This started out as a way to get large voronoi flattened rocks on a slope (with the stream meandering across), and small displacements and stones in the gullies. But the large voronoi are not visible anymore. The huge stones are huge fake stones indeed, masked to be within those gullies as well, and with 1 (later 2) masked strata shaders attached as texture input. I'll probably completely change it again, too much invisible stuff that can be dumped. I was actually going for something like these (not exactly, but kind of):
I'll keep your ideas about wetness of the stones in mind, and like to get more visibility in the warping of the water. It's too rugged now to see.
