Catching fish in the Khone Falls area, Southern Lao.

Mekong Mainstream Dams

    The revival of plans to build a series of dams on the Mekong River's mainstream in Cambodia, Laos, and Thailand presents a serious threat to the river's ecology and puts at risk the wellbeing of millions of people dependent on the river for food, income, transportation and a multitude of other needs.

    Since the 1960s, several mega-schemes to dam the Lower Mekong River's mainstream to generate electricity have been proposed. The most recent plan, prepared by the Mekong Secretariat in 1994, was shelved in part due to public outcry over the predicted impacts on the river's fisheries and the large number of people who would be displaced or otherwise affected.

    But now there are troubling signs that the tide is turning. Since mid-2006, the Governments of Cambodia, Laos and Thailand have granted approval to Thai, Malaysian, Vietnamese, Russian and Chinese companies to investigate eleven mainstream hydropower dams. The projects are located at Pak Beng, Luang Prabang, Xayaburi, Pak Lay, and Sanakham in northern Laos; Pak Chom and Ban Koum on the Thai-Lao border; Lat Sua and Don Sahong in southern Laos; and Stung Treng and Sambor in Cambodia (see map). That these projects are once again being actively investigated is cause for alarm.

    Already serious concerns have been raised by non-governmental organizations and scientists over the Xayaburi Dam, which is at the most advanced stage of development.  In September 2010, this dam became the first mainstream dam to be submitted for approval by the region's governments through a regional decision-making process called the "Procedures for Notification, Prior Consultation and Agreement" (PNPCA), facilitated by the Mekong River Commission (MRC). This leapfrogged the publication of the MRC's Strategic Environmental Assessment report by a mere three weeks, which provided a critical appraisal of the dam plans and recommended that decisions on whether to proceed with the mainstream dams be deferred for a period of ten years until further studies can be conducted to ensure that decision-makers are fully informed of the risks.  With so much at stake, it is crucial that the Mekong region's decision-makers endorse and adopt the SEA's recommendations before it's too late.

    China's dam construction on the Upper Mekong has already caused downstream impacts, especially along the Thai-Lao border where communities have suffered declining fisheries and changing water levels that have seriously affected their livelihoods. By changing the river's hydrology, blocking fish migration and affecting the river's ecology, the construction of dams on the Lower Mekong mainstream will have repercussions throughout the entire basin.

    International Rivers is working with partners in the region and internationally to keep the Lower Mekong River's mainstream flowing freely.


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