Improved habitat quality can be achieved through a reduction of fine sediments (see erosion) or through controlled gravel deposition.
Dams in the upper reaches prevent the transport of gravel from the upper to the lower reaches. As a consequence, the river bed is deprived of gravel.
20m3 gravel will be added to the Our and Sauer at 5 sites during the duration of the project. The gravel distributes itself on the river bed within a short time.
The habitat restoration aims to provide appropriate withdrawal sites for young mussels. Additionally, many fish species will benefit from gravel beds for egg deposition. Thus, the mussels and host fishes will be in optimal proximity.