This blog originally appeared on Cool Green Science, the science blog of The Nature Conservancy.
A recent article by the Economist offers a richly complex review of the conflicts roiling the waters of the Mekong River in Southeast Asia. The magazine’s nuanced synthesis is summarized by a non-subtle plea on its cover: “don’t dam the Mekong.”
Several dozen hydropower dams are under construction or planned in the basin, including 11 for the main-stem of the river, threatening the largest and most important freshwater fish harvest in the world. The Mekong fishery produces more than 2 million tons per year, nearly 20 percent of theglobal total for freshwater fish harvest, and provides the primary source of protein and livelihood for tens of millions of low income, rural people in Laos, Cambodia and Vietnam.
Specifically, the editorial and essay in the Economist support a moratorium on dam construction on the main-stem of the Mekong, proposed in a 2010 report by the Mekong River Commission. The moratorium hasn’t changed the rapid pace of dam development, however. China has built six large dams on the upper river, and two-main stem dams are now under construction in Laos in the Mekong’s productive heart — the so-called Lower Mekong Basin. This area is characterized by productive floodplains, networks of channels that serve as a highway for migratory fish and huge populations that depend on this bounty of fish.
The Economist notes that “the biggest problem with the dam-building schemes is their lack of co-ordination.” This lack of coordination is no doubt exacerbated by the fact that Mekong flows through six countries. However, hydropower development around the world is characterized by a lack of coordination, and this deficiency represents a huge lost opportunity to chart a course toward a future with sustainable energy and healthy rivers.
The Nature Conservancy recently released a report, The Power of Rivers, which showed that coordinated planning, as advocated by the Economist, could result in better outcomes for 100,000 kilometers of rivers worldwide during the next few decades of hydropower expansion. This research suggests that coordinated planning that strives to balance a range of river values could help manage the projected hydropower boom in a way that leaves the world with far more free-flowing rivers, productive fisheries and healthy communities than will result from status quo development.
A recent study by researcher Guy Ziv and colleagues provides a specific demonstration for the Mekong: among nearly 30 potential dams on Mekong tributaries, careful selection of which dams are built and which are not built could lead to a system that provides 75 percent of all the available energy from tributary dams, while only diminishing basin-wide migratory fish populations by 3 percent. However, building just a few of the most damaging projects — those with the biggest impact on fish migration — could cut migratory basin-wide fish populations by nearly 20 percent. That’s nearly a seven-fold increase in impacts for a system of dams with similar, or potentially even less, energy levels (note that main-stem dams would have greater impacts than tributary dams).
The world is currently looking to maximize most forms of energy — particularly those with a small carbon footprint. Hydropower will no doubt contribute a major part to the world’s energy mix in the coming decades. But we shouldn’t solve the climate crisis on the backs of unique and productive rivers around the world. There is a better way, and governments, companies, civil society and communities need to work together to find solutions to get this right. Too much is at stake, in the Mekong and other rivers around the world, to get it wrong.