I got to sit down at a waterfall garden one day. Lemme scribble down what I observed...

A waterfall, I've noticed starts calm and orderly on the top but it gets more chaotic as gravity and water's cohesion property starts doing stuff.
The cohesion property bunches the water up into sections since water wants to bunch up into itself, not stretch itself apart. Waterfalls will also be narrower on the bottom than on the top.
The gaps in between these sections gets bigger as gravity stretches them farther apart and as the cohestion property pulls water together.
Water won't split up perfectly into these clearly identifiable sections but starting at waterfalls, but looking at them paying attention to the 'big picture' lead me to notice that there are visible 'waves' in waterfalls.
Of course, my notes from staring at waterfalls and not from still photos that may be useful as well.