Erik Hankins
History of Dams-
This link leads to an article that explains the evolution of the dam from early egyptian times to modern times. The dam evolves from primative gravity and earth dams to the widely used multiple arch dams. It goes into how the first dams in America were built in California and continued to evolve there.
http://cee.engr.ucdavis.edu/faculty/lund/dams/Dam_History_Page/History.htm
Background-
The Three Gorges Dam was first proposed in 1919 by Sun Yat-sen for flood prevention (1). For thousands of years the Yangtze River has been flooding farmers' land and causing great damage (2). Supporters of the dam agree that it would decrease damage by floods downstream, thus saving money in the process (3). This proposal of such a large dam had many people questioning if it could be done, or even if it was completed, if it would be worth it (3). Many years went by, and many attempts by leaders and governments took place to start the planning of the dam, but construction of the dam did not start until December 14, 1994 (1). Such a great project costs billions and billions of dollars (approximately 39 billion U.S. dollars), which is a substantial amount of money for any structural project (2). This is especially a great cost when taking into account that many citizens of China do not agree with the project.
Scale of the project-
(Courtesy of Wikipedia (1))
The dam wall is made of concrete and is about 2,309 meters (7,575 ft) long, and 101 meters (331 ft) high. The wall is 115 meters (377.3 ft) thick on the bottom and 40 meters (131.2 ft) thick on top. The project used 27,200,000 cubic meters (35,600,000 cu yd) of concrete, 463,000 tonnes of steel, enough to build 63 Eiffel Towers and moved about 102,600,000 cubic meters (1.342E+8 cu yd) of earth.
When the water level is maximum at 175 meters (574 ft) over sea level (91 meters (299 ft) above river level), the reservoir created by the Three Gorges Dam is about 660 kilometers (410 mi) in length and 1.12 kilometers (0.70 mi) in width on average, and contains 39.3 cu km (9.43 cubic miles) of water. The total surface area of the reservoir is 1045 km². The reservoir will flood a total area of 632 km² of land compared to the 1,350 km² of reservoir created by the Itaipu Dam. The Three Gorges Dam reservoir is longer than the 560 kilometers (348 mi) length of Lake Superior, but only 1.1 % of the surface area of the lake (82,400 km²) and about 1/700 of the volume of the lake (28700 cu km).
The Government Prospective-
The Sanzia was well appreciated and supported by many senior and professional officials. The claim was that it was going to improve hydroelectric energy, flood control, and the people’s safety. The knowledge of the dam producing 84,000million KWh played a major roll. To match this amount of power would be the equivalent to fourteen 1200 MW thermal power plants or over forty-five million coal plants. There are going to be some positive and negative aspects of the Dam which show us the true meaning of what the government’s true plans were.
Hydroelectric generation power is looking more positive than negative. The dam is expected to have 17,680MW. After construction the first two generators will be fully operating for nine years. One claim stated that the dam at full power could cover 1/8 PRC’s 1991 electric supply. The Three George Dam will be combined with the Gezhouba Dam an extra 400MW making it even more powerful. Also with future plans of their hydroelectricity, the Dam has to be built other wise the demand will never be made. This also puts the Three George to be the largest hydroelectric plant of its time.
Some have negative feelings about the hydroelectricity potential not being able to match up to the effectiveness. Some believe this because of the distance the electricity has to travel all the way across China. With this distance there will be a considerable amounts wasted, some speculate. There also would be twelve years before generation, means that the dam will not be able to solve immediate energy problems. China is not in a good situation with money at the moment either. Many thought the budget should be spent on smaller projects dealing with up stream dams not dealing with then main channel.
In 1991, the official reason or purpose would be for stronger flood prevention. Cause every ten years they have an annual flood on the Chang River. In 1981 flood left 1.13 million homeless, but in 1991 the death toll was around 3,075. Also in 91 there was 82,100 million yuan about twenty-five percent of the Chinese budget. Over 230 million people were affected by the flood that year.
There are many advantages expected of the Three George Dam, one being the flood water storage capacity. Able to support 22,150 million meters cubed fifty-six percent of the valley’s upstream area surface will be affected. This will protect over fifty million people claimed by Gue Shuyan in Edmonds article. With new protection the Chinese save 970 million annually dealing with flood control expenses. Even with the worst conditions of the 1000 year flood the dam and dikes, Jianghan Plain, minim damages would be obtained.
The negatives of the flood protection would be are kind of hard to point out being a flawless structure. One of the only clams I’ve came across was said to be right below the dam there is a weakness. Cause the numbers of tributaries which inter the Chang River in the middle an lower reigns have possible flooding of Chosngquing stated y Zou Jianva in Edmonds article. The dam could also create a under cut to the dikes downstream. The failure of the dikes would cause a substantial amount of damage.
Another positive aspect of the government’s views on the population is the idea that the resettlement of the reservoir population is the key to the success of failure. Most government officials believe it’s the best position dealing with population, and understand that this is a 20 year migration process. Also with the population mainly consist of peasants the moving wouldn’t hurt many agricultural zones. Funds toward movers which pretty much put them in a program to teach them construction to help productivity.
Last the resettlement of the people there is a lot of cons towards their part. If the dam’s reservoir rose to 175 meter there would be 725,000 people an in estimated three hundred people per kilometer squared in 1992 would have to be relocated. In estimated 1.13 million will need to be relocated by the year 2008 though some say around then the population growth might be up to 1.4-1.6 million people. A third of the projects budget is on the resettlement, which a third of those people are still poor and starving.
Last, another bad aspect of the money and the people moving about. A study of the population transfers, an experiment which started around 200 million yuan. This adds to the one third of the budget going towards the resettlement. A lot is going to be under water starting with one hundred forty market towns and one hundred thirty nine power stations. This also brings up to six hundred and fifty seven factories and mining sights with include over 950 kilometers of roads.
The government had many things on their mind when dealing with the construction of the Three Georges dam. The sole purpose was for the people and the flood but the electricity became a positive aspect of the dam. Every pro comes with a con and in this short article u can see the differences of the hydroelectric, flood control, and the resettlement of the peasant. In this government case the consequences don’t seem too dramatic and fine in their opinion. In my belief it was the right decision to fallow though with construction in this circumstance because it’s protecting the people in the long run.
Cons- (Sources 4-8)
Relocation
Thirteen cities, 140 towns and 1,300 villages will be underwater due to the construction and reservoir. This could include upwards of 10-12 million people. One-third of the citizens already moved are at a disadvantage because of it. (5)
Cost effective?
China is already in an internal debt of 30,000 million US dollars. The foreign debt is only 52 million, but both figures are predicted to increase as the construction continues. This brings up questions as to when the Dam will actually repay its construction and maintenance costs. (6)
Environmental effects/problems
The Yangtze River is known to have a large amount of silt in it (8). This is what gives the river its tan color. If this silt were to pile up at the upstream wall of the dam, it could create a large amount of pressure which could eventually break the walls. It will require a lot of manpower and resources to keep this problem under control. (4)
Earthquakes are very possible in the area where the dam is being built. The dam is built to withstand an earthquake up to 5.5 on the Richter scale. However, earthquakes as high as 6.5 on the Richter scale have been recorded. This would cause a very large flood in the areas downstream from the dam. (4)
Also, there are two species native to the area that could very well become fully extinct from the project. The Yangtze River Dolphin has not been sighted for many years, and is thought to be extinct already because of the river traffic. Also, the Yangtze River Sturgeon could become extinct with such a large part of their habitat being altered. (7)
_____River Sturgeon __________________River Dolphin____
Alternative
The Most common alternative to the Three Gorges Dam, besides no dam at all, is the construction of several smaller dams. There are many tributaries in the gorge that would be suitable for smaller dams. This would create less of a hold on river traffic, put less of a burden on the wildlife in the Yangtze River, and create more jobs. It wouldn’t cause near as many people to be relocated either.
Conclusion-
The Three Gorges Dam is seen to be a huge controversy. Maybe this is not rightfully so. I do believe that there could have been an alternate way to deal with energy and water shortages, but the overall idea to build a huge dam to reverse some limiting resources and make many people's lives easier was justified. The idea to create a smaller dam (or more than one) would let China develop better technology and techniques to help with the energy problem. This would save some money and decrease the risk of such a loss. But, under the specific circumstances that China is going through I believe that the decision to construct the dam was not a bad one. This subject is very important, but should not be a gigantic controversy, yet. If the dam succeeds due to proper design, construction, and maintainance then it will bring great benefits to many people. Is it a risk? Yes, very much so, but its possible benefits are great.
Related Links-
These links provide more information on big dams and there possible effects on their surroundings.
http://www.commondreams.org/archive/2008/07/14/10340
http://www.guardian.co.uk/commentisfree/2006/may/19/post103http://internationalrivers.org/en/africa/big-dams-bringing-poverty-not-power-africa
http://www.irrawaddy.org/article.php?art_id=3769
http://www.americanscientist.org/bookshelf/pub/damning-big-dams
http://findarticles.com/p/articles/mi_m2465/is_1_31/ai_70910940
Works Cited-
1) (2008). "Three Gorges Dam." Wikipedia,
<http://en.wikipedia.org/wiki/Three_Gorges_Dam> (Nov. 10, 2008).
2) Wertz, R. R. (2008). "Special Report, Three Gorges Dam." Exploring Chinese History, <http://www.ibiblio.org/chinesehistory/contents/07spe/specrep01.html> (Nov. 9, 2008).
3) Yang, L. (2007). "China's Three Gorges Dam Under Fire." Time, <http://www.time.com/time/world/article/0,8599,1671000,00.html> (Nov. 9, 2008).
4) Edmonds, Richard Louis. (1992) The Sanxia (Three Gorges) Project: The Environmental Argument Surrounding China's Super Dam. pp. 117-22.
5) Boxer, Baruch. (1988) China's Three Gorges Dam: Questions and Prospects.
6) (2008). "Yangtze River Dam." China Highlights, <http://www.chinahighlights.com/yangtzeriver/> (Nov. 11, 2008).
7) (2006). "Study: Yangtze River Dolphin May Have Gone Extinct." FOX News, <http://www.foxnews.com/story/0,2933,236326,00.html> (Nov. 13, 2008).
8) (2008). "Great Wall Across the Yangtze." PBS, <http://www.pbs.org/itvs/greatwall/dam1.html> (Nov. 13, 2008).
