Nearly a dozen mainstream hydropower dams planned along the Mekong River could threaten the food security of tens of millions of people relying on the water source for fish as a source of protein, a conservation group said Monday.
The World Wildlife Fund (WWF) said that based on a joint study with the Australian National University, the impact of the 11 planned dams would extend far beyond the waterway, including driving those affected by the depleting fish catch to take up farming and impose new demands for land use.
The report was presented during World Water Week in Stockholm, Sweden and highlighted current concerns over the continued construction of the Xayaburi Dam on the Mekong in Laos, despite a decision by the intergovernmental Mekong River Commission (MRC) to halt the project pending further studies.
By 2030, developers plan to have constructed 11 dams on the Mekong mainstem and 77 dams in the river’s basin.
According to the latest study, if all 11 mainstem dams are built, fish supply to the region would be reduced by 16 percent with an estimated financial loss of U.S. $476 million per year. If all 88 dams were built, the fish supply could fall by 37.8 percent.
Stuart Orr, WWF International’s freshwater manager, said that policymakers often underestimate the essential role of inland fisheries in contributing to regional food security.
“The Mekong countries are striving for economic growth, and they see hydropower as a driver of that growth,” he said.
“But they must first fully understand and take into account the true economic and social value of a free-flowing Mekong.”
The lower Mekong River flows through Cambodia, Laos, Thailand, and Vietnam, and contains more than 850 freshwater fish species. According to the report, some 80 percent of the 60 million people in the region rely directly on the river for their food and livelihoods.
Land use
In addition to the cited losses incurred by changes in the river, the report said that the dams would cause dramatic changes in the use of land in the area as people seek to replace fish protein with livestock.
It said that on top of the 1,350 square kilometres (521 square miles) of land lost to dam reservoirs, the countries along the Mekong would need a minimum of 4,863 square kilometres (1,878 square miles) of pasture land for cows, pigs, poultry, and other sources of protein.
The high end of the estimate, assuming all 88 dams were built, would require 24,188 square kilometres (9,339 square miles) of pasture land—a 63 percent increase in the amount of land dedicated to livestock.
The report said that water requirements for agriculture and livestock would jump on average between 6 and 17 percent, but that the cost particularly for impoverished Cambodia and Laos would be considerably higher.
It said that with the 11 mainstream dams, Cambodia would need to provide 29 to 64 percent more water, while Laos would need an additional 12 to 24 percent. With all 88 dams built, those numbers would grow to 42 to 150 percent and 18 to 56 percent, respectively.
“Policymakers in the region need to ask themselves where they are going to find this additional land and water,” Orr said.
“The Mekong demonstrates the links between water, food and energy. If governments put the emphasis on energy, there are very real consequences for food and water—and therefore people.”
The WWF urged the countries of the lower Mekong to defer a decision on the mainstream Mekong dams for 10 years “to ensure critical data can be gathered and a decision can be reached using sound science and analysis.”
The conservation group also suggested prioritizing dams on the river’s tributaries which it said are easier to assess and are considered to have a much lower impact and risk.
Freshwater dolphin
The release of the joint study follows reports last week that the Cambodian government will limit fishing in a 180-kilometer-long (110-mile) zone on the Mekong in an effort to protect critically endangered freshwater Irrawaddy dolphins.
The zone will run from eastern Kratie province to the border with Laos and will ban the use of floating houses, fish cages, and gill nets, though fishing will still be permitted. Gill nets are seen as the leading cause of death in adult Irrawaddy dolphins.
The Cambodian government estimates there are between 155 and 175 dolphins left in its stretch of the Mekong, while the WWF, which in 2004 listed the animal as critically endangered, says only 85 remain.
Irrawaddy dolphins also suffer from high calf mortality rates, although it is unclear why, and from environmental degradation.
Reported by Joshua Lipes.