The San Clemente Dam was an arch dam on the Carmel River about 15 mi (24 km) southeast of Monterey in Monterey County, California of the United States . It was located just downstream of the Carmel River and San Clemente Creek confluence. Completed in 1921 to supply water to the Monterey Peninsula , the dam was removed in November 2015 due to safety and environmental concerns.
112-692: The San Clemente Dam was implemented by Samuel Morse, owner of the Del Monte Properties Company, in order to supply municipal water to the growing population on the Monterey Peninsula . It would replace the Old Carmel River Dam which was built just downstream in 1883. At a cost of US$ 300,000, the 106-foot-tall (32 m) arch dam was designed by J.A. Wilcox and constructed by Chadwick & Sykes Inc of San Francisco from 1918 to 1921. About 7,070 cu yd (5,410 m) of concrete
224-471: A 12 mm pipe, plus ball valve, and then supply the house on 22 or 28 mm pipes. Gravity water has a small pressure (say 1 ⁄ 4 bar in the bathroom) so needs wide pipes to allow for higher flows. This is fine for baths and toilets but is frequently inadequate for showers. A booster pump or a hydrophore is installed to increase and maintain pressure. For this reason urban houses are increasingly using mains pressure boilers ("combies") which take
336-646: A Ministry of Public Works (such as in Ecuador and Haiti ), a Ministry of Economy (such as in German states) or a Ministry of Energy (such as in Iran ). A few countries, such as Jordan and Bolivia , 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
448-577: A US$ 1 million project which drilled holes in the face of the dam to relieve hydrostatic pressure . In February 2008, the CDWR approved a plan to reroute the Carmel River and demolish the dam. It became known as the Carmel River Reroute & San Clemente Dam plan. An agreement was reached with CAW in 2010 to implement this option. The project includes rerouting the Carmel River upstream of the dam through
560-689: A brass foundry in Rotherham . The first documented use of sand filters to purify the water supply dates to 1804, when the owner of a bleachery in Paisley, Scotland , John Gibb, installed an experimental filter, selling his unwanted surplus to the public. The first treated public water supply in the world was installed by engineer James Simpson for the Chelsea Waterworks Company in London in 1829. The practice of water treatment soon became mainstream, and
672-559: A component of effective policy for health protection." In 1990, only 76 percent of the global population had access to drinking water. By 2015 that number had increased to 91 percent. In 1990, most countries in Latin America, East and South Asia, and Sub-Saharan Africa were well below 90%. In Sub-Saharan Africa, where the rates are lowest, household access ranges from 40 to 80 percent. Countries that experience violent conflict can have reductions in drinking water access: One study found that
784-611: A conflict with about 2,500 battle deaths deprives 1.8% of the population of potable water. Typically in developed countries , tap water meets drinking water quality standards , even though only a small proportion is actually consumed or used in food preparation. Other typical uses for tap water include washing, toilets, and irrigation . Greywater may also be used for toilets or irrigation. Its use for irrigation however may be associated with risks. Throughout history, people have devised systems to make getting and using water more convenient. Living in semi-arid regions, ancient Persians in
896-493: 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 varied between US$ 0.66 per cubic meter in
1008-467: 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/10 m height). So people at the bottom of a 30-metre (100 ft) hill will get about 3 bars more than those at the top. The effective pressure also varies because of the pressure loss due to supply resistance, even for the same static pressure. An urban consumer may have 5 metres of 15-mm pipe running from
1120-408: A drop in the ground surface. In unconsolidated aquifers, groundwater is produced from pore spaces between particles of gravel, sand, and silt. If the aquifer is confined by low-permeability layers, the reduced water pressure in the sand and gravel causes slow drainage of water from the adjoining confining layers. If these confining layers are composed of compressible silt or clay, the loss of water to
1232-675: 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 . Utilities that provide water, sanitation and electricity can be found in Frankfurt , Germany (Mainova), in Casablanca , Morocco and in Gabon in West Africa. Multi-utilities provide certain benefits such as common billing and
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#17328524489261344-402: A former lake bed, has experienced rates of subsidence of up to 40 centimetres (1 foot 4 inches) per year. For coastal cities, subsidence can increase the risk of other environmental issues, such as sea level rise . For example, Bangkok is expected to have 5.138 million people exposed to coastal flooding by 2070 because of these combining factors. If the surface water source
1456-1070: A global level, although priority chemicals will vary by country. There is a lot of heterogeneity of hydrogeologic properties. For this reason, salinity of groundwater is often highly variable over space. This contributes to highly variable groundwater security risks even within a specific region. Salinity in groundwater makes the water unpalatable and unusable and often occurs in coastal areas, for example in Bangladesh and East and West Africa. Municipal and industrial water supplies are provided through large wells. Multiple wells for one water supply source are termed "wellfields", which may withdraw water from confined or unconfined aquifers. Using groundwater from deep, confined aquifers provides more protection from surface water contamination. Some wells, termed "collector wells", are specifically designed to induce infiltration of surface (usually river) water. Aquifers that provide sustainable fresh groundwater to urban areas and for agricultural irrigation are typically close to
1568-503: A great degree of autonomy. In the United States regulatory agencies for utilities have existed for almost a century at the level of states, and in Canada at the level of provinces. In both countries they cover several infrastructure sectors. In many U.S. states they are called Public Utility Commissions . For England and Wales, a regulatory agency for water ( OFWAT ) was created as part of
1680-453: A half-mile-long channel into San Clemente Creek, which contains the least amount of sediment. The Carmel River currently contains most of the sediment and the section between the reroute and immediately upstream of the dam will be a permanent holding area since it was determined there is no feasible way to remove all of the sediment. About 380,000 cu yd (290,000 m) of sediment will also have to be excavated from San Clemente Creek to
1792-408: A home and then returned to the ground in another well. During cold seasons, because it is relatively warm, the water can be used in the same way as a source of heat for heat pumps that is much more efficient than using air. Groundwater makes up about thirty percent of the world's fresh water supply, which is about 0.76% of the entire world's water, including oceans and permanent ice. About 99% of
1904-429: A huge amount of capital investment in infrastructure such as pipe networks, pumping stations and water treatment works . It is estimated that in developing countries investments of at least US$ 200 billion have to be made per year to replace aging water infrastructure to guarantee supply, reduce leakage rates and protect water quality. International attention has focused upon the needs of developing countries . To meet
2016-424: A long time to fill a bath but suit the high back pressure of a shower. 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. Water supply policies and regulation are usually defined by one or several Ministries, in consultation with
2128-519: A long time without severe consequences. Nevertheless, over the long term the average rate of seepage above a groundwater source is the upper bound for average consumption of water from that source. Groundwater is naturally replenished by surface water from precipitation , streams , and rivers when this recharge reaches the water table. Groundwater can be a long-term ' reservoir ' of the natural water cycle (with residence times from days to millennia), as opposed to short-term water reservoirs like
2240-410: 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
2352-705: A permanently reduced capacity to hold water. The city of New Orleans, Louisiana is actually below sea level today, and its subsidence is partly caused by removal of groundwater from the various aquifer/aquitard systems beneath it. In the first half of the 20th century, the San Joaquin Valley experienced significant subsidence , in some places up to 8.5 metres (28 feet) due to groundwater removal. Cities on river deltas, including Venice in Italy, and Bangkok in Thailand, have experienced surface subsidence; Mexico City, built on
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#17328524489262464-496: A poor or very poor quality of service. 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; that is, it is intermittent . This is especially problematic for informal settlements , which are often poorly connected to the water supply network and have no means of procuring alternative sources such as private boreholes . It
2576-459: A single city, town or municipality . However, in many countries municipalities have associated in regional or inter-municipal or multi-jurisdictional utilities to benefit from economies of scale . In the United States these can take the form of special-purpose districts which may have independent taxing authority. An example of a multi-jurisdictional water utility in the United States is WASA ,
2688-543: A sustained improvement track, but many others keep falling further behind best practice. Benchmarking the performance of utilities allows the stimulation of 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. The cost of supplying water consists, to
2800-554: A system of pumps and pipes . Public water supply systems are crucial to properly functioning societies. These systems are what supply drinking water to populations around the globe. Aspects of service quality include continuity of supply, water quality and water pressure. The institutional responsibility for water supply is arranged differently in different countries and regions (urban versus rural). It usually includes issues surrounding policy and regulation, service provision and standardization . The cost of supplying water consists, to
2912-576: 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 pressurised water tank serving an urban area, by pumping the water up into a water tower and relying on gravity to maintain a constant pressure in the system or solely by pumps at the water treatment plant and repeater pumping stations. Typical UK pressures are 4–5 bar (60–70 PSI ) for an urban supply. However, some people can get over eight bars or below one bar. A single iron main pipe may cross
3024-485: 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
3136-690: A utility serving Washington, D.C. and various localities in the state of Maryland . 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 and some states in Mexico (see Water supply and sanitation in Mexico ). In England and Wales , water supply and sewerage
3248-509: A utility to better locate distribution losses (technical objective). Fourth, it allows suppliers 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 . In developing countries it is estimated that half of all urban water supply systems are metered and
3360-399: 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
3472-418: 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 )
San Clemente Dam - Misplaced Pages Continue
3584-434: 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". Water supply service quality has many dimensions: continuity; water quality ; pressure; and the degree of responsiveness of service providers to customer complaints. Many people in developing countries receive
3696-437: A wider variety of purposes, primarily agriculture . 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
3808-399: Is a highly useful and often abundant resource. Most land areas on Earth have some form of aquifer underlying them, sometimes at significant depths. In some cases, these aquifers are rapidly being depleted by the human population. Such over-use, over-abstraction or overdraft can cause major problems to human users and to the environment. The most evident problem (as far as human groundwater use
3920-571: Is a system of engineered hydrologic and hydraulic components that provide water supply. A water supply system typically includes the following: 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
4032-622: Is also a risk that staff are appointed mainly on political grounds rather than based on their professional credentials. International standards for water supply system are covered by International Classification of Standards (ICS) 91.140.60. Comparing the performance of water and sanitation service providers ( utilities ) is needed, because the sector offers limited scope for direct competition ( natural monopoly ). 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
4144-466: Is also subject to substantial evaporation, a groundwater source may become saline . This situation can occur naturally under endorheic bodies of water, or artificially under irrigated farmland. In coastal areas, human use of a groundwater source may cause the direction of seepage to ocean to reverse which can also cause soil salinization . As water moves through the landscape, it collects soluble salts, mainly sodium chloride . Where such water enters
4256-632: Is an additional water source that was not used previously. First, flood mitigation schemes, intended to protect infrastructure built on floodplains, have had the unintended consequence of reducing aquifer recharge associated with natural flooding. Second, prolonged depletion of groundwater in extensive aquifers can result in land subsidence , with associated infrastructure damage – as well as, third, saline intrusion . Fourth, draining acid sulphate soils, often found in low-lying coastal plains, can result in acidification and pollution of formerly freshwater and estuarine streams. Groundwater
4368-559: Is an essential governance reform in order to reduce the high levels of Unaccounted-for 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. An estimated 10 percent of urban water supply is provided by private or mixed public-private companies, usually under concessions , leases or management contracts . Under these water service contract arrangements
4480-454: 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
4592-566: Is being provided by CAW, US$ 25 million by the State of California and the remaining by Federal and other funding. Other benefits from removing the dam include freeing up 7 mi (11 km) of the river for rainbow trout migration and to improve the California red-legged frog habitat. Municipal water Water supply is the provision of water by public utilities , commercial organisations, community endeavors or by individuals, usually via
San Clemente Dam - Misplaced Pages Continue
4704-417: Is concerned) is a lowering of the water table beyond the reach of existing wells. As a consequence, wells must be drilled deeper to reach the groundwater; in some places (e.g., California , Texas , and India ) the water table has dropped hundreds of feet because of extensive well pumping. The GRACE satellites have collected data that demonstrates 21 of Earth's 37 major aquifers are undergoing depletion. In
4816-455: Is estimated that about half of the population of developing countries receives water on an intermittent basis. Drinking water quality 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 or the use of ultraviolet light—or it may need to undergo treatment, especially in
4928-412: Is fresh water located in the subsurface pore space of soil and rocks . It is also water that is flowing within aquifers below the water table . Sometimes it is useful to make a distinction between groundwater that is closely associated with surface water , and deep groundwater in an aquifer (called " fossil water " if it infiltrated into the ground millennia ago ). Groundwater can be thought of in
5040-448: 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
5152-399: Is often cheaper, more convenient and less vulnerable to pollution than surface water . Therefore, it is commonly used for public drinking water supplies. For example, groundwater provides the largest source of usable water storage in the United States , and California annually withdraws the largest amount of groundwater of all the states. Underground reservoirs contain far more water than
5264-459: 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 . A water supply network or water supply system
5376-468: Is rapidly increasing with population growth, while climate change is imposing additional stress on water resources and raising the probability of severe drought occurrence. The anthropogenic effects on groundwater resources are mainly due to groundwater pumping and the indirect effects of irrigation and land use changes. Groundwater plays a central role in sustaining water supplies and livelihoods in sub-Saharan Africa . In some cases, groundwater
5488-572: 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 , Jordan and Uruguay (see also water supply and sanitation in Uruguay ). In rural areas, where about half
5600-553: Is susceptible to saltwater intrusion in coastal areas and can cause land subsidence when extracted unsustainably, leading to sinking cities (like Bangkok ) and loss in elevation (such as the multiple meters lost in the Central Valley of California ). These issues are made more complicated by sea level rise and other effects of climate change , particularly those on the water cycle . Earth's axial tilt has shifted 31 inches because of human groundwater pumping. Groundwater
5712-400: Is the most accessed source of freshwater around the world, including as drinking water , irrigation , and manufacturing . Groundwater accounts for about half of the world's drinking water, 40% of its irrigation water, and a third of water for industrial purposes. Another estimate stated that globally groundwater accounts for about one third of all water withdrawals , and surface water for
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#17328524489265824-452: Is used for irrigation. Occasionally, sedimentary or "fossil" aquifers are used to provide irrigation and drinking water to urban areas. In Libya, for example, Muammar Gaddafi's Great Manmade River project has pumped large amounts of groundwater from aquifers beneath the Sahara to populous areas near the coast. Though this has saved Libya money over the alternative, seawater desalination,
5936-736: The Millennium Development Goals targets of halving the proportion of the population lacking access to safe drinking water and basic sanitation by 2015, current annual investment on the order of US$ 10 to US$ 15 billion would need to be roughly doubled. This does not include investments required for the maintenance of existing infrastructure. Once infrastructure is in place, operating water supply and sanitation systems entails significant ongoing costs to cover personnel, energy, chemicals, maintenance and other expenses. The sources of money to meet these capital and operational costs are essentially either user fees, public funds or some combination of
6048-581: The Punjab region of India , for example, groundwater levels have dropped 10 meters since 1979, and the rate of depletion is accelerating. A lowered water table may, in turn, cause other problems such as groundwater-related subsidence and saltwater intrusion . Another cause for concern is that groundwater drawdown from over-allocated aquifers has the potential to cause severe damage to both terrestrial and aquatic ecosystems – in some cases very conspicuously but in others quite imperceptibly because of
6160-407: The fractures of rock formations . About 30 percent of all readily available fresh water in the world is groundwater. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table . Groundwater is recharged from
6272-442: The hydraulic pressure of groundwater in the pore spaces of the aquifer and the aquitard supports some of the weight of the overlying sediments. When groundwater is removed from aquifers by excessive pumping, pore pressures in the aquifer drop and compression of the aquifer may occur. This compression may be partially recoverable if pressures rebound, but much of it is not. When the aquifer gets compressed, it may cause land subsidence,
6384-405: The vadose zone below plant roots and is often expressed as a flux to the water table surface. Groundwater recharge also encompasses water moving away from the water table farther into the saturated zone. Recharge occurs both naturally (through the water cycle ) and through anthropogenic processes (i.e., "artificial groundwater recharge"), where rainwater and/or reclaimed water is routed to
6496-516: The 1st millennium BC used qanat system to gain access to water in the mountains. Early Rome had indoor plumbing, meaning a system of aqueducts and pipes that terminated in homes and at public wells and fountains for people to use. Until the Enlightenment era , little progress was made in water supply and sanitation and the engineering skills of the Romans were largely neglected throughout Europe. It
6608-716: 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
6720-515: The World Bank the average ( 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
6832-545: The age of groundwater obtained from different parts of the Great Artesian Basin, hydrogeologists have found it increases in age across the basin. Where water recharges the aquifers along the Eastern Divide , ages are young. As groundwater flows westward across the continent, it increases in age, with the oldest groundwater occurring in the western parts. This means that in order to have travelled almost 1000 km from
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#17328524489266944-405: The aquifer reduces the water pressure in the confining layer, causing it to compress from the weight of overlying geologic materials. In severe cases, this compression can be observed on the ground surface as subsidence . Unfortunately, much of the subsidence from groundwater extraction is permanent (elastic rebound is small). Thus, the subsidence is not only permanent, but the compressed aquifer has
7056-525: The aquifers are likely to run dry in 60 to 100 years. Groundwater provides critical freshwater supply, particularly in dry regions where surface water availability is limited. Globally, more than one-third of the water used originates from underground. In the mid-latitude arid and semi-arid regions lacking sufficient surface water supply from rivers and reservoirs, groundwater is critical for sustaining global ecology and meeting societal needs of drinking water and food production. The demand for groundwater
7168-598: The atmosphere and fresh surface water (which have residence times from minutes to years). Deep groundwater (which is quite distant from the surface recharge) can take a very long time to complete its natural cycle. The Great Artesian Basin in central and eastern Australia is one of the largest confined aquifer systems in the world, extending for almost 2 million km . By analysing the trace elements in water sourced from deep underground, hydrogeologists have been able to determine that water extracted from these aquifers can be more than 1 million years old. By comparing
7280-510: The atmosphere through evapotranspiration , these salts are left behind. In irrigation districts, poor drainage of soils and surface aquifers can result in water tables' coming to the surface in low-lying areas. Major land degradation problems of soil salinity and waterlogging result, combined with increasing levels of salt in surface waters. As a consequence, major damage has occurred to local economies and environments. Aquifers in surface irrigated areas in semi-arid zones with reuse of
7392-475: 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
7504-441: The best forms of public management. As Ryutaro Hashimoto , former Japanese Prime Minister, notes: "Public water services currently provide more than 90 percent of water supply in the world. Modest improvement in public water operators will have immense impact on global provision of services." Governance arrangements for both public and private utilities can take many forms (Kurian and McCarney, 2010). Governance arrangements define
7616-924: The capacity of all surface reservoirs and lakes in the US, including the Great Lakes . Many municipal water supplies are derived solely from groundwater. Over 2 billion people rely on it as their primary water source worldwide. Human use of groundwater causes environmental problems. For example, polluted groundwater is less visible and more difficult to clean up than pollution in rivers and lakes. Groundwater pollution most often results from improper disposal of wastes on land. Major sources include industrial and household chemicals and garbage landfills , excessive fertilizers and pesticides used in agriculture, industrial waste lagoons, tailings and process wastewater from mines, industrial fracking , oil field brine pits, leaking underground oil storage tanks and pipelines, sewage sludge and septic systems . Additionally, groundwater
7728-427: The case of surface water . Water quality is also dependent of the quality and level of pollution of the water source. Water pressures vary in different locations of a distribution system. Water mains below the street may operate at higher pressures, with a pressure reducer 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
7840-491: The current population growth rate. Global groundwater depletion has been calculated to be between 100 and 300 km per year. This depletion is mainly caused by "expansion of irrigated agriculture in drylands ". The Asia-Pacific region is the largest groundwater abstractor in the world, containing seven out of the ten countries that extract most groundwater (Bangladesh, China, India, Indonesia, Iran, Pakistan and Turkey). These countries alone account for roughly 60% of
7952-404: The extended period over which the damage occurs. The importance of groundwater to ecosystems is often overlooked, even by freshwater biologists and ecologists. Groundwaters sustain rivers, wetlands , and lakes , as well as subterranean ecosystems within karst or alluvial aquifers. Not all ecosystems need groundwater, of course. Some terrestrial ecosystems – for example, those of
8064-407: The extent, depth and thickness of water-bearing sediments and rocks. Before an investment is made in production wells, test wells may be drilled to measure the depths at which water is encountered and collect samples of soils, rock and water for laboratory analyses. Pumping tests can be performed in test wells to determine flow characteristics of the aquifer. The characteristics of aquifers vary with
8176-451: 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 bonds (in the case of some developed countries and some upper middle-income countries). Almost all service providers in the world charge tariffs to recover part of their costs. According to estimates by
8288-472: The geology and structure of the substrate and topography in which they occur. In general, the more productive aquifers occur in sedimentary geologic formations. By comparison, weathered and fractured crystalline rocks yield smaller quantities of groundwater in many environments. Unconsolidated to poorly cemented alluvial materials that have accumulated as valley -filling sediments in major river valleys and geologically subsiding structural basins are included among
8400-404: The globe includes canals redirecting surface water, groundwater pumping, and diverting water from dams. Aquifers are critically important in agriculture. Deep aquifers in arid areas have long been water sources for irrigation. A majority of extracted groundwater, 70%, is used for agricultural purposes. In India, 65% of the irrigation is from groundwater and about 90% of extracted groundwater
8512-416: The ground surface (within a couple of hundred metres) and have some recharge by fresh water. This recharge is typically from rivers or meteoric water (precipitation) that percolates into the aquifer through overlying unsaturated materials. In general, the irrigation of 20% of farming land (with various types of water sources) accounts for the production of 40% of food production. Irrigation techniques across
8624-494: The iron main, so the kitchen tap flow will be fairly unrestricted. A rural consumer may have a kilometre of rusted and limed 22-mm 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
8736-643: The legislative branch. In the United States 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 and Colombia ), to a Ministry of Health (such as in Panama , Honduras and Uruguay ),
8848-518: The local hydrogeology , may draw in non-potable water or saltwater intrusion from hydraulically connected aquifers or surface water bodies. This can be a serious problem, especially in coastal areas and other areas where aquifer pumping is excessive. Subsidence occurs when too much water is pumped out from underground, deflating the space below the above-surface, and thus causing the ground to collapse. The result can look like craters on plots of land. This occurs because, in its natural equilibrium state,
8960-584: The main losers from this institutional arrangement are the urban poor in these countries. Because they are not connected to the water supply network , they end up paying far more per liter 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. The fact that 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
9072-412: The most productive sources of groundwater. Fluid flows can be altered in different lithological settings by brittle deformation of rocks in fault zones ; the mechanisms by which this occurs are the subject of fault zone hydrogeology . Reliance on groundwater will only increase, mainly due to growing water demand by all sectors combined with increasing variation in rainfall patterns . Groundwater
9184-459: The national government. This is, for example, the case in the countries of continental Europe, in China and India. 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. Many water utilities provide services in
9296-671: The open deserts and similar arid environments – exist on irregular rainfall and the moisture it delivers to the soil, supplemented by moisture in the air. While there are other terrestrial ecosystems in more hospitable environments where groundwater plays no central role, groundwater is in fact fundamental to many of the world's major ecosystems. Water flows between groundwaters and surface waters. Most rivers, lakes, and wetlands are fed by, and (at other places or times) feed groundwater, to varying degrees. Groundwater feeds soil moisture through percolation, and many terrestrial vegetation communities depend directly on either groundwater or
9408-545: The option to cross-subsidize water services with revenues from electricity sales, if permitted by law. 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-subsidization between richer and poorer consumers
9520-470: The other two thirds. Groundwater provides drinking water to at least 50% of the global population. About 2.5 billion people depend solely on groundwater resources to satisfy their basic daily water needs. A similar estimate was published in 2021 which stated that "groundwater is estimated to supply between a quarter and a third of the world's annual freshwater withdrawals to meet agricultural, industrial and domestic demands." Global freshwater withdrawal
9632-428: 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. Water supply and sanitation require
9744-683: The percolated soil moisture above the aquifer for at least part of each year. Hyporheic zones (the mixing zone of streamwater and groundwater) and riparian zones are examples of ecotones largely or totally dependent on groundwater. A 2021 study found that of ~39 million investigated groundwater wells 6-20% are at high risk of running dry if local groundwater levels decline by a few meters, or – as with many areas and possibly more than half of major aquifers – continue to decline. Fresh-water aquifers, especially those with limited recharge by snow or rain, also known as meteoric water , can be over-exploited and depending on
9856-462: The permanent holding area on the Carmel River. Once the sediment is secure, the San Clemente Dam and Old Carmel River Dam will be completely removed. Construction began in 2013 and the Carmel River was diverted by December 2014. By November 2015 the San Clemente Dam was removed. The Carmel River Dam removal and project completion is slated for 2016. The project will cost US$ 84 million. $ 49 million
9968-541: 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. ) Many countries do not have regulatory agencies for water. In these countries service providers are regulated directly by local government, or
10080-714: 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 and in Spain . Only in few parts of the world water supply systems have been completely sold to the private sector ( privatization ), such as in England and Wales as well as in Chile . The largest private water companies in
10192-451: 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 labor productivity. Ironically,
10304-412: 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
10416-594: 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
10528-423: The same terms as surface water : inputs, outputs and storage. The natural input to groundwater is seepage from surface water. The natural outputs from groundwater are springs and seepage to the oceans. Due to its slow rate of turnover, groundwater storage is generally much larger (in volume) compared to inputs than it is for surface water. This difference makes it easy for humans to use groundwater unsustainably for
10640-565: The setting of tariff rules and the approval of tariff increases; setting, monitoring and enforcing norms for quality of service and environmental protection; benchmarking 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. Dozens of countries around
10752-416: The source of recharge in 1 million years, the groundwater flowing through the Great Artesian Basin travels at an average rate of about 1 metre per year. Groundwater recharge or deep drainage or deep percolation is a hydrologic process, where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer . This process usually occurs in
10864-497: The subsurface. The high specific heat capacity of water and the insulating effect of soil and rock can mitigate the effects of climate and maintain groundwater at a relatively steady temperature . In some places where groundwater temperatures are maintained by this effect at about 10 °C (50 °F), groundwater can be used for controlling the temperature inside structures at the surface. For example, during hot weather relatively cool groundwater can be pumped through radiators in
10976-462: The surface; it may discharge from the surface naturally at springs and seeps , and can form oases or wetlands . Groundwater is also often withdrawn for agricultural , municipal , and industrial use by constructing and operating extraction wells . The study of the distribution and movement of groundwater is hydrogeology , also called groundwater hydrology . Typically, groundwater is thought of as water flowing through shallow aquifers, but, in
11088-430: The technical sense, it can also contain soil moisture , permafrost (frozen soil), immobile water in very low permeability bedrock , and deep geothermal or oil formation water. Groundwater is hypothesized to provide lubrication that can possibly influence the movement of faults . It is likely that much of Earth 's subsurface contains some water, which may be mixed with other fluids in some instances. Groundwater
11200-482: The tendency is increasing. Water meters are read by one of several methods: Most cities are increasingly installing automatic meter reading (AMR) systems to prevent fraud, to lower ever-increasing labor and liability costs and to improve customer service and satisfaction. According to the World Health Organization (WHO), "access to safe drinking-water is essential to health, a basic human right and
11312-410: The two. It is also important to consider is the flexibility of the water supply system. 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
11424-408: The unavoidable irrigation water losses percolating down into the underground by supplemental irrigation from wells run the risk of salination . Surface irrigation water normally contains salts in the order of 0.5 g/L or more and the annual irrigation requirement is in the order of 10,000 m /ha or more so the annual import of salt is in the order of 5,000 kg/ha or more. Under
11536-403: The virtues of the system were made starkly apparent after the investigations of the physician John Snow during the 1854 Broad Street cholera outbreak demonstrated the role of the water supply in spreading the cholera epidemic. Groundwater This is an accepted version of this page Groundwater is the water present beneath Earth 's surface in rock and soil pore spaces and in
11648-400: The world are Suez and Veolia Environnement from France; Aguas de Barcelona from Spain; and Thames Water from the UK, all of which are engaged internationally (see links to website of these companies below). In recent years, a number of cities have reverted to the public sector in a process called " remunicipalization ". 90% of urban water supply and sanitation services are currently in
11760-423: 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 systems. Sometimes they also have
11872-504: 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. Some water utilities provide only water supply services, while sewerage is under the responsibility of a different entity. This is for example the case in Tunisia . However, in most cases water utilities also provide sewer and sewage treatment services. In some cities or countries utilities also distribute electricity. In
11984-519: The world's liquid fresh water is groundwater. Global groundwater storage is roughly equal to the total amount of freshwater stored in the snow and ice pack, including the north and south poles. This makes it an important resource that can act as a natural storage that can buffer against shortages of surface water , as in during times of drought . The volume of groundwater in an aquifer can be estimated by measuring water levels in local wells and by examining geologic records from well-drilling to determine
12096-420: The world's total groundwater withdrawal. Groundwater may or may not be a safe water source. In fact, there is considerable uncertainty with groundwater in different hydrogeologic contexts: the widespread presence of contaminants such as arsenic , fluoride and salinity can reduce the suitability of groundwater as a drinking water source. Arsenic and fluoride have been considered as priority contaminants at
12208-512: The years, leaving the water storage capacity at 70 acre⋅ft (86,000 m) by 2008. Due to the threat sediment build-up poses to a dam and that the location of the dam is near a fault line, in 1991 the California Department of Water Resources (CDWR) issued a warning of potential dam failure and sought alternatives. In 1992, CAW was required to upgrade the dam for safety which, along with an annual drawdown in reservoir levels, included
12320-481: Was in the 18th century that a rapidly growing population fueled a boom in the establishment of private water supply networks in London . London water supply infrastructure developed over many centuries from early mediaeval conduits, through major 19th-century treatment works built in response to cholera threats, to modern, large-scale reservoirs. The first screw-down water tap was patented in 1845 by Guest and Chrimes,
12432-402: Was probably around 600 km per year in 1900 and increased to 3,880 km per year in 2017. The rate of increase was especially high (around 3% per year) during the period 1950–1980, partly due to a higher population growth rate, and partly to rapidly increasing groundwater development, particularly for irrigation. The rate of increase is (as per 2022) approximately 1% per year, in tune with
12544-544: Was used in its construction. A fish ladder was constructed on the dam shortly after its completion. In 1930 Morse sold the dam to Chester Loveland, owner of the California Water and Telephone Company (CWTC). In 1966 California American Water (CAW) purchased CWTC and acquired the dam for US$ 42 million. The dam's reservoir originally had a storage capacity of 1,425 acre⋅ft (1,758,000 m), but over 2,150,000 cu yd (1,640,000 m) of sediment built up over
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