Blair Holtby, retired career scientist (fish specialist) at the Pacific Biological Centre happened to be there photographing the fish.
He said that these are ODD YEAR pink salmon, that the males have been here for awhile and now the females are here. This observation shows a male (hump in the back). He estimated there were about 500 salmon in the Mamquam fish channels that day.
There has been much more rain than usual this September.
They were first discovered spawning in Kootenay National Park in 1984
See Journal -
https://inaturalist.ca/journal/larryhalverson/29764-kokanee