Vietnam's National Mekong Committee voiced more arguments against the Don Sahong, Laos’ latest hydropower project, at a conference held in Hanoi on Monday.
Nguyen Hong Phuong, deputy spokesman of the committee, said the new dam will block the river’s Hou Sahong tributary and the migratory pathways used by numerous fish species in the area, Vietnam News Agency reported.
Few fish will survive the dam's turbines, Phuong told an audience of hydropower experts.
She said the 260-MW dam will destroy the ecology of the tributary and endanger the livelihood of people in the area, especially those who make their livelihood fishing the river.
Participants at the conference said the dam threatens the last remaining members of the endangered Irrawaddy dolphin population, which is split between Laos and Cambodia.
Vietnamese officials, experts and residents in the Mekong Delta have denounced the Don Sahong in recent months, arguing that Vietnam's downstream communities have already suffered from damage caused by salinization and erosion brought on by upstream Chinese dams.
China has built seven dams along the upstream Mekong and has planned or is building 20 others.
Laos and Cambodia have plans for another 11, including the US$3.8-billion Xayaburi, which they started building in 2012.