I sympathize with the people in Watsonville, and highly doubt the existance of a "dental epidemic"...or if there is one, I am sure there are other reasons for it other then a lack of floride in the water...but they are fighting a loosing battle, I'm afraid.
San Juan Capistrano went floride a few years ago...and so I just started buying (more)bottled water for drinking and cooking. I couldn't afford a water purifier...and most of them don't get the floride out very well, if at all, anyway. It's not a perfect solution,but its better then nothing.