Troutslayer76, you should be able to catch cutties on almost any stretch of the Alouette system, some places may be better than others. There is an area upstream of Jerry Sulina Park to the 216th St. bridge that is private property (including the river bottom, you could float thru OK, but not anchor or stand without trespassing) and there is no fishing above 216th from May 1 to June 30 and no fishing at all above the signs near Alouette River Corrections Branch. They tend to move around a bit, so where you catch one, or more, one day there may not be any the next. The few I've caught have been on smaller spoons, and I haven't tried the N. Alouette yet, I would think that fry patterns would be a good bet for the next while.
Remember, single barbless hooks, ANY wild trout must be released unharmed, and ANY trout/char under 30cm (roughly 12in.) must be released as well, and you can only keep two hatchery fish from any stream/slough. DeBoville Slough is on the PoCo side of the Pitt River, and while I haven't seen any info on it, Hyde Creek which flows into it is marked as no fishing at all.
Tight lines, and looking forward to a post on how well you did.