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Uses of Dams
Since we have developed a basic understanding of what a dam is, let
us look into the uses of dams. It is considered as a significant water
resource. They provide water for a variety of reasons, including home
usage, irrigation, and industrial applications. Dams are also utilized to
produce hydropower power and make river transportation easier.
Dams are becoming increasingly important in everyday activities.
Moreover, dams also promote local tourism thus contributing to
national development. There are several uses of dams. Some of the
most common ones are as follows
 The water conserved in reservoirs provides freshwater to
residential, industrial, and mining areas.
 The conserved water satiates irrigation purposes.
 Facilitates the process of generating energy from renewable
sources, like hydropower.
 Helps to regulate the flow of water of rivers and streams and
protects communities residing down in the valley.
 Facilitates water conservation for meeting future requirements.

With that being said, let’s proceed to find out the associated merits
and demerits of dams.

Advantages of Dams
Dams offer an array of economic, social and environmental benefits
and are useful for most problems pertaining to water conservation and
its crisis management. On that note, let’s glance through the top
advantages of dams –

 Water Storage
Arguably, this is one of the primary uses of dams and reservoirs.
The water stored in reservoirs helps to make up for water crises
in dry seasons. It also ensures the regular water supply for
residential, industrial and agricultural consumption.
 Flood Control
Undoubtedly, mitigating floods is a major importance of dams.
Dams help to control the flow of floodwater by diverting its
course towards other uses, storing the excess water or releasing
it with caution. In turn, it helps to save lives and resulting
displacement.

 Irrigation
One of the most significant merits of dams is the role they play in
irrigation. Dams have helped farmers tackle the problem of
watering crops significantly, which has resulted in a boost in crop
production.

 Electricity Production
Over the years, hydropower has emerged as an effective way of
meeting the energy crisis in many regions of India. Also, being a
clean source of energy, hydropower does not contribute to any
kind of pollution. Tehri Dam, Srisailam Dam, and Sardar Sarovar
Dam are some of the top hydropower plants in India.

 Debris Control
Besides mitigating floods, dams often prove useful in retaining
detrimental sedimentation. In fact, they may also come in handy
in preventing the disposition of hazardous material and
subsequent contamination.

 Recreation
One of the benefits of dams is that they also provide recreational
facilities to human beings. One can enjoy boating, skiing and
fishing in the stagnant water. Maithon dam and Bhakra Nangal
dam are popular among tourists as recreational hubs.
Disadvantages of Dams
Irrespective of their array of benefits, dams have a significant share of
disadvantages. The following offers a brief idea about it.
 Displacement of people during construction.
 Reservoirs often emit a high percentage of greenhouse gases.
 Often disrupts local ecosystems.
 It disrupts the groundwater table.
 Blocks progression of water to other countries, states or regions.

In conclusion of the article, we have discussed the advantages and

disadvantages of dams, we have learned about the uses of a dam.
 Components of Dams | Functions of Components of Dams
 Core: It is made up of impervious material and its object is to make the dam water
tight. ...
 Shell: Shell is made up of pervious material (porous material). ...
 Transition filters: ...
 Cut off trench: ...
 Sheet pile wall: ...

Main Dam

This is the main structure built across the river. The height of a dam depends upon
desired storage capacity and the site conditions. The crest length of he dam depend
upon topography at the dam site. The dam may be built of many different materials. The
stored water is released from the dam as per requirements.

1.6.2 Flanks/Abutment:

The rock mass on right & left banks of the river constitute abutments. Dam is joined with
and supported by the abutments. In addition outlet tunnels, diversion tunnel, spillway
are also placed in the flanks. The geology of the abutments has to be strong enough to
enable placing various structural components without any risk. In addition abutments
need to be of competent rock without any structural defects and lowest permeability

1.6.3 Saddle Dam:

The reservoir is usually formed by the main dam on one side and low/high hills on all
other sides of the reservoir. In most cases the elevation of the hills along the rim of the
dam is much higher than the reservoir maximum water level. In some other cases
elevations of surrounding hills along a part of the rim/periphery of the reservoir is not
high enough over a small section to completely contain the stored water and a saddle
(low level place) is formed. Water can flow out through the saddle. A small embankment
is then constructed at this low/saddle point to seal off the reservoir rim and is called as
saddle dam. Example: Sukian dam and Jari dam for Mangla Dam project.

1.6.4 Diversion Channel/Tunnel

These channel or tunnel are constructed prior to dam construction such that river flow is
passed around and away from the dam site through the diversion tunnels and that than
dam site remain dry and accessible to construction at all time. The capacity of diversion
structure is set such that most probable floods likely to occur during the construction
period can be passed over without danger of overtopping of cofferdam and inundation
of construction area. Necessary arrangements are made at d/s end for energy
dissipation. These tunnels may be abandoned (plugged – Simly dam) after project
completion or converted to irrigation / power / desilting tunnels. Diversion tunnel may
not be provided (Mirani dam) and u/s coffer dam.

Cofferdam

These are small temporary dams built u/s and d/s of the dam site to make the
construction area dry and workable. The u/s cofferdam causes water to flow through the
diversion tunnel and the d/s cofferdam prevents backwater level to inundate the
construction area. Coffer dam may be dovetailed in u/s part of dam (Mangla) or
abandoned. Material used earth, rock, concrete etc. Arrangemnet are required for
control of seepage across the coffer dam.

1.6.6 Spillway

This is a water release/conveyance structure to pass the large flood volumes safely
across the dam without danger of overtopping of the dam crest. There would be one or
more spillways usually at different levels (Service, additional, emergency). The lower
spillway is used to release often occurring flood and regular inflows and is called as
service spillway. It has usually more elaborate arrangements and may be free flowing or
gated. The auxiliary or emergency spillway is set at or above normal conservation level
and has fewer arrangements and is usually free flowing. This is used only during flood
events of extra-ordinary nature. Fuse plug, rubber dam etc may be used to delay water
release and possible additional storage at the reservoir.
The spillway may be a integral part of the main dam (mostly for concrete dams) or be a
separate structure in the dam abutments.

1.6.7 Outlet Works

(a) Intake Structure / Tower: This is a structure to admit and control flow of water into
the irrigation/power outlets. It would be a tower or inlet flush with reservoir side walls.
Gates may be provided at u/s, intermediate or d/s end of the outlet tunnel. Necessary
provision is made to keep the intake operation for long after sedimentation by having
multiple water entry levels particularly for domestic supply purposes. Multi level inlet
openings may be used.

(b) Irrigation/Power Outlet Tunnel: This is a large water conveyance structure to release
water to irrigation network and/or powerhouse turbines. The outlet is in the form of a
tunnel dug or formed through the abutment / flank for earth / rockfill dams or through the
dam body for a concrete dam. At the u/s end an intake is provided along with gates,
trash rack. The tunnel design must eliminate risk of cavitation and/or aeration. Gates
may be placed at u/s, d/s or intermediate location. The power tunnel is transitioned into
surge chamber, penstock/scroll case etc. Energy dissipation structure may be provided
at d/s end, if needed. Irrigation outlet may release into a canal or into the river if demand
site is at distance from the dam. The intake level of the tunnel is kept below or at the
dead storage level. Air vent is provided to minimize cavitation. Water cushon for vortex
control are also provided.

Types of dam

Embankment: Constructed from compacted or rock with an impervious core

Designed to transfer the entire water load downward

Gravity
Arch

Buttress

COMPONENTS EXPLAINED
OCTOBER 17, 2022 VINOD GOPINATH 5 COMMENTS

Components of dams have specific functions in managing their primary

responsibility of water management. Dams are structures built across water
bodies to control water flow and levels. Furthermore, dams are also required
for a wide range of projects, including small irrigation and water supply
schemes as well as larger hydropower and disaster management schemes.
Dams’ primary responsibility of managing water is managed by each
component in a specific way. The components of the dam and their functions
are discussed in this article.

The upstream side of a dam is the area where the water is collected. The
water level is high on the upstream side. The downstream is the section of
the barriers with low water levels.