclosure, they also clearly spell out that such revelations are not mandatory in cases where national regulations require confidentiality.
A now-deleted notice posted on the National Forestry and Grassland Administration’s website last year, later reposted on the Qilian Mountain National Park’s WeChat account, stated that the Yarlung Tsangpo Great Canyon National Nature Reserve would see nearly 42,000 hectares of land removed from the reserve’s more than 920,000 hectares due to “project use.” However, it did not specify the location of the removed areas.
On a public WeChat account in August, a Chinese lawyer shared a document from a petitioner who had filed an application to obtain government information on the project; the Ministry of Ecology and Environment denied the request—and subsequent requests to disclose the project’s environmental impact assessment—saying it involved “state secrets.”
Medog’s mega-dam project, with a planned generation capacity of 300 billion kilowatts-hours of electricity annually—about three times the annual output of the Three Gorges Dam—lies in an ecologically fragile and politically sensitive area. It is located near the Great Bend, where the Yarlung Tsangpo makes a U-turn, cutting through the Himalayas and flowing south into India’s plains to become the Brahmaputra and then to Bangladesh as Jamuna before entering the Bay of Bengal. The construction site is just over 30 miles from the disputed area between China and India.
With most hydropower in Sichuan and Yunnan provinces already tapped, analysts now see the upstream rivers of the Tibetan Plateau as the last big frontier, with large hydropower potential.
Sabrina Habich-Sobiegalla, a professor of modern China at Germany’s Freie Universität Berlin, said the Chinese government now views Tibet not just as the water tower for Asia but also as the clean energy hub for China, turning its rivers into renewable energy bases. Although Tibet’s many protected areas make it an ecological hot spot on paper, she said there is a “fundamental contradiction in Chinese policy.”
“Conservation zones often overlap with energy development zones, and ecological fragility does usually not override state development priorities,” Habich-Sobiegalla said. “If you ask whether the party-state is on a mission to destroy the ecological environment in Tibet, I think that sounds too deliberate. I would say that they are willing to sacrifice the environment for these other goals, though.”
China is the world’s largest carbon emitter but plans to peak emissions by 2030 and achieve carbon neutrality by 2060. The country is investing heavily in renewable energy to realize those goals, aiming to have non-fossil fuels make up 25 percent of its energy consumption in the next five years.
China invested 6.8 trillion yuan ($940 billion) in clean energy last year, slightly more than the 6.3 trillion yuan ($890 billion) it spent in 2023. The country continues to lead global hydropower development, accounting for nearly 60 percent of the world’s new hydropower capacity added last year, according to the International Hydropower Association.
But clean energy projects aren’t always good for the local environment. As early as 2010, the Hong Kong-based environmental nonprofit CWR called hydropower a “double-edged sword”—while the plants reduce emissions, they pose grave threats to animals, fish, and birds due to construction as well as displace local people.
A 2024 report by the International Federation for Human Rights notes that the hydropower boom in Tibet is “causing irreparable damage” to the Tibetan civilization, the environment, and downstream countries and that China’s agenda “disregards the human impact, the science, and worsening climate change hydropower brings.”
Tempa Gyaltsen Zamlha, an environmental expert and the deputy director at the India-based Tibet Policy Institute, told Foreign Policy that the notion of mega-hydropower projects as a source for green energy is “outdated” and that they are no longer considered green energy due to their short lifespan and the heavy ecological and social costs.
“This particular site is a sacred region in Tibetan culture and a sanctuary for ancient forests and rare species,” he said. “The dam would submerge vast tracts of these forests, destroy wildlife habitats, and destabilize the fragile mountain ecosystem, leading to increased landslides and floods both locally and downstream.”
When the Chinese legislature approved the Three Gorges Dam in 1992, there was a rare pushback—177 of 2,633 National People’s Congress deputies voted against the resolution, 664 of them abstained, and 25 submitted “no” votes due to concerns and controversies associated with the project. Studies show that the dam construction led to a reduced number of fish larvae and a change in fish species, downstream riverbed erosion, and reservoir-induced landslides and seismic hazards. It also displaced more than 1 million people.
As China is pursuing another colossal project, any space for dissent or pushback has vanished under President Xi Jinping. The Medog dam project wasn’t voted on in the legislature but instead appeared in China’s 14th Five-Year Plan in 2020, with Xinhua announcing its approval in 2024.
“The public debate sparked by the Three Gorges Dam is far more extensive, in-depth, and enduring than this project,” Wen said. “The Three Gorges Dam involved a large number of displaced people, and the planning details of this project have been kept strictly confidential.”
Based on available information and conversations with locals in Medog county, Wen said the mega-dam project doesn’t appear to involve large-scale population displacement, as happened with the Three Gorges Dam. Wen said a few locals they spoke with believed the project would bring good business, adding that they hadn’t heard about any relocation plans.
In a letter submitted to the United Nations Human Rights Council in January, the nonprofit International Campaign for Tibet (ICT) estimated that the project would forcibly displace more than 24,000 locals in a 31-mile radius and said it ignored the rights and traditions of Tibetan communities, though it is unclear how the ICT derived the number.
Last year, the construction of the Kamtok dam in eastern Tibet led to mass protests and a government crackdown, the BBC reported. The dam’s reservoir would submerge several villages and monasteries and relocate an estimated 4,287 people.
Zamlha said claims over the dam’s benefits to locals were “misleading,” adding that there were few settlements nearby, contrary to Chinese media reports that the Medog dam was expected to “boost local people’s livelihood.” He said the electricity generated would also be supplied to Chinese cities, benefiting urban elites rather than Tibetans.
Meanwhile, some analysts say that because the dam is linked with China’s climate goals and personally backed by Xi, the government will spare no effort to complete it, especially if it can become a showcase for China’s large infrastructure projects.
“That’s why many observers see the Medog dam less as a climate necessity and more as a political and symbolic project: a demonstration of engineering prowess and Xi Jinping’s push for ‘world-leading’ infrastructure,” Habich-Sobiegalla said.
While celebrated in China, the construction has sparked concerns among downstream countries, notably India and Bangladesh. China is not a signatory to the United Nations Watercourses Convention, which prevents conflicts, promotes information sharing and environmental protection, and ensures equitable use of water resources between countries.
Habich-Sobiegalla noted that building large-scale infrastructure in border regions was a part of China’s long-standing state-building strategy, as it asserts control, integrates these regions more tightly into national economic networks, and creates on-the-ground capacity for state presence. With the Yarlung Tsangpo, the transboundary issues are also apparent.
In the northeastern Indian state of Arunachal Pradesh, which borders the construction site and which China claims as its territory almost entirely, there are worries that the dam could divert or regulate water and disrupt the ecosystem. Experts say that while sudden water release could see catastrophic floods, especially during the monsoon season when the Brahmaputra basin already experiences devastating deluges, China withholding water could lead to potential droughts, impacting the farming economy in India’s northeast and Bangladesh.
“It is going to cause an existential threat to our tribes and our livelihoods,” Arunachal Pradesh Chief Minister Pema Khandu told Indian media in July. “It is quite serious because China could even use this as a sort of ‘water bomb.’”
Neeraj Singh Manhas, a special advisor for South Asia at the South Korea-based Parley Policy Initiative, said the dam construction is a “power move” from a geopolitical perspective. He added that controlling the river flow grants China considerable influence over its neighbors amid an absence of water-sharing treaties between China, India, and Bangladesh.
China claims express ownership of upstream rivers in Tibet that flow as major rivers to several downstream countries, giving it strategic leverage. An estimated 718 billion cubic meters of surface water is said to flow from Tibet, Xinjiang, and Inner Mongolia to neighboring countries, of which 48 percent runs into India. A 2020 report by the Lowy Institute said control over the rivers “effectively gives China a chokehold on India’s economy.”
“It’s not solely about energy; it’s about water control in a region already tense with Sino-Indian border disputes,” Manhas told Foreign Policy. “India fears China could weaponize water—either by obstructing flows or unleashing sudden floods.”
In March, India’s Ministry of External Affairs said the Indian government has “registered its concerns” with the Chinese authorities, including on the “need for transparency and consultation with downstream countries.” A Right to Information query submitted to India’s water ministry by India Today revealed in May that China hadn’t shared river data with India since 2022. The two countries signed a data agreement in 2002, helping India to forecast floods and water management issues.
Experts say India’s fears are valid, considering China’s hydropolitics in the Mekong in Southeast Asia. A 2020 report by the Stimson Center said China’s dams restricted nearly all upper Mekong wet season flow and the increasing trend of wet season drought in the lower basin “tracks closely to the way China releases water during the dry season and restricts water during the wet season.”
According to Manhas, countries such as India and Bangladesh could take a lead in establishing a regional body, like a Mekong Commission for South Asia, to negotiate water rights. While the lower Mekong nations—including Cambodia, Laos, Thailand, and Vietnam—formed the Mekong River Commission in 1995, it doesn’t have the power to enforce decisions, and China is absent as a signatory.
“The issue is China’s track record—it has often been reluctant to fully engage with the Mekong setup, tending to prioritize its own interests,” Manhas said. “Gaining China’s cooperation for a South Asian equivalent would be difficult but not impossible. It’s a long shot, but a united front could persuade China to adopt more cooperative water management practices.”
But as China kicks off the mega-dam construction, there are no indications yet of a potential partnership with downstream countries to share data that could help assess its environmental impacts. For now, the dam reflects the ambitions of a rising China—shrouded in secrecy.