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water supply

water supply, process or activity by which water is provided for some use, e.g., to a home, factory, or business. The term may also refer to the supply of water provided in this way.

In the United States, the average residential daily water supply demand is 100 gal (380 liters) per person, although it can go as high as 500 gal (1900 liters) per person. The stringency of the requirements that a supply of water must meet depends on the use to be made of it. For example, water used to wash semiconductor material from which transistors are made must be extraordinarily pure. The more usual requirements, however, are that water be free enough of harmful bacteria, chemicals, and other contamination to be drinkable; free of substances that make its taste or appearance unpleasant; and if the water is to be used for washing, free of salts of calcium and magnesium that will interfere with the action of soap.

The basic source of water is rainfall, which collects in rivers and lakes, under the ground, and in artificial reservoirs. Water from under the ground is called groundwater and is tapped by means of wells. Most often water must be raised from a well by pumping. In some cases a well will draw water from a permeable rock layer called an aquifer in which the water is under pressure; such a well needs little or no pumping (see artesian well). When the groundwater that is extracted is replenished slowly or not at all, the aquifer is depleted and deeper wells, or new water sources, are needed. (The depleted water-bearing layer can also compact, leading to subsidence at the surface.) Water that collects in rivers, lakes, or reservoirs is called surface water. Most large water supply systems draw surface water through special intake pipes or tunnels and transport it to the area of use through canals, tunnels, or pipelines, which are known as mains or aqueducts. These feed a system of smaller conduits or pipes that take the water to its place of use. The California Water Plan, initiated in 1957, eventually entailed twenty dams, seven power plants, and more than 700 mi (1100 km) of canals, tunnels, and pipelines to meet the needs of southern California residents—a total of more than five billion cubic meters of water per year.

A complete water supply system is often known as a waterworks. Sometimes the term is specifically applied to pumping stations, treatment stations, or storage facilities. Storage facilities are provided to reserve extra water for use when demand is high and, when necessary, to help maintain water pressure. Treatment stations are places in which water may be filtered to remove suspended impurities, aerated to remove dissolved gases, or disinfected with chlorine, ozone, ultraviolet light, or some other agent that kills harmful bacteria and microorganisms. Sometimes hard water is softened through ion exchange, by which dissolved calcium and magnesium salts are replaced by sodium salts, which do not interfere with soap. Salts of iodine and fluorine, which are considered helpful in preventing goiter and tooth decay, are sometimes added to water in which they are lacking.

Not all water supply systems are used to deliver drinking water. Systems used for purposes such as irrigation and fire fighting operate in much the same way as systems for drinking water, but the water need not meet such high standards of purity. In most municipal systems hydrants are connected to the drinking water system except during periods of extreme water shortage. Because many cities draw water from the same body into which they discharge sewage, proper sewage treatment has become increasingly essential to the preservation of supplies of useful water (see sewerage; water pollution).

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(civil engineering)
The whole system of supply and treatment utilized in acquisition and distribution of water to consumers.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


A complete system of pipelines, conduits, and so forth for distributing water from one or more reservoirs, purifying the water, and then pumping it through a distribution system for use by a community.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.


1. an establishment for storing, purifying, and distributing water for community supply
2. a display of water in movement, as in fountains
3. Brit informal euphemism the urinary system, esp with reference to its normal functioning
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
From a financial perspective, it is natural for individual residents to want lower waterworks rates.
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WaterWorks 2013 is the premier forum where water professionals meet to exchange ideas and gain greater insight into current economic conditions and challenges being faced by cities and counties across the country.
When the Waterworks declined to consider a price cut, county supervisors considered plans on how to resell water to the brewery at a reduced rate.
Summary: BEIRUT: The Union of Waterworks employees in the northern governorate put an end Monday to an open strike it staged last week.
The addition of Jones Water Supply to the RAMSCO family will allow them to take their services in this area to a higher level, and will enable the company to access new markets in both the waterworks products and services industries.
The alert, at 8.10pm last night, prompted the fire service's specialist chemical spill unit to descend on Waterworks Street.