Well, I was going to do some science, math, nature deal here of how much water flows over that rock per second (CFS..Cubic Feet a Second). I noted this stretch of the Sandy River (Oregon) is running at 1300 CFS, which is about average right now. Well, the science says 1 CFS fills a box 1′ x 1′ x 1′ per second. So, now I start to get lost when I picture 1300 cubic boxes right there per second. See, I spared you the whole improbable bit of boxes whizzing by over that rock. I will just stick to the image and hope for the best.