I would say at least 60 on the bridge for a low flow. 75 would be be down right killer. If your thinking of going in. There are 3 river wide tree's that need to be portaged. One is in a rapid towards the bottom of the run. The other two are in flat/boogie water sections.
75 on the gauge is more like a medium level. This year it's going to go big. By 85 or so the creek really changes character - there are some sticky holes and many of the eddies disappear. At the higher levels it's a good idea to have good tree-grabbing skills.