Underground cavern/pool

[bmmurphy]

So this is my first post here, though I've been watching and learning for a little while now. Right away - thanks to everyone here whose posted tutorials, links to resources, brush sets, etc. etc. Every trick I've learned thusfar has been adapted (or stolen outright) from the geniuses who make this place awesome. As 80% my work is based on his tutorials, Ascension gets double-awesome

Okay, so I'm re-drawing the maps for the adventure Keep on the Shadowfell, both for use in battlemaps and because its a good way to get practice for when I'm going my own, original ones. It's going pretty well for the most part, and I plan on putting the whole thing up once it's finished.. One thing I've been having trouble with and wanted feedback on, though, is a tunnel area that has a small underground pool that has a tiny raised "island" in the middle of it. I've attached the original PSD so you can see all the details.

Correction: Due to file size, I can't upload the PSD file.

Mainly I'm looking for feedback on the pool/island - I think it looks alright, but am not sure what to do to improve it. Also, I'd love to know what other people think of the natural steps at the top of the map. I think they worked out pretty well, but was hoping someone who does this thing more often could give me their thoughts.

Thanks everyone.