Blocking flow to Asia bread basket

Blocking flow to Asia’s bread basket

Milton Osborne

The Australian

13 November 2012

P. 8

On November 5 the Lao government confirmed it would construct a hydropower dam at Xayaburi, a remote site on the Mekong River roughly halfway between Luang Prabang and Vientiane.

This will be the first dam built on the mainstream of the Mekong River after it flows out of China into mainland Southeast Asia and it will be substantial: 830m wide, a dam wall rising 49m and a reservoir stretching 60km upstream.

The controversial decision comes after a year of equivocal statements from the Deputy Minister for Energy and Mines, Viraphonh Viravong, in the face of opposition from officials and politicians in neighbouring Cambodia and Vietnam.

Impoverished Laos is pursuing a hydropower policy it hopes will make it ``the battery of Southeast Asia''. The dam, with a projected capacity of 1260MW, will be built by Thai company CH Karnchang and the power it generates will be sold to Thailand and possibly Cambodia.

The decision is a dramatic break with an apparent consensus that no dams should be built on the river without a thorough environmental assessment of their impacts. The dangers that dams pose were made clear in a detailed study commissioned by the Mekong River Commission and completed in 2010, which recommended a 10-year moratorium on dam building on the river below China.

There are particular concerns that dams will block the transit of migratory fish in the river and diminish the flow of sediment carrying vital agricultural nutrients. Eighty per cent of the 1000 species of fish in the lower Mekong are migratory, often travelling many hundreds of kilometres during their life cycle, and in the case of Xayaburi estimates are that at least 20 and possibly as many as 100 fish species would be blocked by the dam.

Studies have shown that none of the means used elsewhere in the world to move fish over or around dams will work in the Mekong. Fish ladders have been tried on tributaries and failed.

There are concerns that dams built by China on the Mekong's upper reaches are already blocking sediment flow. Nowhere is sediment more vitally important than in the Mekong delta, Vietnam's most productive agricultural region.

While the Lao government maintains that only 2100 people will need to be relocated because of the dam, critics say the real number will be as high as 200,000 as river bank farming will be damaged by the dam's reservoir.

There are fears that the Lao decision could lead to the construction of other planned dams in the lower Mekong basin, in Cambodia and Laos, which could put in jeopardy the lives of 65 million people who rely on the bounty of the river for their sustenance. In Cambodia alone, fish taken from the Mekong provide 80 per cent of the population's annual protein intake.

It won't be until the dam has been built that the true costs of the decision to go ahead with construction will become apparent.

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Milton Osborne is a visiting fellow at the Lowy Institute and the author of The Mekong: Turbulent Past, Uncertain Future.