A renewed push to build hydropower dams on the lower Mekong mainstream is threatening the river’s ecosystems, aquatic resources and the fishery-dependent livelihoods of millions of people.

As of November 2007, the governments of Laos, Thailand and Cambodia have granted permission to Thai, Malaysian and Chinese companies to conduct feasibility studies for the construction of six large hydropower dams on the Mekong mainstream, including: Pak Beng, Xayabouri, and Pak Lay, in northern Laos, Don Sahong, in southern Laos, Ban Koum on the Thai-Lao border, and Sambor, in Cambodia. These same six dam sites were previously recommended by Canadian and French consultants in a report published by the Mekong Secretariat in 1994, but were roundly dismissed as too costly and environmentally damaging [see map].

The adverse transboundary impacts of large hydro dams on fisheries and fishing based-livelihoods have already affected thousands of communities on the banks of the Upper Mekong and the tributaries to the Lower Mekong.  Scientists, hydro-power consultants, community organisations and the Mekong River Commission (MRC) have confirmed the links between fish productivity and biodiversity in addition to the links between maintained seasonal water flows and connectivity among the river’s diverse habitats and ecosystems.  Research published by the MRC in 2004 identifies dams built for such purposes as irrigation, hydroelectricity and flood control as the “the overriding threat to the future of the Mekong’s fish and fisheries”. Most recently, in a 2007 report by the Cambodian National Mekong Committee and the WorldFish Center, the loss of even a small percentage of fisheries in the Mekong basin was found to represent thousands of tonnes and millions of dollars worth of fish, threatening the food and income security of people who rely on the Mekong for their way of life.

Despite the enormous ecological, social and economic costs of damming the lower Mekong, plans for six mainstream dams are proceeding in secrecy and without consideration of the countries sharing the river.

The loss of resources to the people of the Mekong, the impacts to their livelihoods and cultures are unacceptable.  Livelihoods cannot be allowed to be surreptitiously traded for electricity to feed the emerging energy giants elsewhere. An open and transparent process with full participation of affected communities must be held, and the inequities between the cost to the local communities and benefit to richer metropolises must be held to public account.