well driller steve arthur is a very busy man. >> steve arthur: all the farmers, they don't have no surface. they've got to keep these crops alive. the only way to do that is to drill wells, pump the water from the ground. >> stahl: so it's either drill or go out of business? >> arthur: yes. >> stahl: so there's something of a groundwater rush going on here. arthur's seven rigs are in constant use, and his waiting list is well over a year. and because some wells here are running dry, he's having to drill twice as deep as he did just a year or two ago. this well will cost the farmer a quarter of a million dollars and go down 1,200 feet, about the height of the empire state building. are you and are the farmers worried that, by going that deep, you are depleting the groundwater? >> arthur: well, yes, we are depleting it. but on the other hand, what choice do you have? this is the most fertile valley in the world. you can grow anything you want here. if we don't have water to grow something, it's going to be a desert. >> stahl: he said many farmers think the problem is cyclical and that once t