Water exploitation, water use, water consumption
Water is used in Switzerland for a variety of purposes. This precious liquid is not only used for domestic purposes like showering and washing dishes, but also in trade, industry and agriculture. In addition, more than half of Switzerland’s electricity comes from hydropower. By making wise choices about the products and foods we consume and about how we manage our drinking water, we can make a contribution to the global conservation of water resources.
There are two different purposes for extracted water: consumption and use. Use refers to the water that is taken for energy or cooling and later returned, clean, to the environment. Consumption refers to water withdrawals that are consumed or contaminated, such as drinking water, irrigation water, rinse water, and water used for evaporative cooling or sewage.
Hydropower as the primary water user
Most extracted water is used to produce energy. Hydroelectric plants produce 50-60% of the energy used in Switzerland, or about 36 TWh (terawatt-hours). This corresponds to roughly 50 times the energy contained in the Rhine Falls near Schaffhausen. On average, a drop of water flows ten times through a turbine before leaving Switzerland. About 30% of the total energy contained in Swiss rivers is currently used to generate electricity (BFE 2004). According to the Swiss Federal Office of Energy, it is possible to increase this share by 10% by 2050 without relaxing the existing environmental and water protection laws (BFE 2012). Due to increasing temperatures, hydropower stations in heavily glaciated catchments will benefit over the short term, and most likely not experience negative impacts over the medium term.
Water consumption
Mr. and Mrs. Swiss need about 170 liters of drinking water a day for drinking, cooking, washing and cleaning. Thus, domestic consumption constitutes about a quarter of the total water consumption in Switzerland. Agriculture accounts for another 25%. However, about half of the water attributed to agriculture is actually pumped through the farmers fountains and is not actually used. A good half of the total water budget is used by commerce and industry (see Figure). Thus, about half of all used water is extracted by public services (drinking water) and half by the private sphere (agriculture, industry). Each year, one-third of the water volume of Lake Thun is consumed in Switzerland (2.2 km3).
Drinking water
Where does the drinking water in Switzerland come from? 40% comes from spring water, 40% is pumped from groundwater, and the final 20% is taken from surface water, usually lakes. Lake water needs a two-step treatment process to reach drinking level quality. A third of the drinking water goes through a single step treatment, and half of the water doesn’t need any treatment at all. Thus, the drinking water in Switzerland has a level of quality that can compete with that of mineral water. Drinking water is distributed throughout Switzerland via 53,000 kilometers of piping, a length sufficient to circle the country 28 times. These pipes must be replaced about every 50 years, which corresponds to 1,000 kilometers of new pipeline every year. This is necessary because about 15% of drinking water is lost each year to leaky pipes.
As the figure below shows, water consumption per capita is declining. This indicates that people are aware of water issues and use water-saving devices and methods, such as water-saving showerheads. In addition, devices like dishwashers and laundry machines have become more efficient. However, a substantial portion of water savings is not actually saved, but relocated: water-intensive industries such as textile production have been transferred abroad. In addition, an increasing amount of goods and foodstuffs, which require plenty of water to produce, are imported. Thus, “virtual water” is an important element of the water budget.
It is a matter of concern that, of our daily consumption of agricultural and industrial goods, only about 25% is supplied by domestic water resources. Three quarters of our needs are supplied by other regions of the world, where water restrictions (if any) are often less stringent than in Switzerland.
Events, News, Publications
Das Bundesamt für Umwelt (BAFU) sucht eine/n Wissenschaftliche/r Mitarbeiter/in Trockenheit und Wassernutzung (70 %). Sie arbeiten am Aufbau der neuen Trockenheitsinformations- und Warnplattform des Bundes mit und koordinieren den Aufbau eines Wassernutzungsmonitorings für die Schweiz.
Image: Gabriela Brändle, Agroscope
Der Bundesrat hat an seiner Sitzung vom 18. Mai 2022 einen Bericht zur Wasserversorgungssicherheit verabschiedet. Angesichts des Klimawandels stellen sich Fragen, wie künftig die bestehenden Bedürfnisse am besten abgedeckt werden können. Der Bundesrat schlägt verschiedene Massnahmen vor. Unter anderem empfiehlt er den Kantonen, ein regionales Wassermanagement durchzuführen und den aktuellen Wasserverbrauch umfassender zu messen. Der Klimawandel wird sich auch auf die Wassernutzung in der Landwirtschaft auswirken.
Image: C. RitzThe report ‘Effects of climate change on Swiss waters’ gives a concise overview of the results of the HydroCH-2018 project and is a gateway to further technical information and data.
Image: BAFU
Das zweite Modul «Wallis – Wassernutzung im Wandel» enthält die Themen «Wasserdargebot», «Nutzung des Wassers», «Wasserverteilung» und «Wasserbewirtschaftung bis 2100».
Der Klimawandel hat zunehmend Auswirkungen auf die Verfügbarkeit von Wasser – als Trinkwasser, zur Bewässerung, als Energieressource und als Lebenselixier für die Natur. Zwar wird es in der Schweiz auch im Jahr 2100 insgesamt genügend Wasser haben, aber die Verteilung wird regional und saisonal noch stärker schwanken als heute schon. Mehrzweckspeicher – in der Schweiz sind dies meist Stauseen für die Lagerung von Wasser für verschiedene Nutzer – können hier Abhilfe schaffen. Um dies zu erreichen, ist eine nationale Wasserstrategie notwendig.