# What purpose generally water is required in a town or city

While designing the water supply schemes of the town. It is necessary to determine the total year demand as well as monthly demand variation in the demand rates.

Following are the various types of water demand of city or town :

• Domestic water demand
• Commercial and industrial demand
• Fire- demand
• Demand for public uses
• Compensate losses demand

In the community, water is used for various purposes as described above. For the purpose of estimation of the total requirement of water, the demand is calculated on average basic, which is expressed as so many litres\capita\day.
If a is the total quantity of water required by a town per year in litres, and the population of the town is p, the per capacity demand will be

Per capita demand = Q/(p×365liter day)

The per capita demand of town depends on the various factors and will be according to the living standard of the public and number and type of the commercial places in the town etc.
For an average Indian town, the requirement of the water in various uses is as under

• Domestic use 135 liter\capita\day
• Industrial 40 liter\capita\ day
• Public use 25liter\capita\day