I don't think you're looking at the right gauge. If you're pulling it from AW they probably have it linked to the wrong place. Try this:
South Platte River - Confluence - River Brain
It's below the Cherry Creek confluence, but I can't imagine much is coming from Cherry Creek.
But yeah, there's a lot of stuff going on upstream and coming back from the drought I'm sure they're trying to fill reservoirs more than they would in a normal year.