Finding Underground Utilities Without Selling Your Soul

In my last post, I wrote about digging up things in my yard. One of the things I dig up most frequently is the buried telephone line. I understand the appeal of buried utilities, but frankly, I like the wires to be up in the air where I'm not likely to hit them with a shovel.

Fulfilling Murphy's Law, the buried lines always run right where I want to plant something. I've nicked the phone line several times, with no ill effects--if I sever it, I think I'll just get internet phone service and not mention it to Bellsouth...and be really careful about not hitting the cable TV line (also buried) which brings internet service into LMAID World Headquarters. I'm more worried about cutting the big phone line that serves the entire street, including one neighbor who works for the phone company. Let's don't even talk about the buried power line. I give that one a WIDE berth when I'm digging.

When we first bought the house, I had enough sense to summon the utility locating service to mark the lines. They came out and marked all the lines with different colored paint. I took photos so that I would have something to refer to later, but they said that the actual line could be located like 1-2 feet on either side of the painted stripe. Thanks, guys. That helps a lot.

I was talking with a geologist friend of mine one day about the problems of gardening around buried lines, especially when the photos aren't clear and you can't remember how close the phone line is to the tea olive.

"I wish I had one of those locator machines," I said.

"Go get me a couple of those survey flags," she said. "I'll show you a trick."

I retrieved two of the little red flags that I had used for a previous project and handed them to her. She bent the wire stakes into an L-shape.

"Here," she said. Hold these out in front of you, parallel to each other, and walk. When you get close to a line, the flags will cross."

I looked skeptical.

"No, really. It works."

Wary of the power of suggestion, I handed the flags back to her. "You do it," I said. "I already know where the lines are, and I might unconsciously move them over the right location."

So she took the flags and began walking across the yard. To my astonishment, she located all four of the buried lines.

I have no idea how this works; I assume it has something to do with magnetic fields. (I'm an English teacher, so this is way out of my area of expertise.) Internet searches reveal little in the way of explanation. Some experts deny that this method has any validity, but other sources said that most workers whose jobs involve digging keep a pair of L-shaped wires or coat hangers behind the seat of the pickup, just in case. And there are always the people who say that this power comes from the devil. (I find it hard to believe that the evil one doesn't have anything better to do than try to lure me into his snares by helping me find a buried phone line. That said, the lighting in this photo is kind of creepy, and I had all kind of error messages when I tried to publish this post...)

I'd be interested to know if anyone else has tried this, and with what success. Any of you science types know how this works?