To preface this I haven't ran this stretch of river, but I scouted it extensively at 600 cfs on the gauge. At 600 cfs, I'd call it low, low runnable.
The Walloomsac was one of the VT rivers that got destroyed by Hurricane Irene. It clearly is massively eroded and now has a very large riverbed for a river its size.
Here is a video from Irene of the Walloomsac during Irene in Bennington. Therefore, it now often splits into one or two channels around sandy rocky islands - and needs more water to run.
During the 4 mile stretch I scouted, between the AT crossing and right outside Bennington, there were no significant drops. However, it is pretty much continious class II-III for 4 miles. Very few stops and a shallow riverbed wouldn't make it friendly for beginner-intermediate paddlers, but I can imagine having a bunch of fun at levels above 800 or 1000 cfs on the gauge. There appeared to be one or two nasty holes, but all avoidable.
The gauge is far below this run - where the Walloomsac continues on from Bennington to Hoosick Falls, NY. I don't know what's in that section - however, there is a class III on it under the rt 22 bridge north of Hoosick Falls. Substantial two-tiered ledge drop. Runnable at 600 cfs.
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