The plan by Laos to build a large dam across the Mekong River at Xayaburi is not just raising serious concerns about its potential environmental impact, but also creating some tension between Laos and Vietnam.
And for the first time, concerns about the effects of building dams on the river have spilled in a big way across international boundaries.
The Mekong spans six countries and directly or indirectly supports the livelihoods of tens of millions of people.
The US$3.5 billion (S$4.5 billion) 1,260MW hydropower project is being built by Thai company CH Karnchang. Thailand is expected to buy 95 per cent of its power.
But the Xayaburi dam is being called an environmental disaster in the making by local Thai activists and a range of non-governmental organisations, from the World Wide Fund for Nature to International Rivers.
Concerns centre on the disruption to the hydrology, or water regime and patterns, of the Mekong, which would in turn severely affect fish catch.
The dam is one of six planned for the 1,100km-long stretch of the river from Chiang Saen in northern Thailand to Vientiane in Laos. There is concern that it will be the worst culprit in terms of ‘disconnecting’ the lower river from its upper reaches - severely reducing aquatic life in terms of volume and biodiversity.
In Laos itself, over 200,000 people will be directly affected, including more than 2,000 who will have to be resettled.
At a forum this month in Bangkok, Mekong River Commission (MRC) outgoing chief executive Jeremy Bird, based in Vientiane, acknowledged that the dams would inevitably trigger a decline in fish catch unless measures to mitigate it are put in place.
But he added that the Xayaburi project in particular would be of ‘significant net benefit’ to Laos.
Downstream of the dam, though, is where the impact could be even more significant, and Vietnam is worried.
The MRC was set up in 1995 by an agreement between the governments of Cambodia, Laos, Thailand and Vietnam to promote cooperation on water resources.
For the first time, Vietnamese officials were vocal in their concerns at a recent meeting of the MRC, officials said.
Vietnam’s media has in recent weeks published several reports citing a chorus of objections to the dam by some of the country’s foremost scientists.
Dr Le Anh Tuan from the Research Institute for Climate Change was quoted as saying Vietnamese companies should not invest in or buy power from dams on the Mekong.
The country’s leaders and scientists should call for a 10-year delay before more dams are built on the river which is critical to millions in Vietnam, he said.
Environmental organisations have generally agreed that there should be a 10-year moratorium on dam construction especially on the Mekong - the most productive natural fishery in the world.
At the forum in Bangkok, Mr Bird said the objective of consultations under the MRC was to reach agreement.
A crucial joint committee meeting of the MRC is scheduled for this week, in which issues about the Xayaburi dam are to be thrashed out.
Mandatory public hearings are also under way, but observers have said the process appears to be a mere formality.
Given the concerns of Vietnam, there is a possibility of some delay to the project.
But in essence, it seems unstoppable, and last month, the Laos government said the project would go ahead.
Independent water experts have said it is better to have the MRC than have no mechanism at all for technical study, consultation and dialogue.
One expert familiar with the issues told The Sunday Times: ‘We are still choosing to support the MRC, with eyes wide open.’
