Water use

Water is one of the most important resources for life and the economy. It is essential for drinking water, irrigation, producing energy and in industry. As a result of climate change, both the supply of water and the demand for water for various uses will change. It is therefore essential to have suitable base data on water use in order to ensure sustainable management of the water resources as they become increasingly scarce.

Public water supply system and drinking water consumption
End use and future trends
Collection of data on water demand in Switzerland

Public water supply system and drinking water consumption

The public water supply system provides drinking water for households, industry and commerce. The Association for Water, Gas and District Heating (SVGW) gathers data and produces projections on public water supply in Switzerland on an annual basis. In 2021, the public water supply system provided 914 million m³ of water (FSO 2023). Even though consumption has increased again slightly in recent years, following a steady decline since the 1990s, relatively steady demand is expected in the future according to the current consumption forecasts. However, prolonged hot and dry spells will be critical, as they lead to high peak demand, and could overload the infrastructure of the water supply system.

Trends in output volumes from the Swiss public water supply system 1970–2020 (image: Association for Water, Gas and District Heating (SVGW), 2023)

Water consumption in millions of m3 in 2006 in Switzerland, differentiated by end use and access to use, according to SVGW data (image: Freiburghaus, 2009).

The results of a one-off collection of data and projections from 2006 are available on consumption of water from a private supply by industry, commerce and the service sector. In 2006 water consumption stood at 1,120 million m³. Two thirds of this was used on cooling and air conditioning. Added to this is the volume of water used for cooling nuclear power plants – around 1,600 million m³ of river water per year.

End use and future trends

Water supply for industry and commerce

Only local increases in demand for water are to be expected for the supply of water to industry and commerce, and only for individual cases, particularly because there is still potential for more efficient water usage.

Thermal use

Demand for thermal usage is expected to increase mainly for the purposes of cooling in processing and buildings. However, since the rivers are getting warmer and warmer, their use will be limited in the future, although there is potential for using the heat from large lakes. The phasing out of nuclear power means that large amounts of heat will no longer be discharged into individual stretches of water, which will relieve the pressure on ecosystems.

Snow on the ski pistes

In 2006 around 15 million m³ of industrial water was used to create snow on ski pistes. The proportion of pistes covered by artificial snow has risen steadily since the 1980s, which is why the water requirement is likely to be higher today. The water use for this is restricted to the winter months and leads to considerable peak consumption locally and in the short term.

Agriculture

The water requirements for agriculture in 2006 stood at around 410 million m³ of industrial water, most of which comes from private supplies, with a smaller proportion also coming from the public water supply. A third of this was used for irrigation, while the rest was used in processing and supplying fountains. During dry years, such as in 2018 and 2022, the consumption for irrigation is likely to have been significantly higher, but there is no available data on this. By the end of the century, the water requirement for agricultural irrigation will increase by around 40% for crops that are already irrigated today. A trend is also emerging in Switzerland towards special crops that need to be watered. For example, the irrigated areas for growing vegetables have increased sharply in the recent past (+24% between 2010 and 2016). The water for irrigation is being withdrawn from the bodies of water on an ongoing basis and thus also from the residents downstream.

Data on agricultural water use in Switzerland is also incorporated into the global water usage database AQUASTAT, held by the Food and Agriculture Organization of the United Nations (FAO). Switzerland is not currently in a position to provide the data in the required level of detail. As part of a project funded by the FOEN, the Bern School of Agriculture, Forest and Food Sciences has compiled an overview of the data available on agricultural irrigation in the cantons.

Datengrundlage und künftige Datenerfassung zur landwirtschaftlichen Bewässerung in der Schweiz (PDF, 8 MB, 19.04.2023)Project 'Swiss Irrigation Info': Final report module 1 (in German)

Hydropower

Hydropower utilises the energy potential of water without actually consuming the water. Yet the abstraction and diversion of water does lead to water flow being reduced in certain sections of water bodies (residual flow stretches). Approximately 6,000 million m³ per year is currently stored in reservoirs. No estimate is available for the volumes of water passing through run-of-river power plants. Rainwater and meltwater are stored in the reservoirs temporarily during the spring and summer and released back into the rivers in winter to generate electricity. Depending on the control system, can lead to a further reduction or increase in the discharge in the underlying watercourses during summer dry spells.

Hydropower production is due to be increased in accordance with the federal Energy Strategy 2050 and the revision of the Energy and Electricity Supply Act of June 2021, which requires both the expansion of existing hydropower plants and the construction of new plants. In the second half of the 21st century, climate change will lead to a seasonal shift in water discharge into the winter and thus also to a change in electricity production, particularly in run-of-river power plants.

Collection of data on water demand in Switzerland

There are gaps in the information on current water use and future water demand in Switzerland because sufficiently detailed regional and seasonal data on water use and water demand is not being collected on a national basis. However, the Action Plan 2020–2025 for adapting to climate change in Switzerland is already striving to collect water demand data.

Such data is necessary for planning measures to avoid conflicts and supply shortages in advance, so as to be able to take the various interests into account in a balanced manner. This data is also required at international level, for fulfilling Switzerland's international reporting obligations (AQUASTAT, SDG6, EUA).