Who owns the rain?

Interesting story in Popular Mechanics about the use of rain barrels. It seems that depending on where you live, the rain that falls on your property may or may not belong to you. In Colorado you do not own the rain that falls on your property. I can see how this would effect us here in California, as we have no summer rain. All our rain comes in winter, and to be effective we need large holding tanks to get through the dry spell. What happens when homeowners start putting in large cisterns, 5000 gal plus and collect their own water, cutting down revenue to the water company?