Dams are structures built across rivers or streams to retain water. The main purposes of dams include storing water, providing irrigation, controlling floods and droughts, generating hydropower, enabling navigation, and developing fisheries. There are several types of dams defined by their structure and materials, including gravity dams, arch dams, buttress dams, embankment dams, steel dams, and timber dams. Each type has distinct characteristics regarding their design, materials used like concrete or earth, and suitable locations.

1. TYPES AND PURPOSES OF
DAMS
Presented by
Ranjith BSR

2. Contents
Defination
Purposes
Structure of dam
Types of dams

3. Defination
A dam is a barrier that impounds water or
underground streams. A dam is a structure built
across a stream, river or estuary to retain water.

4. Purposes Of Dams:-
® Store water(basic purpose)
® Raise the level of the water upstream to enable water
to be diverted into a canal or to increase ’hydraulic
head’
® Irrigation
® Drought and Flood control
® Hydropower generation
® Navigation
® To develop fisheries

5. Structure of DAMS

6. Terms in dams
Heel: contact with ground on the upstream side
Toe: contact with ground on the downstream side
Abutment: Sides of the valley on which the structure of
the dam rest
Galleries: small rooms like structure left within the dam
for checking operations.
Diversion tunnel: Tunnels are constructed for diverting
water before the construction of dam. This helps in
keeping the river bed dry.
Spillways: It is the arrangement near the top to release
the excess water of the reservoir to downstream
side
Sluice way: An opening in the dam near the ground
level, which is used to clear the silt accumulation
in the reservoir side.

7. Types of Dams:-
Dams are classified on the basis of following types:
By structure
By material

8. By Structure
 Arch dams
 Gravity dams
 Buttress dam
 Embankment dams

9. Gravity Dam
Gravity dams are dams which resist
the horizontal thrust of the water
entirely by their own weight.
Concrete gravity dams
are typically used to
block streams through
narrow gorges.

10. Gravity Dam
Material of Construction:
Concrete, Rubber Masonry

11. Arch Dam
An arch dam is a curved dam
which is dependent upon arch
action for its strength.
Arch dams are thinner and
therefore require less
material than any other
type of dam.
Arch dams are good for
sites that are narrow and
have strong abutments.

12. Arch Dam
Material of Construction:
Concrete

13. Buttress Dam
Buttress dams are dams in which
the face is held up by a series of
supports.
Buttress dams can take many
forms - the face may be flat or
curved.

14. Buttress Dam
Material of Construction:
Concrete, Timber, Steel

15. Embankment Dam
Embankment dams are
artifical massive dams made
of earth or rock.

16. Embankment Dam
Material of Construction:
Earth, Rock

17. By Mateial:-
 Steel dams
 Timber dams

18. STEEL DAM
 Steel dam is a type of dam that is
made of steel, rather than common
masonry ,earthworks , concrete or
construction material
 It is an experiment which failed
 Maintenance cost is high due to rust
and corrosion

19. TIMBER DAM
o Timber dams were widely
used in early part of
industrial revolution and
rarely used now
o Suitable location for
construction
o In order to maintain
water retension property
they must be kept wet