Fish ladders don’t work. Salmon want a river to swim up to spawn and a river to flush salmon fry down to the ocean. Farmers and recreationists will never agree to breach the four lower Snake River dams that are blocking access to some of the best spawning grounds.
How to keep the dams and the salmon runs?
Simple. Replace the fish ladders with a bypass river from below the dams to above the reservoirs. Use diversion gates to control the flow of water into the reservoir or the bypass river. Spawning salmon swim up a river and salmon fry are flushed down to the ocean without the disorientation of four 10-mile-long reservoirs.
If tunnels are needed for slope, artificial lighting can be installed. If predation on salmon in a concentrated channel is a problem, place grates over the channel. If we can construct tens of thousands of miles of interstate highways, surely we can dig a 10-mile trench around a few reservoirs. It doesn’t even have to be particularly straight!
Let’s get it done and re-establish the spectacular Snake River runs!