fishway

fish +‎ way

fishway (plural fishways)

1. A structure built on or around dams or locks to facilitate the migration of fish.
   • 1997, J. H. L'Abée-Lund, J. E. Brittain, “Weir construction as environmental mitigation in Norwegian hydropower schemes”, in Hydropower '97, pages 51–54:

     The weir must not represent a physical barrier to fish migration, both locally and throughout the whole river system. If necessary, a fishway is included in the weir.

• fish ladder