Unternavigation

State of watercourses

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.

Water flow & flow regime

In principle, Switzerland has a large water supply that depends on natural factors such as weather conditions or glaciation. However, the volume of water in watercourses is influenced by hydropower production in many areas (residual flow, hydropeaking). In the future, water availability will be limited regionally during dry periods as a result of climate change. The FOEN is monitoring the water flow and flow regime of Swiss bodies of water.

Temperature

Water temperature is one of the key physical parameters that determines chemical and biological processes in a watercourse. The FOEN’s measurements are the basis for monitoring temperature changes and understanding their causes.

Water quality

Water quality in watercourses has improved significantly since the 1970s in terms of nutrient pollution. Micropollutant contamination is the new and biggest challenge at this time.

Structure and morphology

Swiss watercourses are heavily developed with control structures and their natural functions are limited. Around half of the watercourses located at elevations of up to 600 metres above see level are in poor morphological condition and have many obstacles that impede the migration of fish.

Bed load and suspended solids

Sediment is an important component of ecologically intact rivers and streams. However, the sediment budget is disrupted in around one-third of watercourses. The FOEN monitors the transport of sediment by watercourses across Switzerland.