For the water areas, I outlined in Stirland Mud, drybrushed in Karak Stone. This left the water parts in a sort of ditch, which I painted Fenrisian Grey, then splotchily painted the middle in Lothern Blue, then the very middle in The Fang.
I then washed the tiles in Agrax Earthshade, even brushing some over the water area, to dirty it up a little bit. Then I applied three coats of gloss over the surface of the water. I did this with a Wash brush, loading it up with gloss, then plopping a big drop of gloss in each square. I then brushed it around to coat the surface, waited for it to dry, then repeated. In the end, it has a nice slightly ripply surface to it. Anyway, here's some pics!