Lecture : 3 Fundamentals of Water Supply Network

Lecture : 3 Fundamentals of Water Supply

Network

By Iqra Ismail Lecturer CRP Dep, LCWU

Course Title Infrastructure Planning & Management (Maj/CRP-304)

Fundamentals of Water Supply Network


Water infrastructure can be

defined as a stoke of facilities

and installations needed to

develop and manage water

resources,

treatment,

including

supply

delivery,

and

distribution of water to its users

as well as for the collection,

removal, treatment and disposal

of sewage and wastewater.

Definition


Public water supply scheme should meet the following requirements:

1. Ensured quality of water supply

2. Ensured sufficient quantity of supply

3. Ensured convenient and easy accessibility of water supply distribution

4. Ensured economic and financial viability of water supply


Sources of Water

Source of Water

Surface Water Ground Water

Ponds

Lakes

Streams

Rivers

Storage Reservoir

Stored Rain Water

Springs

Infiltration Galleries

Infiltration Well

Wells:

Dug Well

Tube Well

Artesian Well

French Well


Water Requirements

The total consumption per day will be a product of total population and the consumption of

water per person per day.

Determination of total water requirement involves determination of:

1. Water Demand (Per day)

• Domestic or residential demand

• Industrial demand

• Institutional demand

• Fire demand

• Demand for public uses

• Water required to compensate losses in waste and thefts

2. Population Determination

• It is one of the most important factors in planning a water supply project, if the project has

to serve the community for a certain design period.

• Design period of 20 to 40 years is selected.


Components of water supply scheme Factors Affecting Rate of Demand

Size and type of community

Standard of living

Climatic condition

Quality of water

Pressure in the supply

Development of sewerage facilities

Metering of water

Cost of water

System of water supply

Industrial and commercial activities


Components of water supply scheme Quality of Water

Potable water should have the following properties:

1. It should be colorless

2. It should be odorless

3. It should have good taste

4. It should not contain any harmful microorganisms or it should be safe

microbiologically


Components of water supply scheme Quality Parameters

Quality Parameters

Physical Quality Parameters

Chemical Quality Parameters

Biological Quality Parameters

Temperature

Color

Taste

Odor

Turbidity

Conductivity

Total Solids

Chlorides

Hardness

pH

Alkalinity

Acidity

Nitrogen and its

compounds

Metals and other

chemical substances

Dissolved Gases


Components of water supply scheme

Components

Collection Work Transmission Work Purification Work/ Water Treatment

Plant Distribution Works

Components of Water Supply Scheme


Diagram of Water Supply Scheme

Reservoir

River

Dam

tri D

is

bution

s m te ys

Water treatment plant

Pump house

Elevated

reservoir

Collection works

Transmission works

Pump house

Purification works

ks

Distribution wor



Components



Meant for collecting

the water from the

selected source of

water

(Surface/Ground)



Collection of Water

Function of intake:

To help in safely collecting or

withdrawing water from the surface

source over a predetermined pool

levels and then to convey this water

either by gravity or pumping to the

treatment plant via intake conduits.

Intake structure


Types of intake

According to the type of source

River intake

Reservoir intake

Canal intake

Lake intake

According to the position of intake

Submerged intake

Exposed intake

According to the presence of water in the tower

Wet intake

Dry intake

Types of Intakes


Types of intake


River intake

Reservoir intake

Canal intake

Lake intake

According to the position of intake

Submerged intake

Exposed intake

According to the presence of water in the tower

Wet intake

Dry intake

Types of Intakes


River Intake


River Intake

Reservoir Intake

Canal Intake

Lake Intake

Location

Upstream side of city to get

comparatively better quality of water

Components

Closed concrete or masonry well

Pumps

Rising main

Entry ports with screens

Located sufficiently inside the river

so that necessary demand of

water can be met in all seasons of

the year

Located slightly away from the

river bed when river bed is soft or

unstable



River Intake

Reservoir Intake

Canal Intake

Lake Intake

Intake towers are separately

constructed in case of earthen dams

but in gravity dam it is constructed

inside the dam itself.

It is constructed when the flow

in the river is not guaranteed

throughout the year.

A dam is constructed across

the river to store the water in

the reservoir so formed.

Reservoir Intake



River Intake

Reservoir Intake

Canal Intake

Lake Intake

Canal Intake

For small town a nearby irrigation canal can be used

as the source of water.

The intake well is generally located in the bank of

the canal.

Canal should be lines on upstream and downstream

side of the intake to prevent erosion of sides and

bed of canal.



River Intake

Reservoir Intake

Canal Intake

Lake Intake

lake Intake

It is submersible intake.

These intakes are constructed in the

bed of the lake below the low water level

so as to draw water even in dry season.



Components




the water from the

selected source of

water

(Surface/Ground)

Meant for

conveyance of water

from source to water

treatment plant



Transmission of Water

Water is conveyed to the city by means of

conduits.

If the source is at higher elevation than the

treatment plant, the water can flow under

gravitational force.

If the source of supply of water is river or

reservoir and the town is situated at higher

level, the water will have to be pumped and

conveyed through pressure pump.

Aqueduct

Water can be conveyed from source to the

treatment plant by open channels, aqueducts,

tunnels, flumes, pipes.

Open channel



Components




the water from the

selected source of

water

(Surface/Ground)

Meant for

conveyance of water

from source to water

treatment plant

Meant for supplying

potable water


0


The main aim of water treatment is to produce and maintain water that

is hygienically safe, aesthetically attractive and potable in an

economical manner.

Water treatment processes are basically meant for removal of

impurities of raw water and bringing the quality of water to the required

standards.

Purification of Water


Distribution system

Flow Diagram of Water Treatment Plant Process

Aeration Pre-

Chlorination Channel Flow Measurement

Alum Mixing Clari-

Floculation Filter Process

Outlet Flow Measurement

Post - Chlorination


Lecture : 3 Fundamentals of Water Supply Network

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