When we find a waterfall to photograph, the first thing we do is search for foreground interest for composition. One of the coolest things that we can use is an eddy. An eddy is where the flow of water turns back against the main flow and causes a swirling effect. Some are very large and take an extremely long shutter speed of 8 seconds or more to capture. Others, like the one in the foreground of today's image, are much smaller and in this case spin more rapidly and are able to be captured in a couple of seconds.
Today's image even has a bonus in that there were several yellow leaves trapped in the eddy and adding color to the swirl.