The fish migration screw (FAS) system Rehart/Strasser can be retrofitted into existing plants (also at turbine installations).








The practical feasibility of our pilot plant in Pilsing has been confirmed by successful monitoring. Compared to conventionally built fish migration tubes, this fish migration screw is considerably more space-saving and cost-effective.

Fish migration screw FAS system Rehart/Strasser

  • With this fish migration screw already filed at the European Patent Office no guaranteed water volume is lost.
  • The inlet and outlet area, as well as the attraction current, comply with the latest directives for fish migration tubes from 2012.
  • A part of the water being outlet from the hydropower screw is used for generating the attraction current.
  • The fish can freely enter the attraction current and are guided upwards without effort.
  • The fish migration screw is optimally adapted to the predominant fish. Here individual settings at constant rotation speed are possible.
  • A special riverbed interface has been developed for weak swimmers or bottom-oriented fish. 
  • There is no rigid coupling between the hydropower screw and fish migration screw. Both areas are freely adjustable. The hydropower screw can be operated optimally whereas the fish migration screw can be adapted to the respective fish population. 
  • The upstream water is separated in the inlet area to generate a stabilizing zone between the hydropower plant and the fish migration screw. This prevents the ascended fish being re-directed downstream by the suction of the hydropower screw.
  • The outlet and inlet zones are adapted in accordance with local conditions and planned individually.
  • The functionality of our fish migration screw at the pilot plant Pilsing has been officially confirmed by successful monitoring and expertise.

You can request expertise and monitoring results. Please use the contact form.