Lably
Skip to content

Water supply

Provision of water by public utilities, commercial organisations or others

  • 22 min read
  • 8 chapters
  • 4 labs on Lably
A young girl collects clean water from a supply at her home near Kawempe in Uganda. Australia recognises the importance of access to clean water to the health and livelihoods of people.
Kate Holt/AusAID · CC BY 2.0

Learn it on Lably

The cost of supplying water consists, to a very large extent, of fixed costs (capital costs and personnel costs) and only to a small extent of variable costs that depend on the amount of water consumed (mainly energy and chemicals). Almost all service providers in the world charge tariffs to recover part of their costs.

Water supply is a separate topic from irrigation, the practice and systems of water supply on a larger scale, for a wider variety of purposes, primarily agriculture.

Technical overview

Water supply systems get water from a variety of locations after appropriate treatment, including groundwater (aquifers), surface water (lakes and rivers), and the sea through desalination. The water treatment steps include, in most cases, purification, disinfection through chlorination and sometimes fluoridation. Treated water then either flows by gravity or is pumped to reservoirs, which can be elevated such as water towers or on the ground (for indicators related to the efficiency of drinking water distribution see non-revenue water). Once water is used, wastewater is typically discharged in a sewer system and treated in a sewage treatment plant before being discharged into a river, lake, or the sea or reused for landscaping or irrigation.

Supply network

A water supply network or water supply system is a system of engineered hydrologic and hydraulic components that provide water supply. A water supply system typically includes the following:

  1. A drainage basin (see water purification – sources of drinking water)
  2. A raw water collection point (above or below ground) where the water accumulates, such as a lake, a river, or groundwater from an underground aquifer. Raw water may be transferred using uncovered ground-level aqueducts, covered tunnels, or underground pipes to water purification facilities..
  3. Water purification facilities. Treated water is transferred using water pipes (usually underground).
  4. Water storage facilities such as reservoirs, water tanks, or water towers. Smaller water systems may store the water in cisterns or pressure vessels. Tall buildings may also need to store water locally in pressure vessels in order for the water to reach the upper floors.
  5. Additional water pressurizing components such as pumping stations may need to be situated at the outlet of underground or aboveground reservoirs or cisterns (if gravity flow is impractical).
  6. A pipe network for distribution of water to consumers (which may be private houses or industrial, commercial, or institution establishments) and other usage points (such as fire hydrants)
  7. Connections to the sewers (underground pipes, or aboveground ditches in some developing countries) are generally found downstream of the water consumers, but the sewer system is considered to be a separate system, rather than part of the water supply system.

Water supply networks are often run by public utilities of the water industry.

Use

In the United States, the typical single family home uses about 520 L (138 US gal) of water per day (2016 estimate) or 222 L (58.6 US gal) per capita per day. This includes several common residential end use purposes (in decreasing order) like toilet use, showers, tap (faucet) use, washing machine use, leaks, other (unidentified), baths, and dishwasher use.

During the beginning of the 21st Century, especially in areas of urban and suburban population centers, traditional centralized infrastructure have not been able to supply sufficient quantities of water to keep up with growing demand. Among several options that have been managed are the extensive use of desalination technology, this is especially prevalent in coastal areas and in "dry" countries like Australia. Decentralization of water infrastructure has grown extensively as a viable solution including rainwater harvesting and stormwater harvesting where policies are eventually tending towards a more rational use and sourcing of water incorporation concepts such as "Fit for Purpose".

Sign in to keep reading

7 more chapters are free with a Lably account.

More in Industry