(This graphic on its own does a good summary)
The Three Gorges Dam is the largest Hydroelectric Power scheme. The dam blocks the 3rd largest river in the world, the Yangtze.400 million people live in it’s drainage basin.
Reservoir can flood up to 1045 km^2 at peak capacity. 1200 villages have been disappearing since 2002. 1500 factories and 70 waste management plants have had to close or move.
Of the more than a million relocated people, there have been numerous complaints:
- Inadequate compensation
- Reduction in land quality- the government recompensated with giving new, lower quality land
- Widespread fraud and corruption among officials
- 1,000s forced to live in squalid conditions.
Environmentally the dam has also had a huge impact:
- Pollutants are leaked into the water flow
- Water is too slow to remove these pollutants
- This has caused algal blooms and eutrophication (a process in which life within an aquatic environment starts to slowly die out due to light being prevented from reaching the plants)
- The dam traps sediment, causing deposition in the reservoir
- River is sediment free downstream. This has changed the ecology and caused habitat loss.
- Erosion has increased
- The dam is thought to be responsible for the extinction of the Yangtze river dolphin (That said, it’s unknown if they are actually extinct. Either way, it has not helped their population.)
- Loss of wildlife
- 91 shoreline collapses
- increased mud slides
Social and cultural impacts include:
- 100s of cultural, archaeological and historical sits destroyed by the water
- 600 km long reservoir destroying the natural beauty and character of the area.
Economically, the area has been affected by:
- the loss of 30,000 hectares of farm land
- sediment trapped by the dam has meant that there is less alluvial soil downstream, and farmers have naturally less fertile land, having to buy fertilisers for their fields.
- East China Sea has suffered reduction in sediment, affecting habitats there (and so fish stocks)
- Fish catches have fallen by 10 ^6 tons annually
- Flooding has caused a permanent loss of coal and metal mines
All of this said, the Three Gorges Dam is better for the PRC than the coal power stations that would otherwise be needed to produce the same amount of energy.
(Image sources: https://geognis.edublogs.org/dp-geography/the-ib-five/china/chinas-three-gorges-dam/ http://www.yangziexplorer.org/destination/three-gorges-dam.html )