I had the same reaction as James. I wonder about Vertical because a waterfall tends to be a vertical element. Your exposure is great with just enough time to give the water a sense of motion. For some reason the brown grass on the left distracts me more in the vertical shot. Sometimes changing the angle slightly can help. As you go back and explore this just try different angles and heights. One of the great things about digital photography is that you can explore a subject with exposure, angles, and time of day and purposefully take too many photos. If you do this do take notes and refer back to them when you review the photos.
Great job.