I have not seen what the canyon the Bailey run is in looks like, but if there are a lot of small mountain streams/tributaries that flow or can flow into it I would say that you can be optimistic about water.
The Deckers run is showing 500, the Foxton 225. These don't add up to the 1520 that Waterton is crankin' right now. We did a shorter Deckers run last night after work and I can tell you that there is WAY MORE than 500 in there. There were tributaries and small streams flowing into that thing all over the place and parts of it were ragin'.
Even if the Deckers run was all the way up to 900ish, which was definitely possible last night, that still leaves over 500 for the North Fork. I am not sure if all of that water is coming into the North below Bailey or not, but its at the confluence to say the least.