Recently, I spent hours reading comments to an excellent article, "Tighter, costlier water shifting focus to curbing demand" by Shaun McKinnon in the Dec. 27, 2009 edition of the Arizona Republic.
It became obvious most of the commentators knew little about water or how it interacts with our environment.
1. Water can neither be created nor destroyed.
2. The state of water can be changed and it can exist as a liquid, vapor, or frozen (as snow or ice).
3. Water, as we are accustomed to seeing it, can be unavailable for use.
4. A somewhat reliable statistic is that 0.6% of water on earth is available for drinking.
5. Most importantly, it may take decades or centuries for surface water to trickle 400ft - 500ft or deeper to aquifers.
Taken singly or collectively, these facts should make us question the practice of (a) pumping aquifers or (b) the validity of terms such as "assured safe yield", "sustainable use", or "assured 100 year supply."
Water for the West comes from the snow pack of the Sierra Mountains or the western slope of the Rockies. If anyone can characterize this snow pack as "assured" or "sustainable", I'll buy a 100 yr pass to Aspen or Crested Butte.