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)

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.

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

FACTORE AFFECTING THE WATER DEMAND

Big city

• Size of the citySmall towns

Example: Delhi 244 l/c/d Vijayawada 135 l/c/d

• Climate condition

less in wintermore in summer

• Cost of water

rate demand rate demand

• Supply system

Bad Supply

• Distribution System

Good supply

demandPressure high

Pressure low

demand

demand demand

• Industry

• Quality of water

good demand demandbad

demand demandindustryindustry

• Habit of people

demand demandEWS MIG

(Living style)

Per Capita Demand

The demand of water per person per day.

yearly water demandpopulation x 365

per capita demand :

An average Indian town per capita consumption varies from 150 to 300 liters.

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

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