UN study advises caution over dams

ByABC News
May 21, 2009, 7:36 PM

BANGKOK -- A dam-building spree in China poses the greatest threat to the future of the already beleaguered Mekong, one of the world's major rivers and a key source of water for the region, a U.N. report said Thursday.

China is constructing a series of eight dams on the upper half of the Mekong as it passes through high gorges of Yunnan Province, including the recently completed Xiowan Dam, which at 958 feet (292 meters) high is the world's tallest. Its storage capacity is equal to all the Southeast Asia reservoirs combined, the U.N. report said.

Laos, meanwhile, has started construction on 23 dams expected to be finished by 2010 on the Mekong and its tributaries, the U.N. said, as a means to spur development and lift the country from poverty. Cambodia and Vietnam also have ambitious dam-building plans.

"China's extremely ambitious plan to build a massive cascade of eight dams on the upper half of the Mekong River, as it tumbles through the high gorges of Yunnan Province, may pose the single greatest threat to the river," the report said.

The report went onto to say that the impacts of the proposed dam development include "changes in river flow volume and timing, water quality deterioration and loss of biodiversity."

China's Foreign Ministry spokesman Ma Zhaoxu said in a regular briefing the government pays equal attention to the development of the Mekong and its protection. The Mekong is known as the Lancang river in China.

"I would like to point out that the Chinese government attaches great importance to the exploration and the protection of cross-border rivers and conducts the policy of equal attention to development and protection," Ma said.

The proposed dams would add further pressure to the Mekong, which runs through China, Myanmar, Laos, Thailand, Cambodia and Vietnam. The 307,000-square-mile (795,000-square-kilometer) river network is home to dozens of rare bird and marine species, including the Mekong giant catfish, and is a source of food and jobs for the 65 million people who live in the river basin.