If it was real dry when they spawned, in low flows, then the thalweg runs right through it. For wild Skagit Chinook I seem to recall a pretty good inverse relationship between flows and fry production the next spring.

Ya know, back in the Dark Ages before all those fancy computers we had run reconstruction, which included escapements, by late December/early January. I was starting to explore what update models would work in Feb?March using data that included the previous year.

Hell, WDG used to publish publicly the rec catch of steelhead in the fall before the next season got started. Used to.