More than 140 NGOs have called on the Mekong River Commission to freeze all hydropower dam construction in the Lower Mekong River.

“The degradation of fish production in the river can’t be replaced and the blockage of sediment will affect the fisheries resources in the river’s flood plain areas and the Great Lake of Cambodia,” notes the open letter, released late last month and signed by 149 international and local groups including Adhoc, the 3S Rivers Protection Network, and the Fisheries Action Coalition Team.

“[We] would like to request to the four MRC governments of the Lower Mekong mainstream not to construct any hydropower dam in the Mekong mainstream now or in the future,” the letter says.

An estimated 80 per cent of the 60 million people living in the Lower Mekong River rely on it as a source of livelihood and food.

Clearly, the stakes are high, said Youk Senglong, a program director at FACT, who pointed out that there has been insufficient research by the companies involved in delineating the impacts of the dam construction.

“We need a more high-quality impact assessment, which is why we asked [in the open letter] for a delay in construction,” Senglong told the Post.

Though environmental groups have lambasted their construction and a 1995 Mekong Treaty requires consensus from the four affected governments, hydropower projects on the river’s mainstream have been moving forward.

Construction has begun on Laos’ controversial Xayaburi dam, while the second of 11 planned mainstream dams – the Don Sahong – has also recently seen development.

Te Navuth, secretary-general of the Cambodia National Mekong Committee, said no notification of any preliminary building at Don Sahong dam had been confirmed or received by the committee.

“We are issuing a request to the committee’s Laos representatives” for further information about any preliminary building at Don Sahong dam, he said.