In this post [Link] I discussed the water situation on Terlingua Ranch, and had this to say about water wells: "Wells are not out of the question, either. I've been told that water is about 300 feet down in most areas of the ranch. That's not bad. I don't know how much a drilling company charges in the area, but I think $10 per foot is an average rate in most areas."
I have since received better data from what I consider a very reliable source, to the effect that the average well is between 600 and 1000 feet deep; and that drilling costs $20 per foot. Also that a large percentage of attempts come up dry.
Now I don't know about you, but that takes it out of the realm of being an option for me. I can haul an awful lot of 3 cents per gallon water for that $20,000. In fact, I can haul water for years before finally building a catchment system, without spending 20 grand.