Cambodia has decided to go ahead with the construction of a dam on a Mekong tributary, but conservation groups are concerned that not enough study has been done on the hydropower project’s environmental consequences.
Construction on the 400 megawatt Lower Sesan 2 dam in northwestern Cambodia’s Stung Treng province is set to begin in 2014, after the project received a stamp of approval from the country’s cabinet on Nov. 2.
A statement issued by the Council of Ministers said the decision came after eight years of research into the possible environmental and social consequences of the U.S. $800 million project to be undertaken by a Cambodia-China-Vietnam joint venture.
But green groups question the research findings, saying the studies have not been thorough.
Their concerns come after neighboring Laos decided two weeks ago to push ahead with the Xayaburi dam on the main Mekong River despite concerns by environmentalists.
U.S.-based Conservation International said in a statement this week that it is “highly concerned” about Cambodia’s plans to move forward with the Lower Sesan 2 dam, which it said could affect food security and the livelihoods of millions in the region.
“The impacts of the proposed dam are not yet known as there has been very little research undertaken on the effects of the proposed dam, or the entire river system, [with which] to make a well informed decision,” said Tracy Farrell, the senior technical director of the group’s Greater Mekong program.
The group called on Cambodia to carefully consider the tradeoffs between the benefits of power generation and any negative effects that damming the Lower Sesan could have on those who rely on the Mekong River’s ecosystem, including the Tonle Sap lake that provides much of the country’s fish.
Reduction of water flow and increased sedimentation that dams often create downstream “could lead to a decline in Cambodia’s fisheries, rice farming, and aquaculture yields, all of which are crucial to national food security,” Farrell said.
“Such effects must be thoroughly analyzed prior to any such plans are put into action, otherwise millions lose access to food, water and [could face] related health problems.”
Experts warn that 9.3 percent of the Mekong River Basin’s fish biomass will be lost and between 6-8 percent of the basin’s sediment flows will be blocked if the Lower Sesan 2 dam is built, according to a recent report by environmental group International Rivers.
“The Lower Sesan 2 Dam is a perfect example of a project that should not be built, as its potentially as environmentally and socially destructive as many of the proposed mainstream hydropower projects,” said Ame Trandem, the group's Southeast Asia program director.
“The economic feasibility and practicality of the project is highly questionable due to increasing water scarcity issues from poorly planned upstream hydropower projects.”
Construction of the 75-meter (246-foot) dam, which will inundate 32,000 hectares (79,000 acres) of land, is being led by an unnamed Chinese power company along with Cambodia’s Royal Group and Vietnamese power giant Electricity Vietnam International, according to a government statement in November.
Officials have said that half of the electricity generated by the dam is set to be sold to Vietnam, despite Cambodia’s critical power shortages.
Some 5,000 people from villages in the dam’s future reservoir area will be relocated over the next year, the council said, and site preparations for the construction on the dam have been going on since 2011.
In March, more than 500 ethnic minority residents of Sesan River communities held protests against the dam, saying it will displace them from their ancestral land. The same month, a coalition of fishermen wrote a letter to Prime Minister Hun Sen calling for the project’s cancellation.
Cambodia, which is championing hydropower as a solution to its power shortages that hamper business investment in the country, has nine dams set to be completed by 2019, generating an estimated 2,045 megawatts of power.
The country’s first major hydropower project, Chinese-built Kamchay dam, was completed last year, with Hun Sen calling it a “historic event” in the nation’s development.
Environmental concern about hydropower projects in Southeast Asia have focused on the Xayaburi dam, the first across the mainstream of the Lower Mekong.
Critics fear Xayaburi could pave the way for progress on the dozen dams that have been proposed on the mainstream Lower Mekong—five of them in Cambodia—and warned that damming the key Southeast Asian artery will harm the region’s food security.
But the combined effects of all proposed dams on tributaries that flow into the Mekong—including the Lower Sesan 2—could be even more disastrous than the combined effects of the proposed mainstream dams, a study from the U.S.’s National Academy of Sciences said this year.
Over 70 dams have been proposed or are under construction on tributaries that flow into the Mekong, particularly in the “3S” river region that is home to the Sesan, Srepok, and Sekong rivers at the intersection of Cambodia, Laos, and Vietnam.
Reported by RFA’s Khmer service. Written in English by Rachel Vandenbrink.