Three Gorges Dam

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Three Gorges Dam
Three Gorges Dam
Three Gorges Dam, downstream side.
Official name 长江三峡大坝
Impounds Yangtze River
Creates Three Gorges Reservoir
Locale Sandouping, Yichang, Hubei, China
Maintained by China Three Gorges Project Corporation
Length 2,335 metres (7,661 ft)
Height 185 metres (607 ft)
Width (at base) 115 metres (377.3 ft)
Construction began 1994-12-14
Construction Cost Estimated 180 billion yuan (22.5 billion U.S. dollars)
Reservoir information
Capacity 39.3 cu km 

(9.43 cu mi)
Catchment area 1,000,000 km² (386,102 sq mi)
Bridge information
Carries 598
Geographical Data
Coordinates 30°49′48″N 111°0′36″E / 30.83, 111.01

The Three Gorges Dam (simplified Chinese: 长江三峡大坝; traditional Chinese: 長江三峽大壩; pinyin: Chángjiāng Sānxiá Dà Bà) is a Chinese hydroelectric river dam that spans the Yangtze River in Sandouping, Yichang, Hubei, China. The total electric generating capacity of the dam will reach 22,500 megawatts, at which point it will be the largest hydro-electric power station in the world by capacity. This is the largest project that has been undertaken in China since the Great Wall and the Grand Canal. Several generators still have to be installed; the dam is not expected to become fully operational until about 2011.

As with many dams, there is a debate over costs and benefits. Although there are economic benefits such as flood control and hydroelectric power, there are also concerns about the relocation of over 1,400,000 people who have or will be displaced by the rising waters,[1] siltation that could limit the dam's useful life, loss of numerous valuable archaeological and cultural sites, and significant adverse effects upon animal, fish and vegetation species.

Contents

The dam was originally envisioned by Sun Yat-sen in The International Development of China in 1914. The project was delayed though due to The Chinese Civil War and the Chinese-Japanese War which caused the government to reduce the priority of planned structural developments.

After the 1949 communist victory, the project was revived under the leadership of the People's Republic of China, but the Gezhouba Dam project was begun first. The Three Gorges Dam was approved in 1992, and the construction started on December 14, 1994. The dam was expected to be fully operational in 2009, but due to additional projects such as the underground powerplant with 6 additional generators, and due to the complexity of the ship lift, it is still uncertain when the dam will be fully operational.

The dam wall is made of concrete and is about 2,335 metres (7,661 ft) long, and 185 metres (607 ft) high. The wall is 115 metres (377.3 ft) wide on the bottom and 40 metres (131.2 ft) wide on top. The project used 28,000,000 m³ (36,600,000 cu yd) of concrete, 463,000 metric tonnes of steel, enough to build 63 Eiffel Towers, and moved about 134,000,000 m³ (175,000,000 cu yd) of earth.

The reservoir that Three Gorges Dam creates is over 600 kilometres (373 mi) long and 1.12 km wide on average, and contains 39.3 billion cubic meters (9.43 cubic miles) of water, when the water level is at 175 m.

Three Gorges Dam Turbine
Three Gorges Dam Turbine

When finished, the project will have cost no more than 180 billion yuan , 20 billion yuan less than the initial estimated budget of 203.9 billion yuan. This calculation accounts for the effect of inflation, and the lower costs are attributed to a low inflation rate in recent years.[2] It is estimated that the cost of construction will be recovered when the dam generates 1000 TWh of the electricity, which will be sold at the price of 250 billion yuan. This will take 10 more years after the dam starts full operation. Sources for funding include the Three Gorges Dam Construction Fund, revenue from Gezhouba Dam, policy loans from the China Development Bank, loans from domestic and foreign commercial banks, corporate bonds, and revenue from Three Gorges Dam before and after it is fully operational, with additional charges for electricity contributing to the Three Gorges Construction Fund. The additional charges are as follows: Every province receiving power from the Three Gorges Dam has to pay an additional charge of ¥7.00 per MWh. Provinces that will not receive power from the Three Gorges Dam have to pay an additional charge of ¥4.00 per MWh. Tibet does not have to pay any additional money.[3]

Electricity production in China by source. Compare: The fully completed Three Gorges dam will add about 100 TWh of generation per year.      thermofossil      hydroelectric      nuclear
Electricity production in China by source. Compare: The fully completed Three Gorges dam will add about 100 TWh of generation per year.      thermofossil      hydroelectric      nuclear

The Three Gorges Dam is the world’s largest hydro-electric power station by total capacity, which will be 22,500 MW. It will have 34 generators in total. 32 of them are main generators, each with a capacity of 700 MW; and the other two are plant power generators to power other 14 generators, each with capacity of 50 MW. Fourteen are installed in the north side of the dam, twelve in the south side and the remaining six in the underground power plant in the mountain south of the dam. After completion, the expected annual electricity generation would be over 100 TWh, 18% more than originally predicted 84.7 TWh, since 6 more generators are added to the project in 2002. It could support four cities the size of Los Angeles.

According to The National Development and Reform Commission of China, the average consumption of coal to produce one kWh of electricity in China is 366 grams (2006).[4] Therefore, the Three Gorges Dam will potentially reduce the coal consumption by 31 million tons per year, cutting the emission of 100 million tons of greenhouse gas,[5] millions of tons of dust, 1 million tons of sulfur dioxide, 370 thousand tons of nitric oxide, 10 thousand tons of carbon monoxide and a significant amount of mercury into the atmosphere.[6]

The 14 generators in north side of the dam have already been installed and they first ran to full power (9800 MW) on October 18, 2006 after the water level had been raised to 156 m.[7]

Six generators on the south side of the dam are currently being installed, with another 6 already completed. The sixth generator in the south side (No. 20) started working on Dec. 7 2007. It brought the total capacity of the dam to 14.1 GW, surpassing the generating capacity of Itaipu(14.0 GW), to became the largest hydroelectric power plant in the world. The underground power plant and its six generators are still under construction.[8] [9]

Until December 7, 2007, the Three Gorge Dam Project had generated over 205 TWh of electricity, more than one fifth the amount it needs to generate to cover the cost(1000 TWh, see the section "Costs and funding sources").[10] [11]

Three Gorges Dam (left), Gezhouba Dam (right).
Three Gorges Dam (left), Gezhouba Dam (right).
Annual Production of Energy
Year Number of
installed units		 GWh
2003 6 8,607
2004 11 39,155
2005 14 49,090
2006 14 49,250
2007 20 59,000
Total 20(32) 205,000

The electricity generated by the Three Gorges Dam project is sold to the State Grid Corporation and China South Power Grid Corporation at a rate of ¥250 per MWh ($32.5 US). Nine provinces and two cities consume the power from it, including Shanghai.
The power distribution and transmission of the Three Gorges Dam project cost about 34.387 billion Yuan. It was completed in December 2007, one year ahead of time.[12]

Power is sent in three directions. The 500 kV DC transmission line to the East China Grid has a capacity of 7,200 MW. There are three 500 kV DC transmission lines: HVDC Three Gorges-Shanghai(3,000 MW), HVDC Three Gorges-Changzhou(3,000 MW) and HVDC Gezhouba - Shanghai(1,200 MW). The 500 kV AC transmission line to Central China Grid has a capacity of 12 GW. The other 500 kV DC transmission line HVDC Three Gorges-Guangdong to South China Grid has a capacity of 3,000 MW and supplies Guangdong.

In the original plan, it was expected to provide 10% of electricity consumption in China. However, China’s demand for electricity has increased at a higher rate than was planned, and if fully operational now, it would support about 3% of the total electricity consumption in China.[13]

The most significant function of the dam is to control flooding, which is a major problem of a seasonal river like the Yangtze. Millions of people live downstream of the dam, and many large and important cities like Wuhan, Nanjing and Shanghai lie next to the river. Plenty of farm land and the most important industrial area of China are built beside the river.

In 1954, the river flooded 47.75 million acres (193,000 km²) of land, killing 33,169 people and forcing 18,884,000 people to move. The flood covered Wuhan, a city with 8 million people, for over three months, and the Jingguang Railway was out of order for more than 100 days.

In 1998, a flood in the same area caused damage to the value of billions of dollars. The Chinese government asked for support from its military to fight the flooding. Two thousand and thirty-nine square kilometers of farm land was flooded. The flood affected more than 2.3 million people, and 1,526 were killed.[14]

The reservoir's flood storage capacity is 22 cubic kilometers (18 million acre feet). This capacity will reduce the frequency of major downstream flooding from once every 10 years to once every 100 years. With the dam, it is expected that major floods can be controlled. If a "super" flood comes, the dam is expected to minimize its effect.

Ship locks for river traffic to bypass the Three Gorges Dam, May 2004
Ship locks for river traffic to bypass the Three Gorges Dam, May 2004

The installation of ship locks is intended to increase river shipping from 10 million to 50 million tonnes annually, with transportation costs cut by 30 to 37%. Shipping will become safer, since the gorges are notoriously dangerous to navigate. Each ship lock is made up of 5 stages taking around 4 hours in total to complete. Critics argue, however, that heavy siltation will clog ports such as Chongqing within a few years based on the evidence from other dam projects.

The locks are designed to be 280 m long, 35 m wide, and 5 m deep (918 x 114 x 16.4 ft).[15][16] That is 30 m longer than those on the St Lawrence Seaway, but half as deep.

In addition to the canal locks, the Three Gorges Dam is equipped with a ship lift, a kind of elevator for vessels. The ship lift will be capable of lifting ships of up to 3,000 tons.[17][18][19] In the original plan its capacity was to be 10,000 tons. The ship lift was not yet complete when the rest of the project was officially opened on May 20, 2006.[20][21] On October 3, 2006, China Daily predicted that the shiplift would be completed in 2008.[22]

The relocation of local residents is the central part of the Three Gorges Dam Project. It is considered as important as the construction of the dam. During the planning stages in the 1990s, it was estimated that 1.13 million residents would be forced to relocate. That estimate has been increased by nearly 25% to 1.40 million people，which is about 1.5% of the total population of Hubei Province (60.3 million) and Chongqing City(31.44 million) where the reservior is located. About 140,000 residents will be relocated out of Hubei province to eastern provinces and some central provinces, and the majority of the remaining people will be relocated within Hubei Province.

On one hand, the massive relocation demonstrates the Chinese government's determination and will to complete the huge project. On the other hand, widespread corruption and human rights violations have occurred throughout the process. Although most of the residents have been properly relocated, there remains a significant number of residents who haven't received the necessary government assistance and are still living in poor conditions.

Through September 2007, 1.22 million people have been relocated according to the Xinhua Net. This amounts to about 1.3% of the population of the two provinces the reservoir covers. The fourth phase of the relocation is still ongoing. Phase four involves moving people living just below the 175 metre water level.

As of 13 October 2007, an estimated 1,400,000 citizens have been displaced and, with government assistance, have settled in neighbouring areas.[23] On October 11, 2007, Chinese state media announced that under a development plan of Chongqing city, an additional 4 million people will be encouraged to move from their homes near the dam to the Chongqing metropolitan area by the year 2020.[24][25][26]

Currently, the quality of water in the higher banks of Yangtze is falling slowly, due to the dam's preventing dispersal of pollutants; algal blooms have risen progressively since the dam’s construction; and soil erosion has increased, causing riverbank collapses and landslides.[27] The report detailing this was officially released in September 2007.[23] Senior Chinese government officials and scholars said the dam could cause a “huge disaster ... if steps are not taken promptly.”[27] The same scholars and officials previously had defended the Three Gorges Dam project.[28] Xinhua News Agency also reported that tens of billions of yuan had been spent to prevent pollution and geological disasters by tree planting, measures to maintain biodiversity, shutting 1500 polluting industrial and mining enterprises and building 70 sewage and waste treatment plants, all of which are "progressing well." [28]

Three Gorges Dam
Three Gorges Dam

Of the 3,000 to 4,000 remaining critically endangered Siberian Crane, a large number currently spend the winter in wetlands that will be destroyed by the Three Gorges Dam.[29] While logging in the area was required for construction which adds to erosion, stopping the periodic and uncontrolled flooding of the river will lessen bank erosion in the long run. The build up of silt in the reservoir will, however, reduce the amount of silt transported by the Yangtze River to the Yangtze Delta and could reduce the effectiveness of the dam for electricity generation and, perhaps more importantly, the lack of silt deposited in the peninsula could result in erosion and sinking of coastal areas[citation needed].

The 600 kilometre (375 mi) long reservoir has or will flood some 1,300 archaeological sites and alter the appearance of the Three Gorges as the water level rises over one hundred meters at various locations.[citation needed] Cultural and historical relics are being moved to higher ground as they are discovered but the flooding of the Gorge will undoubtedly cover some undiscovered relics. Some other sites cannot be moved because of their location, size or design. For example the hanging coffins site high in the Shen Nong Gorge is inherently part of the sheer cliffs themselves.[30]

These historical sites contain remnants of the homeland of the Ba, an ancient people who settled in the region more than 3000 years ago.[31] One of the traditions of the Ba was to bury the dead in coffins in caves high on the cliff, some of which are submerged and others will soon be submerged.[30]

There are two hazards uniquely identified with the dam:[32] One is that sedimentation projections are not agreed upon, and the other is that the dam sits on a seismic fault.

Excessive sedimentation can block the sluice gates which can cause dam failure under some conditions. This was a contributing cause of the Banqiao Dam failure in 1975 that precipitated the failure of 61 other dams and resulted in over 20,000 deaths. Critics believe that the Yangtze will add 530 million tons of silt into the reservoir on average per year; in time, this silt could accumulate behind the walls of the dam, clogging the turbines' entranceway. Further, the absence of silt down stream would have two dramatic effects:

  • Unburdened by silt, the Yangtze below the dam would flow more quickly[citation needed]. This, in turn, would cause the river to scour the banks and riverbed more severely, even to the point of altering the character and predictability of the river itself. In addition, flood diversion dikes along the river would require expensive and continual re-strengthening and rebuilding.
  • The city of Shanghai, more than one thousand miles (1600 km) away from the dam, rests on a massive plain of sediment. The "arriving silt -- so long as it does arrive -- strengthens the bed on which Shanghai is built... the less the tonnage of arriving sediment the more vulnerable is this biggest of Chinese cities to inundation..."[33]

Also, the weight of the dam and reservoir can cause induced seismicity, which occurred with the Katse Dam in Lesotho. They Benthic sediment build up is a cause of biological damage and reduction in aquatic biodiversity.

In an annual report to the United States Congress, the Department of Defense cited that in Taiwan, “proponents of strikes against the mainland apparently hope that merely presenting credible threats to China’s urban population or high-value targets, such as the Three Gorges Dam, will deter Chinese military coercion.”[34] The notion that the Military of the Republic of China would seek to destroy the Dam provoked an angry response from the mainland China media. People’s Liberation Army General Liu Yuan was quoted in the China Youth Daily saying that the People’s Republic of China would be “seriously on guard against threats from Taiwan independence terrorists”.[35]

In order to maximize utility of the Three Gorges Dam and cut down on sedimentation from the Jinsha a tributary of the Yangtze river, China plans to build a series of dams upstream of the Yangtze river, including Wudongde, Baihetan, Xiluodu Dam, Xiangjiaba, and downstream of Jinsha. The total capacity of those four dams is 38,500 MW, almost double the capacity of the Three Gorges. There are also another eight dams in the midstream of the Jinsha and eight more upstream of it.[36]

  • In Max Brooks’ novel World War Z, the large artificial lake upstream of the Three Gorges Dam is the site of the initial zombie outbreak before the war; a superstitious character suggests that the outbreak is a retribution for the destruction of ancient holy sites. Later in the novel, the Dam is overrun by zombie hordes, which make the emergency pressure release valves impossible to reach. This eventually results in the Three Gorges Dam rupturing, resulting in a massive tsunami which races to the ocean, destroying what remains of Wuhan, Nanjing, and Shanghai.[citation needed]
  • Jia Zhangke’s film, Still Life, describes the destiny of two couples with connections to the dam.
  • In the novel Dragon Bones by Lisa See, a murder investigation takes place at the Three Gorges Dam.
  • In the video game Civilization IV Three Gorges Dam is a World Wonder, providing power to the entire continent
  • In Matthew Crawfords book, 'The Yangtze River', the Three Gorges dam is used to describe how the Chinese are industrialising this part of the country.

Three Gorges Dam, downstream side

Inside a lock of the Three Gorges Dam

Three Gorges Dam, upstream side

  1. ^ Tony Cheng, Bitter memories above the Yangtze, Aljazeera, updated dec 9, 2007)
  2. ^ "Brief explanation of TGP", CTGPC, 20 May 2006. Retrieved on 2007-05-27. (Chinese) 
  3. ^ Three Gorges Dam (Chinese). China Three Gorges Project Corporation (April 20, 2003). Retrieved on 2007-04-29.
  4. ^ Three Gorges Dam (Chinese). NDRC (March 7, 2007). Retrieved on 2007-05-15.
  5. ^ Greenhouse Gas Emissions By Country. Carbonplanet (2006). Retrieved on 2007-05-16.
  6. ^ Three Gorges Dam (Chinese). TGP (June 12, 2006). Retrieved on 2007-05-15.
  7. ^ Three Gorges Dam (Chinese). Government of China (October 18, 2006). Retrieved on 2007-05-15.
  8. ^ Three Gorges Dam (Chinese). Xinhua (Oct 22, 2007). Retrieved on 2007-10-22.
  9. ^ Three Gorges Dam (Chinese). Xinhua (Dec 8, 2007). Retrieved on 2007-12-8.
  10. ^ Three Gorges Dam (Chinese). TCGPC (Nov 2, 2007). Retrieved on 2007-11-2.
  11. ^ Three Gorges Dam (Chinese). Xinhua (Dec 8, 2007). Retrieved on 2007-12-8.
  12. ^ Three Gorges Dam (Chinese). National Development and Reform Commission (Dec 20, 2007). Retrieved on 2007-12-20.
  13. ^ Three Gorges Dam (Chinese). Chinese Society for electrical engineering (May 25, 2006). Retrieved on 2007-05-16.
  14. ^ Three Gorges Dam (Chinese). CTGPC (April 20, 2002). Retrieved on 2007-06-03.
  15. ^ Three Gorges Dam. Missouri Chapter American Fisheries Society (April 20] 2002). Retrieved on 2007-01-28.
  16. ^ Its Buildings with Biggest Indices. China Three Gorges Project (2002). Retrieved on 2007-01-28.
  17. ^ Three Gorges Shiplift resurfaces. Three Gorges Probe (November 7, 2003). Retrieved on 2007-01-28.
  18. ^ "China's west seeks to impress investors", BBC, May 4, 2005. Retrieved on 2007-01-28. 
  19. ^ Ship lift work to begin at Three Gorges site,. Three Gorges Probe (March 23, 2005). Retrieved on 2007-01-28.
  20. ^ "Three Gorges dam ready to go", Taipei Times, May 21, 2006. Retrieved on 2007-01-28. 
  21. ^ "China Completes Three Gorges Dam", CBS News, May 20, 2006. Retrieved on 2007-01-28. 
  22. ^ "300,000 more to be relocated from Dam region", China Daily, October 3, 2006. Retrieved on 2007-01-28. 
  23. ^ a b MWC News, Agency reports, "China dam to displace millions more, October 13, 2007, retrieved October 13, 2007.
  24. ^ BBC News, "Millions forced out by China dam", October 13, 2007, retrieved October 13, 2007.
  25. ^ Xinhua, "Millions more face relocation from Three Gorges Reservoir Area", October 11, 2007, retrieved October 14, 2007.
  26. ^ Xinhua, "China warns of environmental "catastrophe" from Three Gorges Dam", September 26, 2007, retrieved October 14, 2007.
  27. ^ a b "China's Three Gorges Dam Under Fire", Time, October 12, 2007. 
  28. ^ a b Mary Ann Toy, The Age AU, "Three Gorges Dam 'could be huge disaster'", October 13, 2007, retrieved October 13, 2007.
  29. ^ American University, Three Gorges Dam Case Study, Washington DC
  30. ^ a b C.Michael Hogan, Shen Nong Gorge Hanging Coffins, The Megalithic Portal, Andy Burnham: editor
  31. ^ Terry F. Kleeman, Great Perfection: Religion and Ethnicity in a Chinese Millennial Kingdom, ISBN 0-8248-1800-8
  32. ^ Topping, Audrey Ronning. Environmental controversy over the Three Gorges Dam. Earth Times News Service.
  33. ^ Winchester, Simon, The River at the Center of the World, Henry Holt & Co. New York (1998) p.228
  34. ^ Annual report on the military power of the People's Republic of China (.pdf). US Department of Defense. Retrieved on 2007-01-28.
  35. ^ "Troops sent to protect China dam", BBC, Tuesday, September 14, 2004. Retrieved on 2007-01-28. 
  36. ^ Water Power Magazine, "Beyond Three Gorges in China", January 10, 2007, retrieved October 13, 2007.

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