The river was a challenge, I could not ass to many rocks, and the water looked like it was only flat. The image below is before.
By making the plain rotate about 45 degrees and add some particle effect over the water it looked much better. I added some stones where it was appropriate and added some nice fog over the river. The image changes completely. Now it looks much better and the scene looks alive. One of my challenges is that I found no good tutorials or free particles for water or river, I tried to make many different particles before this was the one that worked well. The Image below is after.