LIVE TELECAST ON IRRIGATION ENGINEERING

FOR DCE III YEAR STUDENTS

BY

P.V.SRINIVASA RAO

HEAD OF CIVIL ENGG

MRAGR GOVT POLYTECHNIC

VIZIANAGARAM

DISTRIBUTION WORKS

Major Heads Canals- Types –cross

sections- Alignments Regulators- Drops – Escapes -

Sluices Silt theories - canal Designs Cross drainage works

DISTRIBUTION WORKSPART - II

CANAL REGULATION

Canal Regulation Works

• A Structure constructed to regulate the discharge, velocity and Full supply levels in a canal is known as

“Canal regulation Work”

Types of Canal Regulation Structures

• Canal Head Regulator or Head Sluice• Cross regulator• Distributory Head regulator• Canal Drops or Falls• Canal Out lets or Sluices or Modules• Canal Escapes

Canal Head Regulator It is a structure constructed

at the head of off taking canal Functions• It regulates the flow of water in to main canal• It controls entry of silt in to the canal• It prevents entry of river floods in to the canal

Over View

Features of Canal Head Regulator

• It is placed on U/S of barrage in front of under sluices and aligned at 90o-1100 to the axis of barrage for smooth entry of water

• It contains a raised crest with abutments on both sides

• It is provided with number of vents, separated by piers depending upon the discharge to be carried through it .

Features of Canal Head Regulator

(contd)

• The crest of the HR is kept sufficiently above that of under sluices for controlling the entry of silt in to canal

• Solid apron and cut offs are provided on both U/S and D/S, so as to protect the structure from seepage and hydraulic failures

View

Cross Regulator

It is a structure constructed

across the parent canal at the down

stream of off taking branch canal

View

Cross Regulator

Functions

• To effectively control the entire canal Irrigation system.

• It regulates the flow of water in parent canal

• It facilitates repairs to the canal

contd . . .

Cross Regulator

Functions It controls entry of silt in to canal

It prevents breaches of canals by absorbing fluctuation of discharge

It feeds the off taking canal to meet the full supply demand even at low water levels by heading up View

Distributory Head Regulator

It is a structure constructed across an off taking Distributory

Canal

Functions• It regulates the flow of water in to a Distributory• It controls entry of silt in to canal• It can be used as a measuring Device View

A DISTRIBUTORY HEAD REGULATOR

CANAL REGULATOR

Movie Clippings on Live Structures

BARRAGE AND HEAD REGULATOR

Head Regulator

Off taking Main Canal

at Head Works

Branch Canal

CANAL DROP• A Drop is a vertical step in the bed level

of a canal• Situation: When the slope of natural

ground is steeper than the bed slope of canal, the difference is adjusted by constructing vertical walls at

regular intervals

LOCATION OF CANAL DROPS

NATURAL GROUND LEVEL

CANAL FSL

LONGITUDINAL SLOPE OF CANAL

DROP STRUCTURES

CANAL DROP COMPONENT PARTS1 Body Wall2 U/S & D/S protection works3 Notches and Notch pier4 Bank connections

CANAL DROP - COMPONENTS

TYPES OF CANAL DROPS

• Depending upon the Depth of fall and energy dissipation on D/S, the following types of Canal Drops are in use

TYPES OF FALLS

• 1 Vertical Drop Fall• 2 stepped Fall • 3 Rapid Fall• 4 Montague Fall• 5 Ogee Fall• 6 Notch type fall

VERTICAL DROP FALL

• It consists of a body wall with its crest at the U/S bed Level.

• A water cushion is provided at the foot of body wall on D/S for effective Energy Dissipation

View

STEPPED FALL

FEATURES A stepped Fall will be provided when the

Natural Ground is steeply falling. Stepped body wall will be provided A water cushion and solid apron will be provided on D/S to protect the D/S floor

from scour and uplift

View

RAPID FALL

FEATURES The Down stream profile is provided

in the form of gently sloping glacisThe slope of the glacis will be 1:15

to 1:20 The sloping surface will be formed

with rough stone boulders View

MONTAGUE TYPE FALL

FEATURES It is a modified form of straight glacis fall,

in which a parabolic glacis is provided which is called ‘Montague profile’

The Energy dissipation is more effective View

OGEE FALL

FEATURES The crest and down stream

profile of the body wall will be provided in the form of Convex and Concave curves for smooth gliding of water and also to avoid suction on body wall.

U/S & D/S Protection works will be provided as usual VIEW

NOTCH TYPE FALLS

FEATURES A Notch Pier will be constructed on the top of

body wall in which Notches will be provided Notches may be Triangular, Trapezoidal or

stepped Sill of the Notch will be at Bed Level of canal

on U/S and its top will be at FSL of canal View

Canal Escapes

• It is a structure constructed in a canal bank with a side channel to relieve the excess discharge of the main canal

• The escapes may be provided on the canal at suitable points and also at its tail end

• -contd

Canal Escapes

TYPES OF ESCAPES

1 Surplus Escape ( Regulator Type)

2 Tail Escape (Weir Type)

- contd

Canal Escapes

• Surplus Escape ( Regulator Type) Features: 1 It resembles like a canal regulator with its sill kept at the Bed Level of the canal

2 It can discharge the excess flow of the canal or even empty the entire canal flow through its gate controlled vents View

Canal Escapes ( Weir Type )

Features In this type of Escape, the crest of the weir is kept at the FSL of the canal to drain off the excess discharge of the canal in to a natural drain Protective works will be provided on D/S to prevent scouring

View

IMAGES OF TANK ESCAPES

( Weir Type )

VIEW

CANAL OUTLETS

• It is a structure built at the head of water course to regulate water flow to the fields

• It is also called ‘Sluice’ or ‘Module’

( contd )

CANAL OUTLETS

FEATURESIt receives water from a Minor or

a Distributory and supplies to the fields

It facilitates equitable distribution of available water to the users

contd

CANAL OUTLETS

Types of outlets or Modules

1 Non Modular outlets :- Discharge through the outlet depends upon the difference of head between the distributory and the water course Examples: Pipe outlets and Masonry Sluices - - contd

CANAL OUTLETS

PIPE OUTLET-FEATURES A pipe is placed in the bank of a Distributory to draw the water for supplying to the water course Masonry Head walls are to be constructed at both the ends of

the pipe View

CANAL OUTLETS

2 Modular outlets :- Discharge

through the outlet is constant and is independent of the difference of head between the distributory and the water course

Examples: Gibb’s Module

GIBB’S MODULE

FEATURESIt consists of a pipe with a bell mouth

entrance.The discharge end of the pipe is in

the form of a raising spiral pipe in which free circular flow is developed.

The discharge is constant VIEW

REVIEW

Types of Canal Regulation Structures

• Canal Head Regulator or Head Sluice• Cross regulator• Distributory Head regulator• Canal Drops or Falls• Canal Out lets or Sluices or Modules• Canal Escapes

TYPES OF FALLS

• 1 Vertical Drop Fall• 2 stepped Fall • 3 Rapid Fall• 4 Montague Fall• 5 Ogee Fall• 6 Notch type fall

Canal Escapes

TYPES OF ESCAPES

1 Surplus Escape ( Regulator Type)

2 Tail Escape (Weir Type)

- contd

CANAL OUTLETS

• It is a structure built at the head of water course to regulate water flow to the fields

• It is also called ‘Sluice’ or ‘Module’

( contd )

THE END

TREPEZOIDAL NOTCH FALL

NEXT

VERTICAL DROP FALL

BACK

NOTCH TYPE FALL

NEXT

RAPID FALL

BACK

OGEE FALL

BACK

STEPPED FALL

Water Cushion

Back

MONTAGUE FALL

U/S FSLD/S FSL

BACK

SURPLUS ESCAPE(REGULATOR TYPE)

NEXT

BACK

SURPLUS ESCAPE(Regulator type)

SURPLUS ESCAPE(WEIR TYPE)

NEXT

SURPLUS ESCAPE(WEIR TYPE)

NEXT

SURPLUS ESCAPE(WEIR TYPE)

BACK

PIPE OUTLET

IMAGES

GIBB’S MODULE

BACK

A water course taken off from a Minor Distributory

NEXT

A WATER COURSE WITHPIPE OUTLET

NEXT

A view of water course

NEXT

Regulation of water to the fields from water course

BACK

FUNCTIONING OF HEAD REGULATOR

IMAGE

Barrage

River

Head Regulator

Off taking Canal

Features

AN OVER VIEW OF RIVER HEAD AN OVER VIEW OF RIVER HEAD WORKSWORKS

Cross & Distributory regulators

BACK

JUNCTION OF MAIN AND BRANCH CANALS

U/S

D/S CROSS REGULATOR

Distributory Head Regulator

D/S

Home

JUNCTION OF MAIN AND BRANCH CANALS

U/S

D/S CROSS REGULATOR

Distributory Head Regulator

D/S

Home

D/S view of Head Regulator

BACK

Trapezoidal Drop

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