Two-way fish siphon overpass

A method and apparatus for transporting migratory fish over dams. Fish are transported over dam in downstream migration to the sea and upstream migration to spawning beds. The method includes transporting threatened or endangered species from spawning beds by means of fish nets 46 to fish siphon 28 if needed; powering closure gates 14 and louvers 06 by hydro-power generated by power siphon 26; slowing water for returning fish; using attractants to guide fish to fish siphon 28; operating the apparatus manually or with timing devices; allowing fish to be emptied both upstream and downstream of dam. The apparatus includes a fish siphon 28 and power siphon 26 with propeller 12; planetary gears 30 for operation of closure gates 14 and louvers 06; and foils 08, air pump 10, food, lighting to aid returning fish moving through fish siphon 28. Where steep terrain is encountered, apparatus can be repeated as units of dual siphons 26, 28 and pools 42 or tanks 42 to transport fish migrating upstream or downstream.