Dams put Mekong on knife's edge

Dams put Mekong on knife's edge

Reuters Singapore

China's damming of the Mekong river to help power its economy could pose a grave threat within a decade to the livelihoods of millions of Southeast Asian farmers and fishermen, an Australian researcher said on Tuesday.

Evidence suggested that completion of two dams on China's stretch of the 4,800 km waterway, along with work to make the Mekong more navigable, had triggered damaging changes in the river's flow patterns, said Milton Osborne, a visiting fellow at the Australian National University in Canberra.

The Mekong fell to record lows in the recent dry season. Sudden drops in the river's levels stranded boats. In impoverished Cambodia, the fish catch dropped by almost 50 percent after a 15 percent decline the year before, Osborne told Singapore's Institute of Southeast Asian Studies.

"Many of these problems, which have been identified not just by mad-eyed greenies but by serious scientists, are a cause for concern," Osborne said.

Seventy percent of the 70 million people living in the Mekong Basin, an area the size of France and Germany, depend on the fish that teem in the river or on the crops that it irrigates.

Although experts would not be able to deliver a definitive verdict for a decade, their current projections were worrying, Osborne said. The Mekong was on a knife-edge.

"The cumulative effects of the developments that have taken place, plus the additional physical changes that are planned with more dams in China and the extension of river clearances further downstream into Laos, mean that there is reason to be concerned about the Mekong's future," Osborne said.

China began work this year on a third Mekong dam at Xiaowan in the southwestern province of Yunnan that Osborne said would be a "monster" with a wall 300 metres high and a reservoir 169 km long. Only the Three Gorges dam on the Yangtze river would be larger.

China says that, as well as generating much-needed hydroelectric power, the dams benefit countries downstream -- Thailand, Myanmar, Laos, Cambodia and Vietnam -- by smoothing the flow of the mighty river.

But Osborne said the opposite was happening: construction of the dams and the release of water to enable Chinese ships to sail downstream were leading to substantial changes in river levels.

Apart from preventing some species of fish from returning to their breeding grounds, the dams were blocking 35 percent of the nutrient-rich sediment that used to flow down the Mekong, forming fertile soil for millions of peasants.

Osborne, who acknowledged that drought and overfishing were also factors behind dwindling fish catches, said the imbalance of influence between China and the downstream countries meant Beijing was unlikely to stop building dams on the Mekong.

China has declined repeated invitations to join the Mekong River Commission, which oversees the health of the waterway.

"The construction of dams without consultation, the promotion of river clearances and the extension of Chinese trade down the river sit alongside other aspects of China's steady push to assert its position of dominance in the region," Osborne said.