1. HERITAGE INSTITUTE OF TECHNOLOGY
Department - CIVIL
Presented by- Abhijit Pal
TOPIC - DAM
2. OUTLINE
What is a Dam
Structure of Dam
Purposes of Dam
Selection of Dam sites
Classification of Dam
On structure
Dam failure
Disadvantages of Dams
Conclusion
Bibliography
3. WHAT IS A DAM
A Dam is an obstruction
or barrier built across a
steam or river
It is a structure built to
retain water
4. STRUCTURE OF DAM
Heel- contact with
the ground on the
upstream side
Toe– contact on the
downstream side
Sluiceway- An
opening in the dam near
the ground level, which
is used to clear the silt
accumulation in the
reservoir side
5. STRUCTURE OF DAM
Spillway– It is the
arrangement near the top to
release the excess water of the
reservoir to downstream side
Gallery- Small rooms like
structure left within the dam
for checking operations
Abutment- Sides of the
valley on which the structure
of the dam rest
6. PURPOSES OF DAM
Water supply- Dams gather drinking water for people
Flood control- Dams keep areas from flooding
Irrigation- Dams help farmers bring water to their farms
Hydroelectric- Dams help create power and electricity
from water
Navigation- Dams create lakes for people to sail on from
one part to another
Recreation- Dams can be used for swimming
10. ARCH DAM
An Arch Dam is a curved
dam built where access to
materials is limited
Ex- Idukki Dam in Kerala
Arch Dams are thinner and
therefore require less
material than any other
type of dam
These are dependent upon
arch action for its strength
12. GRAVITY DAM
Gravity Dams resist the
horizontal thrust of the
water entirely by their own
weight
Ex- Dworshak Dam in
Idaho
Gravity Dams are typically
used to block streams
through narrow gorges
14. BUTTRESS DAM
• Buttress Dams are dams
in which the face is held
up by a series of supports
• Ex- Bartlett Dam in
Arizona
• Most Buttress Dams are
made of reinforced
concrete and are heavy,
pushing the dam into the
ground
16. EMBANKMENT DAM
Embankment Dams are
massive dams made of
earth or rock
Ex- Tataragi Dam in Japan
Typically created by the
placement and
compaction of a complex
mound of various
compositions of soil,
sand, clay and/or rock
18. DAM FAILURE
Faults in construction
methods eg-Teton Dam in
Idaho, USA in 1976
Geological problems with the
dam foundation eg- St.Francis
dam
Landslides which fall into the
storage reservoir eg- Vaiont
Dam in Italy in 1963
19. DAM FAILURE
Earthquakes can certainly
cause damage to dams eg-
Lower San Fernando Dam
Dangerous alterations to the
operation of the dam and/or
its structure may lead to
failure eg- South Fork
Dam (Johnstown) in 1889
20. DISADVANTAGES OF DAMS
The natural environment
is destroyed
The building of large dams
can cause serious
geological damage
Dams have endangered
some species of fish,
inhibited the seasonal
migration of fish
Displaces people
21. CONCLUSION
Dams support 30%-40% of the irrigated area and 12%-
16% of the global food production
Thus dams can be a source of huge profit both in terms
of fresh water resource and generation of electric
power
Therefore construction of dams should be made
keeping in mind its long terms of service