A new dam planned in Vietnam just upstream from the Cambodian border will only make things worse for northeastern villagers whose livelihoods have been threatened by an existing dam, a natural resource economist said last week.
“Cambodia should not be lulled by vague promises that Se San 3 [dam] will help the situation,” US-based expert Wayne White said via e-mail. “Under present designs it won’t, it will push the problems farther downstream.”
As many as 50,000 villagers in Ratanakkiri and Stung Treng provinces have seen their fisheries and farms threatened by irregular water levels and have been sickened due to poor water quality since the building of the existing Yali Falls dam, according to two studies by NGO and government officials.
More sparsely populated downstream areas in Vietnam have suffered from similar problems, according to a study last year by Vietnam National University.
The $1 billion Yali Falls, located 70 km from the Cambodian border, started influencing water levels in 1996 and exacerbated floods in 1999 and 2000.
Preliminary construction on the Se San 3 dam, 20-km closer to Cambodia on the same river, began last month. Environmental and water flow studies of the effects of the dam are still being planned.
Earlier this month, a Vietnam National Mekong Committee official said the $273 million, 720-megawatt dam could reduce both flooding and drought downstream through controlling water releases depending on the season.
But a Hanoi-based engineer hired by Vietnam said last week that the dam would have no effect on river flows.
“The flow downstream of Se San 3 will be the same irrespective of [whether] the dam is built or not,” Sten Palmer of Sweco, the Swedish firm hired by Vietnam as a technical adviser, said via e-mail.
Irregular water flows have been blamed for many of the problems associated with the Yali Falls dam. So-called “run-of-the-river” dams such as Se San 3 are purported to have fewer environmental drawbacks than dams with larger storage reservoirs like Yali Falls.
But that also means the Se San 3 could play little role in restoring the river’s natural flows. And some experts have begun to question whether run-of-the-river dams are as harmless as believed.
US expert White’s observations that the dam will “only push the problems further downstream” conform with a 1999 Sweco feasibility on the dam, which reported that the dam, “being (more or less) a run-of-river scheme will, by and large, only transfer the hydrological changes some 20 km further downstream. Likewise the water quality will not be significantly changed by the Se San 3 reservoir since the retention time of water is 7.4 days only.”
The Sweco study did not study potential effects of the new dam in Cambodia.
Meanwhile, further conflicting evidence is emerging on the progress of the planned environmental and water flow studies on the new dam, to be conducted jointly by Cambodia and Vietnam. Cambodian National Mekong Committee Vice-Chair Sin Niny acknowledged that disagreements among Cambodian officials are holding up the studies.
The Vietnamese official, speaking on condition of anonymity, said Vietnam had again selected Sweco to do the environmental study. But Palmer, chief engineer of the Sweco office in Hanoi, said last week that his firm had only been hired to perform “advisory services for the detail design of a plant layout already decided by the ministry.”
“I have no information on that [sic] Sweco is selected for the referred [environmental impact assessment] study,” he added.
White, who has reviewed the 1999 study, was skeptical that further studies would have any effect on the design or operation of the dam. He said the environmental reports should have been completed before construction began.
He also expressed doubts about Vietnam’s decision to rehire Sweco, a major multinational which has helped build dams in Egypt, China and elsewhere. In his prior review of the feasibility study, completed in 2000, he charged that Sweco had far overstated the benefits of the project.
“The Sweco Feasibility Study on Se San 3 overstated benefits by at least 367%, understated project cost by at least one half, and neglected the social and environmental damages such as you now see downstream in Cambodia,” he wrote. “This is not a good precedent from which to expect full, accurate and balanced reports going forward.”
Pich Dun, deputy secretary-general of the Cambodian National Mekong Committee, said he believed the studies would be completed early enough to have an impact on the dam construction because the studies would take only several months, while dam construction could take a few years.
Vietnam has started building a road to the site and shelter for dam workers, the Vietnamese official said. It has not started work on the dam’s wall or reservoir.
The Mekong River Commission, a multilateral agency that monitors development in the Mekong Basin, will review the studies when completed and judge whether modifications in construction are needed, he said.
Pich Dun said Cambodia has not made a formal request to Vietnam for compensation for the damage caused by the Yali Falls dam, despite the two NGO-funded studies documenting drownings, farm and fisheries damage, and illnesses among villagers dependent on the river.
Vietnam donated 10 tons of rice to Ratanakkiri province after massive water releases from the dam were blamed on at least five drownings in 2000, Pich Dun said. Any further requests for compensation should be decided between the bordering provinces, he said.
Rather than discussing compensation, the two countries formed a joint committee on development of the Se San river “to avoid further damage” from future dams, Sin Niny said.
Vietnam plans to build six dams on its side of the Se San, official media have reported. The Vietnam News Service reported Friday that a feasibility study for the so-called Se San 4 dam, slotted to be built just a few kilometers from the Cambodian border, will commence later this year. The $280 million dam, scheduled to begin construction in 2004, would be the country’s second-largest dam after the Yali Falls, the agency reported.
Cambodia is considering two dam sites on its own side of the river, which flows into the Mekong at Stung Treng town.
A 1998 study commissioned by the Asian Development Bank identified the so-called Lower Se San 2 and Lower Sre Pok 2 as beneficial sites for hydropower. But the study predicted that bank money for design and feasibility studies would not be available until 2007.
The Asian Development Bank has been shying away from dam construction in recent years as controversy has grown about their effects. But Pich Dun said Cambodia needs the electricity now, either for domestic consumption or to sell internationally through planned transmission lines.
“If we have the money, we need to build as soon as possible,” he said.