A river basin hosting three Mekong tributaries and providing a livelihood for 3.4 million people is under threat because of the construction of 65 dams, according to a study issued in Phnom Penh on Thursday by conservation groups.
Conservation International (CI) and the International Union for the Conservation of Nature (IUCN) collaborated with Cambodia National Mekong Committee (CNMC) on the study, which evaluated the freshwater health of the ecosystem in the Sesan, Srepok and Sekong (3S) basin which spans Cambodia, Laos and Vietnam.
The research found that the ecosystems are facing “stress” and could hinder the livelihood of 3.4 million people. Despite a yearly budget of $10 million, conservation and restoration for the basin are limited.
The Freshwater Health Index (FHI) shows that the 3S ecosystem has a vitality score of 66 out of 100, indicating that it is “moderately healthy”. In addition, the report gave the area a score of 80 for ecosystem services, but only 43 for governance.
The groups pointed out that the dam constructions on 3S are seriously impacting the seasonal flows, sediment transports and fish migration.
Nick Souter, Asia-Pacific’s freshwater research manager at CI, who presented the study’s key results, said that 65 dams were constructed on the 3S basin, mostly for generating electricity. Of those, 59 are in Vietnam, five in Laos and two in Cambodia. In addition, one dam is under construction in Vietnam, seven in Laos and over 30 dams have the potential to be built in the basin.
“The dams cause sediment transports on the stream because [dams] block water flows . . . However, we don’t have specific data on water pollution,” Souter said.
Jake Brunner, IUCN’s head of Indo-Burma Group, said the governance and stakeholder’s score is the weakest of the three indicators, but that is not surprising to him.
“The changing of ecosystems just happened recently. The sediment and fishing issues due to dams did not seriously exist 20 or 30 years ago,” Jake said. He added that the importance of monitoring the basin has just come about in the last five years.
The conservation work needs around $10 million per year, half of which comes directly from the three nations, mostly from Vietnam, with conservation NGOs raising the remainder, according to Jake.
Te Navuth, secretary-general at CNMC, remarked that the key findings are very important to strengthening cross-border cooperation.
“Our roles are to assist the Cambodian government to coordinate the water resource management, preservation and development within the Mekong basin,” he said.
Dr Tracy Farrell, senior technical director from CI, said more collaboration from the three governments and stakeholders is necessary for sustainable development.
“The development depends on the agreements of governments on how to strive for preservation and development to reach the goal,” she said.
Srang Lanh, a Banong ethnic woman, who was displaced from her home by the controversial Lower Sesan II Dam near the border with Laos in Stung Treng, said
the closure of the dam is flooding their homes, farmland, crops and graveyards. She said much of the water is stagnant and unusable.
“It looks like an ocean because water does not flow. We could not use it normally like natural water,” she said.