[dreamcompiler]

When I built my house in the country, the well driller insisted on witching. He said "we should drill right here." I said "No, move it 100 feet that way. Your spot is right in the middle of my future driveway."

"I can't guarantee we'll hit water there" he said.

"I paying you. Just drill where I said" I said.

And of course we hit water.

[bombcar]

Finding & Buying Your Place in the Country has a whole section on wells. The main key seems to be onsite when it is drilled, because otherwise they'll just leave after drilling one, even if it is dry.