I did a little test yesterday, and found that lake doesn't work properly, but an inverted plane (or sphere) does. I also set glass shader to single-sided and an inverted decay distance. Some reeds in water, some palms on shore, which can both be seen.
I must say, I find the reflection of the trout (courtesy of Doug Campbell) rather vague (though that vagueness was better visible without all the reeds).
Path tracer nicely blurs everything above water, this is a standard render.