Calm Down, Peter
I think you're going a little too far and too fast here.
There is no particular evidence in this photo for water or anything else exotic. Check the context. This image is at the edge of the southern pole cap. Admittedly it is late summer here (Ls=340), but ground temperatures are still pretty low due to permafrost in the immediate subsurface.
http://barsoom.msss.com/moc_gallery/m13_m18/images/M14/M1401682.html