I doubt there is any water running in Black Canyon but since your title is "Agua Fria," I'll assume you're asking if the Agua Fria is flowing?
The Black Canyon Trail (BCT) crosses the Agua Fria in five places. The northernmost crossing, north of Mayer is usually dry and I doubt it is flowing now. From the Black Canyon City trailhead, you cross the Agua Fria within a few miles going north and also going south. Both of those crossings are pretty much always flowing. I know they were last month. The BCT crosses the Agua Fria two more times south of there, once on the east side of Little Pan Loop and also on the west side of Little Pan Loop. Water was flowing on the east side last month. It probably isn't flowing on the west side crossing, however, there are large pools of water near the crossing. The Agua Fria is actually flowing there, however the flow is underground and you just see the pools.
See my trip report from last month: [ triplog ]