The European eel lives in running waters, but spawns in the sea. When migrating downriver, the eel has to pass through many hydropower plants and faces a variety of dangers in the form of screens and turbines. We minimise this risk and offer the eel a system that diverts it unharmed around the plant. The crowning jewel of this system is a zigzag-shaped pipe with several openings that the fish can swim into. From this pipe, the eels swim through a bypass that deposits them safely in the backwater.

The KLAWA eel bypass is now regarded as a recognised protection system in some of Germany’s federal states. Field surveys at a plant in north Hesse prove that more than 1,500 eels have already migrated safely using this system. Another benefit is that water consumption is very low at 10-30 l/s. This makes hydropower plant operators more receptive to the system and paves the way for permanent operation.

Engineers and biologists at the University of Kassel developed the eel bypass, which has been tested by animals and is protected by patent.

The number of eels that have successfully made it through the bypass is being counted at the Edermünde-Grifte hydropower plant in north Hesse. A huge number of fish have safely continued their migration downriver thanks to this technology.