THREE GORGES DAM
boat navigates the Yangtze River through gorges that will be flooded when
the $25 billion Three Gorges Dam is completed in 2003.
THE CONSTRUCTION PROJECT:
- Excavation: 102.6 million cubic meters of earth and
stone (134 million cubic yards).
- Concrete: 27.2 million cubic meters (35.5 million cubic
- Steel reinforcing bars: 354,000 tons.
- Dam height: 185 meters (607 feet).
- Dam length: 2,309 meters (1.4 miles) divided into three
parts. In the center will be a 484-meter spillway section with 23
bottom outlets and 22 sluice gates. On the left and right of the
spillway will be two giant power stations (see below).
- Timing: Phase 1 began in 1994 and ended in 1997 with the
initial diversion of the
. Phase 2 began in
1998 and is due to end in 2003 when the water level rises to 156
meters (511 feet) and the dam starts generating electricity. Phase 3
should end in 2009 when the water level reaches 175 meters (574 feet)
and full power generation begins.
THE DOWNSIDE CONSEQUENCES:
- Water pollution in the dammed Yangtze will double _ at
least _ as the dam traps more than 50 types of pollutants from mines,
factories and human settlements that were formerly flushed out to sea
by the swift Yangtze currents.
- About 1,300 archaeological sites will be moved or
- Critics contend that the heavy silt in the river will
form thick deposits near the upstream end of the dam, clogging the
major river channels of the city of
- Facing Inundation: 632 square kilometers (244 square
miles), 19 cities, 326 villages, including 27,000 hectares (66,700
acres) of farms and orchards.
- Facing resettlement: 1.1 million to 1.9 million people.
THE FUTURE RESERVOIR:
- Average width: 1.1 kilometers (0.7 miles).
- Length: 600 kilometers (370 miles).
- Storage: 39.3 billion cubic meters of water (51.4
billion cubic yards).
- Water level: elevated 175 meters (574 feet) above
- Runoff: 451 billion cubic meters (589 billion cubic
water will flow into the reservoir annually.
- Silt: The muddy Yangtze will discharge 530 million tons
of silt into the reservoir in a typical year.
- Machinery: The two power stations flanking the dam's
central spillway will operate 26 of the world's largest turbine
generators, 700 megawatts each.
- Capacity: Total generating capacity will be 18,200
megawatts, or as much as big 18 nuclear power stations.
- Transmission: Fifteen 500,000-volt transmission lines
will send electricity to
- Output: 84.7 billion kilowatt hours of electricity
annually, equivalent to burning 40 million tons of coal.
- Ship lock will consist of five locks, each 280 meters
(918 feet) long and 35 meters (114 feet) wide, with a water depth of 5
meters (16.4 feet). Supposed to handle 10,000 ton barges.
- Ship lift will be a one-stage vertical lift capable of
carrying a 3,000-ton passenger or cargo vessel.
- River shipping through central Yangtze estimated to
increase from 10 million to 50 million tons annually, with
transportation costs cut by 30-37 percent.
THE FLOOD CONTROL:
- Dam sponsors say the reservoir's 22.1 billion cubic
meter (28.9 billion cubic yards) flood control storage capacity should
lessen the frequency of big downstream floods from once every 10 years
to once every 100 years.
city of Wushan rises from the banks of the Yangtze River. In 2009, the
area beneath the arrow drawn on the photo will be under water.
OF WORLD'S TEN LARGEST HYDROELECTRIC PROJECTS
(in megawatts of installed generating capacity)
- Three Gorges,
- LaGrande 2,
Story and photos by Marcia Kunstel and Joseph
Albright c.1998 Cox News Service