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