Scott Learn for The Oregonian

When Robert Costanza and colleagues traveled to Laos earlier this year, the decision to build the lower Mekong River’s first mainstream dam seemed close to done.

Then the researchers, most from the Northwest, pointed out the poor history of predicting environmental and social damage from big hydropower dams. Their study (check out interesting comments here-MouthtoSource) also put new dollar signs on the potential cost to the environment and traditional fisheries — figuring the net economic impact of a string of electricity-producing dams could range from a gain of $33 billion to a loss of $274 billion.

“There’s a pretty high probability that things are not going to go the way they had planned, given the history of dam projects worldwide and in the Pacific Northwest,” says Costanza, the study’s lead author and a sustainability professor at Portland State University. “All the evidence pointed toward their assumptions being highly optimistic.”

Last week, the Mekong River Commission recommended Laos postpone dam building, citing the need for further study of the “sustainable development and management of the Mekong River.”

Costanza’s study highlights the biological importance of the Mekong, painfully familiar to Americans during the Vietnam War. It also shows how PSU is brokering its sustainability reputation worldwide, with contributions from Costanza and other researchers at its Institute for Sustainable Solutions.

Costanza, 61, got the shoulder tap for the study late last year from U.S. Agency for International Development. After years of discussion, the foreign aid agency wanted a new look at costs and benefits of Mekong dams, which would affect Laos, Thailand, Cambodia and Vietnam.

Costanza, who arrived at PSU last fall, was a logical choice. In 1997, he helped advance the notion of valuing the world’s environmental capital when he co-authored a study published in the journal Nature that pegged the value of global “ecosystem services” at $33 trillion a year, more than the world’s gross domestic product at the time.

In general, Costanza says, economists have downplayed the importance of maintaining the environment — say a wetland that helps with flood control, or a free-flowing river that supports indigenous fisheries and delivers nutrient-laden sediment to rice fields.
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“If you’re not making the environmental costs explicit, you could make the wrong decisions,” he says. “You don’t understand what you’re trading off.”

The Xayaburi dam, the first of up to 11 proposed for the lower Mekong, would be built in Laos, with power going primarily to Thailand.

The researchers traveled to Thailand and to Vientiane, Laos, last February, returning to Thailand in March and June. In Vientiane, they saw fishermen casting nets, people picking rice in fields fed by side channels, children crossing the river, low at the time, to get to sandbars for pickup soccer games. Fish make up about 70 percent of the protein intake in the region.

“It was pretty amazing,” says Ida Kubiszewski, an assistant professor at Portland State. “From young to old, life revolves around the river.”

Hydropower dams would provide badly needed revenue to Laos. The initial dam would have about the same electric-generating capacity as Bonneville Dam, the first of 14 federal dams in the Columbia and Snake river system.

China has built dams on the upper Mekong, and leaders in Laos consider dam building “an opportunity to become a power generation hub,” says Shpresa Halimi,a member of the study team and an assistant professor at PSU. “They’re also looking at it as a way to combat chronic poverty.”

Even with more realistic estimates of environmental and social costs, Laos would still come out ahead, the study concluded. But Thailand, Vietnam and Cambodia could all lose, with foregone fisheries and altered wetlands a big part of the tab.

Proponents say passage facilities at the dams to help migratory fish — including the endangered giant catfish — can minimize damage, and aquaculture can compensate for lost fisheries.

That had a familiar ring to Peter Paquet, wildlife and resident fish manager for the Northwest Power and Conservation Council. Paquet, who was among the study group, has seen hundreds of millions devoted to correct problems with fish passage at Columbia dams. Performance of the Columbia’s aquaculture system, otherwise known as hatcheries, has also fallen short of predictions.

“You can’t go into a place like that and say, ‘Don’t do this,’ because they can turn around and rightly say, ‘Look what you’ve done,’” Paquet says. “We were trying to say, don’t make the mistakes that we’ve made, because fixing these things after the fact is hugely expensive.”

The Mekong hosts some 1,200 fish species, far more than the Columbia, Paquet says. Many are migratory, and none can jump up fish ladders at dams the way salmon and steelhead can.

Laos could still build the dam — the river commission’s opinions are just advisory. Costanza said he hopes the country’s leaders agree to delay the decision and study other carbon-free power, such as wind and solar.

Dam developers could be required to post bonds to cover a worst-case scenario, an incentive to keep environmental effects low. Or other countries in the region and international groups could pay Laos for foregoing the benefits of dam construction.

Costanza says the poor, particularly in fishing villages, could bear the brunt of unexpected damage.

“There’s always uncertainty,” he says. “The real question is who bears the burden. The way it’s setting up now, it’s the public that will pay.”

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