As a rule, general requirements for fish protection and/or descent are formulated in the Land Fisheries Acts, more rarely in the Land Water Acts. When constructing e.g. water intake facilities, pumping stations or power plants, suitable devices must be provided to prevent fish from entering. Fishways are to be created when, for example, transverse or barrier structures are built or substantially altered. In some laws, the requirements for the respective devices are supplemented by additions such as "according to the generally recognised rules of technology", "according to the state of the art" or "according to the state of knowledge and technology".

General requirements for fish protection and fish bypass are specified by eight federal states in ordinances, decrees, handouts or prioritisation concepts, see table below. This concerns in particular the requirements for bar spacing of rakes. Depending on the target species or protection goal, bar spacing of 10 to 20 mm is required. Specification of the inflow velocity, the bypass discharge or the descent.

The illustration provides an overview of concrete fish conservation measures and targets in German federal states. It is part of a fact sheet on fish protection and downstream fish migration measures.

The infographic is published under a creative commons license CC BY 4.0. That means it can be copied and redistributed in any medium or format and for any purpose as long as appropriate credit to the authors (Ecologic Institute, Ingenieurbüro Floecksmühle) is given.