A 6.8 magnitude earthquake in Tibet this week killed 126 people and damaged four water reservoirs, drawing attention to the dangers of rapid hydropower development by China and India in this remote, earthquake-prone region, experts warn. 

About 68 large dams in the Himalayan region take advantage of the massive hydropower potential of high-altitude lakes and rivers; however, only 5% of these have been used, according to researchers, and they are at risk from earthquakes. An additional 101 are currently being planned or constructed. Before the quake struck Tingri County, the northern entry point to the Mount Everest region, experts had expressed alarm over both countries' plans to build the largest hydropower dam in the world. 

The project is expected to supply 34 gigawatts of renewable energy, essential to China's goal of reaching its peak carbon emissions by 2030. It is more than three times the size of the Three Gorges Dam, the largest in the world. A report published in October 2022 about the province's Motuo project, which was approved in late December, stated that "A strong earthquake could cause direct damage," according to Fan Xiao, a former chief engineer in Sichuan's geology and mineral bureau in southwest China. On the messaging service WeChat, Fan did not reply to Reuters' inquiries about the article, despite warning that the project was located in an area vulnerable to powerful earthquakes. Hydropower projects in remote mountain regions highlight the challenge of balancing the risks of building in such areas with the growing need for clean energy in China and India, the top and third-largest greenhouse gas emitters in the world.

In the past, earthquakes have caused damage to dams, often triggering landslides and rockfalls. For example, a massive earthquake in Nepal in 2015 disrupted nearly 20% of the country's hydropower for over a year, according to research published in 2018. C P Rajendran, a geologist at India's National Institute of Advanced Studies, stated that it is not sustainable to build further dams in the Himalayas due to ecological issues and the risk of earthquakes caused by the weight of massive reservoirs on faultlines. China's water resources ministry has expressed concerns about ageing reservoirs, with over 80% of them built between the 1950s and 1970s.

The ministry has not responded to a faxed request for comment and has not provided details about the reservoirs damaged in the Tibet earthquake. China's foreign ministry stated that the Motuo project has undergone thorough testing to ensure it can handle disasters and reduce risks. However, tectonic activity in the region could make the area risky. Wolfgang Schwanghart, an expert from Potsdam University who studies how the earth's surface forms and changes, said further analysis is needed to understand the specific risks at the site on the upper reaches of the Yarlung Zangbo River. In 2018, his research revealed that about 25% of the region's projects could face moderate to severe damage if an earthquake occurs.

China claims the dam will be crucial for achieving its carbon peaking and neutrality goals. It also aims to boost the economy and create jobs. Hydropower is considered more reliable and adaptable than wind and solar energy, which are inconsistent. It is seen as a key solution to reduce reliance on coal, a major polluting energy source. However, Fan argued that the project isn’t necessary due to the low demand for hydropower in the sparsely populated Tibet region and the high costs of transporting the energy to other areas. According to him, some Chinese mega-dam construction may be driven more by economic considerations than by energy need. "The gross domestic product brought by huge hydropower projects, as well as the increase in investment and tax revenue, is a great temptation for the government and related interest groups," Fan said.