mm..il tel what i knw.. i don't exactly know if flows affect the fish but it surely does affects fishing.. cfs means cubic flows per second and the greater the streamflow, the harder it is to fish. a 4,600 cfs is still good for fishing..figures extremely higher than that won't be easy anymore.
Imagine a basket ball. That is about one cubic foot. So at 600 CFS, there are 600 basketballs a second coming down stream. At least that is how it made sense to me.