Water Divining. Hocus Pocus, but sometimes useful…

You may have detected a skeptical vein in me whilst reading. I am skeptical. I am a scientist, it’s my job! Furthermore, I am a geologist who specializes in groundwater. I earn money through the planning and delivery of water (potable or construction water typically) to major projects. Part of that process is the exploration for water. Through a combination of looking at maps, on the ground reconnaissance, and clever things like geophysics, I decide where precisely to drill water wells. It is a scientific process, with a lot of learning along the way. You really do get better with experience, and for me anyway, my background in gold and nickel exploration has helped. I’ve been doing all these various exploration tasks for a several years now (about 6 in fact) and definitely I’ve improved. I know how drill rigs work and I have a decent idea of how (basically) to tease out from the local geology in a given area the better places to look for water (or gold, or nickel or whatever). Again, it relies on the collective knowledge from generations of geological science. Knowledge that I started to learn at university.

Enough about my scientific credentials already! Why I write this is that I am currently working on a project where we are trying to find enough groundwater for the construction of 100km of railway. Railway line construction requires a lot of water (about 800,000L per day every 10-15km of line in this case).

We’re working in a pastoral area, sheep and wheat country. The geology is pretty much granite through and through, and anyone who knows what that’s like will tell you that water is scarce. Surface water is practically non-existent and groundwater is hard to come by. This is nearly a desert. How do I know this specifically in this area? Because I have been talking to the local farmers. These guys have been breaking their backs for generations, eeking out the precious value this land will throw up to those who persevere. The one thing that determines success or otherwise more than anything is water. Stock need it to survive, and having no mains water system, a farmer’s house supply relies on it. Subsequently, the farmers invest a large amount of thought and effort into finding water. The country is pock-marked with drill holes and windmills. With this effort comes a culture of great interest in the techniques deployed to find that precious water.

From my discussions, the number one technique employed to find water here is water divining (“water witching” or “water dowsing”, depends where in the world you are). Before you sigh and stop reading, consider this: a water bore can cost more than $10,000 whether or not you actually find water. A farm would quickly go broke drilling holes if their success rate wasn’t too good. But then, hiring geological consultants such as myself is not cheap either, and materially adds to the cost.

What you need is a method of locating the holes yourself (or even getting a mate to do it for a few beers). Enter divining. You know who they are – they’re the ones with bent pieces of wire or Y-shaped sticks who wander about and find the “stream” and tell you where to drill. There is no scientific evidence for its efficacy whatsoever. Indeed there is scientific evidence that demonstrates that diviners have success rates no better than chance (for a good summary, I do recommend the Wiki page). This scientific ‘disproof’ has been around for at least half a century. Despite claims by practitioners to the contrary, we can probably consign water diving to the quack-bin and declare it bogus. Hocus pocus pseudoscience.

BUT, does it work “in the real world”? Given that so many still use it, even rely on it, what residual value might it poses for the farmers out here?

Well, my unscientific study of the local farmers deploying this unscientific technique suggests that it is valuable indeed. The process of divining has located many successful bores in this district (together with a largely unmentioned number of failed bores!). Any geologist will tell you that drilling completely at random will not give you a good success rate. To this end, drilling on “crossing streams” found by diviners is not random. There is a great deal of local land knowledge that is deployed when divining, thus narrowing the focus of the search. The divining really then just delivers a reason for siting the drill rig in a particular location. With limited resources at-hand, this is perhaps just what is needed – comfort in spending the money.

So how am I to react when confronted with several ‘divined locations’ (I can’t help but make the mistake of pronouncing it ‘divine locations’ here!)? This is difficult country to explore, and even I, the skilled geologist, have limited data. My locations are beset with large error margins. In fact I will plan for a certain failure rate given the known geology.

I decided to let them have the run of it for a while, as the divined spots had some features that made them acceptable exploration targets. One diviner, we’ll call him ‘Bruce’, comes with, it is said, a 100% success rate! (Forgive my skepticism, 100%?) I have spent the last week drilling his targets. So far, we’ve drilled four holes. The first one was an absolute gusher! More water than we hoped for. Even the farmer, lets call him ‘Barry’, said he’d never seen anything like it! Then the second came up with water too. Not as much, but adequate.

At this stage, I’m running through the stats in my head. This is getting like some sort of baseball or cricket statistic. Surely the ‘run’ must end soon. But then comes the third hole, better than the second. So Bruce is 3 from 3. Pretty good. Don’t worry, I’m not about to be ‘converted’.

The fourth hole comes. I press on, drilling deeper than I usually would. Barry is telling me I have to go deeper, Bruce is never wrong! Bare in mind, this is hard, dry granite. No water in that. But then, sure enough, there’s the water! This time though, it’s minimal; not enough for a bore. So how to call this? 3.5 out of 4?

It’s hard to explain this without saying that there was simply a network of water baring fractures in the granite that would have been found anyway. That would be the logical, geologically appropriate explanation. I happen believe this to be the case. We may even have been able to detect the fracture systems with the right geophysics. And then, we might have drilled proper ‘geological holes’. But, like Bruce the diviner might agree (perhaps not) how will I ever know? We can’t drill everywhere, and geophysics for this kind of exploration is costly in both time and money with limited chance of improving the success rate.

So, what is the upshot of this? Well, I have spent a week drilling holes and conversing with Barry. We get on well and he has been helpful above and beyond the call. It has been a pleasure. What about the divining? Well, Barry wouldn’t let me drill anywhere that didn’t come approved by Bruce anyway. So, the upshot is that we have a happy landholder, and a happy geologist drilling good water bores (the task for which I am paid). Everyone’s a winner, except, perhaps, science. I come out of this a little miffed that I couldn’t show Barry a better way. But then I’m not from round here. It seems that local knowledge has beaten science in this round. Next time, I will have better data, and a better story. I hope.

I still don’t believe that we wouldn’t have found the water without Bruce though!!