Science

What are divining rods and why are some UK water companies still using them to find leaks?

The medieval method is still being used to detect the presence of water.

Divining rods are still being used by water companies to locate underground pipes in the UK despite there being no scientific evidence that this archaic method works, an Oxford University scientist has found.

Evolutionary biologist Sally Le Page said her parents “couldn’t believe their eyes” when the technician they called to their property from Midlands water company Severn Trent began slowly walking around holding two “bent tent pegs” to locate the mains pipe.

Here’s everything you need to know about these instruments.

What are divining rods?

Divining rods.
(Scharfsinn86/Getty Images)

Made usually from copper or plant twigs, divining rods are either L-shaped or Y-shaped.

The technique, also known as dowsing, is believed to have originated in Germany in the 15th century, as part of an attempt to find metals.

Typically, a dowser will hold the rods while walking over land and being alert for any movement or the rods crossing in the belief that this could indicate the presence of water underground or leaks in pipes.

Le Page writes in a blog post on Medium: “Indeed, another name for dowsing is ‘water witching’.”

Which companies are still using it?

Le Page tweeted Severn Trent “to see if they knew that one of their technicians was using equipment that is known not to work” and the company replied: “We’ve found that some of the older methods are just as effective than the new ones, but we do use drones as well, and now satellites.”

She then contacted other water companies, with Scottish Water, Yorkshire Water, United Utilities, Thames Water, Southern Water, South West Water, Northumbrian Water, Welsh Water and Anglian Water all confirming that their technicians occasionally used divining rods.

A Severn Trent spokesman said they used satellite data and drones to monitor pipes and spot leaks adding: “We don’t issue divining rods to our engineers but we believe some of our engineers use them.

“As long as the leak is found and repaired quickly, by whatever means, we’re happy and so are our customers.”

Is the method reliable?

Dowsing.
(Wikimedia Commons)

According to Le Page, there is no hard evidence to support that divining rods work.

She wrote: “I can’t state this enough: there is no scientifically rigorous, doubly blind evidence that divining rods work.”

The phenomenon is said to be caused by the “ideomotor effect”, where a person unconsciously performs actions because of prior expectations, suggestions or preconceptions.

It’s much like an Ouija board, where it feels like the pointer is moving itself, but in reality, the person holding it is making the small movements and pushing the object across the board.

Why is it still being used?

Dowsing.
(Wikimedia Commons)

While there is no hard scientific evidence to support the method, there are theories as to why dowsers believe divining rods work.

According to Groundwater UK: “One theory for this is that the muscles in the body react to some electromagnetic effect caused by the presence of the metal or the water flowing through the pipe; the rods then amplify this effect so that the searcher becomes aware of them.

“Another theory is that some diviners know from their experience and local knowledge where groundwater is likely to be located and subconsciously cause the reaction.”

Enjoy reading the Irish News?

Subscribe now to get full access

Science