National Geographic: When Floyd Arthur moved to California's Central Valley as a child in the mid-20th century, his migrant worker parents found water by digging just a few feet into the ground. But now, the drilling company Arthur and his son own has to bore holes 1,000 or even 2,000 feet (300 to 600 meters) deep for water. "If we don't get a bigger snowpack soon, we're going to be in trouble. I don't know what we're going to do," Arthur said about the most serious drought in California's recorded history. The Arthurs...