The two-day workshop, funded under the BMUV's Environmental Research Plan, took place on 30 and 31 May 2022 at the Federal Environment Agency in Dessau (Germany) and was dedicated to the topic of "Technical-Hydraulic Assessment of Fish Protection and Downstream Migration at Hydropower Plants".

At the past events, fish protection objectives, fish protection measures, functional controls and monitoring were comprehensively discussed, with the topic of assessment being regularly touched upon but not discussed in depth. The focus at the 9th workshop was on the topic of evaluating fish protection and fish migration at hydraulic structures based on technical-hydraulic parameters.

Different technical and legal perspectives as well as value systems are involved in the assessment procedure for fish protection and migration, which can lead to different levels of acceptance of the procedure or to diverging assessments of individual procedural steps or parameters. The event was dedicated to the presentation and discussion of these different points of view. The first block of the event addressed both the technical aspects and challenges of evaluating fish protection and downstream migration at the level of the structure and the watercourse system, and reflected on the expectations of different interest groups regarding an evaluation system.

This discussion was continued with a draft technical-hydraulic classification system for fish protection and downstream migration, which is currently being developed and formed the core of the event. The draft was presented at the forum and applied and tested in three working groups. There was an opportunity for the participants to talk to each other as well as to the procedure developers and to comment on the procedure design, its application and the resulting outcomes.