Research commissioned by Vietnam has warned of devastating environmental and economic effects for millions of people living along the Mekong River if 11 proposed dams are built on its mainstream.
The 2 1/2-year study by Danish water expert DHI was submitted recently by Vietnam to the Mekong River Commission, a body comprising Thailand, Vietnam, Cambodia and Laos that was set up to mediate the conflicting water priorities of Mekong countries. The commission released a five-page summary of the study to The Associated Press on Tuesday.
It predicts "high to very high adverse effects" on fisheries and agriculture in Cambodia and Vietnam if all 11 dams are built, and even greater damage if the Mekong's tributaries also are dammed. The famed Irrawaddy dolphin would likely disappear from the Mekong, it says.
Unmitigated hydropower development will cause "long-lasting damage to the floodplains and aquatic environment, resulting in significant reduction in the socio-economic status of millions of residents," according to the study.
Much of Southeast Asia is suffering a record drought due to El Nino, and officials in Vietnam have said the effects are exacerbated by existing Chinese dams on the upper Mekong. The rice-bowl-sustaining river system flows into Myanmar, Laos, Thailand, Cambodia and Vietnam.
The Mekong is also one of the world's largest inland fisheries, providing a livelihood to millions of people. Dams diminish fishing grounds by creating barriers to breeding-cycle migrations and creating river conditions that destroy habitat and food sources.
The study said agricultural production in the lower reaches of the Mekong Delta would drop steeply because the dams would trap river sediments, resulting in large reductions in the volume of nutrients flowing downstream. Less sediment downstream would also make the delta more at risk of saltwater incursion that can render land infertile.
It predicts annual fishery and farming losses of more than $760 million in Vietnam and $450 million in Cambodia. Fish catches would drop by 50 percent for Vietnam and Cambodia, and 10 percent of the delta's fish species would either disappear from the region or become extinct. The incomes of fishing and farming villages would likely fall by half.
Laos is behind many of the new dams proposed for the lower Mekong and went ahead with construction of the Xayaburi dam in 2012 despite the concerns of neighboring countries. It wants hydropower exports to become a mainstay of its economy, which is among the least developed in Asia.
The river commission said the Vietnamese report will help its own study, which was commissioned in 2011 and is expected to be completed next year.