Three Gorges Dam

Three Gorges Dam. Source: China Absolute Tours, 2012

Hydroelectric power has huge potential to play in increasing the development of renewable energy. The power of water is strong and many other benefits, like flood control, can be reaped from a dams construction.

One such project that has aimed at capturing this energy whilst also implementing many other benefits is the Three Gorges Dam that was built across the Yangtze River in the Hubei province of China. It took 15 years in construction and although officially completed in 2006 it was not fully operational until July 2012, when the last 32 hydropower generators went in to action. The dam is the worlds largest power station and is hailed as one of the great construction feats of the 21st century; symbolizing China's engineering prowess. 

Location map of the Three Gorges Dam. Source: ecobuddhism.com

It is more than 2km in length and has a height of 185 metres (Chaudhuri, 2003). With the functioning of the last turbines the combine generating capacity has been increased to 22.5 gigawatts, amounting to 11% of China's total hydropower capacity (BBC News, 2012).

Water being realised through the Dam after heavy flooding. Source: Clark 2012.

Benefits

- Hydroelectric Power. The rate of energy production, equivalent to burning 11,000 barrels of oil per hour, is enough to supply Beijing with power for one year. By 2020 15% of total energy production is to be from renwable resources (BBC, 2012). This is a large step towards the aim.

- Flood Control. In 1998, a flood of such catastrophic level in the Three Gorges area caused 4,000 casualties, left 14 million people homeless, and created $24 billion in economic loss. The dam can be used to prevent such tragic events. The dam can also be harnessed to alleviate drought risk upstream. 

- Navigation. Yangtze River trade, which counts for 80% of China's inland shipping,  possibilities have been boosted. This new transportation system is said to cut transport costs by one third and increase shipping on the Yangtze from 3 million tons to 50 million tons per year (Bosshard, 2009)

Two barges inside the 9 story high ship lock. Source: Chinadaily.com

- Huge investment and creation of thousands of jobs.

- Engineering feat, recognised Worldwide. 

Negative Implications

- 1.24 million people were displaced. Compensation was offered from the Government but it has been argued that this has not been enough. The Government have not been able to keep up to their promise of rehousing all affected people and it has become clear that with such a large population space would be limited. The compensation is said to be with many local officials.

Reservoir flooding. Source Yang, 2006

- Slope instability in the basin. (Bosshard, 2009)

- River pollution. (Bosshard, 2009). During construction the River became stagnent and this caused the pollution and dirt in the water to become trapped. Millions of tons of raw sewage has been trapped from the city of Chongqing. 

- Reservoir has immersed villages, ancient temples, burial grounds and canyons that were a major tourist attraction. Although the Dam itself will have generated more tourism than these it is argued. 13 cities, 140 towns and 1350 villages were submerged in total (BBC, 2012). 

- Many species have been endangered. The Yangtze River dolphin for example.

- Sediment retainment. The dam will 70% of the sediment discharge from the upper reaches of the river in the first two decades after 2009; over its first 100 years, the reservoir behind the dam is expected to retain more than 44% of the river’s sediment from the upper reaches (Yang et al. 2006).

- Huge cost. It is not known exactly how much the dam cost overall. Some estimate $27.2 billion and the Government insist the project was built within budget. Others claim that many costs do not appear in the official calculations, and that the project may cost up to $88 billion (Bosshard, 2009).

The dam is an incredible example of technical engineering and modern technology.

Documentary on the Dam 

References:
BBC News (2012) 

Bosshard, P. (2009) "Lessons from China’s Three Gorges Dam," The Asia-Pacific Journal, 48-2-09

Chaudhuri, A. (2003) Three Gorges Dam, MURJ, 8, 31-36.

China Absolute Tours (2012) Three Gorges Dam [online] Available at: http://www.absolutechinatours.com/Yangtze-River-attractions/Three-Gorges-Dam.html [accessed on 28th February 2013]

Clark, E. (2012) Breathtaking force: World's most powerful dam opens in China as gushing water generates the same power as fifteen nuclear reactors, Mail Online, [online]25th July. Available at: http://www.dailymail.co.uk/news/article-2178951/Three-Gorges-Worlds-powerful-dam-opens-China-gushing-water-generates-power-15-nuclear-reactors.html [accessed on: 28th February 2013]

Yang, Z., Wang, H., Saito, Y., Milliman, J., Xu, K., Qiao, S. and Shi, G. (2006) Dam impacts on the Changjiang (Yangtze) River sediment discharge to the sea: The past 55 years and after the Three Gorges Dam, Water Resources Research, 42.