Water consumption
The colloquial term for water consumption is the amount of water used for human consumption . This includes direct human consumption ( drinking water ) as well as to the everyday life ( washing , cooking , etc.) and for the agriculture , the trade and industry (see process water delivered) amount of water.
The consumption figures, which are used to calculate them, are determined by water meters . The share of households in consumption in Europe is around 10% to 15% of the water supply used; Electricity and thermal power plants and, above all, agriculture (over 70 percent) are the main consumers of water capacities.
Some of the water used to drive hydropower plants is not counted as part of the water consumption, but it can be statistically included in the quantities used.
Terminology
Instead of the term water consumption , the water management advocacy group prefers the term water use , in order to make it clear that only a negligibly small proportion of the total water used is converted into another substance by a chemical reaction , while the vast majority is changed (deteriorated) Water quality is still available to the water cycle .
The water consumption resulting from the production of products is also called latent or virtual water in connection with the life cycle analysis . Here also are imported products and their transport and thus the amount of water taken into account by non-manufacturing industries.
Figures on water consumption
| Consumption in liters |
country | |
|---|---|---|
| 25th |
 India
|
|
| 120 |
 Belgium
|
|
| 122 |
 Germany
|
|
| 130 |
 Netherlands
|
|
| 139 |
 Denmark
|
|
| 140 |
 Greece
|
|
| 149 |
 England
|
|
| 156 |
 France
|
|
| 162 |
 Austria
|
|
| 165 (-237) |
 Switzerland
|
|
| 170 |
 Luxembourg
|
|
| 197 |
 Sweden
|
|
| 213 |
 Italy
|
|
| 260 |
 Norway
|
|
| 270 |
 Spain
|
|
| 270 |
 Russia
|
|
| 278 |
 Japan
|
|
| 295 |
 United States
|
|
| 500 |
 Dubai |
Worldwide freshwater demand is estimated at 4,370 km³ annually (2015), whereby the limit of sustainable use is given at 4,000 km³ ( see also World Exhaustion Day ). A factor that has hitherto been underestimated is the evaporation of water used or stored for use or by plants (" evapotranspiration "), which, according to new data analysis, is assumed to be around 20% of the demand.
On a global average, 1,385 m³ of water are consumed per year and per person, in Germany the value is 1,426 m³, see also water footprint .
The usage habits for water in private households differ according to the water availability of a country and the condition of the supply networks. The industrial nations generally have a high connection rate (connection density) to a drinking water network and thus a high availability of water in households. Therefore, water uses such as toilet flushing, hygiene and personal hygiene or laundry account for significantly larger proportions of total water use than in developing countries.
The demand for water in the industrial, agricultural and public water supply sectors varies from country to country. In Germany, 72% are in the industrial sector, 14% in agriculture and 14% in the public water supply. In Greece the ratio is reversed: 4% industry, 80% agriculture and 16% public water supply. In developing countries, the agricultural sector is the largest water user (e.g. Sudan 90%), whereas industry and public water supply are not worth mentioning due to a lack of demand or supply systems.
If you balance the virtual water , you get the amount of water actually required regardless of the type and location of use. The consumption in Germany is calculated at around 4,000 liters of water per person per day, i.e. more than 30 times the 122 liters, as shown in the table opposite.
Falling water consumption in Europe
Water supply companies in Germany delivered around 4.6 billion cubic meters of drinking water in 2017. This amount corresponds to an average per capita consumption of 123 liters per day. The long-term trend towards reducing water consumption has thus continued. In 2004, each inhabitant in Germany used 126 liters an average of 3 liters more per day. Compared to 1991, the daily per capita consumption has decreased by 21 liters. In certain areas, water consumption is significantly lower, for example in Saxony, where it was only around 88 liters per day and person in 2005 and had fallen to 85 liters per day and inhabitant by 2008.
According to water management estimates, water consumption in liters per capita and day is distributed roughly as follows:
- 5 l for drinking and cooking
- 7 l for washing dishes
- 7 l for cleaning
- 44 l for showering, bathing, body care
- Wash 15 l for laundry
- 33 l for flushing the toilet
Demand-dependent water prices and environmental protection goals offer water users incentives to save water. Nevertheless, in many countries the water prices are too low to provide incentives to save or the water consumption is not measured with meters. In England, for example, it was only a few years ago that water meters were installed in new buildings, and only 14% of the water consumption of private households was measured.
In Germany, rising water prices (around € 2.00 per cubic meter in August 2018) create an incentive to save water. The disposal costs linked to drinking water consumption in the form of wastewater charges are often higher than the water price. This has led to a demand for water-saving technology (water-efficient washing machines and dishwashers, water-saving toilet flushes and fittings).
The use of gray water , rainwater , cisterns or house wells on your own property can reduce the consumption of drinking water from the public network.
Positive aspects
The decrease in water consumption reduces the interventions in nature that are carried out to remove water. The greater concentration of the wastewater load makes it easier to purify the wastewater. Central Europe does not suffer from a lack of water, but surface waters are often problematic for the drinking water supply due to the pollution with fertilizers and pollutants, so that groundwater is often used. In the vicinity of large cities, the falling groundwater level can lead to the drying out of wetlands and to settlement cracks in buildings.
The reduction in hot water consumption leads to significant energy savings. Turning on the warm water in the shower often corresponds to switching on an electrical consumer with an output of 20 kilowatts. Depending on the circumstances, hot water costs up to € 20 per cubic meter (including fresh water, waste water, heating, billing).
Water management problems
For a long time, politics and water management had the notion of a steadily growing water consumption. Around 1970, when the per capita consumption was just over 140 liters, an increase in this value of a good 50% to 220 liters was assumed for the year 2000. The Federal Environment Agency predicted, for example, in 1993 for Germany an increasing water consumption. As a result, oversized waterworks, pipeline networks and disposal systems were built, especially in East Germany from today's perspective, while the decline of many commercial and industrial companies after the fall of the Wall actually led to a sometimes drastic reduction in water consumption. High fixed costs (80% to 85%) due to capital commitment and depreciation lead to rising water and wastewater prices and charges due to declining plant utilization. Demographic change (declining birth rates and emigration in East Germany, as well as in some cases in West Germany) is leading to a further reduction in plant utilization.
Drinking and sewage systems are optimized for a certain amount of consumption. Missing the assumed flow rates due to incorrect assumptions and changes in usage behavior leads to cost increases.
For the drinking water supply , the decline in consumption and, as a result, lower utilization of the pipe networks are problematic, as this leads to a lower flow rate in the pipe networks and thus the length of time the water stays in the networks increases. There must be sufficient flow through lines so that germs do not develop. This is particularly important if the water is not chlorinated and the mean time in the network is longer than 1 day. Water supply companies therefore preventively flush the networks or, in suspected cases, carry out so-called safety treatments with chlorine for disinfection. In addition to higher operating costs, poor flow leads to adverse effects on the taste of the water, which can also lead to increased corrosion of the pipes. In addition, the tap water can be enriched with iron, copper or lead.
On the other hand, the wastewater discharged from the point of use into the wastewater network leads to problems in the sewer system: the smaller amount of water flowing in prevents the faeces discharged via the sewer system from reaching the sewage treatment plant quickly enough. Especially in warm weather, putrefaction processes can occur in which hydrogen sulphide (H 2 S) is formed, which can lead to considerable odor nuisance and endangerment of the operating personnel. Sulfuric acid promotes the biogenic corrosion of sewage systems.
For the reliable removal of buoyant and non-buoyant substances, as well as to avoid deposits, a flow rate adapted to the pipe diameter with a corresponding flow velocity is required.
In order to flush the sewage system, additional process or surface water must be fed into the pipe and sewer network if necessary in order to artificially increase the flow rate. Dismantling existing oversized pipes is usually ruled out for reasons of economy, as the pipes are laid deep in the ground and have an expected service life of up to 100 years. In the case of sewage networks, it is sometimes possible to subsequently reduce the pipe cross-section. In individual cases, deconstruction (for example with the aim of semi-central treatment of the water) is considered. Corresponding model projects are currently being implemented in Pforzheim , for example .
A groundwater level that rises due to reduced water consumption may require adaptation of the infrastructure (e.g. cellars, sewer ditches) and land management, since these have been adapted to the lowered level over the years. In the greater Berlin area, the groundwater level is expected to rise by one to three meters.
Water consumption by power plants
According to data from the Federal Statistical Office from 1998, fossil and nuclear power plants in Germany have a share of 75% (27 of 36 billion m³) in total water use, followed by the manufacturing industry with 19%. In the EU, their share of total water use makes up 40%, ahead of agriculture with 27% (EUROSTAT 2000). According to data from the US Environmental Protection Agency (USEPA 1993), fossil and nuclear power plants in the United States were almost on par with agriculture (40%), accounting for 39% of total use.
literature
- Thomas Kluge , Jens Libbe, Engelbert Schramm : Effects of demographic change on drinking water supply and wastewater disposal. In: Jürgen Dettbarn-Reggentin, Heike Reggentin (Hrsg.): Practical concepts for demographic urban development. Basics, planning aids and concrete practical solutions. Forum Verlag Herkert, Merching 2006, chap. 6.2, ISBN 3-86586-039-7 .
- D. Weismann, K. Lohse (Hrsg.): Sulfid-Praxishandbuch der Abwassertechnik; Prevent odor, danger and corrosion and control costs! 1st edition, VULKAN-Verlag, Germany 2007, ISBN 978-3-8027-2845-7 .
- Joachim Schleich, Thomas Hillenbrand: Determinants of Residential Water Demand In Germany . Working Paper Sustainability and Innovation No, Fraunhofer ISI. S 3/2007. PDF; 411 KB. Published in: Ecocological Economics (Volume 68, Issue 6, April 15, 2009, pp. 1756–1769, doi : 10.1016 / j.ecolecon.2008.11.012 ). German summary by Bernd Müller: East Germans are water savers (press release). Retrieved August 21, 2008.
Web links
- Federal Statistical Office Germany: Statistical Yearbook 2007 . Water consumption and use in Germany (data up to 2004): Chapters 12.3.4–12.3.5 and pp. 298–299. PDF; 369 KB. Retrieved August 21, 2008.
- Graphic: Water consumption worldwide , from: Figures and facts: Globalization , Federal Agency for Civic Education / bpb
- Determine water consumption: Interactive energy and water consumption calculator in the browser . Retrieved February 7, 2017.
Individual evidence
- ↑ World Agricultural Report: Water - competition for an artificially scarce resource , accessed on January 22, 2017
- ↑ Bundesverband der Deutschen Gas- und Wasserwirtschaft eV: Copy template for water use ( memento from May 9, 2010 in the Internet Archive ), accessed on January 20, 2010
- ↑ http://www.bdew.de/bdew.nsf/id/DE_Stellungnahme_W_AW_zu_Oekologische_Industriepolitik_BMU_10_08/$file/09 01 20 Statement on Ökologische Industriepolitik.pdf (link not available)
- ↑ a b c d e f g h i j k Blikk.it: Water cycle and water consumption , accessed on January 1, 2010
- ↑ Federal Office for the Environment: Drinking Water Consumption , accessed on August 20, 2020
- ↑ Telepolis : Drought record in Spain , February 24, 2008
- ↑ RusslandJournal.de: Russia Economy: Moscow as a Business Location , accessed on January 1, 2010
- ↑ Deutschlandfunk.de , Forschung Aktuell , December 3, 2015, Dagmar Röhrlich : Resources scarcer than expected (last accessed: December 3, 2015) According to: Science , December 4, 2015, 1248–1251, Fernando Jaramillo, Georgia Destouni: Local flow regulation and irrigation raise global human water consumption and footprint , sciencemag.org: Abstract ( Memento from December 20, 2015 in the Internet Archive ) (last accessed: December 3, 2015)
- ↑ welt.de: World water demand
- ↑ fao.org: aquastat Database
- ^ Mathias Brandt: Statistics of the week: Water consumption in Germany - Technology Review. In: heise.de. August 21, 2018, accessed November 30, 2018 .
- ↑ bdew: BDEW Federal Association of Energy and Water Management eV Drinking water use in the household 2017. Accessed on November 30, 2018 .
- ↑ Kira Welling: What does a liter of water cost in Germany? In: praxistipps.chip.de. August 16, 2018, accessed November 30, 2018 .
- ↑ Flushing only with a stopper on energieverbrauch.de, accessed on January 1, 2010
- ↑ Eva Lienemann: The Myth of Saving Water ( Memento from October 21, 2013 in the Internet Archive ) In: Braunschweiger Zeitung , May 10, 2012, Ratgeber, page 14.
- ↑ dpa / lw: sewer system: water-saving madness makes Germany's cities stink. In: welt.de . May 24, 2014, accessed October 7, 2018 .
- ↑ eurosolar.de: Ole von Uexküll: Water and Energy - The fossil-nuclear energy system exacerbates the global water crisis (PDF; 209 kB) , March 2003