As It Happens

Biologist discovers most big U.K. water firms still use 'magic' divining rods to find leaky pipes

A British biologist has discovered that 10 out of 12 of the biggest water companies in the United Kingdom still use divining rods to locate water underground.
A member of the Buctah Dancers on the 1960s television show Don Messer's Jubilee holds divining rods attempting to contact the late Don Messer at the Canadian fiddling icon's grave in Nova Scotia. (Andrew Vaughan/Canadian Press)

Story transcript

A British biologist has discovered that 10 out of 12 of the biggest water companies in the United Kingdom still use divining rods to locate water underground. 

Sally Le Page's investigation was inspired after she learned a man from their water company had used a divining rod to find a buried pipe at her parents' house.

The practice, also known as "dowsing" or "witching," isn't supported by scientific evidence. It involves walking slowly around an area while holding an L-shaped rod in each hand. When the two rods cross, that supposedly means you're standing over water. 

As a scientist, Le Page found it odd that a large water company would use a discredited, unscientific technique like divination.

So she set out to find out how many British water companies were doing it — by asking them on Twitter. Most of the companies were happy to confirm that, in fact, they did. 

As It Happens host Carol Off spoke with Le Page after she published her results in a blog post.
A pair of divining rods. (Eric Risberg/Associated Press)

What have you discovered about the use of divining rods by water companies in the United Kingdom?

I thought this was just going to be a one-off so I tweeted the company in question, Severn Trent, and they said, "No, this is something that our engineers use."

I thought this is very bizarre. It just so happens that there are 12 water companies that do the vast majority of the water services in the United Kingdom.

So, I tweeted every single one of them and all but two replied saying, "Yes, the technicians do use water divining, water dowsing, techniques in order to try to find pipes and leaks underground." 

A lot of people believe that divining works — that these rods and dowsing is actually an effective way of finding water. There are, as you know, people who will swear by it. They say they wouldn't have a well in their yard if it wasn't for someone coming out with their divining rods. So what do you say to them?

The problem is that it is really compelling. ...  I've done it myself and it feels so real. The trouble is that it then depends on why are those rods moving? Are the rods moving together because there's some water under the ground or is it because there is something else going on?
Sally Le Page is a biologist and science blogger who discovered that technicians working for most of the water utility firms in the United Kingdom still use divining rods to help locate pipes. (Sally Le Page/Twitter)

And it turns out that yes, there is something else going on, and it's called the ideomotor effect. What happens is that we subconsciously think, "OK, there's something going on here." Your hands make the tiniest little muscle movements, so small that you don't realize that you're doing them yourself. But that movement is amplified by the rods and causes them to swing wildly and it's nothing to do with the fact that there's water underneath the ground or not. 

It seems these water companies who have engineers, these are experts, they're trained and educated, they believe it works so maybe they've had results?

This where the confirmation bias then comes in. You can say, "OK, I used divination practices this one time and that one time I found some pipes." Then, the next time, maybe you use it and you don't find any pipes but you forget about that one because there was just something wrong that day. So you only remember the times that it works. 

You've raised all of these argument about science. How are the water companies responding?

The most surprisingly thing is when I initially questioned all of the companies they are just like, "Oh yeah, yeah. We use divination practices," as if that's not a problem. They don't realize that there's no evidence for it, that it's completely ineffectual.

Dowsers, also known as water witches, use so-called 'divining rods' made of copper or wood, pendulums or other items to find water deep underground using nothing more than their own intuition. (Eric Risberg/Associated Press)

We will get a lot of people responding to this and disputing what you're saying — arguing that they know for a fact that it works and science has its limits and there are things that we just can't explain. So what should we say to them?

I think it's perfectly fine for individual people to use divination in their own time. I mean it's fun. It's a magic trick. Magic tricks are fun. Tricking your brain is fun.

But for companies that are funded by the public to use techniques that have no evidence that they work and when we have other techniques that do work — there's are so many different techniques that these water companies have available to them. I don't think it's fair that they are spending time and therefore spending money on techniques that don't have any evidence. 

This interview transcript has been edited for length and clarity. For more on this story, listen to our full interview with Sally Le Page.