I think you’re right Rodney, the upper river is underutilized by certain species like steelhead, chum and self-sustaining chinook. As most who have read Pete’s and my steelhead enumerations will know, the upper Chilliwack river is sparse for gravel, with virtually all spawning areas concentrated in manmade off channel areas or augmented gravel sites. In these areas pink and coho are doing well, with one site, Angelwing channel, doing exceptionally well.
We all know the advantage of chums to a coastal watershed so imo, the best enhancement value for this system would be chum augmentation in the upper river. This could be done with fry plants but perhaps the best way would be eyed egg plants in Centennial and Yukalup channels, as well as the outlet of Chilliwack Lake. Egg plants are much more labor intensive but have a proven track record with other salmonids, the advantage being the alevins develop at the ambient water temperature and the returning adults having a better chance of future homing success.