Hells Canyon releases are all based off power demand. Idaho Power is required to release "Fish Flow minimums" out of the dam (around 5000 cfs).
The Green Room starts showing just over 19,000 cfs. Waterspout gets pushier the lower the water (around 11,000 cfs and lower).
When Hells Canyon is releasing 30,000+ cfs the river becomes a big wave train and eddy and boil lines. If running to Heller Bar be aware of the Salmon river flows. With the Salmon run off you can have another 30,000+ cfs at the confluence and makes one hell of a pushy ride threw the last 25 miles to Heller.