A number of points there, thanks :)
You mention depth, but being a ford, the bed wouldn't be that deep - this is also why the rocks are out of the water.
But there is a small difference in colour from the bed and the banks, but you can't see it very well in the photo. If I were doing a deeper river section I would show the depth more.
I also made sure the smoother edges of the rocks were facing the current to show the wearing effect of the water, and as it was an experiment, they are painted a bit blandly.
As for using more layers of scenic effect - there is already 3-4 on there!! Although the effect itself is great.
I am most pleased with the painted "froth" around the rocks.
I've never worked with scenic water, so I don't know how useful or welcome my comments might be. My nitpick is about the rocks, they look like they're on top of the water instead of in the river. Painting the path of the river would give you some illusion of depth, like blending from the color of the banks to a dark green towards the center. A mottled stone color might work for a shallow, rapids style river, since most of the dirt would be washed away. Smooth rocks would be better than jagged ones, since they are most likely worn down by the water. There should be some way to get the rocks to look partially submerged, either by using small ones and painting the base to match or by using more scenic water to partially submerge them.
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