Topic Water

informs about the state of the environment and reveals the links between driving forces, pressures, environmental quality, impacts and responses.

Groundwater is Switzerland's most important drinking water resource. In the past, the ability to extract sufficient quantities of high-quality groundwater has been taken for granted. However, groundwater resources are coming under increasing pressure. Residues of synthetic – and in most cases persistent – substances are adversely affecting groundwater quality. This has been demonstrated by analytical results of the NAQUA National Groundwater Monitoring.

Switzerland’s watercourses are extensively engineered and limited in their natural functions. Water quality has improved markedly since the 1960s. However, micropollutants continue to pose a challenge to water protection. The temperature of watercourses and the flow regime are likely to undergo further changes due to climate change.

Nutrient loads in Swiss lakes have been reduced since the 1980s due to intensive efforts to protect bodies of water. Although water quality has improved, several lakes are still over-fertilized. In addition, many ecologically important sections of shore are affected: Control structures reduce the quality of the habitats of plants and animals.

The FOEN monitors current floods and low-flow situations, issues warnings, analyses the events and informs the public.

Climate change affects the entire water cycle. Surface and underground waters are equally exposed to changes in water quantity and quality. This has direct impacts on hydropower, water supplies, urban drainage, navigation, agriculture, ecology and water-induced natural hazards.

Surface waters are those habitats in Switzerland that have departed the most from their natural state. The federal government's water protection policy aims to restore the value of rivers, streams and lakeshores with the following measures: sufficient space provided for waters, rehabilitation projects and the reduction of negative impacts due to hydropower exploitation.

Wastewater treatment is a success story. Thanks to the virtually nationwide expansion of wastewater treatment plants, water quality in Switzerland has improved greatly in recent decades. The next step is to remove micropollutants. A prerequisite for wastewater treatment to continue to function in the future is charges based on the polluter-pays principle.

Streams, rivers, lakes and groundwater are under pressure. Many waterbodies and watercourses are polluted by fertiliser residues, pesticides and pharmaceuticals. They are channelled, straightened and otherwise regulated. They are also affected by the generation of hydropower. Moreover, introduced plants and animals as well as climate change are having an ever greater negative impact.

Neighbouring countries of Switzerland use the water that flows across its borders. For decades, international agreements, treaties and bodies have been governing cooperation in this area and setting objectives for transboundary waters.

The FOEN collects and publishes a lot of data and derived products on the topic of water. These pages contain links and overviews of the available sets of measurements and geodatasets as well as information on how to obtain current and historical data. Detailed information on individual datasets can also be found on the corresponding topic pages.