This in general. I have always wondered why the test is of something or some method that is different from what is being actually tested for.
Except that Randi says clearly that, whenever they do an actual test, they do agree ahead of time on exactly what the dowser thinks they can do.
Now, if there are lots of dowsers who have negotiated with Randi and been unable to agree on a fair test, then point me to some of them. It would of course be most convincing if the dowsers themselves did suggest some kind of objective test of their abilities.
It’s worth noting that Randi does not think dowsers are frauds. From JREF - Home
In fact, he’s pretty sympathetic:
I can’t find it now, but I thought he wrote once that he hated testing dowsers because they were always so honestly convinced it really worked that it was painful watching them fail in the blind tests.
I could probably use the wires to detect a buried power line. Provided it was buried 11-23 inches below the ground. And I didn’t mind dying in the process.
What Randi says and what Randi does are two different things.
The fact is, Randi does not negotiate the test. He tells applicants the test that he is willing to give, and demands they comply. No discussion, no compromise, agree to his demands, or be disqualified. And it rarely matches what they claim, one of several reasons why so few people agree to be tested by him.
I may be wrong, but the only dowsers I have seen , and most of what I’ve heard about are NOT looking for thousands and thousands of gallons of flowing water—they are usually looking for a 2-inch water pipe at a construction site. Which is pretty much what Randi tests for.
I have personally seen dowsing work twice, and was astounded each time. A contractor or a maintenance worker who needed to find a water pipe that wasn’t on the engineer’s drawings. Grab 2 welding rods, bend 'em as described in post number 55, and start walking–one time on a construction site, one time walking across an asphalt parking lot. Both times, the guy found the line. It blew me away…
(and yes, I tried looking for logical answers–disturbed earth, or maybe nearby manholes or water meters, etc.— . But I never found any such evidence.
So I tried it myself, looking for the water pipe to my own house, but Randi is right!–it sure didnt work for me…
I blame it on the old excuse of confirmation bias.
But it’s like playing with a Ouija board …when you see it actually work successfully, you get a little, well,…worried. 
What if it was buried zero to ten inches below the surface?
You’ve proved the null hypothesis by using copper wire. Copper is non-magnetic. You can’t possibly detect variation in the flux of the Earth’s magnetic field by holding 2 copper wires.
Southern Illinois has a decent rainfall and is largely all Quaternary glacial deposits (silts, sands, gravels etc.). Its highly likely that you can find water in some amount simply by digging anywhere, especially in any topographic depression. It’s not the magic of divination, it’s hydrology.
In fact this goes for pretty much of the surface of this planet. Dig far enough and you’ll find an aquifer, especially in unconsolidated materials suited to digging in.
It’s also worth noting that in finding the 2" water pipe on a construction site, any dowser would need to effectively ‘tune out’ the 40 odd litres they carry around themselves, in much closer proximity to the dowsing rods than the water pipe.
Please hand in your geophysicist card.
This is another lie that Randi has told often. Sorry, but he’s duped you. It isn’t true at all. Dig at a random spot, it is quite likely to come up dry.
Here’s a fact for your consideration. Randi often tells stories like this one:
I challenge all the dowsers in a similar way. Since 94 percent of the Earth’s surface has water within drillable distance my challenge is to find a dry spot! They don’t want to do it. Why? Because they only have a six percent chance of success.
I sent in my application, accepting his protocol exactly as he had described it, in many of his essays and lectures. He refused to carry out the test. Why? Because I’d have a very high chance of success, and he knows it.
Randi fans on this message board hate me for doing this.
I’m very interested in what you can do, and what your protocol would be to test it. Can you post it or a link to it here?
Firstly, accusing James Randi of lying about hydrology without any evidence whatsoever is not really GQ material, or a good line of argument.
Secondly, I’m not surprised he hasn’t accepted, since you haven’t specified the depth you’d be required to reach, making it entirely meaningless. You’d also be able to asses the likelihood of finding water using a geological map, topographic and hydrological information well in advance of any test.
Thirdly, if he did decide to take you up on his actual offer, word for word, he’d have a ≈ 100% chance of retaining his money, since ‘drillable distance’ is further than you think (and would cost you considerably in excess of the prize money).
I put up a website detailing my application, but haven’t maintained it, and it’s offline. Basically, what I did was to accept the “find a dry spot” challenge exactly as laid down by Randi in his many lectures.
If you look through the thread, you’ll see the hatred from Randi supporters, who are obviously aware that he is lying, and who resent me exposing him.
Moderator Note
Further discussion of Randi, or of Peter Morris’s interactions with him, are off limits in this thread, whether by Peter or to anyone else responding to him. We have had too many threads derailed by this topic. You may discuss the substance of the OP, but without reference to Randi. If you wish to discuss Randi, you can open a thread in GD.
Colibri
General Questions Moderator
Wrong. I have supplied the evidence. Namely that Randi refused to carry out the test that he proposed. This is clearly
Wrong. Such things were negotiable. Randi, however, re3fused to even discuss them.
True.
And those maps are the very reason I can make my claim. They support the idea that water is rare in many areas.
Wrong. My proposal was to consult those very maps that you mention to see if a particular spot does, or does not, have underground water. No need to actually drill any holes, when the land has already been surveyed.
And, BTW, I do in fact know how deep it is possible to sink a shaft. You might like to note that mankind has sunk some pretty deep ones WITHOUT striking water along the way.
Note - Collibri hadn’t posted his warning when I started typing the above post.
Noted. (However, it is not a warning, but rather an instruction.)
Others please take the debate elsewhere, if you are inclined to pursue it.
And, Collibri, why exactly do you object to me fighting ignorance? These discussions always are full of incorrect information, such as the claim that there is water everywhere. This claim is invariably made in these discussions, and it is wrong. Please explain why I should not correct the error when it occurs.
You may discuss the substance of the claim. What you may not do is bring in your dispute with Randi.
I this state it is illegal to do any digging without consulting the people at the Call Before You Dig hotline.
Kinda cramps your gardening don’t it? 
This is because groundwater is very widespread. See this article from the Missouri Department of Natural Resources:
Of course Missouri isn’t Southern Illinois but it’s the same principle: Grandpops in Missouri believe they can dowse for the same reason. The US Geological Survey has a very comprehensive document on the subject of groundwater (but doesn’t specifically discuss dowsing) and on this pageputs it very simply: