Rivers and streams

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.

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.

Water flow and discharge 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.

Watercourse temperatures

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 in watercourses

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.

National Surface Water Quality Monitoring Programme (NAWA)

In order to be able to assess the condition waterbodies in Switzerland over time, data must be regularly collected and documented. The FOEN, in cooperation with the cantons, provides this basis with the National Surface Water Quality Monitoring Programme (NAWA). National monitoring programme for loads of substances in swiss watercourses (NAWA FRACHT) is a long-term federal sub-programme in which the two federal research institutes Eawag and WSL monitor the state of rivers on the basis of their substance loads.

Modular Stepwise Procedure

The Modular Stepwise Procedure (MSP) is a series of methods for monitoring and assessing the status of water bodies. It is used to assess the state of the main aspects of watercourses. Initial methods also exist to assess lakes and spring habitats. Other methods have been developed to identify the causes of shortcomings and to assess the impact of remedial measures taken.

Further information

Data, indicators and maps

Pollutants and pressure of use

Water in a changing climate

Gewässer in der Schweiz
This publication does not exist in English. It is available in other languages.

Zustand der Schweizer Fliessgewässer
2016

Hydrological data and forecasts

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