(May 16, 2014) On a recent trip to China, Mu Lan, the editor of Probe International’s Chinese Three Gorges Probe news service, explored the link between Poyang’s crisis and the country’s hydro colossus.
Lake Poyang, the largest freshwater lake in China, has in the past decade suffered record low water levels and its worst drought in 60 years. Although uneven rainfall patterns and industry on the lake are partly behind the decline in volume, the Three Gorges Dam has emerged as a major cause of the lake’s shocking dry-up.
“Where is Lake Poyang?” I asked Mr. Yu, the driver I had hired in Jiujiang City. Pointing to the wild “grassland,” he exclaimed: “This is Poyang! Poyang is just below your feet!” “But why don’t I see any water?” I asked.
A new report by Probe International’s Chinese Three Gorges Probe editor, Mu Lan, documents the stark decline of Lake Poyang, China’s largest freshwater lake located on the southern bank of the Yangtze River in east China’s Jiangxi Province.
According to the report, based on a site visit last November, the massive changes to the Yangtze’s water flows, brought on by the operations of the Three Gorges Dam almost one thousand kilometres away on the upper reaches of the Yangtze River, have caused the size of the lake to decrease dramatically and permanently.
The surface area of Lake Poyang has always fluctuated between the wet and dry season — indeed that was the source of the ecological and economic vitality of this once thriving floodplain. The interchange of water between the Yangtze and the lake made it one of China’s most productive fisheries as aquatic species — including many now endangered — migrated, spawned, and fed there. The floodplain also played a crucial role in storing the Yangtze’s raging floodwaters, thus protecting downstream populations.
All that has changed now. With the Three Gorges Dam trapping water in the reservoir to generate electricity, the water and sediment flow regime downstream has been turned upside down. The figures are stunning.
According to Fan Xiao, a respected Sichuan geologist who has been monitoring the effect of the Three Gorges Dam on the hydrogeomorphology of the Yangtze River, by blocking the natural flow of sediment down the Yangtze and releasing only “clear water,” the Three Gorges Dam has caused the scouring and lowering of the Yangtze’s riverbed by a phenomenal 11 metres. With the Yangtze now so much lower, Lake Poyang inevitably drains into it, as if a plug had been pulled.
Satellite images show Lake Poyang’s total surface area — once 3,500 square kilometers — shrank by 90% to 293 square kilometres at the end of 2013. Meanwhile, water levels in Lake Poyang dropped from the normal 12.22 metres above sea level to 7.99 metres, the lowest recorded level in decades.
Kong Fanxiang, a senior researcher at the Nanjing Institute of Geography and Limnology, warns: “The continuous decline of water levels and shrinking of rivers and lakes means not only that local people will have difficulty accessing water supply, but local climate conditions are likely to change, resulting in a more frequent occurrence of droughts and floods.” It should be noted that part of the much-vaunted mandate of the Three Gorges Dam was flood control.
For the millions of fisherman, who once prospered on the aquatic rich floodplain ecology, the consequences have been devastating.
The descendents of generations of fishermen, with decades of experience earning their livelihoods on Poyang, report business has been so affected by the lake’s decline they have been forced to sell their boats and find work elsewhere. One such career fisherman told a newspaper he remembers an abundance of fish in his youth, including highly valued species such as saury, eels and turtles, then commonplace. Saury is now so rare, he says, its price has risen steeply and he reports sighting only one eel in Poyang’s waters last year. Unable to earn his living any longer on the lake, he says he now works as a cook at a local restaurant instead.
So desperate are the millions who once depended on the lake for their daily water supplies and livelihoods, authorities are proposing building a dam to stop the outflow of the lake’s water into the Yangtze. But, say experts, the “Poyang Water Conservation Project” as it is known, will only accelerate the decline of the lake initiated by the Three Gorges Dam.
According to Fan Xiao, attempts to plug Lake Poyang’s waters would simply make a bad situation worse by cutting off the remaining free-flowing link between the Yangtze and the lake that has allowed the exchange of water between the two for millions of years. Not even considered by the plan, he says, are its environmental impacts on wetlands, aquatic plants, animals, migrating fish species and transient bird species.
Similar disasters to river systems around the world have been triggered by the construction of hydro dams — on the Volta River, the Senegal River and the Mekong, for example. As a result, under the banner of “negotiated river management,” attempts have been made to restore natural water and sediment flows and halt the cascade of damage to downstream ecosystems and economies. Dam operations have been altered to accommodate the water needs of upstream and downstream parties, usually forfeiting power generation revenues in the process. It is clear that such attempts will need to be made for the Yangtze, if it isn’t too late given the profound changes to the flow of water and sediment that have been caused by the Three Gorges Dam.
To read Mu Lan’s findings in full, see: Is the Three Gorges Dam to blame for extreme drought in the Lake Poyang area?
To view a picture gallery of images taken by Mu Lan during his visit to the Lake Poyang area, see here.
For more information, contact:
Patricia Adams, Executive Director, Probe International
Tel. 1 (416) 964-9223 (ext. 227)