Three Gorges - the Three Gorges Dam
The Three Gorges Dam site is 27 miles upstream from Yichang City proper, at Sandouping Town, 38km upstream from the Gezhouba Dam Lock, inside the third of the Three Gorges. It is planned to be by far the largest hydroelectric project in the world. The Project calls for the construction of a concrete dam, a hydroelectric power plant and a series of locks just below the scenic Three Gorges region.
The project is designed to be built in three phases and was scheduled for completion in year 2009. Upon arrival at Sandouping, passengers will take a bus across the Three Gorges Bridge, which leads toward the top of Three Gorges Project the hill for a birds-eye view of the construction from the observation deck. Visitors will observe the five-step ship lock, the diversion canal, the dam in construction, and the power station. English speaking professional guides will be on hand to provide detailed information on the history of the dam and facts on its construction. In addition, an exhibition room displays a model of the dam, and offers passengers another opportunity to ask questions and learn about the benefits of this amazing project.
One of the largest construction projects ever undertaken in the world, the Three Gorges Project will forever change the face of the Yangtze River as we know it today. Possessing comprehensive utilization benefits mainly for flood control, power generation and navigation improvement. It will be a vital important and backbone project in harnessing and developing of the Yangtze River. Measures have been taken to preserve and move the historical and cultural relics found along its banks; however many scenic spots will be adversely affected.
The most dramatic section of the river, what we refer to as "the heart of the Yangtze"-the area from the Three Gorges all the way upstream to Chongqing-will eventually be drowned by the completion of the Three Gorges Dam, an integral part of the Three Gorges Project.
Although a Yangtze River cruise takes guests to a variety of destinations, one of the excursions well worth the visit is to the Three Gorges Dam. This hydropower dam is the largest in the world. Being able to use water for generating power is vital to the Chinese people. Unfortunately, the construction of the dam displaced more than one million people from a number of nearby towns and cities.
Initially, Three Gorges Dam was the vision of Sun Yat-Sen dating back to 1919 but only in April of 2009 was the dream to become a fully functioning reality. Today, some scientists, engineers, researchers, and world governments have raised concern over the Three Gorges Dam, believing this project is a disaster waiting to happen. However, other experts have helped fund the project, believing it is an example of how hydropower can be used for generating power on a massive level.
Already, 30% of the cost for construction has been recouped, estimated at 39 billion USD, with the dam having a capacity of generating 300 TWh of electricity. Consisting of 32 primary generators, this dam has stamped a place in history specific to engineering. The massive turbines are specially designed to help navigate the flow of the river, improve electricity production, lower risk of downstream flooding, and even reduce greenhouse gases.
One of the main challenges for the Chinese people is the high degree of pollution. To help cut back on the amount of coal required to generate electricity, the Three Gorges Dam has a significant and positive impact, reducing coal usage by more than 30 million tons! In addition, water pollution is another serious problem in China. With the development of new water treatment plants, as much as 65% of dumped water is treated.
Keep in mind, cities such as Nanjing, Shanghai, and Wuhan where millions of people live are located downstream from the Three Gorges Dam and with farming being a prime industry and resource throughout China, being able to control flooding is imperative. With the new dam, experts state that major flooding to these and other cities would be dramatically reduced. This way, past flooding to include the 1954 and 1998 Yangtze River flood would be avoided.
The design of the Three Gorges Dam is unique, divided into a left and right side, allowing water to flow from the top left to the bottom right portion. As you look at the dam, you will only see the impressive structure but not the underlying components to include the underground power plant. The wall of the dam was built from 35,600 cubic yards of concrete, as well as 456,000 tons of steel. To give you a perspective, the materials used would have been enough to construct 63 Eiffel Towers!
No matter the controversy that may involve the Three Gorges Dam, this is a site worth visiting. The dam stretches 7,661 feet long, 331 feet high and 377 feet wide at the base, towering over nearby cliffs and peaks that reach more than one mile high. Controlling the Wuxia Gorge, Xiling Gorge, and the Outang Gorge, the Three Gorges Dam plays an important role for the Chinese people. In addition to controlling the Yangtze River, the third largest river in the World, you will find the view from the dam simply stunning. Yichang airport has about 10 flights a day in/out major airports in China.
Layout of Three Gorges Dam
Spillway
The Three Gorges Project is designed with a concrete gravity dam with a crest elevation of 185 meters and maximum height of 175 meters. The dam axis runs 2, 309. 47 meters long, which is even longer than the noted Grand Coulee Dam of US.
The 483-meter spillway, located in the middle of the main dam, has 23 bottom outlets dimensioned at 79 meters. Each of its 22 surface sluice gates measures 8 meters wide. The maximum discharge capacity of the TGP is 116,000 cubic meters, the biggest in the world.
Left Powerhouse
Two powerhouses, flanking the spillway, accommodate altogether 26 sets of turbine-generators. As the world's biggest unit ever made, each has a generating capacity of 700MW. The 643.6-meter-long left powerhouse, 60 meters longer than the 584.2-meter-long right one, houses 14 sets of generators. With all these huge generators, the TGP is designed to generate electricity of 84.7 TW/h.
Right Powerhouse
On the right bank, enough room has been preserved for the future underground powerhouse of 6 turbine generator units with 4, 200 MW of installed capacity. The intakes of these units will be constructed simultaneously with the project.
Shiplift
The TGP shiplift is the world's largest. With a one-step vertical hoisting mechanism, the ship lock, equipped with a 120*18*3.5-meter container, is capable of carrying a 3,000-ton passenger liner or cargo boat at a time.
Temporary Ship lock
A temporary ship lock was built during the TGP construction period with an effective chamber at 240*24*4 meters.
Permanent Ship lock
The Three Gorges Project (TGP) permanent ship lock is designed in a two-way, five-step pattern with each lock chamber measuring 280 meters and capable of passing a 10,000-ton barge fleet.
Dam Site
After a long but prudent study on 15 alternatives, the dam site for Three Gorges Project was finally determined at Sandouping, where a number of favorable factors gather at the small town 30 kilometers west to the Yichang city.
Sandoupin has a firm crystalline rock foundation, which is the most important geological condition a massive hydraulic project required of. The River valley here at Sandoupin is much broader than other site alternatives and hills on each sites lower.
A small islet, called Zhongbaodao by locals and cleaving the Yangtze River at its center, offers the most favorable pattern for the river diversion needs scheduled in the first phase of the TGP.
The bedrock of the dam site is sound and intact granite with 100 MPa of compressive strength. The faults and fissures in the bedrock are less developed and most of them are well cemented. The permeability of the rock mass and the weathered layers in the hills on both sides are also ideal.
No potentially devastating geological structures was detected within 15 kilometers of its vicinity. The regional seismic activities are small and not frequent.
World Records of the Three Gorges Project
The world's largest water conservancy project with the biggest flood-control capability
The total storage capacity of the reservoir is 39.3 billion m3 ,of which 22.15 m3 is for flood control. After the completion of the TGP,The flood -discharging capacity of the Yangtze river would be 27,000 to 33,000 m3 /s,thus the floods from the upstream reaches of the Yangtze River could be controlled and the middle and lower reaches of the river,especially in Jinjiang reaches could be regulated or relieved.
The world's largest hydropower station
The total installed capacity of the Three Gorges Hydropower Station is 18,200 MW with an annual electricity output of 84.68 billion KW/h.
The world's largest water conservancy project with the world's largest project building scale
The total length of the dam axis is 2309.37 meters. The spillway section, which is located in the middle of the river course,is 483 meters long in total.There are 26 sets of turbine generator units in total, 700 MW for each.The shiplock is schemed out as a double-way and five-step lock.It is the world's largest water conservancy project with the world's largest project building scale.
The world's largest water conservancy project with the biggest project workload
The earth-rock excavation of the main structure of the project is 134 million m3 and the concrete placement is 27.94 million m3. The installation of reinforcing bar and metal structure is 463 thousand ton and 256.5 thousand ton respectively.
The world's largest water conservancy project with the biggest construction difficulty
The concrete placement of the TGP in 2000 is 5.4817 million m3, 550 thousands m3 for each month ,which created a new world record .It is the world's largest water conservancy project being built with the biggest construction difficulty.
The world's largest water conservancy project with the strongest flood-discharge capability in the world
The maximum flood -discharge capacity of the spillway is 102.5 thousands m3/s, which ranks the top one in the world.
The world's largest water conservancy project with the biggest and the most complicated shiplift in the world
The shiplift is designed as one stage vertical hoisting type with a maximum hoisting distance of 113 meters.the ship container of the shiplift is in a size of 120*18*3.5 m,capable of carrying 3,000 tons of passenger or cargo boat each time.It is the biggest and the most complicated shiplift in the world.
The world's largest water conservancy project with the world's largest and the most arduous resettlement
The total number of the migrants to be resettled of the reservoir area of the TGP may reach 1.13 million by the end, It is the largest and the most arduous resettlement project in the world.
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