The Three Gorges Dam is the largest hydroelectric dam in the world, located on the Yangtze River in China. It took over 17 years and 40,000 workers to build the 2,335 meter long and 181 meter tall dam. The dam provides significant benefits like flood control, clean electricity generation, and improved navigation on the Yangtze River. However, building the dam also had large social and environmental impacts, such as the relocation of over 1.2 million people and submergence of important archaeological sites.

1. THE THREE GORGES
DAM

2. INTRODUCTION
 The Three Gorges Dam is the
largest concrete structure on the
planet.
 Built on the Yangtze river in china.
 It is the largest hydro power project
in the world.
 It is a multi objective dam with great
benefits in flood control, power
generation, navigation and so on.

3. The Yangtze river
 The Yangtze river is the largest river
in Asia and the third largest in the
world.
 The river is more than 6000 kms long
and at places several kms wide.
 It is one of the biggest rivers by
discharge volume in the world.
 River is one of the worlds busiest
waterways.

4. Flood records of the Yangtze river
 The Yangtze river is very notorious and
unpredictable in its flow.
 Some of the major floods occurred in
1931,1935,1949,1954,1998.
 The most severe being the flood in
1935 which killed 1,42,000 people.
 Over the years china has lost billions of
dollars due to the flooding in the
Yangtze river.

5. Scale of Three Gorges Dam
 The Three Gorges Dam is 2335 metres long
and 181 metres high.
 It took over 40000 workers more than 17
years to build.
 The project used 27.2 million cubic metres of
concrete(mainly for the dam wall).
 463,000 tonnes of steel (enough to build 63
Eiffel towers )was used, and 102.6 million
cubic metres of earth was moved .
 The estimated cost of the project is 22.5
billion USD.
 The dams body was finished in 2006 and it
became fully operational on 4th of July ,2012.
 The dam consists of ship lock facility and ship
lift which is due to complete in 2015.

6. Power generation
 It is the largest hydro electricity producing
dam in the world.
 It generates 22,250 MW of electricity.
 It has 34 generators.(32 main , 2 small ).
 The generators are coupled with huge
turbines.
 Cost of each turbine is 50 million USD.
 Produces electricity to 60 million Chinese.

7. Power comparison
Three gorges dam Itaipu dam Grand coulee dam

8. parameters Three gorges dam Itaipu dam grand coulee dam
country China Brazil/Paraguay USA
river Yangtze Parana Columbia
Installed capacity 22250 MW 14000MW 6809MW
No. of turbines 32 20 33
Annual energy
generation
98.5 TW-hour 98.3TW-hour 20TW-hour
discharge capacity 116,110 m^3/sec 62,200 m^3/sec 14,000m^3/sec
Reservoir surface
area
1084 km sq. 1350 km sq. 285 km sq.

9. Construction
Construction of main body
includes
 Rock and earth excavation of 102.83
million cubic metre.
 Concrete placement of 27.2 million
cubic metre.
 Rock and earth refill of 31.98 million
cubic metre.
 Metal frame installation of 256,500
tonnes.
 Installation of 32 turbine generator
units , each of 700 MW capacity
each.

10. Contd..
Construction was carried out in 3 phases.
Phase 1(1993-1997) - excavation for river diversion
Phase 2(1998-2003) - construction of spillway, left bank power house and ship lock.
Phase 3(2004-2009) - construction of right bank channel.

11. Coffer dams for river diversion.

12. Ship lock facility
 the ship lock is five step and double
way type.
 The locks are 280 metres long ,35
metres wide and 5 metres deep.
 The transit time is 4 hours.
 The max vessel size is 10,000 tonnes.
 40,000 tonnes of metal structures
were used to construct the ship lock.

13. Ship lift facility
 Ship lift is a kind of elevator for vessels.
 Designed to lift ships upto 3000 tonnes.
 Will lift ships vertically upto 113 metres
high.
 Lift basin is 120 metres long, 18 metres
wide and 3.5 metres deep.
 Transit time 30-40 minutes.
 Due to be completed in 2015.

14. Relocation and resettlement
 The TGP reservoir inundated 632 km sq. of
land and 24,500 hectares of farmland.
 1.24 million people were relocated to higher
grounds.
 So far 13 cities, 140 towns and 1600 villages
have been submerged under the worlds
largest reservoir.
 The total cost spent on relocating people
was 6.5 billion dollars.
 The relocation process was the largest for a
river water project.

15. Relocation cont.…

16. Benefits of the dam
 FLOOD CONTROL.
 CHEAPER AND CLEAN SOURCE
OF ELECTRICITY.
 IMPROVED NAVIGATION.
 BETTER IRRIGATIONAL FACILITIES
DURING DRY SEASON.
 BETTER WASTE MANAGEMENT.
 IMPROVED TOURISM.

17. Environmental Benefits
 By providing hydroelectricity at such
a high scale, the TGP has saved 31
million tonnes of coal and
prevented..
 100 million tonnes of green house
gas per year.
 1 million tonnes of sulphur dioxide
per year.
 370,000 tonnes of nitric oxide.
 10,000 tonnes of carbon
monoxide.

18. Navigational benefits
 The installation of ship locks and ship lift
has increased river shipping from 10 million
tonnes to 100 million tonnes annually.
 Transportation rates are cut by 30-37 %.
 The water traffic on the Yangtze has
increased by 6 times.
 Improved navigation on the upstream side
.

19. Drawbacks of the TGP
 SILT FACTOR
 LAND SLIDES
 EROSION AND SEDIMENTATION
 LOSS OF WILDLIFE
 RELOCATION OF OVER A MILLION
PEOPLE.
 LOSS OF IMPORTANT
ARCHEOLOGICAL SITES

20. Drawbacks (cont.)..
 530 million tonnes of sediment into the
reservoir every year.
 The 600 km long reservoir flooded
1400 archaeological sites .
 Due to high water levels on upstream
side, major landslides have occurred in
the recent past.
 80% of the land area is experiencing
erosion.
 Shanghai sits on a sedimentary plain.
 Loss of endangered species due to the
change in water level and water
quality. (ex-Chinese river dolphin)

21. THANK YOU
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