Since the revised Water Protection Act of 11.12.2009 came into force on 01.01.2011, the cantons have been responsible for taking the necessary measures to mitigate the ecological impacts of hydropower. These include obstacles to the free migration of fish. According to the law, any obstacle linked to hydropower that has a significant impact on fish migration must be sanitized.
In this context, restoring fish migration downstream is a legal obligation in the same way as restoring fish migration upstream, and a large number of structures to aid fish migration downstream should be built on hydroelectric power stations in the near future. In fact, the legal deadline is 31.12.2030, the date by which work on remediation measures is supposed to have started on all the facilities concerned by the remediation of downstream migration. In Switzerland, this means around 700 facilities. Once the remediation measures have been implemented, the effects must be monitored. OFEV is then responsible for evaluating the results of the effects monitoring and, if these are deemed unsatisfactory, for requesting improvements. However, given the current state of knowledge, it is difficult to define clear objectives for the expected efficiency of a downstream migration system.
This mandate allowed us to establish the current state of knowledge in terms of monitoring the effects of downstream migration measures, with the aim of defining relevant objectives that will be applied in the context of restoring fish migration in Switzerland.
Project partner(s)
Project leader - team
Franck Cattaneo
(HEPIA),
Juliette Becquet (HEPIA)
