Hanoi (AsiaNews/Agencies) – Some 65 million people call the Mekong River home, living off the fisheries (estimated to be worth US$ 3 billion a year) and fish farming. The 4,880-kilometre long waterway, with the second-richest biodiversity in the world, is threatened by hydroelectric development, including the Xayaburi dam project, which Laos submitted to the Mekong River Commission (MRC) for examination last month.

Poverty-stricken Laos wants to build the dam to sell power to Thailand and Vietnam. A Thai company will bear most of the cost. However, environmentalists and residents are concerned that no serious environmental impact study has been done to this and other projects. Until that is done, they want a moratorium to be put in place.

A Thai parliamentary committee is studying the issue."The effect of the Xayaburi dam will be a devastating on all the countries, Laos, Thailand, Cambodia and Vietnam," said committee chairman Kraisak Choonhavan, a former senator and a deputy leader of the ruling Democrat Party.

The World Wildlife Fund (WWF) has also issued a warning that the dam, which will be located on the border with Thailand, would almost certainly wipe out the endangered giant catfish (a species that can reach up to 300 kg in weight) and place an additional 41 species of fish on the path to extinction.

The dam would also block fish migration and negatively affect Cambodians who depend on freshwater fisheries for more than 80 per cent of their protein intake.

Experts also note that the lives and livelihoods of some 200,000 Thais would be affected. On the Thai side of the would-be dam project, residents wrote a letter to Thai Prime Minister Abhisit Vejjajiva to oppose the dam.

The confrontation is heated because the Xayaburi (expected to generate 1,260 megawatts), is set to be the first of 11 dams on the lower Mekong, 9 of which in Laos, whose plan is to become the region’s electrical powerhouse.

Laos, Cambodia, Thailand and Vietnam have set up the Mekong River Commission (MRC) to regulate dam development in the river and the Xayaburi will be the first dam project examined as an international issue.

Although the MRC was founded in 1995, its first meeting was only held last April. Neither China nor Myanmar is a member of the association but they have observers.

China has already built four dams on the Lancang (the Chinese stretch of the Mekong), including the tallest high-arch dam in the world, at 292 metres, and plans more.

There is great concern here as well. Dr Philip Hirsch, director of The Mekong Research Centre at the University of Sydney, told the South China Morning Post, that "The two dams, Xiaowan and Nuozhadu [the next Chinese dam to be built in Yunnan], will impact the flow regime of the entire system all the way down to the delta in Vietnam". Chinese authorities have responded, blaming any drop in water flow on the worst drought in a century in four of its southwestern provinces, with more than 24 million people short of drinking water.

Beijing holds the view that each nation has to look after its own national interests first and rejects any demand to have the issue discussed at international forums, even if dam projects will affect other countries. For experts, this is a lethal approach because no country can take into full account the overall effects of various interventions on the river.

At a MRC meeting, Prasam Maruekpithak slammed the four Chinese dams for destroying the river’s ecosystem. For this reason, both Thailand and Vietnam are in favour of the United States playing a role to counter Chinese power.

Recently, US Secretary of State Hillary Clinton met in Hanoi the foreign ministers of Cambodia, Laos, Thailand and Vietnam to discuss the Lower Mekong Initiative, a regional plan set up to foster regional cooperation in the fields of health, education, environment and infrastructural development.

Many fear that Beijing, through its upstream dams, will reduce the flow of water in the river, especially during the dry season, that it will have a lethal impact on the Mekong’s ecosystems as well as the communities who live off farming downstream.