The area around Pissis is dry...

The area around Pissis is dry and to find sources of water is your main concern to/from the peak. To play it safe; bring lots of water bottles from the beginning of the valley where the path towards Pissis starts. Hide these bottles along the road and pick them up when you leave the peak.
We always tried to hide the bottles in places where they would be easy to find, here at a newly constructed copy of an "inca-pillar".