The pool that you found with 8 inches of water in it, the Arizona Pool is now filled with lots of sand. Someone earlier this year attempted to build a higher dam wall but their work was damaged by recent flooding and the water drained from the pool, and also big thunderstorms earlier this year filled it in from runoff coming off the mountains through the big sandy area above it. This hotpool has always had various problems over the years since it constantly gets hammered by big floods and at its south end the pool is built on a rocky area with many cracks and holes at the bottom near the big boulder. Big summer downpours also cause large runoff to come off a small canyon just to the east which runs into this pool and fills it up with sand. There is a great source of hotwater there, just too bad there isn't more of a solid base to build a more bullet proof pool on :-)