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clean water | basic sanitation | water withdrawal | unequal consumption | wasted water | the future


source: www.who.int/docstore/water


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wasted water

In most water systems, a large percentage of the water is lost in transit from treatment plants to consumers...
  • water loss occurs in all distribution systems - only the volume of loss varies, depending on the characteristics of the pipe network and other local factors. The amount of water that is lost is typically 20-30% of production. Some systems, especially older ones, may lose as much as 50%; (1)

  • it is important to differentiate between total water loss and leakage. Total water loss is the difference between the amount of water produced and the amount which is billed or consumed. Leakage is one of the components of water loss, and comprises the physical losses from pipes, joints and fittings, and also overflows from service reservoirs. These losses can be severe, and may go undetected for months or even years.

  • leaks waste both money and a precious natural resource. High levels of leakage in the municipal water supply system increase the costs of water supply and also raise the price of water in urban areas. The primary economic loss is the cost of the lost raw water, its treatment, and its transportation. Leakage leads to additional economic loss in the form of damage to the pipe network itself. Such damage may include erosion of pipe bedding and pipe breaks, and damage to the foundations of roads and buildings;

  • leaks also waste substantial amounts of water resources. This is particularly critical in areas where the demand for water is outstripping available supplies. In the United States, for example, the City of Detroit illustrates the potential cost of water as a lost commodity. In Detroit, citizens endure annual mid-summer water rationing and pressure problems, yet they pay an estimated US$23 million per year for water that never reaches their homes and businesses, because over 35 billion gallons (about 138.48 billion litres) of water leak from the Detroit water system each year;
Illegal connections, infrastructure damage during conflicts, and economic decline are only a few among many causes for water loss in developing or partially developed countries...
  • in most developing-world municipal water utilities, there are tremendous inefficiencies throughout the system. It has been documented in some water utilities as much as 80% of the water entering the system is lost before it reaches a billable customer. Pump systems are improperly sized, poorly maintained, operated at less than their optimal load, and - because the systems were built a long time ago, usually for the lowest possible cost - they are inefficient to begin with. These and other inefficiencies increase the amount of energy needed to deliver water to end-users, leading to unnecessary CO2 emissions but also to poor water service for millions of urban inhabitants worldwide;

  • the pressure on water and energy resources in urban India is increasing rapidly due to increase in population and unplanned growth of the cities. The State of Karnataka in Southern India, for example, has 208 municipalities that are all facing a huge water and energy crisis. Electricity makes up 40-60% of water supply costs. 30% to 40% of water is lost through leakage and unaccounted use during distribution; (4)

  • leakage is the major component of water loss in developed countries, but this is not always the case in developing countries (or partially developed countries), where illegal connections, meter errors, or accounting errors are often major contributors. Particular regions of some developing countries have higher levels, e.g. Hanoi, Vietnam, had 70% losses (1996) due to infrastructure damage from bombing in the war;

  • in Bosnia and Herzegovina, much of the country’s water and waste facilities suffered damage during the war. It is estimated that nowadays up to 50% of the fresh water in storage is lost through leakage. Intermittent supply and a general depletion of water collection and storage have led to fluctuations in pressure within the water systems. When the pressure falls polluted groundwater can infiltrate the system and puts additional strain on existing equipment that causes further breakage; (2)

  • in many Eastern Europe, Caucasus and Central Asia (EECCA) countries, the water supply networks are in poor condition due to faulty design and construction, as well as lack of maintenance and ineffective operation as a consequence of the economic decline in the past decade. Leakage is generally high and in many cases 30–50% of the water is lost; (3)

  • in China, on average, 20% of the water supply system is lost through leakage. However, the rate is only 10% in Japan, 8% in the United States, and less than 5% in Germany. China wastes more than 10 billion cubic meters of its water resources annually. In Beijing, the annual volume of water used to wash cars is more than the total water volume of the Kunming Lake or six Beihai Lakes; (5)

  • the scarcity of water in Jordan is widely seen as the single most important restriction on the country's sustainable economic growth. About 70% of the population is urban, with 2 million living within the Greater Amman area. Amman's distribution has long been dogged by problems and many residents receive a supply on just 1 day a week. Until very recently, over 50% of the water entering the city's distribution system was effectively unaccounted for, with half of this being lost by leakage and the rest due to poor administration, inadequate billing and lax payment collection. As a result of a series initiatives designed to address these problems, leakage has been reduced to roughly 1/3. Education campaigns have also been supported, which have been very successful in boosting greater consumer awareness of the country's pressing water concerns. (6)

(1) According to an inquiry made in 1991 by the International Water Supply Association (IWSA).

(2) [ www.seerecon.org/bosnia/ec/sectors/water.htm]

(3) [ www.grid.unep.ch/product/publication/freshwater_europe/consumption.php]

(4) [ carbonfinance.org/cdcf/router.cfm?Page=html/IndiaKarnatakaMunicipalWaterPumping.htm]

(5) Wei Qing, “Hundreds of Cities in China Face Water Shortages”, Epoch Times, June 22, 2005. [ www.waterconserve.info/articles/reader.asp?linkid=43308]

(6) [ www.water-technology.net/projects/greater_amman/]

clean water | basic sanitation | water withdrawal | unequal consumption | wasted water | the future
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