Water demand and factor affecting water demand

2. WATER DEMAND
This includes the water required in private building for drinking
,bathing, gardening, sanitary purpose, etc.
As per IS : 200 l/c/d (with fully flushing system)
135 l/c/d (for weaker sections and LIG)
•Domestic demand
•Public demand
it represents the water demand for public utility purpose.
like washing of public parks, gardening, washing on roads, public
fountain. 20 l/c/d
•Industrial demand
It represents the water demand of industries which are earlier
existing or are likely to be started in future.
As per IS : 50 l/c/d (for normal industries )
450 l/c/d (industrial cities)

3. WATER DEMAND
Water requirement for institutions , hotels , schools, colleges,
offices.
As per IS : 20 l/c/d (for normal commercial area)
50 l/c/d (highly commercial area)
•Commercial demand
•Fire demand
in populated or industrial area fires generally breakout and may lead to
serious problem. For control that situation require sufficient quantity
water that is called fire demand.
•Water demand require for thefts and wastes
This includes the water lost in leakage and stolen water due to
unauthorised water connection.

4. Domestic demand 135 l/c/d
Public demand 20 l/c/d
Industrial demand 50 l/c/d
Commercial demand 20 l/c/d
Fire demand 15 l/c/d
Loss and waste 50 l/c/d

Water requirement for different uses
270 l/c/d

5. FACTORE AFFECTING THE WATER DEMAND
Big city
•Size of the city
Small towns
Example: Delhi 244 l/c/d Vijayawada 135 l/c/d
•Climate condition
less in winter
more in summer
•Cost of water
rate demand ratedemand

6. •Supply system
Bad Supply
•Distribution System
Good supply
demand
Pressure
high
Pressure
low
demand
demand demand

7. •Industry
•Quality of water
good demand demandbad
demand demandindustryindustry
• Habit of people
demand demandEWS MIG
(Living style)

8. Per Capita Demand
The demand of water per person per day.

yearly water demand
population x 365
per capita demand :
An average Indian town per capita consumption varies
from 150 to 300 liters.

9. Total amount of water required : no. of fires X discharge X time of each fire
Amount of water required per person: amount of water/total population


Kuichling ‘s formula : Q= 3182√P
[ Q = amount of water required in
liters/minute]
[ P = population in thousands]
Freeman formula : Q= 1136[(P/10)+10 ]
Buston’s formula : Q= 5,663√P (Quantity of water required in liters per day)
(Kuichling formula, Freeman formula and buston formula give higher results. Because
water for fire fighting is required for few times in a year.)

Q = 100√P (water is kiloliter per day)
Fire Fighting Required Calculation

10. National board of fire under writers formulas :
When population is less than or equal to 2,00000
Q= 4,637 √ P[1-0.01 √P ]
When the population more than 2,00000 a provision for 54,600 liters/minute may be
made with an extra additional provision of 9,100 to 36,400 liters/minute for a second
fire.
For a residential city
1)Small or low buildings = 2200 litres/minute
2)Larger or higher buildings = 4500 litres/minute.
3)High value residence ,apartments, tenements= 7650 to 13500 litres/minute
Fire Fighting Required Calculation