
Water in motion can make striking images. Our eyes naturally blend the motion of falling water drops and make water falls / rapids into silky ribbons of water even when they are actually individual droplets of water. A camera can freeze that motion, or allow it to flow, it all depends on the shutter speed.
The accompanying shot of the water wheel was shot at 1/50 of a second. This allowed the water to move a short distance during the exposure and blurring, but not forming a long smooth silky fall. In this case, I wanted the water to show motion, to make the shot feel like it's in motion, but I wanted the spokes of the wheel to be relatively sharp, nearly frozen in time. That's what I was seeing when I looked at the scene and that shutter speed (on a tripod, BTW) was just right.