Just think, if the dams were down on the Credit and Bronte, the west end would be an amazing year around fishery with thousands of fish in the rivers at all times.
vxp/\
There isn't any significant road blocks for a salmonid on the Bronte. I've paddled it quite a few times. There's a low dam at Lowville and a weird structure at Sidrabeen the fish easily get past.
I think it will always be a put and take fishery. These are originally ocean dwelling, west coast fish.