Seriously, you folks don't understand west coast weather. The massive volume of water that drops out of storms coming off the pacific is nothing like the rest of the country. Unlike storms on the east coast the Pacific storms march onshore, hit the mountain ranges and DUMP water for days. With steep mountain terrain that stuff comes blasting down stream moving boulders the size of an SUV. Forget power generation, having some control over this flooding and destruction is a very good idea.
Next, these dams have fish ladders easier for salmon to traverse than the natural river. Salmon runs are closely monitored and harvesting is tightly controlled to ensure these specie's survival. Things that are actually impacting salmon, invasive species that are gobbling up the baby salmon. You can make good money fishing for these scumbag invasive predator fish. To help there are vast numbers of fish hatcheries all along the west coast. They raise and release millions of baby salmon.
The environmentalist idiots are pushing for the destruction of dams. Yet another half baked non-science based emotional outburst from these freaks.