Running 4,000 kilometers south through Yunnan Province of China, Burma, Thailand, Cambodia, Laos and Vietnam, the Mekong is the world's tenth longest river. It supports one of the world's most diverse fisheries with more than 50 million people depending upon it and its tributaries for food, water, transport, and many other aspects of daily life.
Dams currently regulate less than five percent of the Mekong basin, but over the past ten years more than 100 large dams have been proposed for the region. Some of these dams are already under construction and others are in the advanced stages of planning. These dams will have widespread impacts on the livelihoods of Mekong communities and on the natural ecology of the river system. Important dam projects in Laos are Nam Leuk, Nam Theun-Hinboun and Nam Theun 2, wheras similar programs in Thailand are the Pak Mun and Rasi Salai dams on the Mun River.
Thanks to the Swedish Nationalencyklopedin encyclopedia and my Vietnamese friend for facts