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Based on a presentation by Based on a presentation by
Sushil KumarSushil Kumar
DirectorDirector
National Water AcademyNational Water Academy
Infrastructure for W R Development-an overview
Infrastructure for Water Resource Projects
Broadly of three categories:
Storage / Diversion
Irrigation
Hydro Power
Storage/Diversion Structures
Dam Weir Barrage
Storage - Dams
A dam is a barrier built across a stream or river. It creates a reservoir behind it and controls the flow of water.
A dam can be classified based on-its use or functionmaterial of its constructionits size
Power House
Long Distance Power Lines
Turbine
Intake
Sluice gates
Spillways
River
River
Reservoir
Classification of Dams based on Use
Storage Dammost commonfor impounding water (creating a reservoir or lake)
behind it during excess supply, to be used in periods of deficient supply
purpose(s): Irrigation, Hydropower, Water Supply, Recreation
Diversion Damraises water level for diversion into other conveyance
system for irrigation, municipal or industrial usesof smaller heightno reservoir (or very limited storage) behind itfull waterway available across dame.g. Weir, Barrage
Large
Ht of dam > 15 m from its deepest foundation
Medium
Ht of dam=10-15 m from its deepest foundation
Small
Ht of dam >10 m from its deepest foundation
Classification of Dams based on height
Dam Population in India GROWTH OF LARGE DAMS IN INDIA DECADE- WISE
64365
604
1095
2375
3618
4223
5100
0
1000
2000
3000
4000
5000
6000
UP
TO
190
0
1901
-50
1951
-60
1961
-70
1971
-80
1981
-90
1991
-200
0
Bey
ond2
001
TIME IN DECADES
CU
MU
LA
TIV
E N
O.
OF
LA
RG
E D
AM
S
India ranks third in the world in dam population, after China and USA
Indian Register of Large Dams available here: http://cwc.gov.in
Large Dams – state wise
State-Wise Distribution of Large Dams(existing & ongoing) in India
Madhya Pradesh, 906
Karnataka, 236
Maharashtra, 1821
Rajasthan, 203
Other States, 676Chhattisgarh, 259
Gujarat, 665
Andhra Pradesh, 334
Total=5100
Large Dams – height wise
HEIGHT WISE DISTRIBUTION OF LARGE DAMS
37%
2%1%
9%
51%
10-15 15-30 30-60 60-100 100 and above
Concrete / RCC damsMasonry damsEarth fill damsRockfill dams (Earth core rockfill
dam)
Classification of Dams based on material
Concrete DamsConcrete damMaterial of construction : Plain ConcreteIts own weight provides resistance to the forces exerted on itNeeds sound rock foundation Straight or curved in planStraight = Gravity Dam (most common)Curved = Arch Dam
Roller compacted concrete (RCC) damNew technique, first used in 1986 in USAFaster construction, rapid placement of concrete in layersConstruction operation very similar to road construction Concrete mix uses large quantity of fly ash, environmental friendlyFirst RCC Dam in India – in Maharashtra, at Ghatghar
Concrete Dam-a typical section
Heel
Gallery
Toe
Spillway(inside dam)
Crest
Full Reservoir Level
Free board
Under sluice
UpstreamDown stream
River Flow
Foundation Level
Masonry dam• a gravity dam,
constructed of stone masonry (stone and cement)
• now a days constructed for small heights only
• in past, number of large and important dams were constructed in masonry,
• e.g. Srisailam, Krishnarajsagar, Tungabhadra, Malaprabha, Peechi, Barna, Ranapratapsagar, Khadakwasla
Earthen Dam
F.R.L.
PITCHING
AXIS OF DAM
TURFING
ROCK TOE
GROUT CURTAINCUT OFF TRENCH
M.D.D.L.
SEMI PERVIOUS SEMI PERVIOUS
Generally built of locally available natural materials with minimum processing.Most common and the first kind of dam to be built have gentle side slopes and hence a wide base.
Typical section of an earth-core rockfill dam using a
central core
Impervious membraneConcrete, asphaltic concrete, steel, impervious soil
Spillway• Overflow portion of a dam over
which surplus discharge flows in a controlled fashion, from the reservoir to downstream
• Invariably provided for all storage dams, a very important component
• It is the safety valve for a dam
• Capacity of spillway is of paramount importance
• Must have the capacity to discharge major floods anticipated or expected
• Referred to as controlled or uncontrolled, depending upon whether gated or un gated
SIDE CHANNEL & CHUTE SPILLWAY ARRANGEMENT
Channel Rest
Channel Rough
Chute
Chute Blocks
Dentated Sills
Stilling Basin
WeirWeir• Weir is a solid obstruction put across the river to raise
its water level and divert the water into the canal
• If a weir also stores water for tiding over small periods of short supplies, it is called a storage weir.
• The main difference between a storage weir and a dam is only in height and the duration for which the supply is stored.
• A dam stores the supply for a comparatively longer duration.
WITHOUT FALLING SHUTTERS
POND LEVEL
POND LEVEL
MASONRYFLOW
FLOW
Weir
Barrage
• Function of a Barrage is similar to a Weir.
• There is no solid obstruction across river (dams and weirs have a solid obstruction across the river).
• Raising of water level for diversion in to a canal is done by gates alone, which are set between flanking piers and are responsible for supporting the water load.
• Crest level in barrage is kept low
• Barrages are much more costlier than the weirs
• Can be used to regulate water flow in a lagoon or estuary
Infrastructure for Irrigation
Canal
Canal Regulation Work
Cross Drainage Work
Lining of Irrigation Canal
Canalan artificial channel
generally trapezoidal in shape
alignment in such a way that it covers the entire area proposed to be irrigated with shortest possible length and at a minimum cost
Types of canalsRidge Canal
Contour Canal
Canal Regulation Works
These are structures constructed to regulate the flow rate and volume of waternecessary for the efficient working and safety of an irrigation channel
Important Regulators:Head regulator or head sluiceCross regulatorCanal outlet
Cross Drainage WorksCanals comes across obstructions like rivers, natural
drains and other canals.The various types of structures that are built to carry a
canal’s water across the above mentioned obstructions or vice versa are called cross drainage works.
cross-drainage works are generally very expensive, and should be avoided as far as possible.
Lining of Irrigation Canals
To minimize the seepage losses in canals
To increase the discharge in canal section by increasing the velocity
To prevent erosion of bed and side due to high velocities
to reduce maintenance of canal
Lining material : concrete, stone tiles, HDPE geomembrane
Infrastructure for Hydro Power
Main components of a Hydro Power Scheme:
Intake StructureHeadracePenstocksSurge ShaftPower HouseTurbinesTailrace
A typical Hydro power SchemePOWER HOUSE COMPLEX
ELECTRICITY TO THE GRID
An schematic description of Hydropower Plant