FISH PASS Russian patent published in 2007 - IPC E02B8/08 

FIELD: hydraulic structures, particularly fish passes permitting fish passage through support structures to fish hatchery and growth areas.

SUBSTANCE: fish pass comprises waterway with stepped bottom made as gutter with rectangular cross-section. Bottom mark for each downstream stage increased towards inlet port. Outlet fish pass port is connected to upper pool of hydrosystem, inlet one is communicated with lower pool thereof. Transversal partitions with bottom swimming-in orifices and transition areas arranged between transversal partitions are made along fish pass length. The transition areas include bottom baffle extending for the full fish pass width in stage step section. Bottom swimming-in orifices are made in horizontal partition adjoining downstream transversal partition by one end thereof. Another end is connected to bottom baffle so that bottom gallery is created. Bottom gallery has one inlet swimming-in orifice and several outlet swimming-in orifices. Bottom outlet swimming-in orifices are distributed across horizontal partition area.

EFFECT: possibility to create hydraulic conditions, which facilitate fish movement along fish pass.

8 cl, 10 dwg