A good defense of this exhortation is to be found in the before and after pictures of some California lakes and reservoirs. Still etched in my brain is an aerial shot taken last year of a once big lake in California that had been reduced to a puddle crowded with houseboats that had clustered in the only patch of water where they wouldn’t be sitting on dry ground. This morning in the online Washington Post is a picture taken last year of what would look like a valley on Mars if there weren’t a bridge spanning it. The same shot this year shows a sparkling clear lake. As the headline proclaims, it’s a miracle. Too bad California needs one every year.