WEED, Calif. — The water that gurgles from a spring on the edge of Weed, a Northern California logging town, is so pristine that for more than a century it has been piped directly to the wooden homes spread across hills and gullies.

To the residents of Weed, which sits in the foothills of Mount Shasta, a snow-capped dormant volcano, the spring water is a blessing during a time of severe and prolonged drought. MORE