In terms of what - how easy various river crossings on trails are, i.e. the crossings on Owl's Head? If that is what you mean I would say 500 cfs or lower is a good benchmark for safe and relatively dry attempts at those crossings. If you mean historically obviously time of year is a huge factor. TJsname outlined how to review that above.
Is there a more specific question? For example, I know from experience that <500 CFPS means you can get to Owl's Head via the trails with dry feet. <750 CFPS you can get there via Black Pond BW with dry feet. Above those thresholds, you may have to hunt for rocks. Of course given any major storms, the rocks might get moved around, but those numbers have been reliable for me for many years.
If historical records going back to 10/20/2007 exist, whatever that number was, it's too high for safely making the crossings on the way to Owl's Head. I would estimate they were at least a few hundred feet too high for adults to safely recommend doing. One moron did it one way and took the fisherman bushwhack. He also saw no after making the first crossing so everyone else was smarter.