Water supply

Water supply

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Encyclopedia
Water supply is the provision of water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

 by public utilities
Public utility
A public utility is an organization that maintains the infrastructure for a public service . Public utilities are subject to forms of public control and regulation ranging from local community-based groups to state-wide government monopolies...

, commercial organisations, community endeavours or by individuals, usually via a system of pumps and pipes. Irrigation
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

 is covered separately.

Global access to clean water


In 2010 about 84% of the global population (6.74 billion people) had access to piped water supply through house connections or to an improved water source
Improved water source
According to the Joint Monitoring Program for Water Supply and Sanitation by the World Health Organization and UNICEF the following are considered as "improved" water sources:* household connections* public standpipes* boreholes* protected dug wells...

 through other means than house, including standpipe
Standpipe (street)
A standpipe is a freestanding pipe fitted with a tap which is installed outdoors to dispense water in areas which do not have a running water supply to the buildings....

s, "water kiosks", protected springs and protected wells. However, about 14% (884 million people) did not have access to an improved water source and had to use unprotected wells or springs, canals, lakes or rivers for their water needs.

A clean water supply, especially so with regard to sewage, is the single most important determinant of public health. Destruction of water supply and/or sewage disposal infrastructure after major catastrophes (earthquakes, floods, war, etc.) poses the immediate threat of severe epidemics of waterborne diseases
Waterborne diseases
Waterborne diseases are caused by pathogenic microorganisms which are directly transmitted when contaminated fresh water is consumed. Contaminated fresh water, used in the preparation of food, can be the source of foodborne disease through consumption of the same microorganisms...

, several of which can be life-threatening.

Technical overview


Water supply systems get water from a variety of locations, including groundwater (aquifer
Aquifer
An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...

s), surface water (lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

s and river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

s), conservation
Water conservation
Water conservation refers to reducing the usage of water and recycling of waste water for different purposes such as cleaning, manufacturing, and agricultural irrigation.- Water conservation :Water conservation can be defined as:...

 and the sea through desalination
Desalination
Desalination, desalinization, or desalinisation refers to any of several processes that remove some amount of salt and other minerals from saline water...

. The water is then, in most cases, purified
Water purification
Water purification is the process of removing undesirable chemicals, materials, and biological contaminants from contaminated water. The goal is to produce water fit for a specific purpose...

, disinfected through chlorination
Chlorination
Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water...

 and sometimes fluoridated. Treated water then either flows by gravity or is pumped to reservoirs, which can be elevated such as water tower
Water tower
A water tower or elevated water tower is a large elevated drinking water storage container constructed to hold a water supply at a height sufficient to pressurize a water distribution system....

s or on the ground (for indicators related to the efficiency of drinking water distribution see non-revenue water
Non-revenue water
Non revenue water is water that has been produced and is “lost” before it reaches the customer. Losses can be real losses or apparent losses . High levels of NRW are detrimental to the financial viability of water utilities, as well to the quality of water itself...

). Once water is used, wastewater is typically discharged in a sewer
Sanitary sewer
A sanitary sewer is a separate underground carriage system specifically for transporting sewage from houses and commercial buildings to treatment or disposal. Sanitary sewers serving industrial areas also carry industrial wastewater...

 system and treated in a wastewater treatment plant
Sewage treatment
Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater and household sewage, both runoff and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants...

 before being discharged into a river, lake or the sea or reused for landscaping
Landscaping
Landscaping refers to any activity that modifies the visible features of an area of land, including:# living elements, such as flora or fauna; or what is commonly referred to as gardening, the art and craft of growing plants with a goal of creating a beautiful environment within the landscape.#...

, irrigation
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

 or industrial use (see also sanitation
Sanitation
Sanitation is the hygienic means of promoting health through prevention of human contact with the hazards of wastes. Hazards can be either physical, microbiological, biological or chemical agents of disease. Wastes that can cause health problems are human and animal feces, solid wastes, domestic...

).

Service quality


Many of the 3.5 billion people having access to piped water receive a poor or very poor quality of service, especially in developing countries where about 80% of the world population lives. Water supply service quality
Service quality
Service quality involves a comparison of expectations with performance.According to Lewis and Booms service quality is a measure of how well a delivered service matches the customers expectations....

 has many dimensions: continuity; water quality
Water quality
Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which...

; pressure; and the degree of responsiveness of service providers to customer complaints.

Continuity of supply


Continuity of water supply is taken for granted in most developed countries, but is a severe problem in many developing countries, where sometimes water is only provided for a few hours every day or a few days a week. It is estimated that about half of the population of developing countries receives water on an intermittent basis.

Water quality


Drinking water quality
Water quality
Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which...

 has a micro-biological and a physico-chemical dimension. There are thousands of parameters of water quality. In public water supply systems water should, at a minimum, be disinfected — most commonly through the use of chlorination
Chlorination
Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water...

 or the use of ultra violet light — or it may need to undergo treatment, especially in the case of surface water
Surface water
Surface water is water collecting on the ground or in a stream, river, lake, wetland, or ocean; it is related to water collecting as groundwater or atmospheric water....

. For more details please see the separate entries on water quality
Water quality
Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which...

, water treatment
Water treatment
Water treatment describes those processes used to make water more acceptable for a desired end-use. These can include use as drinking water, industrial processes, medical and many other uses. The goal of all water treatment process is to remove existing contaminants in the water, or reduce the...

 and drinking water
Drinking water
Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...

.

Water pressure



Water pressures vary in different locations of a distribution system. Water mains below the street may operate at higher pressures, with a pressure reducer
Pressure regulator
A pressure regulator is a valve that automatically cuts off the flow of a liquid or gas at a certain pressure. Regulators are used to allow high-pressure fluid supply lines or tanks to be reduced to safe and/or usable pressures for various applications....

 located at each point where the water enters a building or a house. In poorly managed systems, water pressure can be so low as to result only in a trickle of water or so high that it leads to damage to plumbing fixtures and waste of water. Pressure in an urban water system is typically maintained either by a pressurized water tank serving an urban area, by pumping the water up into a tower and relying on gravity to maintain a constant pressure in the system or solely by pumps at the water treatment
Water treatment
Water treatment describes those processes used to make water more acceptable for a desired end-use. These can include use as drinking water, industrial processes, medical and many other uses. The goal of all water treatment process is to remove existing contaminants in the water, or reduce the...

 plant and repeater pumping stations.

Typical UK pressures are 4-5 bar
Bar (unit)
The bar is a unit of pressure equal to 100 kilopascals, and roughly equal to the atmospheric pressure on Earth at sea level. Other units derived from the bar are the megabar , kilobar , decibar , centibar , and millibar...

 for an urban supply. However, some people can get over eight bars or below one bar. A single iron main pipe may cross a deep valley, it will have the same nominal pressure, however each consumer will get a bit more or less because of the hydrostatic pressure (about 1 bar/10m height). So people at the bottom of a 100 feet (30.5 m) hill will get about 3 bars more than those at the top.

The effective pressure also varies because of the supply resistance even for the same static pressure. An urban consumer may have 5 metres of ½" lead pipe running from the iron main, so the kitchen tap flow will be fairly unrestricted, so high flow. A rural consumer may have a kilometre of rusted and limed ¾" iron pipe so their kitchen tap flow will be small.

For this reason the UK domestic water system has traditionally (prior to 1989) employed a "cistern feed" system, where the incoming supply is connected to the kitchen sink and also a header/storage tank in the attic. Water can dribble into this tank through a ½" lead pipe, plus ball valve, and then supply the house on 22 or 28 mm pipes. Gravity water has a small pressure (say ¼ bar in the bathroom) but needs wide pipes allow higher flows. This is fine for baths and toilets but is frequently inadequate for showers. People install shower booster pumps to increase the pressure. For this reason urban houses are increasingly using mains pressure boilers (combies) which take a long time to fill a bath but suit the high back pressure of a shower.

Comparing the performance of water and sanitation service providers


Comparing the performance of water and sanitation service providers (utilities) is needed, because the sector offers limited scope for direct competition (natural monopoly
Natural monopoly
A monopoly describes a situation where all sales in a market are undertaken by a single firm. A natural monopoly by contrast is a condition on the cost-technology of an industry whereby it is most efficient for production to be concentrated in a single form...

). Firms operating in competitive markets are under constant pressure to out perform each other. Water utilities are often sheltered from this pressure, and it frequently shows: some utilities are on a sustained improvement track, but many others keep falling further behind best practice. Benchmarking
Benchmarking
Benchmarking is the process of comparing one's business processes and performance metrics to industry bests and/or best practices from other industries. Dimensions typically measured are quality, time and cost...

 the performance of utilities allows to simulate competition, establish realistic targets for improvement and create pressure to catch up with better utilities. Information on benchmarks for water and sanitation utilities is provided by the International Benchmarking Network for Water and Sanitation Utilities.

Institutional responsibility and governance


A great variety of institutions have responsibilities in water supply. A basic distinction is between institutions responsible for policy and regulation on the one hand; and institutions in charge of providing services on the other hand.

Policy and regulation


Water supply policies and regulation are usually defined by one or several Ministries, in consultation with the legislative branch. In the United States
Water supply and sanitation in the United States
Issues that affect water supply and sanitation in the United States include water scarcity, pollution, a backlog of investment, concerns about the affordability of water for the poorest, and a rapidly retiring workforce...

 the United States Environmental Protection Agency‎, whose administrator reports directly to the President, is responsible for water and sanitation policy and standard setting within the executive branch. In other countries responsibility for sector policy is entrusted to a Ministry of Environment (such as in Mexico
Water supply and sanitation in Mexico
Water supply and sanitation in Mexico is characterized by achievements and challenges. Among the achievements is a significant increase in access to piped water supply in urban areas as well as in rural areas between 1990 and 2006; a strong nationwide increase in access to improved sanitation ...

 and Colombia
Water supply and sanitation in Colombia
Water supply and sanitation in Colombia has been improved in many ways over the past decades. Between 1990 and 2004, access to sanitation increased from 82% to 86%, but access to water increased only slightly from 92% to 93%.. In particular, coverage in rural areas lags behind. Furthermore, despite...

), to a Ministry of Health (such as in Panama
Water supply and sanitation in Panama
Water supply and sanitation in Panama is characterized by relatively high levels of access compared to other Latin American countries. However, challenges remain especially in rural areas.- Access :...

, Honduras
Water supply and sanitation in Honduras
Water supply and sanitation coverage in Honduras has increased significantly in the last decades. However, the sector is still characterized by poor service quality and poor efficiency in many places. Coverage gaps still remain, particularly in rural areas....

 and Uruguay
Water supply and sanitation in Uruguay
Uruguay is the only country in Latin America that has achieved quasi universal coverage of access to safe drinking water supply and adequate sanitation . Water service quality is considered good, with practically all localities in Uruguay receiving disinfected water on a continuous basis...

), a Ministry of Public Works (such as in Ecuador
Water supply and sanitation in Ecuador
Water supply and sanitation in Ecuador is characterized by a number of achievements and challenges. One key achievement is a significant increase in both access to an improved water source and adequate sanitation...

 and Haiti
Haiti
Haiti , officially the Republic of Haiti , is a Caribbean country. It occupies the western, smaller portion of the island of Hispaniola, in the Greater Antillean archipelago, which it shares with the Dominican Republic. Ayiti was the indigenous Taíno or Amerindian name for the island...

), a Ministry of Economy (such as in German states) or a Ministry of Energy (such as in Iran
Water supply and sanitation in Iran
Water supply and sanitation in Iran has witnessed some important improvements, especially in terms of increased access to urban water supply, while important challenges remain, particularly concerning sanitation and service provision in rural areas....

). A few countries, such as Jordan
Jordan
Jordan , officially the Hashemite Kingdom of Jordan , Al-Mamlaka al-Urduniyya al-Hashemiyya) is a kingdom on the East Bank of the River Jordan. The country borders Saudi Arabia to the east and south-east, Iraq to the north-east, Syria to the north and the West Bank and Israel to the west, sharing...

 and Bolivia
Water supply and sanitation in Bolivia
Bolivia’s water and sanitation coverage has greatly improved since 1990 due to a considerable increase in sectoral investment. However, the country continues to suffer from what happens to be the continent’s lowest coverage levels as well as from low quality of services...

, even have a Ministry of Water. Often several Ministries share responsibilities for water supply. In the European Union, important policy functions have been entrusted to the supranational level. Policy and regulatory functions include the setting of tariff rules and the approval of tariff increases; setting, monitoring and enforcing norms for quality of service and environmental protection; benchmarking
Benchmarking
Benchmarking is the process of comparing one's business processes and performance metrics to industry bests and/or best practices from other industries. Dimensions typically measured are quality, time and cost...

 the performance of service providers; and reforms in the structure of institutions responsible for service provision. The distinction between policy functions and regulatory functions is not always clear-cut. In some countries they are both entrusted to Ministries, but in others regulatory functions are entrusted to agencies that are separate from Ministries.

Regulatory agencies


Dozens of countries around the world have established regulatory agencies for infrastructure services, including often water supply and sanitation, in order to better protect consumers and to improve efficiency. Regulatory agencies can be entrusted with a variety of responsibilities, including in particular the approval of tariff increases and the management of sector information systems, including benchmarking
Benchmarking
Benchmarking is the process of comparing one's business processes and performance metrics to industry bests and/or best practices from other industries. Dimensions typically measured are quality, time and cost...

 systems. Sometimes they also have a mandate to settle complaints by consumers that have not been dealt with satisfactorily by service providers. These specialized entities are expected to be more competent and objective in regulating service providers than departments of government Ministries. Regulatory agencies are supposed to be autonomous from the executive branch of government, but in many countries have often not been able to exercise a great degree of autonomy. In the United States
Water supply and sanitation in the United States
Issues that affect water supply and sanitation in the United States include water scarcity, pollution, a backlog of investment, concerns about the affordability of water for the poorest, and a rapidly retiring workforce...

 regulatory agencies for utilities have existed for almost a century at the level of states, and in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 at the level of provinces. In both countries they cover several infrastructure sectors. In many US states they are called Public Utility Commissions. For England and Wales, a regulatory agency for water (OFWAT) was created as part of the privatization of the water industry in 1989. In many developing countries, water regulatory agencies were created during the 1990s in parallel with efforts at increasing private sector participation. (for more details on regulatory agencies in Latin America, for example, please see Water and sanitation in Latin America and the regional association of water regulatory agencies ADERASA http://www.aderasa.org)

Many countries do not have regulatory agencies for water. In these countries service providers are regulated directly by local government, or the national government. This is, for example, the case in the countries of continental Europe, in China and India.

For more information on utility regulation in the water sector see the body of knowledge on utility regulation http://www.regulationbodyofknowledge.org/ and the World Bank's knowledge base on the same topic at http://rru.worldbank.org/Themes/UtilityRegulation/

Service provision


Water supply service providers, which are often utilities, differ from each other in terms of their geographical coverage relative to administrative boundaries; their sectoral coverage; their ownership structure; and their governance arrangements.

Geographical coverage



Many water utilities provide services in a single city, town or municipality
Municipality
A municipality is essentially an urban administrative division having corporate status and usually powers of self-government. It can also be used to mean the governing body of a municipality. A municipality is a general-purpose administrative subdivision, as opposed to a special-purpose district...

. However, in many countries municipalities have associated in regional or inter-municipal or multi-jurisdictional utilities to benefit from economies of scale
Economies of scale
Economies of scale, in microeconomics, refers to the cost advantages that an enterprise obtains due to expansion. There are factors that cause a producer’s average cost per unit to fall as the scale of output is increased. "Economies of scale" is a long run concept and refers to reductions in unit...

. In the United States these can take the form of special-purpose district
Special-purpose district
Special-purpose districts or special district governments in the United States are independent governmental units that exist separately from, and with substantial administrative and fiscal independence from, general purpose local governments such as county, municipal, and township governments. As...

s which may have independent taxing authority. An example of a multi-jurisdictional water utility in the United States is WASA
District of Columbia Water and Sewer Authority
The District of Columbia Water and Sewer Authority provides drinking water, sewage collection and wastewater treatment in Washington, D.C., USA. DC Water also provides wholesale wastewater treatment services to several adjoining municipalities in Maryland and Virginia...

, a utility serving Washington, DC and various localities in the state of Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...

. Multi-jurisdictional utilities are also common in Germany, where they are known as "Zweckverbaende", in France and in Italy.

In some federal countries there are water service providers covering most or all cities and towns in an entire state, such as in all states of Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

 and some states in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 (see Water supply and sanitation in Mexico
Water supply and sanitation in Mexico
Water supply and sanitation in Mexico is characterized by achievements and challenges. Among the achievements is a significant increase in access to piped water supply in urban areas as well as in rural areas between 1990 and 2006; a strong nationwide increase in access to improved sanitation ...

). In England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 and Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...

 water supply and sewerage is supplied almost entirely through ten regional companies. Some smaller countries, especially developed countries, have established service providers that cover the entire country or at least most of its cities and major towns. Such national service providers are especially prevalent in West Africa and Central America, but also exist, for example, in Tunisia
Tunisia
Tunisia , officially the Tunisian RepublicThe long name of Tunisia in other languages used in the country is: , is the northernmost country in Africa. It is a Maghreb country and is bordered by Algeria to the west, Libya to the southeast, and the Mediterranean Sea to the north and east. Its area...

, Jordan
Jordan
Jordan , officially the Hashemite Kingdom of Jordan , Al-Mamlaka al-Urduniyya al-Hashemiyya) is a kingdom on the East Bank of the River Jordan. The country borders Saudi Arabia to the east and south-east, Iraq to the north-east, Syria to the north and the West Bank and Israel to the west, sharing...

 and Uruguay
Uruguay
Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...

 (see also water supply and sanitation in Uruguay
Water supply and sanitation in Uruguay
Uruguay is the only country in Latin America that has achieved quasi universal coverage of access to safe drinking water supply and adequate sanitation . Water service quality is considered good, with practically all localities in Uruguay receiving disinfected water on a continuous basis...

). In rural areas, where about half the world population lives, water services are often not provided by utilities, but by community-based organizations which usually cover one or sometimes several villages.

Sector coverage


Some water utilities provide only water supply services, while sewerage
Sewage
Sewage is water-carried waste, in solution or suspension, that is intended to be removed from a community. Also known as wastewater, it is more than 99% water and is characterized by volume or rate of flow, physical condition, chemical constituents and the bacteriological organisms that it contains...

 is under the responsibility of a different entity. This is for example the case in Tunisia
Tunisia
Tunisia , officially the Tunisian RepublicThe long name of Tunisia in other languages used in the country is: , is the northernmost country in Africa. It is a Maghreb country and is bordered by Algeria to the west, Libya to the southeast, and the Mediterranean Sea to the north and east. Its area...

. However, in most cases water utilities also provide sewer
Sanitary sewer
A sanitary sewer is a separate underground carriage system specifically for transporting sewage from houses and commercial buildings to treatment or disposal. Sanitary sewers serving industrial areas also carry industrial wastewater...

 and wastewater treatment
Wastewater Treatment
Wastewater treatment may refer to:* Sewage treatment* Industrial wastewater treatment...

 services. In some cities or countries utilities also distribute electricity. In a few cases such multi-utilities also collect solid waste and provide local telephone services. An example of such an integrated utility can be found in the Colombian city of Medellín
Medellín
Medellín , officially the Municipio de Medellín or Municipality of Medellín, is the second largest city in Colombia. It is in the Aburrá Valley, one of the more northerly of the Andes in South America. It has a population of 2.3 million...

. Utilities that provide water, sanitation and electricity can be found in Frankfurt
Frankfurt
Frankfurt am Main , commonly known simply as Frankfurt, is the largest city in the German state of Hesse and the fifth-largest city in Germany, with a 2010 population of 688,249. The urban area had an estimated population of 2,300,000 in 2010...

, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 (Mainova), in Casablanca
Casablanca
Casablanca is a city in western Morocco, located on the Atlantic Ocean. It is the capital of the Grand Casablanca region.Casablanca is Morocco's largest city as well as its chief port. It is also the biggest city in the Maghreb. The 2004 census recorded a population of 2,949,805 in the prefecture...

, Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...

 and in Gabon
Gabon
Gabon , officially the Gabonese Republic is a state in west central Africa sharing borders with Equatorial Guinea to the northwest, Cameroon to the north, and with the Republic of the Congo curving around the east and south. The Gulf of Guinea, an arm of the Atlantic Ocean is to the west...

 in West Africa. Multi-utilities provide certain benefits such as common billing and the option to cross-subsidize water services with revenues from electricity sales, if permitted by law.

Ownership and governance arrangements


Water supply providers can be either public, private, mixed or cooperative. Most urban water supply services around the world are provided by public entities. As Willem-Alexander, Prince of Orange (2002) stated, "The water crisis that is affecting so many people is mainly a crisis of governance — not of water scarcity." The introduction of cost-reflective tariffs together with cross-subsidisation between richer and poorer consumers is an essential governance reform in order to reduce the high levels of Unaccounted or Water (UAW) and to provide the finance needed to extend the network to those poorest households who remain unconnected. Partnership arrangements between the public and private sector can play an important role in order to achieve this objective
Private sector participation

An estimated 10 percent of urban water supply is provided by private or mixed public-private companies, usually under concession
Concession (contract)
A concession is a business operated under a contract or license associated with a degree of exclusivity in business within a certain geographical area. For example, sports arenas or public parks may have concession stands. Many department stores contain numerous concessions operated by other...

s, lease
Lease
A lease is a contractual arrangement calling for the lessee to pay the lessor for use of an asset. A rental agreement is a lease in which the asset is tangible property...

s or management contract
Management contract
A management contract is an arrangement under which operational control of an enterprise is vested by contract in a separate enterprise which performs the necessary managerial functions in return for a fee. Management contracts involve not just selling a method of doing things but involves...

s. Under these arrangements the public entity that is legally responsible for service provision delegates certain or all aspects of service provision to the private service provider for a period typically ranging from 4 to 30 years. The public entity continues to own the assets. These arrangements are common in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 and in Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

. Only in few parts of the world water supply systems have been completely sold to the private sector (privatization
Privatization
Privatization is the incidence or process of transferring ownership of a business, enterprise, agency or public service from the public sector to the private sector or to private non-profit organizations...

), such as in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 and Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...

 as well as in Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

. The largest private water companies in the world are Suez and Veolia Environnement from France; Aguas de Barcelona from Spain; and Thames Water
Thames Water
Thames Water Utilities Ltd, known as Thames Water, is the private utility company responsible for the public water supply and waste water treatment in large parts of Greater London, the Thames Valley, Surrey, Gloucestershire, Wiltshire, Kent, and some other areas of in the United Kingdom...

 from the UK, all of which are engaged internationally (see links to website of these companies below).
Public water service provision

90% of urban water supply and sanitation services are currently in the public sector. They are owned by the state or local authorities, or also by collectives or cooperatives. They run without an aim for profit but are based on the ethos of providing a common good considered to be of public interest. In most middle and low-income countries, these publicly-owned and managed water providers can be inefficient as a result of political interference, leading to over-staffing and low labour productivity.
Ironically, the main losers from this institutional arrangement are the urban poor in these countries. Because they are not connected to the network, they end up paying far more per litre of water than do more well-off households connected to the network who benefit from the implicit subsidies that they receive from loss-making utilities.
We are still so far from achieving universal access to clean water and sanitation shows that public water authorities, in their current state, are not working well enough.
Yet some are being very successful and are modelling the best forms of public management. As Ryutaro Hashimoto
Ryutaro Hashimoto
was a Japanese politician who served as the 82nd and 83rd Prime Minister of Japan from January 11, 1996 to July 30, 1998. He was the leader of one of the largest factions within the ruling LDP through most of the 1990s and remained a powerful back-room player in Japanese politics until scandal...

, former Japanese Prime Minister, notes: “Public water services currently provide more than 90 per cent of water supply in the world. Modest improvement in public water operators will have immense impact on global provision of services."

Governance arrangements

Governance arrangements for both public and private utilities can take many forms. Governance arrangements define the relationship between the service provider, its owners, its customers and regulatory entities. They determine the financial autonomy of the service provider and thus its ability to maintain its assets, expand services, attract and retain qualified staff, and ultimately to provide high-quality services. Key aspects of governance arrangements are the extent to which the entity in charge of providing services is insulated from arbitrary political intervention; and whether there is an explicit mandate and political will to allow the service provider to recover all or at least most of its costs through tariffs and retain these revenues. If water supply is the responsibility of a department that is integrated in the administration of a city, town or municipality, there is a risk that tariff revenues are diverted for other purposes. In some cases, there is also a risk that staff are appointed mainly on political grounds rather than based on their professional credentials.

Tariffs


Almost all service providers in the world charge tariffs to recover part of their costs. According to estimates by the World Bank the average (mean
Mean
In statistics, mean has two related meanings:* the arithmetic mean .* the expected value of a random variable, which is also called the population mean....

) global water tariff is US$ 0.53 per cubic meter. In developed countries the average tariff is US$ 1.04, while it is only U$ 0.11 in the poorest developing countries. The lowest tariffs in developing countries are found in South Asia (mean of US$ 0.09/m3), while the highest are found in Latin America (US$ 0.41/m3). Data for 132 cities were assessed. The tariff is estimate for a consumption level of 15 cubic meters per month. Few utilities do recover all their costs. According to the same World Bank study only 30% of utilities globally, and only 50% of utilities in developed countries, generate sufficient revenue to cover operation, maintenance and partial capital costs.

According to another study undertaken in 2006 by NUS Consulting, the average water and sewerage tariff in 14 mainly OECD countries excluding VAT
Vat
Vat or VAT may refer to:* A type of container such as a barrel, storage tank, or tub, often constructed of welded sheet stainless steel, and used for holding, storing, and processing liquids such as milk, wine, and beer...

 varied between US$ 0.66 per cubic meter in the United States and the equivalent of US$ 2.25 per cubic meter in Denmark. However, water consumption is much higher in the US than in Europe. Therefore, residential water bills may be very similar, even if the tariff per unit of consumption tends to be higher in Europe than in the US.

A typical family on the US East Coast paid between US$30 and US$70 per month for water and sewer services in 2005.

In developing countries tariffs are usually much further from covering costs. Residential water bills for a typical consumption of 15 cubic meters per month vary between less than US$ 1 and US$ 12 per month.

Water and sanitation tariffs, which are almost always billed together, can take many different forms. Where meters are installed, tariffs are typically volumetric (per usage), sometimes combined with a small monthly fixed charge. In the absence of meters, flat or fixed rates — which are independent of actual consumption — are being charged. In developed countries, tariffs are usually the same for different categories of users and for different levels of consumption.

In developing countries, the situation is often characterized by cross-subsidies with the intent to make water more affordable for residential low-volume users that are assumed to be poor. For example, industrial and commercial users are often charged higher tariffs than public or residential users. Also, metered users are often charged higher tariffs for higher levels of consumption (increasing-block tariffs). However, cross-subsidies between residential users do not always reach their objective. Given the overall low level of water tariffs in developing countries even at higher levels of consumption, most consumption subsidies benefit the wealthier segments of society. Also, high industrial and commercial tariffs can provide an incentive for these users to supply water from other sources than the utility (own wells, water tankers) and thus actually erode the utility's revenue base.

Metering


Metering of water supply is usually motivated by one or several of four objectives: First, it provides an incentive to conserve water which protects water resources (environmental objective). Second, it can postpone costly system expansion and saves energy and chemical costs (economic objective). Third, it allows a utility to better locate distribution losses (technical objective). Fourth, it allows to charge for water based on use, which is perceived by many as the fairest way to allocate the costs of water supply to users. Metering is considered good practice in water supply and is widespread in developed countries, except for the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

. In developing countries it is estimated that half of all urban water supply systems are metered and the tendency is increasing.

Water meters are read by one of several methods:
  • the water customer writes down the meter reading and mails in a postcard with this info to the water department;
  • the water customer writes down the meter reading and uses a phone dial-in system to transfer this info to the water department;
  • the water customer logs in to the website
    Website
    A website, also written as Web site, web site, or simply site, is a collection of related web pages containing images, videos or other digital assets. A website is hosted on at least one web server, accessible via a network such as the Internet or a private local area network through an Internet...

     of the water supply company, enters the address, meter ID and meter readings http://www.waterbedrijfgroningen.nl/wag/Wbgr-internet.nsf/frameset?openFrameset&submenu=Algemene%20Informatie%20meterstanden
  • a meter reader comes to the premise and enters the meter reading into a handheld computer;
  • the meter reading is echoed on a display unit mounted to the outside of the premise, where a meter reader records them;
  • a small radio is hooked up to the meter to automatically transmit readings to corresponding receivers in handheld computers, utility vehicles or distributed collectors
  • a small computer is hooked up to the meter that can either dial out or receive automated phone calls that give the reading to a central computer system.


Most cities are increasingly installing Automatic Meter Reading
Automatic meter reading
Automatic meter reading, or AMR, is the technology of automatically collecting consumption, diagnostic, and status data from water meter or energy metering devices and transferring that data to a central database for billing, troubleshooting, and analyzing.This technology mainly saves utility...

 (AMR) systems to prevent fraud, to lower ever-increasing labor and liability costs and to improve customer service and satisfaction.

Costs and Financing


The cost
Cost
In production, research, retail, and accounting, a cost is the value of money that has been used up to produce something, and hence is not available for use anymore. In business, the cost may be one of acquisition, in which case the amount of money expended to acquire it is counted as cost. In this...

 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). The full cost of supplying water in urban areas in developed countries is about US$1–2 per cubic meter depending on local costs and local water consumption levels. The cost of sanitation (sewerage and wastewater treatment) is another US$1–2 per cubic meter. These costs are somewhat lower in developing countries. Throughout the world, only part of these costs is usually billed to consumers, the remainder being financed through direct or indirect subsidies from local, regional or national governments (see section on tariffs).

Besides subsidies water supply investments are financed through internally generated revenues as well as through debt. Debt financing can take the form of credits from commercial Banks, credits from international financial institutions such as the World Bank and regional development banks (in the case of developing countries), and bond
Bond (finance)
In finance, a bond is a debt security, in which the authorized issuer owes the holders a debt and, depending on the terms of the bond, is obliged to pay interest to use and/or to repay the principal at a later date, termed maturity...

s (in the case of some developed countries and some upper middle-income countries).

History




Throughout history people have devised systems to make getting and using water more convenient. Early Rome
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

 had indoor plumbing, meaning a system of aqueduct
Aqueduct
An aqueduct is a water supply or navigable channel constructed to convey water. In modern engineering, the term is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose....

s and pipes that terminated in homes and at public wells and fountains for people to use. London water supply infrastructure
London water supply infrastructure
London's water supply infrastructure has developed over the centuries in line with the expansion of London and now represents a sizeable infrastructure investment. For much of London's history, private companies supplied fresh water to various parts of London from the River Thames and the River Lea...

 developed over many centuries from early mediaeval conduits, through major 19th century treatment works built in response to cholera
Cholera
Cholera is an infection of the small intestine that is caused by the bacterium Vibrio cholerae. The main symptoms are profuse watery diarrhea and vomiting. Transmission occurs primarily by drinking or eating water or food that has been contaminated by the diarrhea of an infected person or the feces...

 threats, to modern large scale reservoirs.

Water tower
Water tower
A water tower or elevated water tower is a large elevated drinking water storage container constructed to hold a water supply at a height sufficient to pressurize a water distribution system....

s appeared around the late 19th century, as building height rose, and steam, electric and diesel-powered water pump
Water Pump
Water Pump is one of the neighbourhoods of Gulberg Town in Karachi, Sindh, Pakistan. It is near main Water Pump that supplies fresh water to the city of Karachi....

s became available. As skyscraper
Skyscraper
A skyscraper is a tall, continuously habitable building of many stories, often designed for office and commercial use. There is no official definition or height above which a building may be classified as a skyscraper...

s appeared, they needed rooftop water tower
Rooftop water tower
A rooftop water tower is a variant of a water tower, consisting of a water container on a roof of a tall building.This structure supplies water pressure to floors at higher elevation than public water towers....

s.

The technique of purification of drinking water by use of compressed liquefied chlorine gas was developed in 1910 by U.S. Army Major
Major
Major is a rank of commissioned officer, with corresponding ranks existing in almost every military in the world.When used unhyphenated, in conjunction with no other indicator of rank, the term refers to the rank just senior to that of an Army captain and just below the rank of lieutenant colonel. ...

 (later Brig. Gen.
Brigadier General
Brigadier general is a senior rank in the armed forces. It is the lowest ranking general officer in some countries, usually sitting between the ranks of colonel and major general. When appointed to a field command, a brigadier general is typically in command of a brigade consisting of around 4,000...

) Carl Rogers Darnall
Carl Rogers Darnall
Brigadier General Carl Rogers Darnall was a United States Army chemist and surgeon credited with originating the technique of liquid chlorination of drinking water...

 (1867–1941), Professor of Chemistry at the Army Medical School
Army Medical School
Founded by U.S. Army Brigadier General George Miller Sternberg, MD in 1893, the Army Medical School was by some reckonings the world's first school of public health and preventive medicine...

. Shortly thereafter, Major (later Col.
Colonel
Colonel , abbreviated Col or COL, is a military rank of a senior commissioned officer. It or a corresponding rank exists in most armies and in many air forces; the naval equivalent rank is generally "Captain". It is also used in some police forces and other paramilitary rank structures...

) William J. L. Lyster (1869–1947) of the Army Medical Department used a solution of calcium hypochlorite
Calcium hypochlorite
Calcium hypochlorite is a chemical compound with formula 2. It is widely used for water treatment and as a bleaching agent...

 in a linen bag to treat water. For many decades, Lyster's method remained the standard for U.S. ground forces in the field and in camps, implemented in the form of the familiar Lyster Bag (also spelled Lister Bag). Darnall's work became the basis for present day systems of municipal water 'purification'.

Desalination
Desalination
Desalination, desalinization, or desalinisation refers to any of several processes that remove some amount of salt and other minerals from saline water...

 appeared during the late 20th century, and is still limited to a few areas.

During the beginning of the 21st Century, especially in areas of urban and suburban population centres, 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
Rainwater harvesting
Rainwater harvesting is the accumulating and storing of rainwater for reuse before it reaches the aquifer. It has been used to provide drinking water, water for livestock, water for irrigation, as well as other typical uses. Rainwater collected from the roofs of houses and local institutions can...

 and Stormwater harvesting
Stormwater harvesting
Stormwater harvesting is the collection, accumulation, treatment or purification, and storing of stormwater for its eventual reuse. It differs from rainwater harvesting as the runoff is collected from drains or creeks, rather than roofs...

 where policies are eventually tending towards a more rational use and sourcing of water incorporation concepts such as "Fit for Purpose".

Standardization


International standards for water supply system are covered by International Classification of Standards (ICS) 91.140.60.

Outbreaks of diseases due to contaminated water supply

  • In 1854, a cholera outbreak in London's Soho district was identified by Dr. John Snow
    John Snow (physician)
    John Snow was an English physician and a leader in the adoption of anaesthesia and medical hygiene. He is considered to be one of the fathers of epidemiology, because of his work in tracing the source of a cholera outbreak in Soho, England, in 1854.-Early life and education:Snow was born 15 March...

     as originating from contaminated water from the Broad street pump. This can be regarded as a founding event of the science of epidemiology
    Epidemiology
    Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...

    .
  • In 1980, a hepatitis A surge due to the consumption of water from a feces-contaminated well, in Pennsylvania
  • In 1987, a cryptosporidiosis
    Cryptosporidiosis
    Cryptosporidiosis, also known as crypto, is a parasitic disease caused by Cryptosporidium, a protozoan parasite in the phylum Apicomplexa. It affects the intestines of mammals and is typically an acute short-term infection...

     outbreak is caused by the public water supply of which the filtration was contaminated, in western Georgia
  • Fluoride intoxication in a long-term hemodialysis unit of university hospital due to the failure of a water deionization system
  • In 1988, many people were poisoned in Camelford
    Camelford water pollution incident
    The Camelford water pollution incident involved the accidental contamination of the drinking water supply to the town of Camelford, Cornwall, England with 20 tonnes of aluminium sulphate in July 1988...

    , when a worker put 20 tonnes of aluminium sulphate in the wrong tank.
  • In 1993, a fluoride poisoning outbreak resulting from overfeeding of fluoride, in Mississippi
  • In 1993, Milwaukee Cryptosporidium outbreak
    Milwaukee Cryptosporidium outbreak
    The 1993 Milwaukee Cryptosporidium outbreak was a significant distribution of the Cryptosporidium protozoan in Milwaukee, Wisconsin, and the largest waterborne disease outbreak in documented United States history. The Howard Avenue Water Purification Plant was contaminated, and treated water...

  • An outbreak of typhoid fever in northern Israel, which was associated with the contaminated municipal water supply
  • In 1997, 369 cases of cryptosporidiosis
    Cryptosporidiosis
    Cryptosporidiosis, also known as crypto, is a parasitic disease caused by Cryptosporidium, a protozoan parasite in the phylum Apicomplexa. It affects the intestines of mammals and is typically an acute short-term infection...

     occurred, caused by a contaminated fountain in the Minnesota zoo. Most of the sufferers were children
  • In 1998, a non-chlorinated municipal water supply was blamed for a campylobacteriosis
    Campylobacteriosis
    Campylobacteriosis is an infection by the Campylobacter bacterium, most commonly C. jejuni. It is among the most common bacterial infections of humans, often a foodborne illness. It produces an inflammatory, sometimes bloody, diarrhea or dysentery syndrome, mostly including cramps, fever and...

     outbreak in northern Finland
  • In 2000, a gastroenteritis
    Gastroenteritis
    Gastroenteritis is marked by severe inflammation of the gastrointestinal tract involving both the stomach and small intestine resulting in acute diarrhea and vomiting. It can be transferred by contact with contaminated food and water...

     outbreak that was brought by a non-chlorinated community water supply, in southern Finland
  • In 2000, an E. coli outbreak occurred in Walkerton Ontario Canada. Seven people died from drinking contaminated water. Hundreds suffered from the symptoms of the disease, not knowing if they too would die.
  • In 2004, contamination of the community water supply, serving the Bergen city centre of Norway, was later reported after the outbreak of waterborne giardiasis
    Giardiasis
    Giardiasis or beaver fever in humans is a diarrheal infection of the small intestine by a single-celled organism Giardia lamblia. Giardiasis occurs worldwide with a prevalence of 20–30% in developing countries. In the U.S., 20,000 cases are reported to the CDC annually, but the true annual...

  • In 2007, contaminated drinking water was pinpointed which had led to the outbreak of gastroenteritis with multiple aetiologies in Denmark

See also

  • Catchwater
    Catchwater
    A catchwater is a large-scale man-made device for catching surface runoff from hills and channelling it to reservoirs for later usage as a part of the public water supply....

  • Consumptive water use
    Consumptive water use
    Consumptive water use is water removed from available supplies without return to a water resources system . Evaporation from the surface of the earth into clouds of water in the air which then falls to the ground as "rain" is excluded from this model...

  • Delivery of water to households far from sources of safe water
  • Drinking water
    Drinking water
    Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...

  • Global Water Foundation
    Global Water Foundation
    The Global Water Foundation is a non-profit organization dedicated to delivering clean water and sanitation to the world's neediest communities. Professional tennis player Johan Kriek founded the organization in 2005 after attending meetings of the World Economic Forum in Cape Town, South Africa...

  • Infrastructure security
    Infrastructure Security
    Infrastructure security is the security provided to protect infrastructure, especially critical infrastructure, such as airports, highways rail transport, hospitals, bridges, transport hubs, network communications, media, the electricity grid, dams, power plants, seaports, oil refineries, and...

  • Micro credit for water supply and sanitation
    Micro credit for water supply and sanitation
    Micro credit for water supply and sanitation is an innovative application of micro credit to provide loans to small enterprises and households in order to increase access to an improved water source and sanitation in developing countries...

  • Non-revenue water
    Non-revenue water
    Non revenue water is water that has been produced and is “lost” before it reaches the customer. Losses can be real losses or apparent losses . High levels of NRW are detrimental to the financial viability of water utilities, as well to the quality of water itself...

  • Rural Water Supplies and Sewerage Act 1944
    Rural Water Supplies and Sewerage Act 1944
    The Rural Water Supplies and Sewerage Act 1944 was an Act of Parliament in the United Kingdom, introduced by the coalition government....

     (in the UK)
  • Sanitation
    Sanitation
    Sanitation is the hygienic means of promoting health through prevention of human contact with the hazards of wastes. Hazards can be either physical, microbiological, biological or chemical agents of disease. Wastes that can cause health problems are human and animal feces, solid wastes, domestic...

  • Tap water
    Tap water
    Tap water is a principal component of "indoor plumbing", which became available in urban areas of the developed world during the last quarter of the 19th century, and common during the mid-20th century...

  • Waterborne diseases
    Waterborne diseases
    Waterborne diseases are caused by pathogenic microorganisms which are directly transmitted when contaminated fresh water is consumed. Contaminated fresh water, used in the preparation of food, can be the source of foodborne disease through consumption of the same microorganisms...

  • Water-energy nexus
    Water-energy nexus
    The water-energy nexus is the relationship between how much water is evaporated to generate and transmit energy, and how much energy it takes to collect, clean, move, store, and dispose of water.- Water requirements of energy production :...

  • Water and sanitation program
    Water and sanitation program
    The Water and Sanitation Program is a trust fund administered by the World Bank geared at improving access to water and sanitation for poor people...

  • Water conflict
    Water conflict
    Water conflict is a term describing a conflict between countries, states, or groups over an access to water resources. The United Nations recognizes that water disputes result from opposing interests of water users, public or private....

  • Water crisis
    Water crisis
    Water crisis is a general term used to describe a situation where the available water within a region is less than the region's demand. The term has been used to describe the availability of potable water in a variety of regions by the United Nations and other world organizations...

  • Water efficiency
    Water efficiency
    Water efficiency can be defined as:# The accomplishment of a function, task, process, or result with the minimal amount of water feasible;# An indicator of the relationship between the amount of water required for a particular purpose and the amount of water used or delivered.Though the two are...

  • Water resource policy
    Water resource policy
    This article is about water resource policy, its institutions, the policy making processes and major subdivisions rather than implementation or hydrology, irrigation, geography, fisheries management, implementation, the management of specific water projects or the purchase, ownership and conveyance...

  • Water law
    Water law
    Water law is the field of law dealing with the ownership, control, and use of water as a resource. It is most closely related to property law, but has also become influenced by environmental law...

  • Water supply and sanitation in Sub-Saharan Africa
    Water supply and sanitation in Sub-Saharan Africa
    Although access to water supply and sanitation in Sub-Saharan Africa has been steadily improving over the past two decades, the region still lags behind all other developing regions. Access to improved water supply has increased from 49% in 1990 to 60% in 2008, while access to improved sanitation...

  • :Category:Water supply and sanitation by country

Lawsuits

  • Arizona v. California
    Arizona v. California
    Arizona v. California is a set of United States Supreme Court cases, all dealing with water distribution from the Colorado River.When a dispute arises between two states, the case is filed for original jurisdiction with the United States Supreme Court. This is one of the very limited circumstances...

  • Colorado River Water Conservation District v. United States
    Colorado River Water Conservation District v. United States
    Colorado River Water Conservation District v. United States, 424 U.S. 800 , was a case in which the Supreme Court of the United States created a new doctrine of abstention, to prevent duplicative litigation between state and federal courts....

  • Kansas v. Colorado
    Kansas v. Colorado
    Kansas v. Colorado is a longstanding litigation before the Supreme Court of the United States between two states of the United States, Kansas and Colorado. The Court has rendered numerous opinions in this case:* Kansas v. Colorado, * Kansas v. Colorado,...

  • Tahoe-Sierra Preservation Council, Inc. v. Tahoe Regional Planning Agency
    Tahoe-Sierra Preservation Council, Inc. v. Tahoe Regional Planning Agency
    Tahoe-Sierra Preservation Council, Inc. v. Tahoe Regional Planning Agency, 535 U.S. 302 , is one of the United States Supreme Court's more recent interpretations of the Takings Clause of the Fifth and Fourteenth Amendments....

  • Wisconsin v. Illinois
    Wisconsin v. Illinois
    Wisconsin v. Illinois, also referred to as the Chicago Sanitary District Case, is an opinion of the Supreme Court of the United States which held that the equitable power of the United States can be utilized to impose positive action on one state in a situation in which nonaction would result in...

  • Wyoming v. Colorado
    Wyoming v. Colorado
    Wyoming v. Colorado is a set of court cases, all dealing with water distribution from the Laramie River. Petition for rehearing was granted which revised the original decision. A motion to dismiss was later denied....


External links