The first pilot plant of a flexible FishProtector was realised at the Leinau hydropower plant on the Wertach river in Kaufbeuren (Bavaria). There, the FishProtector serves as a fish protection and fish guiding device at the newly built dotation hydropower plant.
The dotation hydropower plant is located at the beginning of the existing channel of the Leinau hydropower plant and uses the required residual water discharge with a hydropower screw, which also serves for fish migration. The FishProtector spans a length of about 20 m over the headrace channel and guides the fish directly to the hydropower screw so that the fish can find this migration possibility and do not swim into the headrace channel. The 8 mm thick steel cables used are arranged with a clear spacing of 60 mm. The 40 cables form a mechanical barrier about 2.5 m high, which safely guides fish to the hydropower screw. On the right bank, the fixed bearing is located in the embankment, while on the left bank the cables are first directed through an embankment plate in the FishProtector's operating building, then deflected and guided upwards, where they are movably mounted on hydraulic cylinders. Two cables are attached to each cylinder. Due to the reeving of the cables, the maximum cylinder stroke of 0.80 m allows a maximum additional cable length of 1.60 m per cable. Due to the flat design of the embankments, the laid cables can completely clear the flow cross-section.