Knowing how to tell if a pipe burst underground can be trickier than most plumbing problems. Why? Because there’s nothing to see. The pipe, after all, is under your lawn, your driveway, or your slab – quietly doing damage while you go about your day completely unaware.
By the time something obvious is going on, the problem has often been developing for weeks – wreaking absolute havoc. The good news is that an underground pipe failure leaves clues … but they tend to escalate in order of urgency.
How to tell if a pipe has burst underground
Before you’re in the middle of an absolute catastrophe, here’s what to watch for – from the earliest whisper to the point where you needed a plumber a long time ago!
1. Your water bill has quietly crept up
This is the most common firt sign … and the most ignored.
A leaking water pipe underground doesn’t whisper in your ear – but it does add a few hard-earned extra dollars to your quarterly bill. If your usage hasn’t changed but the bill has gone up, and it’s gone up again the following quarter, that pattern is worth investigating.
Water doesn’t disappear on its own. If you’re using more than you should be, it’s going somewhere:
- Check your meter
- Turn off every tap and appliance in the house
- Watch the meter dial.
If it’s moving, water is leaving the system somewhere it shouldn’t be.
2. Water pressure has dropped
Low pressure at a single tap usually means a localised issue – a blocked aerator, a partially closed valve. But low pressure across multiple fixtures simultaneously points to something further back in the system.
When an underground water pipe develops a leak or fracture, water escapes before it reaches your taps, and the pressure drop is felt everywhere at once. If your morning shower feels weaker than it used to and the kitchen tap confirms it, the problem isn’t at the fixture.
3. You can hear water running when nothing’s on
Stand in a quiet room – ideally near where your water main enters the house – and listen.
Do you hear:
- A faint hissing?
- Trickling?
- A rushing sound?
If every tap is off and no appliances are running, and yet your ears are detecting something, don’t ignore it! It means water is moving through the system continuously, which only happens when there’s an unintended exit point somewhere in the line.
4. Wet or soggy patches in the yard
Your lawn is reasonably dry, it hasn’t rained in a few days … and yet there’s a patch near the back fence, or along the side of the house, or near the driveway edge, that stays soft and slightly spongy underfoot.
This is water finding its way to the surface from a pipe burst below ground. In Brisbane’s clay-heavy soils, this can happen faster than you’d expect once a fracture opens up. The wet patch will tend to sit directly above or very close to the pipe run – which is useful information for a plumber when they arrive.
5. An unusually green or lush strip of grass
This one gets missed constantly because it looks like good news. A section of lawn that’s noticeably greener, lusher, or growing faster than the surrounding grass isn’t thriving for no reason – it’s being watered from below by a leaking water pipe underneath it.
Grass loves a consistent underground water source, and a slow pipe leak provides exactly that. If you’ve got a suspiciously healthy strip of turf that tracks in a straight line across your yard, follow where it leads. It’s probably following your pipe run.
6. Discoloured or dirty water at the tap
Clean drinking water coming through a damaged underground water pipe picks up whatever the pipe is running through – could be soil, could be sediment, could be rust from a corroded fracture point.
Brown, murky, or gritty water at the tap is a sign that the pipe’s integrity has been compromised enough for outside material to enter the supply. At this stage, you’re dealing with more than a pressure or loss issue – your water quality is affected, and this moves the problem into territory that needs urgent attention.
Stop using the water for drinking or cooking until it’s assessed.
7. Cracks appearing in paths, driveways, or slabs
When a pipe burst underground releases water into the surrounding soil over time, it changes the soil’s composition and load-bearing capacity.
Clay soils expand when wet and contract when they dry – and repeated cycles of this movement beneath a concrete path, driveway, or slab causes cracking at the surface.
If you’re seeing new cracks appear in paving that wasn’t cracked before – particularly in a line that tracks across your property – underground water movement is a serious candidate for the cause. This is the point where the problem has moved from a plumbing issue to a structural one if left unaddressed.
8. Sinkholes, subsidence, or ground movement
This is the “stop what you’re doing and call someone RIGHT NOW” end of the scale!
The kind of significant burst pipe Brisbane plumbers attend sometimes presents with visible ground subsidence – areas where the soil has been so thoroughly saturated and eroded by escaping water that it can no longer support what’s above it.
Noticing the signs?:
- Small sinkholes in the lawn
- Sections of driveway that have dropped or tilted
- Visible movement in garden retaining walls?
They’re all signs of serious underground water loss that has been occurring for quite some time. At this stage, structural damage to your property is either already happening or imminent.
What to do if you recognise any of these signs
The earlier in this list you catch it, the simpler and cheaper the fix. A high water bill and a meter that won’t stop is a quick leak detection job – but a sinkhole next to your foundation is a much larger conversation.
Either way, a pipe burst is not a wait-and-see situation – underground leaks don’t seal themselves, and every day of delay means more water lost, more soil movement, and a larger repair bill at the end of it.
S&J Plumbing and Gasfitting‘s licensed and friendly Brisbane plumbers carry leak detection equipment to locate underground pipe failures without unnecessary excavation. Book your obligation-free quote today.