There is no gauge on Roaring River but approximate flows can be estimated from the Clackamas River gauge. Generally the Clackamas River at 3 Lynx should be about 2500cfs for Roaring River to be runnable. Be sure to check the flow at the take-out to confirm river level. There is a stick gauge located in the last pool before the take-out on river-right. There is a faint trail on river-right from the take-out that leads to the pool or the gauge can be viewed from the trail leading out of Roaring River campground on river-left. 2.5' on the stick gauge is a good medium flow. If you can't find the stick gauge, the last rapid is very typical of the nature of the run although there are several harder rapids.