I present you the most amazing solution to this:
https://www.youtube.com/watch?v=2z3ZyGlqUkA
Not to mention that the dams in Washington state do account for spawning/migration and slow down flows at certain points of the year.
Not to mention that the dams in Washington state do account for spawning/migration and slow down flows at certain points of the year.
Earlier attempts at fish ladders saw rates as low as like 3% for certain species of fish, per ladder/dam. Even if 50% of salmon got up them, if they have to pass 5 of them on the way to the spawning ground that meant 97% of salmon wouldn't make to the spawning grounds.
Also, obviously, the ecological effects aren't just "tasty fish can't make babies". The impact on seasonal floodplains and sedimentation is huge by itself.