Ideas

Brainiac

Relic of the Week: Divining rods

The UCLA campus was flooded by a broken 30-inch water main in 2014.
Jonathan Alcorn/Reuters/File
The UCLA campus was flooded by a broken 30-inch water main in 2014.

What is it? Divining rods

Users: 10 regional water and sewer utilities in Great Britain

What were they thinking? When British scientist Sally LePage’s parents told her that a technician from the local water company used divining rods to find a water main in their neighborhood, she was flabbergasted. The 450-year-old method of holding two L-shaped rods in parallel until they “magically” cross at the site of a water source seemed a little, well, magical. So she decided to tweet at a dozen utilities in Great Britain and Northern Ireland, and 10 of them reported technicians still use divining, or “dowsing,” rods, alongside more modern tools.

Advertisement

Does it work? A number of studies have discredited water dowsing or “water witching.” And, as LePage wrote in a post on Medium, the companies’ continued use of the technique could have serious consequences if it meant “the difference between an entire town having safe drinking water or not.” But at least one of the utilities she contacted acknowledged divination’s shortcomings. Sort of. “Yes on occasions we use divining or dowsing rods to locate water mains,” South West Water wrote on Twitter, “however they are not accurate 100% of the time.”