Call Northern States Power recorded hotline at 715-893-2213 for discharge information. Minimum for fun is around 500-700cfs. Good is 1400-1700cfs.
Alternatively, looking upstream at the put-in at Saxon Falls (an impressive sight), the falls is split by rocky prominences at the brink. If you see only one 'falls' with water, it is very low; two 'falls' is low-moderate; three 'falls' (adding a narrow center sheer falls) is a good level.
Reports give the public a chance to report on river conditions throughout the country as well as log the history of a river.