The document discusses different types of water demand - domestic, public, industrial, commercial, fire, and losses/waste. It provides estimated per capita daily demand amounts for each type according to Indian standards. Factors that affect water demand are also outlined, such as city size, climate, cost of water, distribution systems, supply systems, industries present, water quality, and living habits. Formulas to calculate firefighting water requirements based on population are also presented.

2. WATER DEMAND
• Domestic 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)
• 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
• Commercial 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)
• 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. Water requirement for different uses
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
270 l/c/d

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

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

7. • Industry
industry demand industry demand
• Quality of water
good demand bad demand
• Habit of people
(Living style)
EWS demand MIG demand

8. Per Capita Demand
The demand of water per person per day.
per capita demand : yearly water demand
population x 365
An average Indian town per capita consumption varies
from 150 to 300 liters.

9. Fire Fighting Required Calculation
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)

10. Fire Fighting Required Calculation
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