Faunapassages - hydraulic conditions for good ecological status

Hydropower accounts for nearly half of the electricity produced in Sweden and is an important renewable energy source.

However, hydropower creates migration barriers in regulated rivers, with detrimental effects on both the up- and downstream aquatic communities.

To fulfil the environmental directives, new ways to improve fauna passages are required, e g methods to ensure suitable positioning of upstream and downstream fauna passages.

Cross-disciplinary research between ecology, biology and technology is therefore necessary understand the connection between fauna behaviour and flow.

An inventory of existing passages helps characterizing the hydraulic parameters affecting the efficient placement of a fauna passage with high passage efficiency.

Further, hydraulic properties and fish behaviour for different configurations for habitat inside the passage solutions are also studied. Finally, a passage solution is proposed where high-flow spillways are used for entrance to the passage.