One of the first questions homeowners ask before drilling is deceptively simple:
“Where on my property should the borehole go?”
The common answers range from folklore to guesswork. Some people follow water diviners with sticks. Others point to where a neighbour’s borehole sits. Some choose a spot that is simply convenient for plumbing. A few leave the decision entirely to the driller on the day the rig arrives.
In reality, borehole positioning is not random and it is not mystical.
It is a practical decision influenced by geology, contamination risk, long-term access, and how the water system will operate for decades after the drilling rig has left.
A poorly positioned borehole can create permanent water quality risks, constant maintenance problems, and avoidable system frustrations. A well-positioned one becomes an invisible, reliable part of the property’s infrastructure.
Why “anywhere on the property” is a costly misconception
Groundwater does not sit under your property like a swimming pool. It moves through fractures in rock, through soil layers, and through aquifers that are influenced by terrain, slope, and surrounding activity.
Two boreholes drilled 20 metres apart can behave very differently. One may produce clean, stable water for years. The other may struggle with sand, contamination, or poor yield, simply because of where it was placed.
Position matters more than most people realise.
Geological reality vs common myths
Many South Africans still rely on divining rods or anecdotal advice when choosing a drilling point. While groundwater is widespread in many regions, it does not occur evenly.
Professional drillers often use geological maps, local drilling experience, and understanding of rock formations to guide positioning. Certain rock types, fault lines, and fractured zones are more likely to produce reliable groundwater than solid, unfractured rock.
This is not guesswork. It is pattern recognition built from thousands of drilled boreholes across regions.
Distance from septic tanks, sewer lines, kraals, and fertilised areas
One of the most overlooked positioning factors is contamination risk.
A borehole drilled too close to a septic system, sewer line, livestock enclosure, compost area, or heavily fertilised garden increases the risk that surface contaminants can travel down through soil and eventually reach the groundwater being drawn into the borehole.
This is why borehole water testing often reveals bacterial or nitrate issues that are not geological, they are environmental and positioning related.
Keeping safe distances from potential contamination sources is critical for long-term water quality.
Elevation, slope, and surface runoff considerations
Water on the surface always flows downhill. During heavy rain, runoff carries contaminants from across the property.
Drilling a borehole at the lowest point of the property increases the risk that contaminated runoff will collect around the borehole head. Over time, this can find its way down into the aquifer through poorly sealed upper layers.
Higher ground, with proper surface sealing, reduces this risk significantly.
Access for the drilling rig and for future maintenance
Borehole rigs are large, heavy vehicles. They need space to enter, manoeuvre, and operate safely. But positioning is not only about the day of drilling.
Years later, pumps may need to be replaced. Pipes may need to be serviced. Electrical connections may require attention. A borehole placed in a cramped courtyard, under paving, or in an inaccessible garden corner creates unnecessary difficulty for future work.
Easy access is a long-term benefit.
Why neighbours’ boreholes matter — and why they don’t
Seeing a successful borehole on a neighbour’s property is encouraging, but it is not a guarantee that the same spot on your property will behave identically.
However, clusters of successful boreholes in an area do indicate favourable groundwater conditions. Experienced drillers use this local knowledge to guide positioning while still assessing your property’s unique features.
How poor positioning can permanently affect water quality
If a borehole is drilled in a position where contamination pathways exist, the problem may not appear immediately. Years later, bacteria or nitrates may show up in testing, and the only real solution may be expensive treatment systems or even abandoning the borehole.
Positioning mistakes are buried underground and very difficult to correct later.
Practical positioning principles homeowners can follow
Homeowners do not need geological training to make good decisions. They need to avoid obvious risks:
- Keep distance from septic systems and sewer lines
- Avoid low-lying runoff collection points
- Ensure space for rig access and maintenance
- Avoid areas near livestock or heavy fertiliser use
- Discuss local drilling experience with the contractor
These simple principles prevent many long-term problems.
How a Borehole Should Sit on a Property
[ Higher Ground ]
House
|
Tanks & Pump
|
Borehole
—————————
↓ runoff direction ↓
Septic Tank Garden Kraal
[ Lower Ground ]
What this shows
- Borehole placed uphill from contamination risks
- Close enough to the house for plumbing and tanks
- Far from septic, waste, animals, and runoff flow paths
This mental picture helps homeowners visualise correct placement instantly.
Where you drill a borehole is not a matter of convenience. It is a decision that affects water quality, reliability, and maintenance for decades.
A good position becomes invisible over time. A bad one becomes a permanent source of frustration hidden beneath the ground.
Borehole Positioning Checklist:
Before you approve a drilling point on your property, walk through this list:
| Question | Yes | No |
| Is the proposed spot at least 20–30 metres away from any septic tank or soakaway? | ☐ | ☐ |
| Is it far from sewer lines, stormwater drains, or waste pipes? | ☐ | ☐ |
| Is it away from livestock enclosures, kraals, or compost areas? | ☐ | ☐ |
| Is it not in a low-lying area where rainwater collects? | ☐ | ☐ |
| Is the area accessible to a large drilling rig and future maintenance vehicles? | ☐ | ☐ |
| Is there space for tanks and a pressure system nearby later? | ☐ | ☐ |
| Is the area unlikely to be paved over or built on in future? | ☐ | ☐ |
| Has the driller explained why this position suits the geology? | ☐ | ☐ |
| Have you discussed where neighbouring boreholes are located? | ☐ | ☐ |
If you cannot tick most of these confidently, the position needs more thought.
Be sure to read: Is Borehole Water Safe to Drink? A South African Guide to Testing, SANS 241 and Treatment