China announces the construction of the world’s largest super dam on the Yarlung Zangbo River.

By Three Gorges Probe

According to a report by China’s official media Xinhua News Agency on Wednesday (December 25), the Chinese government has approved the Yarlung Zangbo River Lower Reaches Hydropower Project. The report described the Yarlung Zangbo River Lower Reaches Hydropower Project as a green project to promote low-carbon development, a popular project to achieve prosperity for Tibet and its people, and a safety project that adheres to ecological priorities. It plays a positive role, the report continues, in promoting high-quality development and is of great significance to deepening the “dual carbon” strategy and responding to global climate change.

Although the Xinhua News Agency report points out that the hydropower project is located in the lower reaches of the Yarlung Zangbo River, it did not disclose the name of the project and the specific location of the dam, nor did it disclose any information related to the scale of construction and the start and completion time. However, the area suitable for building a hydropower station in the lower reaches of the Yarlung Zangbo River is none other than the Yarlung Zangbo River Grand Canyon, known as the Great Bend. In terms of the administrative area, it is basically in Mêdog County, Linzhi City, Tibet Autonomous Region.

What’s even more interesting in regards to the announcement of this major event, almost all official media in China simply reprinted the Xinhua News Agency’s article, most of which copied the article word for word, completely avoiding mention of the engineering and technical data that readers are most concerned about.

Among the English media, South China Morning Post (SCMP) was the first to report this, with the title of its article: “China approves Tibet super dam, its power generation capacity may be three times that of the Three Gorges Project.”

In fact, before this, the Chinese Internet had been hyping up the prospect of the giant hydroelectric dam in the Yarlung Zangbo Grand Canyon, referring to it as the “Mêdog Dam” or “Mêdog Power Station.”

Although the Chinese authorities have not released specific data and technical details of the “Mêdog Dam” or the “Mêdog Power Station,” unofficial sources believe that the scale of the “Mêdog Power Station” is equivalent to three Three Gorges power stations: that means in terms of installed capacity, the Three Gorges Dam is 22.5 million kilowatts, and the proposed “Mêdog Power Station” is 60 million or even 70 million kilowatts; in terms of annual power generation, the Three Gorges Dam has an annual designed power generation of 88.2 billion kilowatt-hours, which places the “Mêdog Power Station” as high as 300 billion kilowatt-hours.

Chinese geologist Fan Xiao has previously introduced the possible design of the “Mêdog Power Station” in an October 2022 article:

“The proposed design is to build a high dam near Pai Town, Milin County, to intercept the Yarlung Zangbo River. A set of three huge tunnels with a diameter of 13 meters and a length of 34 kilometers will pass through the Himalayas, allowing the river water to flow through these three huge tunnels instead of flowing through the big bend of the Yarlung Zangbo River, and then use the 2,400-meter head of the river after the bend is straightened to generate electricity. At the downstream end of the tunnel, that is, at Xirangqu in Mêdog County on the right bank of the Yarlung Zangbo River, six cascade hydropower stations will be built. Once completed, the total installed capacity of the Mêdog Power Station will reach 43.8 million kilowatts (some say 60 million kilowatts), making it the world’s largest super-large hydropower station.”

Schematic diagram of the Yarlung Zangbo Grand Canyon giant hydropower station’s location for straightening water and diverting water for power generation (indicated by the red line).

The South China Morning Post article said that building such a super-large hydropower station in the lower reaches of the Yarlung Zangbo River not only faces huge technical challenges, but its cost will also be unprecedented in the history of China’s dam construction. The total cost is estimated to exceed 1 trillion yuan (equivalent to 137 billion US dollars).

In a report on Thursday, Voice of America pointed out that China officially announced it would launch an ambitious hydropower project in the lower reaches of the Yarlung Zangbo River on the eastern edge of the Qinghai-Tibet Plateau. The project, it said, may affect millions of people in India and Bangladesh downstream, causing concern in both countries.

Indian experts believe that for India, the primary concern is China’s unilateral actions to try to control the flow of water in transnational rivers.

The Washington Post reported on Thursday that if the project is built, it could reignite the border dispute between China and India, which has only just recently eased. However, the easing of relations between the two sides did not involve an agreement on sharing hydrological data, which could trigger tensions in bilateral relations once China officially launches a new hydropower project on this international river.

Geologist Fan Xiao is concerned that developing hydropower and building a mega-project in the Yarlung Zangbo Grand Canyon will incur unprecedented costs and face unprecedented risks.

Fan Xiao points out that since the project is located in an earthquake-prone area, a strong earthquake may cause direct damage to the project. Even if the project design fully considers the seismic intensity and can be expected to withstand the damage of a strong earthquake, the collapse, landslide and mud-rock flow induced by the earthquake are often uncontrollable and will also pose a huge threat to the project, and may cause serious secondary disasters due to the destruction of the project.

The construction of a high water-blocking dam in Pai Town, the digging of a giant tunnel between Pai Town and Xirang Village, and the construction of a large-scale cascade power station group in Xirangqu will still require extremely large-scale engineering excavation, which will greatly change the surface topography and form a high and steep air-facing surface at the front edge of the hillside, aggravating the risk of slope instability and collapse and landslide; the massive amount of waste rock generated by the excavation of the giant tunnel will only be piled up on both sides of the Yarlung Zangbo Grand Canyon or the nearby river valley. Due to the steep terrain and narrow site, this will greatly increase the risk of landslides and mudslides.

High dams and large reservoirs intercept silt, which causes siltation, which is also a major hidden danger. Although the Yarlung Zangbo River has a relatively low sediment content among China’s major rivers, due to the intensification of soil erosion along the coast in recent years, the amount of sediment transported has also tended to increase.

Building a dam in the Yarlung Zangbo Grand Canyon will cause rapid siltation of the reservoir, which will aggravate flood disasters upstream due to the elevation of the riverbed; while flood discharge and sediment discharge will destroy the existing riverbed structure of the downstream Grand Canyon section, increase the rate of riverbed cutting in the big bend section, and aggravate the collapse and landslide of the Grand Canyon. At the same time, due to the reduction of sediment transported to the Brahmaputra-Gangetic Plain, the negative impact on the downstream river environment is also worthy of attention.

Fan Xiao further points out that in terms of the energy needs of the Tibetan region itself, it is not necessary to build such a super-giant hydropower station in the Yarlung Zangbo Grand Canyon. Even if the West-East power transmission or external transmission is considered, on the one hand, there is the problem of high transmission costs, and on the other hand, according to the current water abandonment situation in Sichuan and Yunnan provinces, there is also the problem of lack of power market demand. In addition, the huge negative impact on the ecological and social environment of the Yarlung Zangbo River and the southeastern Tibetan region, hydropower development in the Yarlung Zangbo Grand Canyon is not worth the loss.

Read the original Chinese-language version of this report at the publisher’s website here: http://www.sanxiatansuo.com/index.html?index=view&vid=11001

Read the original article by Fan Xiao at the publisher’s website here:
The impracticability of hydropower development in the Yarlung Zangbo Grand Canyon from the perspective of geological risks

Further Reading

China’s Yarlung Tsangpo Great Bend mega-dam not feasible due to risks