5 Signs Your Borehole Needs Rehabilitation
Know when to act — early rehabilitation saves money and restores your water supply.
A borehole is a long-term investment — but it is not maintenance-free. Over time, screens clog, pumps wear, and water quality can change. The good news is that most problems give clear warning signs well before total failure. Here are the five signs to watch for.
Sign 1.Reduced Water Yield
What you notice
Taps take longer to fill containers. The tank does not fill to the same level it used to. Water pressure has dropped noticeably.
What this means
The borehole screen may be blocked by mineral deposits (incrustation), the aquifer may be partially depleted, or the pump impellers may be worn. Over years of operation, iron and calcium deposits build up on the screen slots, reducing the flow of water into the borehole.
Action
Schedule a yield test to measure current output against the original commissioning data. If yield has dropped by more than 20%, rehabilitation is likely needed.
Sign 2.Orange or Brown-Coloured Water
What you notice
Water has a visible orange, brown, or rust colour. It leaves stains on sinks, clothes, and storage containers.
What this means
Dissolved iron and manganese are being oxidised as the water reaches the surface. This can indicate corrosion of the steel casing, deterioration of the rising main, or changing water chemistry in the aquifer. In some cases, it signals that the casing has been breached and surface water is entering.
Action
Conduct a water quality analysis and a CCTV camera inspection of the borehole to identify the source of contamination. Treatment or casing repair may be required.
Sign 3.Sandy or Gritty Water
What you notice
Fine sand or grit is visible in the water. Filters clog quickly. Sediment collects at the bottom of storage tanks.
What this means
The borehole screen or gravel pack has failed, allowing formation sand to enter the borehole. This is a serious issue — sand damages pump impellers, blocks pipes, and accelerates wear on the entire system. Left untreated, it can lead to pump failure and even borehole collapse.
Action
Stop pumping immediately to prevent further pump damage. Arrange for a camera inspection and screen assessment. Re-development or a new screen liner may be needed.
Sign 4.Unusual Pump Noises or Vibrations
What you notice
The pump makes grinding, rattling, or knocking sounds that were not present when it was new. Unusual vibrations can be felt on the pipework.
What this means
Worn pump bearings, damaged impellers (often caused by sand), or a misaligned rising main. Cavitation (the pump drawing air) can also cause noise and indicates that the water level has dropped below the pump intake.
Action
Pull the pump for inspection. Check impellers, bearings, and shaft alignment. If sand damage is evident, the borehole itself needs rehabilitation before reinstalling a pump.
Sign 5.Increased Running Time to Fill the Tank
What you notice
The pump runs for significantly longer to fill the same tank. Energy bills (electricity or diesel) have increased without a change in usage pattern.
What this means
The pump is losing efficiency — either due to internal wear or because the borehole itself is delivering less water. Pump efficiency drops gradually, making it easy to miss until costs have risen substantially.
Action
Compare current pump hours per tank fill against the original data. If running time has increased by 30% or more, schedule a pump test and borehole assessment.
What Borehole Rehabilitation Involves
Rehabilitation is a systematic process designed to restore your borehole to its original performance — or as close to it as possible. Here are the five key steps.
CCTV Camera Inspection
A downhole camera survey reveals the condition of the casing, screen, and borehole walls — identifying cracks, corrosion, blockages, and collapse zones.
Airlifting / Surging
High-pressure air is injected into the borehole to flush out accumulated sediment, sand, and mineral deposits from the screen and surrounding aquifer.
Chemical Treatment
Acidisation or specialised cleaning agents dissolve mineral incrustation on the screen and gravel pack, restoring water flow.
Pump Replacement
Worn or damaged pumps are replaced with new, correctly sized units. Rising mains and cables are inspected and replaced as needed.
Yield Testing & Commissioning
A full pumping test confirms the restored yield. Water quality analysis ensures the water meets drinking standards before handover.
Catching these warning signs early can save you the cost of drilling an entirely new borehole. If you have noticed any of the signs above, contact Clapson Aqua Engineering Limited for a professional borehole assessment. We will diagnose the issue and recommend the most cost-effective solution.
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