Water Quality of the Yangtze River
Many environmentalists have voiced concerns that the reservoir will collect industrial pollution, farm runoff, and sewage that regularly runs downstream. Levels of E.coli bacteria have risen as the reservoir has began to fill. There are claims that the water here will be to polluted for drinking water. This is expected to also exert a disasterous inlfluence on many terrestrial plants and animals. There will be loss of biodiversity on land and also in the water. The Yangzte River is one of the richest areas in freshwater fish species biodiversity. There are 361 fish species belonging to 29 families and 131 genera, accounting for 36% of all freshwater species in China.
There are as many as 177 endemic fish species in this area. Twenty five of them already have endangered status. These account for 27% of all endangered freshwater species in China. When the Gezhou Dam was built in 1981 led to a great decline in many of three of these edemic fish species. The three are the Chinese Sturgeon, River Sturgeon, and the Chinese Paddlefish. These three species are listed as Grade one endangered . The three gorges dam will likely destroy Chinese Sturgeon Breeding ground by reducing 41% of the water flow below the dam. From 1988, after the completion of the Gezhou Dam, only 3 to 10 adult Chinese Paddlefish have been found below the dam annually. The completion of the Three Gorges Dam will likely reduce the population more.There is also potential salinization to this estruary that will contribute to the extinction of these fish.
The Picture shown above is similar to a Chinese Paddlefish
Shown above is a Chinese Sturgeon
This is a small River Stugeon shown above
The build up of silt behind dams is now reducing their water storage capacity according to the United Nations. An article from the UN says the worlds storage facilities are losing approximately on average 1% of their storage capacity annually. Scientists also think that global climate change will increase the severity of storms and worsen erosion. Many people think that removal of sediment from behind dams should be a regular occurence. There is concern of siltation at Three Gorges Dam. Siltation in areas like this require very expensive maintenence.
An article from Geotimes
said that the Chinese have taken steps to minimize siltation by vegetating
slopes surrounding the Yangtze. It also said that deforestation along
the Yangtze in other spots will still increase erosion, causing the
dam to silt much faster than the rate expected.