2. INFRASTRUCTURE &
TOWN PLANNING
INFRASTRUCTURE OF WATER SUPPLY (ASGMT-2)
DEFINITION:
Water supply is the provision of water by public utilities, commercial organisations, community
endeavors or by individuals, usually via a system of pumps and pipes. Public water supply systems
crucial to properly functioning societies. These systems are what supply drinking water to populations
around the globe.
INTRODUCTION
Water supply system in urban area should be developed in a proper way to meet the demand and at
the same time, quality of water should also be maintained with in standard prescribed limits. Thus the
quality of water and the distributions are the important issues for urban water supply system.
of an adequate quantity of water has been a matter of concern since the beginning of civilization.
in ancient cities, local supplies were often inadequate and aqueducts were built to convey water from
distant sources.
Water Network is defined as the stoke of facilities and installations needed to develop and manage
water resources, including delivery, treatment, supply and distribution of water to its users as well as
the collection, removal, treatment and disposal of sewage and wastewater.
The primary objective of water supply system is to take water from the best available source and to
subject it to processing which will ensure water of good quality, free from unpleasant taste or odor
containing nothing which might be detriment to health, and to distribute it to meet the requirement
the town or the city.
3. INFRASTRUCTURE &
TOWN PLANNING
INFRASTRUCTURE OF WATER SUPPLY (ASGMT-2)
SOURCES OF WATER SUPPLY
The sources of water may be classified into:
Surface water source
• Ponds
• Lakes
• Streams
• Rivers
• Storage Reservoir
Figure 1 Pond Figure 3 River Figure 2 Storage Reservoir
Ground water source
• Springs
• Infiltration Galleries
• Infiltration Well
• Wells
• Dug Well
• Tube Well
• Artesian Well Figure 6 Infiltration Galleries
Figure 4 Spring
Figure 5 Well
4. INFRASTRUCTURE &
TOWN PLANNING
INFRASTRUCTURE OF WATER SUPPLY (ASGMT-2)
QUALITY OF WATER
Rain is the principal source of water. The rain water as it passes through the atmosphere gets
with oxygen, carbon dioxide, other gases and other suspended impurities in the atmosphere. When it
reaches the ground, it gathers particles of silt and mud. While it flows towards a stream it passes
through the decaying vegetative matter and organic acids enter in to water. The impurities in water
may be classified into inorganic and organic impurities which may be present in the form of
colloidal and dissolved state.
Water which is fit or suitable for drinking purpose or which is not injurious to human health is called
potable water or wholesome water.
Potable water should have the following properties:
• It should be colorless
• It should be odorless
• It should have good taste
• It should not contain any harmful microorganisms or it should be safe microbiologically.
Classification of Water Quality Parameters:
Physical: Taste, Odour, Colour, Temperature, Turbidity
Chemical: Inorganic (Calcium, Magnesium, Iron etc.)
Organic (Oil, Gasoline, Detergents etc.)
Biological: Bacteria, Virus, Algae
5. INFRASTRUCTURE &
TOWN PLANNING
INFRASTRUCTURE OF WATER SUPPLY (ASGMT-2)
QUALITY OF WATER
Indian Standards for Physical Parameters of Drinking Water
Parameters Permissible Limit Cause of rejection
Total suspended solids (mg/l) 500 2000
Turbidity (NTU) 1 10
Colour (TCU) 5 25
Taste & odour (TON) 1 3
6. INFRASTRUCTURE &
TOWN PLANNING
INFRASTRUCTURE OF WATER SUPPLY (ASGMT-2)
QUALITY OF WATER
Indian Standards for Chemical Parameters of Drinking Water
Parameter Maximum allowable value General and Health effects
Total dissolved solids 2000 Undesirable taste, incrustation
pH 6.5-8.5 Bitter taste, corrosion
Alkalinity 600 Boiled rice turns yellowish
Hardness 600 Poor lathering with soap, scale forming,
skin irritation
Chloride 1000 Taste affected, corrosive
Free ammonia 0.15 Indicates recent pollution
Organic ammonia 0.3 Indicates quantity of nitrogen before
decomposition has started
Nitrate 45 Indicate old pollution
Nitrite 0 Indicate partial decomposed condition
Fluoride 1.5 Dental and skeletal fluorosis
Note: All units in mg/L except of pH
7. INFRASTRUCTURE &
TOWN PLANNING
INFRASTRUCTURE OF WATER SUPPLY (ASGMT-2)
WATER TREATMENT PROCESSES:
The purpose of water treatment is to remove all
those impurities, which are objectionable, either
form taste or odor point of view or from public
health point of view.
• Following are purposes of water treatment:
A. To remove color, dissolved gas and murkiness
of water.
B. To remove objectionable tastes and odor.
C. To remove the disease-producing micro-
organisms so that water is safe for drinking
purposes.
D. To remove hardness of water.
• For surface waters, following treatment
processes are generally adopted.
Screening
Aeration
Sedimentation With or Without Coagulants.
Filtration
Disinfections
Miscellaneous Processes
Water Treatment Process
8. INFRASTRUCTURE &
TOWN PLANNING
INFRASTRUCTURE OF WATER SUPPLY (ASGMT-2)
DISTRIBUTION OF WATER-SUPPLY
Distribution of water is very much important in any water supply network. Water supply distribution is
designed to satisfy the demand placed by different land use densities and fire fighting requirements
all the time. Piping systems, pumping stations, storage facilities, fire hydrants, house connections, and
water meters constitute the entire distribution system. The distribution system normally costs 60 to
70% of the total cost.
Municipal water supply system consists of the following units:
• Collection works
• Transmission works
• Purification works
• Distribution works
Distribution reservoirs, also called service reservoirs, are the storage reservoirs, which store the
treated water for supplying water during emergencies (such as during fires, repairs, etc.) and also to
help in absorbing the hourly fluctuations in the normal water demand.
Functions of Distribution Reservoirs:
• to absorb the hourly variations in demand.
• to maintain constant pressure in the distribution mains.
• water stored can be supplied during emergencies.
TYPES OF
DISTRIBUTION
RESERVOIRS
Surface Reservoirs
Elevated
Reservoirs
9. INFRASTRUCTURE &
TOWN PLANNING
INFRASTRUCTURE OF WATER SUPPLY (ASGMT-2)
DISTRIBUTION OF WATER-SUPPLY
Methods of water distribution:
Depending upon the level of the source of water and that of the city, topography of the area and other
local conditions and considerations, the water may be forced into the distribution
system in the following three ways:
• Gravity system
• Pumping system
• Combined gravity and pumping system or dual system
Gravity system
This method is suitable when source of supply such as lake or reservoir is at sufficient height than the city. It
can also be used if some ground sufficiently high above the city area is available which can be best utilized
for the distribution system in maintaining pressure in water pipes. The water flows in the mains is due to
the gravitational force. As no pumping is required, it is most reliable and economical system for the
distribution of water
10. INFRASTRUCTURE &
TOWN PLANNING
INFRASTRUCTURE OF WATER SUPPLY (ASGMT-2)
DISTRIBUTION OF WATER-SUPPLY
Pumping system
In pumping system the treated water is directly pumped in to the distribution mains without storing
it anywhere. For this reason, this system is also called pumping without storage system. In this
system, continuous water is required at pumping station. If the power supply fails, there will be
complete stoppage of water supply and if by chance, a fire breaks out at such a time, it will bring
disaster.
Pumping Station
11. INFRASTRUCTURE &
TOWN PLANNING
INFRASTRUCTURE OF WATER SUPPLY (ASGMT-2)
DISTRIBUTION OF WATER-SUPPLY
Combined gravity and pumping system
This is the most common system adopted in most of the cases. In this system, the treated water is
pumped at a constant rate and stored into an elevated distribution reservoir, from where it is
distributed to the consumer by the action of gravity.
Combined gravity and pumping system
