Don’t gamble with your pump: The importance of Borehole Yield Testing
“We have a very good borehole.”
“Ohh really, did you yield test?”
“No, but when we were drilling, we hit water at 10m and we drilled a further 70m down.’
This is an interaction that I have had countless times. It’s a moment of pride for the property owner, but for a solar pump installer, it’s a red flag.
In the world of water, hitting water early and drilling deep is not the same as having plenty. The depth of your borehole and the level where you first ‘hit water’ tell us where the water is, but they tell us absolutely nothing about how much water you can actually take out without the borehole running dry. This is where a Borehole Yield Test comes in. Without one, you aren’t just buying a pump; you are playing an expensive game of Russian Roulette with your groundwater.
I’ll briefly explain why a yield test is the only insurance policy you have for your solar pump investment, and how it prevents you from burning out a brand-new pump in a matter of weeks.
Why You Can't Skip the Test
Imagine trying to drink a thick milkshake through a tiny straw. No matter how much suction you apply, you can only get a small amount out at a time.
A borehole is the same. Just because your hole is 100 meters deep doesn’t mean the ground can “give” you 5,000 litres per hour. If you install a high-capacity pump in a low-yield hole, the pump will empty the shaft in minutes and begin sucking air, leading to motor burnout.
A capacity test involves pumping the well at various rates for several hours (sometimes up to 48 hours for commercial sites) to monitor two things:
- Drawdown: How far the water level drops while pumping.
- Recovery: How fast the water level bounces back once the pump stops.
The test also identifies your Static Water Level (rest) and Dynamic Water Level (during pumping). This tells the installer exactly how deep to hang the pump. Hang it too high, and it runs dry; hang it too low, and you might get buried in silt. Once you know your yield, you can use our Solar Pump Sizing Guide to find the perfect match.
So, are you ready to see what your borehole is truly capable of? Drop by our shop and speak with our technicians about our capacity testing services – we’ll help you find the perfect flow for your borehole.
