TYPES AND PURPOSES OF DAMS

Presented by

Ranjith BSR

ContentsDefinationPurposesStructure of damTypes of dams

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.

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

Structure of DAMS

Terms in damsHeel: contact with ground on the upstream side Toe: contact with ground on the downstream sideAbutment: Sides of the valley on which the structure of

the dam restGalleries: 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.                      

Types of Dams:-Dams are classified on the basis of following

types:By structureBy material

By StructureArch damsGravity damsButtress damEmbankment dams

Gravity DamGravity 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.

Gravity Dam

Material of Construction:Concrete, Rubber Masonry

Arch DamAn 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.

Arch Dam

Material of Construction:Concrete

Buttress DamButtress 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.

Buttress Dam

Material of Construction:Concrete, Timber, Steel

Embankment DamEmbankment dams are artifical massive dams made of earth or rock.

Embankment Dam

Material of Construction:Earth, Rock

By Mateial:-Steel damsTimber dams

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

TIMBER DAMo 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

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