I'm late getting in on this thread, but here goes anyway. I recognize some of the names on this thread from other newsgroups and have a great deal of respect for them, Doug, Dan.. In any case I did not know there was so much controversy about water dowsing, or witching or whatever you like to call it until I read this. I read The Skeptical Inquirer several times as an undergrad when I worked in the library..don't recall any articles about this topic, but, if there were, I probably skipped over them for juicier stuff like bashing Uri Geller.
Anyway, wife & I buy a place in the "country" 10 years ago. A month after I moved there I had to find which way the water line came to our house. My boss, who was there one day, suggested he could find it with two bent coat hangers. I didn't believe him and thought him to be a dolt, but he did find it and he had never been there before. Skip ahead 2 years and I have my back yard torn up to put in a french drain. I needed to find where the underground power line ran to our house. I tried the bent hangers myself just for fun. I found the power line but I also kept coming across something separate from it, running from what seemed to be straight out from the house then angling off parallel, nearly exactly where I was going to dig the drain. I dug down slowly and found a septic line that came from a bathroom off the garage. Prior to this I thought (actually counted on) all the plumbing being in the house (we have a full basement) and I knew and could see in the basement where the main drain line went out from there to the septic tank. The garage bathroom was in an area I had to crawl under and just never looked to make sure about the line. Since the basement ceiling is covered with drywall, I had no idea the line did not go to the main line and was a separate line out from the house to the septic tank.
Flash forward to 1 month ago; we're having tremendous rainstorms. My gutters were continually overflowing, dumping water into the window wells of the basement, then into the basement. There was a drain in the basement that when this water finally reached it, would not drain. The drain was clogged somewhere. I knew where the gutters drained into a PVC pipe several dozen yards away from the house and always thought the gutters and the basement drain all went into the same 4" drain pipe that was visible coming out of the ground. With no flow coming out of it, I wondered if there was a second line (and what in the world this line went to!). I pulled out the bent wires again. Now there is a low spot in the yard I thought might have been a drain exit that always kept water in it. This is where it must be, and must be clogged up with a little dirt. I'd been meaning to dig it out for years, but never had a problem with the gutters before so I was lazy and didn't. I used the wires, criss-crossed and back and forth looking for the line that led to this low spot. Nothing. I was so convinced the line was there and the wires were wrong I dug down about
4' in a about a 5' length. Still nothing.
I went back to the house and started using the wires again walking around the house in a circle. I kept coming across not one, but 3 separate "lines" from the house. Remember now the ground is saturated with several days of rain giving no clue to the location of the drain exits (and I only thought there was 1). I located the exit points of two of the three lines (the third being the one I thought was the one for all previously), covered with years of dirt. Turns out there was one drain line for the gutters, one drain line for the basement, and a third for a drain at the bottom of a basement stairwell. I never knew these lines existed up until then.
Now I don't claim anything at all, but I know it worked in these cases. I have degrees in math and computer science, was raised in the "city" and moved out to the country at the young age of 35 so I'm not a country boy that has lifelong tales of relatives like Aunt Lurleen or Cousin Booger doing this stuff. If you have a better explanation of how this worked in these cases, let me know. Why don't I write Mr. Randi? Well I might, but I'd prefer he or someone in his circle just come out to my place and explain how this works, and how it happens. For fun today and (mainly) because this whole thread made me question everything I had seen, I had my wife walk me around in the yard while it was hot as hell, blindfolded. Walked around & around and the wires did their thing again. Same place. The skeptics claim it "doesn't work", yet I know that it did in these cases. I didn't know where the lines were, I didn't even know the lines existed. I do not claim any super-powers or religious intervention. Nothing of the sort. It just is what it is. Sorry, Randi.
Cheers