Reprieve for Mekong as big dam is delayed

Posted: 19 April 2011

Map showing the Mekong watershed and main tributaries. Credit: © World Resources Institute

The postponement comes following the submission of a growing body of evidence to the Commission highlighting risks to biodiversity, fisheries and livelihoods of millions of people in the Mekong River Basin. Particularly vulnerable areas include fisheries and the Mekong Delta.

A WWF-commissioned review of the Xayaburi project found that the Environmental Impact Assessment (EIA) and Feasibility Study (FS) for the proposed dam were woefully inadequate and fell well below international standards for such studies. Changes in flows, sediment and nutrients are some of the areas that require further analysis, it says.

Any decision made will have implications for generations to come, says Dr Jian-hua Meng, WWF International Sustainable Hydropower Specialist. It is clear that the governments of Cambodia, Thailand and Vietnam are acknowledging the gaps in knowledge of the expected impacts from the dam.

Ten-year delay

The Pak Mun Dam on the Mekong’s largest tributary has caused drastic reductions in fish populations upstream. In 2002, campaigners convinced the Thai government to open the dam’s gates for four months per year to allow for fish migrations. Picture shows a fish ladder at the dam. Photo © Peter Charlesworth

An experts meeting held in Vientiane in 2008 to review the impact of mainstream dams on fish migration concluded that existing mitigation technology used for salmon species in Europe and North America cannot handle the scale of fish diversity and migration in the Mekong mainstream. WWF believes that the Mekong should not be used as a test case for proving or improving fish passage technologies.

WWF supports a 10-year delay in the approval of lower Mekong mainstream dams, including the Xayaburi hydropower dam, to ensure a comprehensive understanding of all the impacts of their construction and operation, while immediate energy needs are met with less challenging projects applying state of the art sustainable hydropower solutions are fast tracked on selected tributaries.

"The MRC has taken an important step towards responsible decision-making and is clearly looking at the potential impacts the Xayaburi dam would have on millions of people in the Mekong River Basin" Dr. Meng said. "Laos needs to build on the knowledge gained in developing sustainable hydropower in the region and follow examples such as the Nam Theun 2 dam."