This photograph is great because you have three very clear layers. What this assignment asked from you was for simplification, and that you’ve provided. You have your first layer which is the water. It’s simple and provides negative space as does your sky. In the middle of your photograph you have your main areas of interest which don’t clutter the photograph and are cut off by the edges of your picture at relatively opportune times.
My concern with this photograph is that it is too balanced and flat. Changing the balance of the photograph is easy by making sure you’re abiding by the rule of thirds and changing the position of your horizon line.
However, all of your action is located roughly on the same depth. There is no foreground or middle-ground. It’s all background.
You can really enhance a photograph by having both a primary object to look at (which you have in this photograph… i.e. The water fountain), but also a sense of depth. It makes the audience feel like “they are there”. They have a sense of space and the image will appear more 3 dimensional and less flat.
In future photographs try playing with the idea of depth a bit. Don’t overlook the importance of a good foreground. I think you’ll be pleased with the results.