In an unexpected decision yesterday, Lower Mekong countries opened a two-day meeting in Bangkok by jointly agreeing a controversial hydropower dam must undergo regional consultation but could continue construction.

Laos’s delegation to the Mekong River Commission – the intergovernmental body responsible for facilitating cooperation along the river – announced that it would yield to neighbouring countries’ demands and submit its Don Sahong Hydropower Project to further evaluation by member countries.

The Lao government representatives made it clear, however, that they were not willing to halt construction on the $300 million project located less than 2 kilometres north of Cambodia.

“This is a problem, because it means that the most influence the other countries can hope to have is to provide input on how it is built and what sort of mitigation measures are used,” said Ame Trandem, Southeast Asia program director at International Rivers. “But under international law, affected countries have the right to request more studies and have a say in the project before it moves forward.”

Cambodia, Thailand and Vietnam have all requested that the Don Sahong’s Malaysian developers Mega First Corporation Berhad postpone assembly until transboundary impact assessments could be conducted to determine what kind of effects the dam may have on the 60 million residents relying on the Mekong, as well as several volatile migratory fish species. But the developers have so far not complied.

“There are options to sustainably manage the water resource that will allow [the countries] to meet power demands while conserving the ecological integrity of the Mekong,” said Marc Goichot, hydropower specialist at World Wildlife Foundation. “We do not need to take inconsiderable risks with Lower Mekong mainstream dams.”

The Don Sahong is the second of nine hydropower dams that Laos plans to use to boost its economy, which is currently the smallest of the ASEAN states.

Earlier this week, the Thai courts accepted a lawsuit against the first of Laos’s dams, the 1,285-megawatt Xayaburi dam, based in part on the lack of scientific study proving that it would not harm downstream villagers.