supplying wholesome water to consumers with suitable methods in economical way,to exist human life water is very important as air is,so,as a civil engineer's we have to supply safe water to consumers in economical way,in this we are going to explain about component parts of water supply scheme,systems of water distribution and layouts of distribution system according to their suitability.

1. WATER SUPPLY SCHEME
BY
SHIVA KUMAR
SOMASEKHAR
SUDHARSHAN
SUNIL KUMAR REDDY

2. CONTENTS :
 IMPORTANCE OF WATER
 OBJECTIVES OF PROTECTED WATER SUPPLY
 COMPONENTS OF A PROTECTED WATER SUPPLY SCHEME
 PERCAPITA DEMAND
 SYSTEMS OF DISTRIBUTION
 LAYOUTS OF DISTRIBUTION SYSTEMS

3. 9C405.5
General Importance of water
 No life can exist without water
 It is as essential for life as air is
 Two-third of human body is constituted of water
 Provides luxuries and comforts to human beings
3

4. 9C405.5
Objectives of protected water supply
 To supply safe and wholesome water to consumers
 To supply water in sufficient quantities
 To supply water at convenient points and timings
 To supply water at reasonable cost to the users
 To encourage personal and house hold cleanliness of users
The objectives of protected water supply scheme are
4

5. 9C405.6
Components of a protected water supply scheme
 Source of water
 Intakes
 Treatment
 Distribution

6. 9C405.6
Sources of water
Surface water Sub surface water
6
Classification of sources of water

7. 9C405.6
Water Supply Scheme
Sources of water
Surface sources Sub-surface sources
Springs Wells
Ponds, lakes Rivers and
streams
Impounding
reservoirs
Infiltration
galleries
Infiltration
wellsArtesian wells Dug wells Driven wells Tube wells
Shallow tube wells Deep tube wells
Intake works
Treatment Works
Aeration Sedimentation Filtration Disinfection Miscellaneous
treatment
Distribution system
Supply to the consumer
7
Fig 1 Schematic diagram of typical water supply scheme

8. 9C405.12 8
Design period
 Water supply projects includes permanent constructions
at Intakes, treatment plants and overhead tanks and
laying of pipe lines
 They can not be replaced or resized or reconstructed
easily in every year, as per the needs of the increased
population, as it include huge amount of capital

9. 9C405.12 9
Design period contd..
 The design periods for various project components may
be taken as follows
Component
Storage reservoir
Infiltration works
Pipe connections
Distribution systems
Water treatment units
Electric motors and pumps
Design period
15 years
15 years
50 years
30 years
30 years
30 years

10. 9C405.6
Intakes
 Intakes are structures which collect water from the
surface sources, for further conveyance to treatment
plant
eg. Reservoir intake, Lake intake, River intake, Canal
intake
10

11. 9C405.6
Treatment of water
 The raw water from different sources contains various
impurities
 It can not be directly used by the public
 To reduce the impurities below the allowable limits, raw
water should be properly treated in a treatment plant
11

12. 9C405.7
Factors affecting ‘per capita demand’
1. Social and economical status of consumer
2. Cost of water
3. Climatic conditions
4. Industrial and commercial activities
5. Pressure in distribution system
12

13. 9C405.9
Per Capita Demand
Definition
 It is the amount of water required by one person per one
day ( based on annual average)
 It includes the domestic use, industrial and commercial
use, public use, wastes and thefts, fire demand etc.
1313

14. 9C405.9
Variation in water demand
 The water demand is not constant through out
 There are wide variations in the use of water in different
seasons, months, days and hours
 The variation depends on the general habits of people,
climatic conditions and character of city such as industrial,
Commercial and residential etc.
14

15. 9C405.9
Types of variations in water demand
 Seasonal variations
 Monthly variations
 Daily variations
 Hourly variations
15

16. 9C405.9
16
Fig 1 variation of water demand in a day

17. 17
Requirements of Good Distribution System
• Simple and easy to operate
• Sufficient pressure head at all points
• The minimum residual pressure for a single storey building is
0.07 N/mm2 and for a double storey building is 0.12 N/mm2
• Requisite amount of water for fire fighting
• Economical
• Distribution pipes should not be laid below sewer lines,
to avoid pollution
• Min. pipe sizes of 100 mm for towns having population up
to 50,000 and 150 mm pipes for those above 50,000

18. 9C405.41 & 42 18
Systems Of Distribution
• COMBINED OR DUAL SYSTEM
• GRAVITY OR DIRECT SYSTEM
• PUMPING OR INDIRECT SYSTEM

19. 9C405.41 & 42 19
Fig. 1 GRAVITY SYSTEM
Systems of distribution contd..

20. 9C405.41 & 42 20
Fig.2 PUMPING SYSTEM
Systems of distribution contd..

21. 9C405.41 & 42 21
FIG.3 COMBINED GRAVITY & PUMPING SYSTEM
Systems of distribution contd..

22. 9C405.45 & 46 22
Fig.2 OHSR (RECTANGULAR)

23. 9C405.45 & 46 239C405.43 & 44 23
Methods / Systems of supply
Water may be supplied by two systems / methods
• Continuous system
• Intermittent system

24. 9C405.47 & 48 24
Layouts in distribution system
• CIRCULAR or RING SYSTEM
• DEAD END OR TREE SYSTEM
• GRID IRON SYSTEM
Depending on method of layout of the pipe lines, the
distribution systems are classified as…
• RADIAL SYSTEM

25. 9C405.47 & 48 25
Fig.1 Dead end or tree system
Dead end
Dead
end
MD
MD
MD
MD
CV
CV
CV
CV
MD – minor distributors
DE – dead end
DE

26. 9C405.49 26
Fig.1 Grid iron system

27. 9C405.50 & 51 27
Fig.1 Circle (or) ring system

28. 9C405.50 & 51 28
Fig.2 Radial system

29. Next to Air, the other important requirement for human life
to exist, is water.As a matter of fact every living soul requires water for
its survival.So,providing purified water to everyone in economicway
with suitable methods.
CONCLUSION:

30. THANK YOU