More traditional divining rods lack the hinges that come on newer models.Eric Risberg / AP

FAR WEST TEXAS—Before Jeff Boyd became the city of Marfa’s public-works director, he had a long career underwater. As a commercial saturation diver, one of the most specialized kinds of divers around, he would spend his days some 400 feet below the surface, breathing a mixture of helium and oxygen, for month-long stretches. Normal air would kill at that depth.

It was around that time, when he worked at offshore drill rigs along the Gulf of Mexico and the Bay of Campeche, a job for which he was regularly tasked with locating underwater pipelines, that he discovered he was a water witch. He calls it a gift.

Boyd, who has a Hulk Hogan handlebar mustache and liquid-blue eyes, might have grown up in the West Texas desert, but he always felt comfortable in and around water. His office is located beneath the town water tower, an Instagrammable silver beacon with Marfa painted on its side that rises above the hip, touristy town. As public-works director, he is in charge of maintaining and improving the city’s water supply and distribution, and often has to find existing underground pipelines. That’s where his sorcery comes in handy.

He even has a wand, of sorts. The handle looks like the notched grip of a ski pole, from which extends a retractable antenna—the kind you might find on an old portable radio—that swivels around and around on a ball hinge. The tool has a fancy name, “the magnetomatic pipe locator,” and is available for purchase for $38.50 online.

In reality, it’s just a tricked out version of a divining rod—typically a Y-shaped twig or bent metal wire used to witch for water. Dowsing, or water witching, is a centuries-old practice in which a person walks with a divining rod in hand until it moves due to unseen forces, indicating a source of water underground. For some, the rod bends downward. For others, it makes more of a bobbing motion. Boyd’s magnetomatic pipe locator likes to swing sideways.

If this all sounds a little hokey, you’re not the first to think so. The practice of water witching has been debunked time and time again. More surprising is the number of people who credit it—you’d be hard-pressed to find a single well-drilling operation in the Southwest that doesn’t believe in and use water witching. This has been going on long enough that in 1917 the U.S. Department of the Interior, in cooperation with the U.S. Geological Survey, issued an official, book-length report to expose its baseless science.

In the report, written by the geologist Arthur J. Ellis, you can hear the raw frustration in Ellis’s prose as he tries, once and for all, to put the matter to bed.

“It is difficult to see how for practical purposes the entire matter could be more thoroughly discredited, and it should be obvious to everyone that further tests by the U.S. Geological Survey of this so-called ‘witching’ for water, oil, or other minerals would be a misuse of public funds,” Ellis wrote in his introductory note.

Ellis’s report traces the origins of water witching to German miners in the Harz mountains who used divining rods to find veins underground that might contain ore, though others claim the practice is as old as the Scythian and ancient-Persian empires. From the Germans, Ellis wrote, the delusion spread across Europe. Eventually, people would use the rods to locate water and minerals, among other things: grave sites, treasure, even murderers. In the 17th century, a French peasant used a divining rod to accuse a man of murder (he confessed), and later to hunt down other alleged murderers belonging to a persecuted ethno-religious minority, who were executed when found.

Ellis’s report, available for 10 cents at the time, was meant to be distributed, and its message disseminated. Yet, more than a century later, the custom of water witching has endured. And almost everyone has a story to tell.

One West Texan told me that his brother, a water witch, can’t wear watches, because they always break, thanks to his body’s internal magnetism. Another person told me that she’d been looking for years for a viable well on her land, and at her wits’ end she paid $75 to a water witch, who found one against the odds.

Walter Skinner, the owner of Skinner’s Drilling and Well Service in the neighboring town of Alpine, keeps several spare copper wires in his car just in case. He told me that when he was a young man, a water witch laid a hand on his shoulder and passed on his power. From that day forth, Skinner possessed the ability to witch, too.

The geologist Jeff Bennett may be the only man in Texas who doesn’t believe in water witching, and he’s well aware of his minority status. He worked as a physical scientist in Arizona, New Mexico, and Texas on a variety of government-backed well-drilling projects and never met a driller who didn’t want to “witch it.”

Bennett makes a compelling argument. You can drill a hole just about anywhere, and if you mine deep enough, you will most likely find water; the chances are ever in the dowser’s favor. “The question is: Is it the easiest water? Is it the most water? Is it the best place to drill?” he says.

Bennett prefers to rely on regular old science instead, looking at the geological features of the landscape—such as clefts and fault lines—that paint a picture of what might lie beneath. Of water witching, he says, “It’s just guessing. And sometimes they’re good guesses. Sometimes they’re not.”

“So, why do you think so many people believe it?” I asked him.

“Everyone loves to believe in magic,” he said.

In the desert Southwest, there is something magical about water, a resource in short supply that has become scarcer with the rapid depletion of critical sources such as the Rio Grande. The late-summer monsoon season brings a boon of storms that build all day and crash through by late afternoon, saturating the once-arid landscape. The flora and fauna are thankful for it; the cacti bloom impetuously and insects emerge from their underground lairs. For the rest of us, there’s nothing much to do but stand by the screen door and stare in stunned silence.

Outside his office, Boyd hands me the magnetomatic pipe locator. He points to two metal caps protruding from the ground—valves off a 10-inch water line that runs beneath the dirt. I walk toward the invisible line, and deliberately slow my pace as I near the valves. The metal antenna slowly keels around when I reach the line, and I can’t tell if I willed it that way.

“I couldn’t tell you how it works,” Boyd says, “I just know that it does.”

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