1. Dam Construction & History
Dam Safety 101
Introduction to dams

2. Why build dams. The purpose of a dam is to impound (store): Water,
flood control, human water supply, irrigation, livestock water supply, energy generation, recreation
Wastewater or liquid borne materials
containment of mine tailings, pollution control, debris control.

3. Types of dams Dams are classified according to:
Type of construction material used,
Methods used in construction,
Slope or cross-section of the dam
Way the dam resists the forces of the water pressure behind it
Means used for controlling seepage
Purpose of the dam.

4. Materials Materials used for construction:
include earth, rock, tailings from mining or milling, concrete, masonry, steel, timber, miscellaneous materials (such as plastic or rubber) and any combination of these materials.

5. Embankment dams Most common type of dam in use today.
Materials include
natural soil or rock, or
waste materials obtained from mining or milling operations.
An embankment dam is termed an “earthfill” or “rockfill” dam depending on whether it is comprised of compacted earth or mostly compacted or dumped rock.
The ability of an embankment dam to resist the reservoir water pressure is primarily a result of the mass weight, type and strength of the materials from which the dam is made.

6. Embankment Dam

8. Concrete dams
Concrete dams may be categorized into gravity and arch dams according to the designs used to resist the stress due to reservoir water pressure.
Typical concrete gravity dams are shown here and are the most common form of concrete dam. The mass weight of concrete and friction resist the reservoir water pressure.
A buttress dam is a specific type of gravity dam in which the large mass of concrete is reduced, and the forces are diverted to the dam foundation through vertical or sloping buttresses.
Gravity dams are constructed of vertical blocks of concrete with flexible seals in the joints between the blocks.

9. Concrete Dam

10. Gravity Dam

11. Concrete arch dams Thin in cross-section and curved.
The force of water acting on the arch holds the dam into the canyon walls.
The shape of the arch resembles a segment of a circle
They are usually constructed of a series of thin vertical blocks that are keyed together;
barriers to stop water from flowing are provided between blocks.
Other types of arch dams include
multi-arch dams in which more than one curved section is used
arch-gravity dams which combine some features of the two types of dams.

12. Arch Dam

13. Arch Dam

14. Hoover Dam Concrete gravity-arch
Location: Nevada /Arizona, US
Purpose: Power, flood control, water storage, regulation, recreation
Construction began:1931
Opening date1936
Construction cost: $49 million ($833 million with inflation)
Operator: U.S. Bureau of Reclamation
Length: 1,244 ft (379 m)
Height: 726.4 ft (221.4 m)
Dam volume: 3,250,000 cu yd (2,480,000 m3)
Installed capacity: 2,080 MW
Annual generation: 4.2 billion kWh

15. Grand Coulee Concrete gravity
Location: Washington, US
Purpose:Power, regulation, irrigation
Construction began: 1933
Opening date: 1942
Original dam: $168 million
Operator: U.S. Bureau of Reclamation
Length5,223 ft (1,592 m)
Height550 ft (168 m)
Dam volume: 11,975,520 cu yd (9,155,942 m3)
Installed capacity: 6,809 MW
Annual generation: 21 billion KWh

16. Shasta Concrete gravity
Location: California
Construction began:1938
Opening date:1945
Operator: U.S. Bureau of Reclamation
Length: 3,460 ft (1,050 m)
Height: 602 ft (183 m)
Dam volume: 6,270,000 cu yd (4,790,000 m3)
Installed capacity: 676 MW
Annual generation: 1.8  billion KWh
Shasta Concrete gravity

17. Folsom Concrete gravity
Location: California
Construction began:1948
Opening date1956
Construction cost: $81.5 million
Operator: U.S. Bureau of Reclamation
Dam volume: 1,170,000 cu yd (890,000 m3)
Length1,400 ft (430 m)
Height340 ft (100 m)
Installed capacity: 198.7 MW
Annual generation: 0.7 billion KWh

18. Oroville Rockfill embankment
Location: California
Construction began:1961
Opening date:1968
Operator: California Department of Water Resources
Length: 6,920 ft (2,110 m)
Height: 770 ft (230 m)
Dam volume: 77,619,000 cu yd (59,344,000 m3)
Installed capacity: 819 MW
Annual generation: 2.2 billion kWh

19. Three Gorges Gravity Dam
Location: China
Purpose: Power, flood control, navigation
Opening date: 2008
Owner(s): China Yangtze Power
Length: 2,335 m (7,661 ft)
Height: 181 m (594 ft)
Installed capacity: 22.5 GW
Annual generation: 80 billion kWh
Three Gorges Gravity Dam

20. Aswan Dam Embankment Location: Egypt Opening date: 1970
Length: 3,830 m (12,570 ft)
Height: 111 m (364 ft)
Installed capacity: 2,100 MW
Aswan Dam Embankment

21. Auburn Dam Gravity Arch
Location: California
Purpose: Power, flood control, recreation
Opening date: Proposed
Owner(s): U.S. Bureau of Reclamation
Length: 4,100 feet (1,200 m)
Height: 700 feet (210 m)[
Installed capacity: MW