Dams and Impounded Rivers - River Dynamics and Integrated River Management - page 437

Jingjiang grand levees and devastating destruction. Simultaneously, by effectively controlling upstream
floods, it is possible to relieve threats to Wuhan, and reduce water and sand discharge into Tongting Lake.
2) Power Generation
Of the many benefits the Three Gorges Project promises, the most direct and most obvious will be its
enormous ability to generate electricity. The hydroelectric station of the Three Gorges Project will be the
biggest in the world, with an installed capacity of about 18,000 MW and an annual generation of 84
billion kwh. It will provide electricity mainly to central and east China and a small amount to the eastern
Sichuan province. The electricity will provide an alternative to the consumption of 40 to 50 million tons
of raw coal or to seven 2.4 million kw thermal power stations.
Coal resources along the Yangtze River are insufficient but water resources are rich. The huge amounts
of energy it would generate could draw high profits and serve to repay loans. Even during the construction
period, accumulated electricity output could reach 435.8 billion kwh and earn about 40 billion Yuan at a
rate of 0.092 Yuan/kwh. After normal operation commences, the annual income of the project from sales
of electricity alone will amount to 7.5 billion Yuan. After all loans are repaid, the project will be able to hand
over 3.56 billion Yuan annually to the state with total profits and taxes turned over to the state treasury
reaching 5.41 billion Yuan.
In addition, the replacement of thermal power stations by the Three Gorges Project will generate
tremendous social benefits and good environmental effects. It will reduce the consumption of coal by 40
million or 50 million tons every year and cut carbon dioxide, sulphur-dioxide, carbon monoxide, and
nitrogen-oxide emissions by 100 million tons, 2 million tons, 10,000 tons, and 370,000 tons, respectively.
It will also greatly reduce the amount of industrial liquid waste and play a great role in cutting sources of
environmental pollution, such as acid rain.
3) Navigation
The Yangtze River, with its mainstream and tributaries running through 18 provinces and municipalities,
provides very favorable water transportation conditions and has always been China's main transport artery
linking its eastern, central, and western regions. Its navigable mileage is more than 70,000 km, accounting
for 70 percent of the nation's inland navigation mileage. Its annual freight volume accounts for 80 percent
of the country's river-borne freight, earning the Yangtze River the name of the "Golden Waterway".
The reach of the Yangtze River to be flooded by the Three Gorges Reservoir includes 130 dangerous
shoals and 46 one-way control sections, and it is not wide or deep enough for the passage of large ships.
The Three Gorges Project will improve navigation conditions on the section from Yichang to Chongqing.
After project completion 10,000-ton towboats will be able to sail unimpeded to Chongqing. With the
construction of ports and modernization of ships, the annual shipping capacity may increase by 5 times
and the transport costs may be cut by 35 to 37 percent.
The construction of the Three Gorges Project also plays a comprehensive role in fish breeding, city
water supplies, and provision of adequate water supply for the transfer of water from the south to the
north of China.
7.4.1.2 Design of the Dam
The Three Gorges Dam site is at Sandouping near Yichang in Hubei Province. A river shaped reservoir has
appeared on the river as shown in Fig. 7.27. The dam is being built on a base of solid granite. Geological
studies, including drilling at the dam site down to 100,000 m and 4,000 sets of rock mechanics tests,
have been carried out, covering various aspects associated with the project construction for more than 3
decades. The design of the dam involves the dam, navigation facilities, and power houses.