This document provides an introduction to dams, including their working principles and types. It discusses how dams are barriers constructed across rivers to store water, which is then used for hydropower, irrigation, drought/flood control, and navigation. The main types of dams covered are gravity dams, earth dams, arch dams, and buttress dams. Advantages of dams include cheap electricity generation and lower emissions than thermal power plants. Disadvantages comprise altering the physical environment and reducing biodiversity. Several major dams in India are also outlined, such as the Tehri Dam, Sardar Sarovar Dam, Nagarjuna Sagar Dam, and Bhakra Dam.

1. Introduction to
DAMS
BY-
ANSHIKA
BSc Hons

2. INTRODUCTION
WORKING PRINCIPLE
TYPES OF DAMS- GRAVITY DAM,EARTH DAM, ARCH
DAM,BUTTRESS DAM
ADVANTAGES
DISADVANTAGE
DAMS IN INDIA
TOPIC COVERED-

3.  A Dam is a barrier that impounds underground stream,
constructed at a suitable location across a river to store
flowing water.
Stored water is used in-
 Hydropower
 Irrigation
 Drought and flood control
 For navigational facilities

4. Hydroelectric power generation

7. TYPES OF DAMS

8. GRAVITY DAMS-
These dams are
heavy and massive wall-
like structures of
concrete in which the
whole weight acts
vertically downwards
Reservoir
Force
As the entire load is transmitted on the small area of foundation, such dams are
constructed where rocks are competent and stable.

9. Earth Dams:
 They are trapezoidal in shape
 Earth dams are constructed
where the foundation or the
underlying material or rocks are
weak to support the masonry
dam or where the suitable
competent rocks are at greater
depth.
 Earthen dams are relatively
smaller in height and broad at
the base
 They are mainly built with clay,
sand and gravel, hence they are
also known as Earth fill dam or
Rock fill dam

10.  These type of dams are
concrete or masonry dams
which are curved or convex
upstream in plan
 This shape helps to transmit
the major part of the water
load to the abutments
 Arch dams are built across
narrow, deep river gorges, but
now in recent years they have
been considered even for little
wider valleys.
Arch Dams:

12. Buttress Dam:
 Buttress Dam – Is a
gravity dam reinforced
by structural supports
 Buttress - a support that
transmits a force from a
roof or wall to another
supporting structure
This type of structure can be considered even if the foundation rocks are little weaker

13. ADVANTAGES

14.  Cheap Electricity: The operating cost of a hydroelectric dam is
minimal as there is no costly fossil fuel required. Hydroelectric
dams also tend to last longer than thermal power plants.
 Less Emissions: Hydroelectric power plants produces less
green house gas emissions when compared to a thermal power
plant.

15. DISADVANTAGES

16.  The physical environment is altered
 Cycles and variation of flow downstream are effected
 Standing water (reservoir) habitats replace flowing water habitats
 Nutrients are unable to move downstream
 Coastal erosion is increased due to loss of sediment transportation
 Productivity and species diversity of estuaries can be reduced due to
the reduction of freshwater flow
 Reduction of biodiversity occurs
 Ocean fish migrations are blocked, most notably the salmon and
steelhead
 Causes relocation

17. DAMS IN INDIA

18.  on BHAGIRATHI RIVER
near Tehri in
Uttarakhand, India
 Multi purpose rock and
earth fill embankment
dam
 Highest dam in India and
8th highest dam in the
world

19.  Second largest concrete
gravity dam on Narmada
river in Gujarat
 Dam has the world’s
third largest spillway
discharging capacity

20.  World’s largest masonry
dam .
 Built across KRISHNA
river on NAGARJUNA
SAGAR, ANDHRA
PRADESH

21.  Gravity dam across
Sutlej river near Panjab
and Himachal Pradesh
 Largest dam of India
and highest gravity dam
in the world

22. THANK YOU