The Gezhouba Dam Hydro Electric Project which is the experimental
dam of the Three Gorges Project (TGP) located at the lower end of
the Three Gorges in the suburbs of Yichang, 38 km downstream of the
TGP. The construction of the Gezhouba Dam project started on December
30, 1970 and ended on December 10, 1988. The dam is 2606.5 meters
long and 53.8 meters high, with a total storage capacity of 1.58 billion
m3 and a maximum flood discharging capability of 110,000 m3/s. The
two hydroelectric plants have
21 generating units with a total installed capacity of 2.715 million
kw and an annual output of 15.7 billion kwh, which is transmitted
to Shanghai, Henan Province, Hunan Province, Wuhan City, etc.
The annual one-way
shipping capacity of the navigation facilities is 50 million tons
and the total investment was 4.848 billion Chinese currency yuan
(US$0.557 billion). The Gezhouba Dam Project is a cascade which
regulates the tailwater flow from the TGP and improves the conditions
between the two dams. After completion of the TGP, the annual guaranteed
output of electricity from the Gezhouba Hydro Power Plant will be
increased by about 430,000kw. Therefore the two projects considered
as twins through thick and thin.
The dam has
several sluice-gates, or ship locks. Some sluice-gates are used
for accumulating water for irrigation during fraught seasons; some
function for generating electricity. But what is most interesting
is how boats are lowered or raised by making use of locks. When
a boat from the lower level enters a sluice-gate, the gate is closed
and the boat is "locked in" between two gates. The water
level rises gradually until it reaches a higher level. When the
other gate opens, the boat has already climbed up to a higher level.
Likewise, boats from a higher level could also easily get to the
lower level. This scene has now become an added attraction for visitors.
out of Nanjin Pass, the Yangtze River slows down and widens from
300 meters to about 2,000 meters. Three kilometers east, in the
suburbs of Yichang
City, a huge dam lies across the river. This is the Gezhouba Dam,
a major part of the multi-purpose water control project to bend
the Yangtze to human purposes.
The main channel here was closed off on January 4, 1981,and navigation
and power generation began in June the same year, marking the completion
of the first phase of the key project. Beyond Nanjin Pass, two islets-Gezhouba
(from which the dam project gets its name) and Xiba-divide the river
into three waterways, the main, second and third channels. The main
channel is filled with water all year round while the other two
are dry during the low-water season. The possibility of diverting
the water of one into the others so that construction work can be
carried out makes the site ideal for the water conservancy scheme.
With the closure
of the main channel, the Yangtze has changed its age-old course
to roll forward through the second channel. Building a dam across
the main section of a river which is wide, deep and has an enormous
flow is something unheard-of before.
Now the 2,561-meter-long
dam has created a reservoir upstream with a holding capacity of
1.58 billion cubic meters. The project involved the removal of 55
million cubic meters of earth and rock, the installation of 65,000
tons of metal structures, and the pouring of 10 million cubic meters
of concrete. This last figure equaled the combined total for the
five other key water conservancy projects in the country - the Liujiaxia,
the Sanmenxia, the Danjiangkou, the Gongzui, and the Xin'anjiang
-and is enough to build a 10-meter-wide and 50-centimeter-thick
road extending from Guangzhou to Beijing.
and construction of the dam and the installation of the equipment
were all undertaken by Chinese personnel. As far as the amount of
work and the technical standard are concerned, this cross-river
structure ranks first among China's hydropower projects.
A major component
of the future Three Gorges multipurpose water conservancy scheme,
Gezhouba project consists mainly of power stations, ship locks,
spillways silt-scouring sluices, silt-prevention dykes and auxiliary
There are two
Power stations at the dam site one in the main channel the other
in the second channel. They have sets of turbo-generators, with
a total installed capacity of 2.715 million KW to generate about
14.1 billion KWH of electricity a year. The biggest in China today,
they supply power to the central China grid, greatly promoting industrial
and agricultural Production in Hubei, east Sichuan, north Hunan
and southwest Henan.
There are three
shiplocks at Gezhouba. Lock No. 1 in the main channel and Lock No.
2 in the third channel each have a chamber 280 meters long and 34
meters wide, with a depth of five meters, allowing the passage of
10,000-ton passenger or cargo ships. They both rank among the world's
largest before Three Gorges Dam. Lock No. 3 in the third channel
is 120 meters long and 18 meters wide, with a depth of 3.5 meters.
It can handle vessels below 3,000 tons and local boats.
sluices and two silt-prevention dykes have been built to facilitate
navigation. When the reservoir is filled with water, the water level
at the dam can be raised by 20 meters. In the dry season, the water
can retreat 180 kilometers, to the west end of Wu Gorge, while at
flood time, the water can move back as far as Badong, a distance
of 100 kilometers. With the conclusion of the first phase of the
project, the water level along the Three Gorges has been elevated
by 10 meters and many shoals have been submerged, greatly improving
operation of the 27-bay spillway and the three silt-scouring sluices
can discharge a water volume of 110,000 cubic meters per second,
the maximum figure of the 1870 flood. Moreover, a railway-highway
bridge has been built atop the dam. The bridge surface can be raised
or lowered to allow large ships to pass, the Maximum lift being
Apart from economic
benefit, the Gezhouba project is a boon to tourism. With its overall
completion, a number of gardens will appear along this section of
the river together with tree-shaded roads at the sites of the three
channels. Chinese and foreign travelers visiting the Three Gorges
will be tempted to include Gezhouba project in their itinerary.
They will find this man-made wonder a feast to the eye and the imagination,
a monument to human ingenuity in taming China's longest river.