The site of Laos’ controversial Xayaburi Dam is located near active fault lines, making it highly susceptible to seismic activity and putting the entire Mekong ecosystem in danger, according to a Thai geologist.
Dr. Punya Charusiri of Chulalungkorn University in Bangkok said the project “poses a potential danger” because of “active faults close to the dam site.”
There is “a 30 percent chance of a medium-sized earthquake hitting the dam site in the next 30 years, and a 10 percent chance of a powerful earthquake of up to magnitude 7,” local media quoted him as saying.
“If the fault at the dam site becomes active…there is no chance for seismic engineering to take care of that,” he said.
Construction should “never have started” at such a site without further research into its potential to become a major disaster, he added.
However, the dam’s builders -- Finland's Pöyry Energy and Thai company Ch. Karnchang -- have maintained that the dam design follows all seismic guidelines and meets the highest safety standards outlined by the International Commission on Large Dams.
There have been recent earthquakes near the construction site. In 2011, two quakes -- one of 5.4 magnitude and the other of 4.6 magnitude -- hit within 50 kilometers of the dam, and another 3.9-magnitude quake hit 60 kilometers away.
Punya said these events had occurred on what were thought to be inactive fault lines, “an unusual development and one that causes additional concern.”
Laos started building the first phase of the $3.5 billion USD, 1,285-megawatt dam last year, despite objections from its downstream neighbors.
Once it is complete, it will be the first dam on the mainstem of the lower Mekong River. The Mekong River Commission (MRC), primarily member states Vietnam and Cambodia, have expressed concerns about the dam’s possible downriver impacts, including reduced water and sediment flows, disruption to fish habitats and increased salinity in the delta, among others.
Earlier this month, Vietnamese environmental umbrella group the Vietnam Rivers Network called for the immediate suspension of the project, citing these risks.
The MRC requested a 10-year moratorium on large dam construction within the entire Mekong River basin in order to better assess the impacts of such projects.
Thailand, which has a company involved in constructing the dam and which is expected to import much of the energy produced by the project, has remained more neutral during country-level discussions. However, many Thai activists have opposed the dam and their government’s involvement in its completion.