The Mekong River Under Threat

Until the 1980s the Mekong River flowed freely for 4,900 kilometres from its 5,100-metre high source in Tibet to the coast of Vietnam, where it finally poured into the South China Sea. The Mekong is the world’s twelfth longest river, and the eighth or tenth largest, in terms of the 475 billion cubic metres of water it discharges annually. Then and now it passes through or by China, Burma (Myanmar), Laos, Thailand, Cambodia and Vietnam. It is Southeast Asia’s longest river, but 44% of its course is in China, a fact of capital importance for its ecology and the problems associated with its governance.

The Mekong is Southeast Asia's largest river, seen here at sunset in Luang Prabang, Laos. (Photograph by Milton Osborne)

In 1980 not only were there no dams on its course, but much of the river could not be used for sizeable, long-distance navigation because of the great barrier of the Khone Falls, located just above the border between Cambodia and Laos, and the repeated rapids and obstacles that marked its course in Laos and China. Indeed, no exaggeration is involved in noting that the Mekong’s overall physical configuration in 1980 was remarkably little changed from that existing when it was explored by the French Mekong Expedition that travelled painfully up the river from Vietnam’s Mekong Delta to Jinghong in southern Yunnan in 1866 and 1867. This was the first European expedition to explore the Mekong from southern Vietnam into China and to produce an accurate map of its course to that point.