Wet Patch in Your Yard? How Adelaide Plumbers Detect Underground Leaks
You have noticed something strange in your front yard. There is a patch of grass that is always green and lush, while the rest of the lawn is dry. Or maybe there is an area near the driveway that never seems to dry out, even when it has not rained for weeks. Perhaps the path along the side of your house is always damp.
These are classic signs of an underground water leak. Somewhere beneath the surface, a pipe is cracked or broken, and water is escaping into the soil. You cannot see the pipe. You cannot see the leak. But you can see where the water is ending up.
Underground leaks are tricky because the wet patch on the surface is not always directly above the leak. Water travels through soil and can emerge metres away from where it is actually escaping. This is why finding underground leaks requires the right equipment and experience. Digging random holes hoping to find the problem usually ends in frustration and a destroyed yard.
Signs You Have an Underground Water Leak
Underground leaks often go unnoticed for months because the water escapes where you cannot see it. Here are the warning signs Adelaide homeowners should watch for.
A wet patch that never dries out – The most obvious sign. An area of your yard stays wet or muddy even during dry weather. The soil might feel spongy underfoot. You might notice water pooling after you walk across it.
One patch of grass is greener than the rest – Grass loves water. If one section of your lawn is noticeably greener and healthier than the surrounding area, it might be getting extra water from a leaking pipe below.
Your water bill has increased for no reason – Underground leaks waste water around the clock. Even a small crack can lose thousands of litres per quarter. If your SA Water bill has jumped and you cannot explain why, a hidden leak could be the cause.
Your water meter keeps running – Turn off every tap and water-using appliance in your home. Go to your water meter and watch it for two minutes. If the dial is still moving, water is escaping somewhere. An underground leak is one possibility.
Low water pressure throughout the house – A significant leak in your water supply line means less water reaches your taps. If pressure has dropped noticeably, especially if it happened suddenly, a burst underground pipe could be responsible.
Cracks appearing in your driveway or paths – Water escaping underground can erode soil and undermine hard surfaces. New cracks or sinking sections in your driveway, paths or paving can indicate water washing away the base material beneath.
Sound of running water when everything is off – Sometimes you can hear water flowing through pipes even when nothing is turned on. If you hear a faint hissing or rushing sound near external walls or in the front yard, water may be escaping underground.
Why Underground Pipes Leak in Adelaide
Adelaide has several factors that make underground pipe leaks particularly common. Understanding these helps explain why your property might be at risk.
Reactive Clay Soils
Much of Adelaide sits on reactive clay soils. These soils expand when wet and shrink when dry. After a wet winter followed by a dry summer, the ground can move significantly. This movement puts stress on buried pipes, cracking joints and splitting pipe walls.
The Adelaide Hills and foothills suburbs experience the most dramatic soil movement. Properties in areas like Blackwood, Belair, Stirling, Crafers, Glen Osmond and Burnside often see pipe damage related to ground movement. But reactive soils affect much of the Adelaide metropolitan area.
Ageing Pipes
Water supply pipes do not last forever. Galvanised steel pipes, common in Adelaide homes built before the 1980s, corrode from the inside out. After 40 to 50 years, they develop pinhole leaks and eventually fail. Copper pipes last longer but can still develop problems after 50-plus years, especially in Adelaide’s hard water conditions.
If your home was built in the 1950s, 1960s or 1970s and the water supply line has never been replaced, there is a good chance it is nearing the end of its life. Suburbs like Norwood, Unley, Prospect, Goodwood, Glenelg, Henley Beach and the inner ring of Adelaide have many homes with original ageing pipes.
Tree Root Damage
Tree roots naturally seek out water sources. A tiny leak in an underground pipe attracts roots, which then grow into the crack and make it worse. Large trees near water supply lines or sewer pipes are a common cause of underground pipe damage in Adelaide’s leafy suburbs.
Eucalyptus trees, fig trees, willows and large natives are particularly aggressive. If you have mature trees within a few metres of where your water line runs, root damage is a real possibility.
Poor Original Installation
Some underground leaks stem from installation problems decades ago. Pipes laid without proper bedding, poor joint connections, or inadequate depth can fail earlier than expected. There is no way to know about these issues until a leak develops.
Suspect an Underground Leak?
We locate underground leaks without digging up your yard using acoustic detection and thermal imaging. Find the exact leak location before any excavation begins. Same-day service available across Adelaide.
Call 0484 600 095 for Underground Leak Detection
Is the Leak Your Responsibility or SA Water’s?
Before you call a plumber, it helps to understand who is responsible for different parts of the water supply system.
SA Water is responsible for: The water main running along your street and the connection point up to and including your water meter. If the leak is in the footpath, nature strip or in the meter pit itself, contact SA Water. They will repair it at no cost to you.
You are responsible for: Everything from the water meter to your house and all plumbing inside your property. This includes the underground pipe that runs from your meter, across your front yard, to where it enters your home. If the leak is on your side of the meter, it is your responsibility to repair it.
Here is a simple way to check. Find your water meter, usually near your front boundary. Turn off your main shutoff valve inside your property. Now check the meter. If the meter stops, the leak is inside your property and is your responsibility. If the meter keeps running with your valve closed, the leak might be between the meter and your shutoff valve, which is also your responsibility, or before the meter, which is SA Water’s responsibility.
If you see water bubbling up in the footpath, nature strip or near the meter box, report it to SA Water directly. They have a 24-hour fault line and will investigate.
How Adelaide Plumbers Find Underground Leaks Without Destroying Your Yard
Years ago, finding an underground leak meant digging trenches and hoping you got lucky. Today, we use technology to pinpoint leaks accurately before any digging begins. This saves time, money and your garden.
Acoustic Leak Detection
Water escaping from a pressurised pipe makes noise. It might be a hiss, a whoosh or a rumble depending on the pipe material, the size of the leak and the soil conditions. Acoustic detection equipment amplifies these sounds so we can hear exactly where the leak is occurring.
We place sensitive microphones on the ground surface and listen. By moving along the pipe route and comparing the sound intensity at different points, we can locate where the leak is loudest. That is where we need to dig. This method works for water supply lines and is extremely accurate in the right conditions.
Thermal Imaging
Thermal cameras detect temperature differences. Water leaking underground is usually a different temperature than the surrounding soil, especially if it is coming from your hot water line. The camera shows these temperature variations as different colours, revealing where water is saturating the ground.
Thermal imaging is particularly useful for leaks under concrete, paving or driveways where acoustic methods are harder to use. It can also help identify the extent of water spread underground, showing us not just where the leak is but how far the water has travelled.
Tracer Gas Detection
For difficult-to-find leaks, we can introduce a harmless tracer gas into the pipe. The gas escapes through the leak and rises to the surface, where a sensitive detector picks it up. This method works even when the leak is too small to make much noise or when soil conditions make acoustic detection unreliable.
Pressure Testing
Before using detection equipment, we often start with a pressure test to confirm there actually is a leak and get an idea of its size. By isolating sections of your plumbing and monitoring pressure drop, we can determine roughly how much water is escaping and narrow down which section of pipe is leaking.
What to Expect: The Underground Leak Detection Process
When you call us for a suspected underground leak, here is how we approach it.
Step 1: We confirm there is a leak – Using your water meter, we verify that water is actually escaping. We rule out other causes like running toilets or dripping taps that might explain meter movement.
Step 2: We identify the pipe route – We work out where your water supply line runs from the meter to your house. In some properties, this is obvious. In others, we may need to use pipe locating equipment to trace the route.
Step 3: We scan for the leak location – Using acoustic detection, thermal imaging or tracer gas, depending on the situation, we systematically scan along the pipe route to find where the leak is occurring.
Step 4: We mark the spot – Once we have pinpointed the leak, we mark exactly where we need to dig. No guesswork, no unnecessary excavation.
Step 5: We explain your options – Before any digging begins, we show you what we have found and provide an upfront quote for the repair. You know exactly what needs to happen and what it will cost.
Stop Paying for Water You Are Not Using
An underground leak can waste thousands of litres and hundreds of dollars every quarter. We find leaks fast, fix them properly and help you claim a leak allowance from SA Water where eligible.
Wills Plumbing Adelaide provides professional underground leak detection across all metro suburbs. We use acoustic, thermal and tracer gas technology to find leaks accurately without destroying your property. Same-day service available. Call 0484 600 095 today to find out where your water is going.
Repair Options for Underground Leaks
Once we have found the leak, the repair approach depends on the pipe material, the extent of damage and the location.
Spot repair
If the leak is in one spot and the rest of the pipe is in good condition, we can excavate just that section, cut out the damaged piece and join in a new pipe. This is the most affordable option when the pipe is otherwise healthy.
Pipe replacement
If the pipe is old, corroded or damaged in multiple places, replacing the entire water supply line makes more sense than repeated spot repairs. We can run new copper or poly pipe from your meter to your house. Modern pipes will last another 50-plus years.
Pipe relining
For sewer and drainage pipes, we can often reline the existing pipe from the inside without excavation. A resin liner is inserted into the pipe and cured in place, creating a new pipe within the old one. This is not suitable for water supply lines but works well for underground drain repairs.
Rerouting
Sometimes the easiest solution is to abandon the old leaking pipe and run a new one along a different route. This can avoid excavating under driveways, paths or established gardens.
Frequently Asked Questions
How much does underground leak detection cost in Adelaide?
Most underground leak detection jobs cost between $200 and $400, depending on the complexity and equipment required. This fee covers locating the leak accurately so we know exactly where to dig. Repair costs are additional and depend on what we find. We always provide an upfront quote for repairs before starting work.
How much water can an underground leak waste?
It depends on the size of the leak, but even small cracks can waste significant water. A leak losing one litre per minute wastes 1,440 litres per day, which is over 525,000 litres per year. At SA Water rates, that is roughly $1,400 per year going straight into the ground. Larger leaks waste even more.
Can I get a refund on my water bill for an underground leak?
SA Water offers a leak allowance for concealed leaks that could not reasonably have been detected. An underground pipe leak typically qualifies. You need to provide proof that the leak has been repaired, usually your plumber’s invoice showing the work completed. Contact SA Water with your account details to apply. They will assess your claim and may credit part of the excess water charges.
Why is the wet patch not directly above the leak?
Water follows the path of least resistance through soil. It flows around rocks, along hard layers and towards low points. The leak might be several metres away from where the water surfaces. This is why detection equipment is so important. The wet patch tells you there is a leak somewhere, but not necessarily where.
How long does it take to find and fix an underground leak?
Detection usually takes one to two hours, depending on the property and conditions. Simple repairs can often be completed the same day once the leak is located. More complex repairs, such as replacing a long section of pipe, pe may take a full day. We give you a time estimate once we have found the leak and assessed the repair needed.
Will you need to dig up my entire front yard?
No. The whole point of leak detection is to pinpoint exactly where to dig so we minimise excavation. For a spot repair, we typically dig a hole about one metre square to access the damaged section of pipe. We backfill and compact the soil after the repair. Your yard will need some time to recover, but we are not digging trenches across your property.
What if the leak is under my driveway?
Leaks under concrete or paving are trickier but still manageable. We can often use thermal imaging to locate these leaks. For repairs, we have a few options. We can cut a section of concrete to access the pipe, we can tunnel under from the side, or we can abandon that section of pipe and reroute around the driveway. We will explain the options and costs before proceeding.
Could the wet patch be something other than a water leak?
Yes. Other possibilities include a leaking sewer pipe, a broken irrigation system, poor drainage causing water to pool, or a natural spring. Your water meter helps distinguish between these. If the meter runs with everything off, you have a water supply leak. If the meter is still, but you have a wet patch, the water is coming from somewhere else,e like sewer, stormwater or groundwater.
