Avon was open on Saturday nights for regular non-lesson kayak pool sessions. I think there was a fee of around $10 or something. Not sure if you also have to pay a seperate entry fee for not being a member, as I haven't gone to it.
This was during the kayak season, it may or may not be still going, I would call. Info is at www.avon.org
Like Philip said, Alpine Quest probably knows too, and may have some lessons or sessions lined up. (Alpine Kayak + Mountain Quest = Alpine Quest)
Ritz pool would be bitchin! Maybe if you made friends with the hot springs pool people... That would be pretty cool, I would go for that.