The interpretation of dreams in which you are floating over a waterfall depends heavily on the object in which you find yourself in the dream.
If you find yourself on a canoe, boat, or other conventional vehicle used to travel water, it means you are ready to brave the rush and have invested some time and energy in self-reflection.
If, on the other hand, you find yourself tumbling down a waterfall in a non-floating item or an unusual vehicle, this implies that you are being carried away by events and emotions that are maybe beyond your control.
Pay attention to the sort of thing you are in since it will tell you which aspect of your life demands your attention.