You can float the buffalo at any level. The only time I have done Rush down in a canoe it was mid august, and the gauge was at 2.5' at Harriet(lowest gauge). We didnt do hardly any dragging. There is a small cut in the island that you can take which will help you get to Riley's easily. BTW, they do not shuttle anymore, but the place across the road from the rush turnoff does for $60.