ADVANTAGES AND DISADVANTAGES OF DAMS

1. MS
PRESENTATION BY

2.  My sincere thanks are to keen philosopher of the Institute Rev. Sister silvy ,
whose inspiring leadership kept the despair and set backs at bay which alone
ensures that this work saw the light of the day. This work would not have
reached the standard and height it has without the guidance and support of
Mrs. Inderpreet Kaur AND miss amita walia whose conviction is reflected on
every page. This work owe’s much to the selfless help and co-operation of our
Teachers.

3. Dam is a solid barrier constructed at a suitable location across
a river valley to store flowing water.
Storage of water is utilized for following objectives:
 Hydropower
 Irrigation
 Water for domestic consumption
 For drought and flood control
 Other additional utilization is to develop fisheries.

5.  This type of dams are concrete
dams which are curved or convex
upstream in plan
 This shape helps to transmits
the major part of the worlds loads
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.

6.  Earth dams are trapezoidal in
shape
 Earth dams are constructed
where the foundation rocks are
weak to support
 Earth 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

7. o Buttress Dam - Is a
gravity dam reinforced
by structural supports
o Buttress Dam –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

8. These dams are heavy and massive wall-like
structure of concrete in which the whole weight
acts vertically downwards

9.  Bhakra dam is the highest
concrete gravity dam in asia and 2nd
highest in the world
 This dam is present across the
river Sutlej in himachal Pradesh
 About construction it was started
in the year 1948,completed in 1963
Details: About measurements 740 ft high from the deepest foundation
as
straight concrete dam being more than 3 times the height of Qutub
Minar.

10. The reservoirs,which lies in the
upstream side(when full),contain an
enormous plenty of water due to
great extent, on downward side of
the dam,the water level wil be very
low.due to this difference in
levels,the reservoir water attempts
to leak through the rocks of dam
with considerable pressure and
emerge in the downstream side

12. Dams are needed in
places of permanent
Drought. To act as
barriers to hold
drinking
Water.

13.  Themostprominentuseof large
damsis forhydroelectricpower
generation,combinedwitha
hydropowerplant.Comparedto
otherrenewablesources,hydropower
producesthemostcost-efficient
energyat costsas lowas 2 US¢/kWh.

14.  Waterstoredin a reservoiris
usedtoirrigateagricultural
crops.It is estimatedthat30-
40%of irrigatedlands
worldwide,whichcontribute12-
16%of globalfoodproduction,
relyon dams.

15.  Ferry transportation began in 1860s, they now use
barges
 Economical
 Consumer Benefits
 Relieves rail congestion
The Pacific Northwest Barge Industry on the Columbia-Snake River
System by American Waterways Operation 1992-3
http://www.bluefish.org/pnbarge.htm

16.  Especially in urban areas, reservoir storage
capacities are used to supply drinking water
or water for industrial purposes.

17.  As a positivesideeffect,dam
structuresoftenofferfloodprotection
by regulatingwaterdischargeand
balancingrunoffdifferences.

18.  The navigability of a water system
enabledthrough the regulation by
the dam may provide an impetus for
trade and development. Inland
navigation is the most cost effective
and least pollutingmeans of
transportation.

19.  Finally, the lakes created
through water storage can
additionally serve recreational
and touristic purposes.

20. Provide Electricity for the
community
Roll on Columbia By Beth Gibson http://members.aol.com/Gibson0817/river.htm
Columbia and Snake River supply 63% of hydro electric energy
Grand Coulee when built provided work after great depression
Brought cheap electricity to the
areaHelped with the war
effortLater Industry moved to Pacific west because of
cheap energy supply
http://www.deniskingphoto.com/coulee_dam/coulee_dam3.html

21. •96%-98% pass safely through turbines
•Dams and turbines are not huge blenders

22.  “60%of totalstreamflowis regulatedby damsandreservoirsforflood
control”(JilesandSpencer,1995).
Thisis duetofloodpeaksbeingreduced,andtheuniformityinbase flow
beingincreasedthroughout.

23. Disadvantages of Dam
Dams have endangered some species of fish
Reservoirs can foster diseases if not properly
maintained
Reservoir water can evaporate significantly
Some researchers believe that reservoirs can
cause
earthquakes

26.  whena damfailsitcanbe catastrophic.
As recentlyas recentlyas 2004theBigBay
Damin Mississippibrokedestroyingnearly
fiftyhomes.It is a majorconcernincivil
engineeringtoseethatdamsare safefrom
hazardssuchaslandslidesand
earthquakes.

27. Dams are very costly projects,so their
construction in seismic areas needs careful
study to ensure their safety.when earth quakes
occurs,a dam is subjected to two forces are
due to the dam and due to reservoir water.

28. THANK U AND ALL