With a still picture of the river, a question came to mind.  Will the same physics for the large body water be used in such small bodies of water?  I could see where that could potentially look very cool or could be problematic, depending on how much motion there will be.
I guess my question is for the terrain makers, and the most wonderful new things they most certainly will be experimenting with.  I can certainly appreciate the fact that many things beyond simply painting a nice picture is involved.  Thanks for the updade, I am positive that the final product will be more than pleasurable.