Watercourse structure and morphology

Swiss watercourses are heavily developed with control structures and their natural functions are limited. Around a quarter of the watercourses are in poor morphological condition and have many obstacles that impede the migration of fish.

Swiss watercourses have been massively altered by human intervention, especially since the 19th century. They have been developed with control structures, canalised and restricted within the landscape. This was done to protect against floods and produce energy, but also to create more land for agriculture and settlement.

Due to these changes, watercourses can no longer fulfil many of their natural functions. Habitats in and around watercourses are deteriorating, and the landscape has become more monotone.

Insufficient structural diversity

One-fourth of all bodies of water are now in a poor ecomorphological state, which means that they are artificial, heavily damaged or converted. More than 100,000 artificial obstacles over 50 cm in height also negatively impact the habitat. Bodies of water in low-lying areas are especially heavily damaged. In the intensively used areas almost half of the watercourses have little to do with their original condition. 

Evaluation methods

The ecomorphological state of watercourses has been measured by the cantons with financial support from the FOEN. They have surveyed and mapped watercourse structures using the modular stepwise procedure.

The FOEN provides the findings of this comprehensive evaluation of state in a report, as well as in survey maps and regional evaluations (see publication (not available in English) under Document)


Further information

Last modification 20.08.2018

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