Downstream Ecological Implications of China's Lancang Hydropower and Mekong Navigation project

Tyson Roberts
Monday, January 1, 2001

China intends to develop Lancang or Mekong mainstream hydropower in Yunnan and make the Mekong mainstream navigable from Yunnan to the South China Sea, a distance of some 2,500 kilometers. This poses unprecedented environmental and social problems for the downstream countries Myanmar, Laos, Thailand, Cambodia and Vietnam. Severe ecological deterioration of the Mekong River is a foregone conclusion if this plan proceeds. And of course the impacts will not be limited to the river. The downstream countries will be forced to undertake exhausting and largely futile efforts to protect themselves and make up for the damage to their agriculture, fisheries, forests, and way of life. Cambodia and Vietnam, the two countries farthest downstream, will benefit little and will experience the worst negative impacts from the scheme. Particularly at risk are Cambodia's Great Lake and Vietnam's Plain of Reeds and Mekong Delta. China itself will not be immune to adverse impacts. Of particular concern will be sedimentation of the Lancang hydropower dam reservoirs. Sediment in the Lancang mainstream, already great, is likely to increase due to larger and more frequent landslides and other effects brought about by the dams and their reservoirs. The useful lifetime of China�s Lancang cascade of hydropower dams is likely to be only about thirty years rather than the one hundred years foreseen by project proponents.