I suspect the area of concern is central Arizona from local rumor. Just a hunch. Perhaps a larger network. Keep your eyes open. Don't get offended if people think you're paranoid, remain persistent. Reality won't click until something like 911 happens and then it'll be too late.
People who live in the desert always store some extra water for times when they might need it.
I treat the situation like Y2K. Nothing hurts with a little rehearsal for tough times and having some emergency supplies around.