Well your waterfall could use some work.
~Be aware you can rotate your doodads, such as the waterfalls, so its not as flat. You have a few waterfalls landing on dry land and ending abruptly.
~Notice how all the waterfalls in that area seem to merge into just one oddly shapped block of blue. You dont need to bunch up a whole amount of small waterfalls. You can separate these with other objects such as rocks, river rushes etc to show more depth.
Both pictures are rather simplistic, try refining both to make them look realistic like Wand said