For people living along the Mekong, the river supplies them with about 80% of their protein intake. Photo: Fredrik Thommesen via flickr.
A few short weeks ago it came out the China had plans in the works to place 20 hydroelectric dams on the upper reaches of the Yangtze. It also has dam plans in the headwaters of the Indus and Brahmaputra Rivers. The Mekong, too, won't be escaping the wrath of large-scale hydroelectric power. In a recent piece for Yale Environment 360, Fred Pearce examines the devastating consequences that these dams will have for millions of people downstream:In case you don't know the Mekong has the world's greatest variation in flow of any river and is second only to the Amazon in terms of biodiversity. And China has plans for eight dams on its upper reaches.
Dams Single Greatest Threat to Mekong
These dams will cut the water flowing in the lower reaches during flood season by a quarter. The UNEP calls them "the single greatest threat" to the future of the Mekong. The International Rivers Network says that China's dams will, "wreak havoc with the Mekong ecosystem as far downstream as the Tonle Sap. They could sound the death knell for fisheries which provider food for over 60 million people."
This is how Pearce describes the serious of the sitiation:
Until now, the waters of the Mekong have been a natural resource for humans and nature alike — on a par with the Amazon rainforest. The 2,800-mile river sustains the world’s second-largest inland fishery, a mainstay of the region’s economy for millennia. It makes the Cambodians, who are among the world’s poorest people, among the best fed. It is a direct result of the intensity of the river’s summer flood, and in particular of one feature of the flood — the river that runs backwards.
That river is the Tonle Sap, a tributary of the Mekong in Cambodia that is the beating heart of the Mekong River system. But according to the author of the UN report, Mukand Babel of the Asian Institute of Technology in Bangkok, Thailand, it is among the river system’s most vulnerable elements. China’s dams could still the beating heart.
The flooded Tonle Sap, photo: Wikipedia
That beating heart is the lake at the end of the Tonle Sap river, which expands so much during the flood season that the surrounding forests are submerged. That lake is the source of two-thirds of all the fish that inhabit the Mekong. There is a real possibility that China's dams could stop the annual reversal of the river.
In the end Pearce points out something which is desperately needed at the international level: Laws to prohibit downstream nations from the upstream actions of their neighbors, something which has been proposed in the UN for some time but not acted on.
More: The Damming of the Mekong: Major Blow to an Epic River
China Wants 20 More Dams on the Headwaters of the Yangtze River
China Mulls Building Hydroelectric Dams in Southern Tibet
China Builds Dam on Indus, Doesn't Tell Pakistan
Hydropower on China's Nu River, Alternatives to Huge Dams (Video)