Types of water demand
The following are the various types of water demand of a town or city:
The domestic demand includes the water required in the houses for drinking, cooking, bathing, washing of clothes and utensils, sanitary blocks, private vehicles, gardening, etc. The requirement of water for domestic animals is also included in this demand. In Indian towns or cities, the domestic consumption of water under normal condition is taken as 135 lits/day/capita ( as per I.S: 1172- 1971). In developed countries, the water demand is very high due to their advanced lifestyle.
It includes the water demand in commercial centres like the office building, hotels, restaurants, shopping centres, cinema houses, motor garages, laundries, diaries etc. For this purpose, the demand is assumed as 25 lits to 40 lits. capita/day.
The industrial demand for water depends on the type of industry in the area. The number and type of industries such as cloth mill, paper mill, cotton mill, sugar mill, chemical industry, hume pipe, rolling mill, etc. should be recorded. The water demand for this purpose is generally assumed as 20% to 25% of the total water demand of the city or town.
It includes the water requirement for public places such as public sanitary blocks, parks, swimming pools, etc. The water demand for this purpose is considered as 5% of the total consumption of water in the town or city.
In case of any outbreak of fire in busy areas of a town or city, sufficient quantity of water may not be available for fire-fighting from the surface sources such as Pounds, ditches, open wells etc. Again these sources may not exist within busy areas of the town or city. Hence, the requisite amount of water for fire-fighting should always be kept is stored in underground reservoirs in specific places and fire hydrants should be established in main pipelines at an interval of about 100 m to 150 m. In the event of a fire, the fire brigade pump is connected to the Fire hydrant and the jet of water is thrown under high pressure over the fire.
Book-Environmental Engineering, Writer-N N Basak