I think by the time the hatchery came into operation the summer runs numbers were pretty low. IIRC an accidental release of chlorinated water into the hatchery water supply killed the entire brood stock one year not so long after it went into operation. Add to that the pressure from the early coho fishery, poaching and low ocean survival, they trickled away to less than nothing. Last I heard the return had been 1 adult fish some years ago.
Any angler in the GVRD ought to think about the dam and it's effect on the Cap salmon every time they water their lawn or have a drink of water.