A wet patch in your garden that stays damp or grows greener grass than the surrounding lawn, especially during dry weather, is a common sign of a leaking supply pipe underground. Check your water meter for movement with everything off. If it moves, acoustic listening and tracer gas can confirm the exact spot without digging up the lawn first.
In This Guide
What a persistent wet patch is telling you
Grass and soil dry out within a day or two of rain under normal conditions. A patch that stays soft, dark or waterlogged well after the rest of the garden has dried is being fed by something other than the weather. In most cases across Scotland, that something is a leaking underground supply pipe.
We get called out to this a lot in spring and summer, when a damp patch that was easy to miss over a wet winter suddenly stands out against a garden that's dried out everywhere else.
Timing matters here. Scotland's winters bring enough rainfall that a small leak can hide in plain sight, masked by ground that's wet everywhere anyway. It's only once the weather turns and the rest of the garden dries out that the leak-fed patch stands apart, which is why so many of these calls land in the drier months even though the pipe's likely been leaking for far longer.
The lush-grass stripe sign
One of the clearest visual signs is a line or patch of grass that's noticeably greener and grows faster than the grass around it. Water escaping from a supply pipe acts like a permanent, localised watering system, feeding the roots directly above and along the leak's path.
- A green stripe running in a straight line. Often follows the route of the supply pipe from the boundary toward the house.
- A single unusually lush patch. Can mark a specific point of failure rather than a whole pipe run.
- Ground that feels spongy underfoot. Even where the grass looks normal, saturated soil underneath is a strong clue.
- Puddling that reappears within hours of drying. Rainwater drains away; a leak keeps refilling the same spot.
Listening for the leak in the ground
Once a suspicious patch is identified, acoustic listening equipment can be used across the garden to pick up the sound of water escaping under pressure, narrowing the search from a general area to a specific spot.
Ruling out ordinary drainage causes
Not every wet patch is a leak. Scottish gardens deal with a lot of rainfall, and some causes are simply about how water moves through the ground rather than a failed pipe.
Likely just drainage
- Low-lying area where water naturally collects after rain
- Heavy clay soil that drains slowly everywhere
- Patch dries out fully within a few days of dry weather
- Nearby downpipe or gutter discharging onto that spot
Points toward a leak
- Wet patch persists through extended dry spells
- Grass is noticeably greener or faster-growing there
- Water meter shows movement with all taps off
- Water bill or pressure has changed alongside the damp patch
Check where your downpipes discharge and whether the ground slopes toward the patch naturally before assuming a pipe is at fault. It's a five-minute check that can save a call-out for something that's really just drainage.
Whose pipe is it: the boundary rule
In Scotland, Scottish Water is responsible for the mains pipe up to the property boundary. From the boundary, or the stopcock, into and through the house, the pipe is the property owner's responsibility, according to Citizens Advice Scotland. A wet patch near the edge of your garden, close to the pavement or boundary line, could sit on either side of that divide.
If the patch is clearly within your boundary, closer to the house than the street, it's almost certainly your responsibility to arrange the repair. If it's right at the boundary or beyond it, it's worth reporting to Scottish Water's 24/7 leak line on 0800 077 8778 so they can check whether it's a mains issue.
On shared driveways or in tenement back courts, a common supply pipe might serve more than one property, and responsibility is typically shared according to the title deeds, or the Tenement Management Scheme where deeds don't specify.
Got a patch of garden that won't dry out?
We locate garden and driveway leaks using acoustic listening and tracer gas, confirming the exact spot before anyone lifts a spade.
Confirming it without digging
Once you suspect a leak, resist the urge to start digging the wet patch to have a look. That spot is often where water has surfaced, not necessarily where the pipe has failed, since water travels along the path of least resistance underground before reaching the top. Dig in the wrong place and you're left with a hole, a damaged lawn, and still no confirmed answer.
Step 1: Check the water meter
Turn off every tap and appliance, then watch the meter for movement. Any movement confirms water is escaping somewhere on your side of the boundary.
Step 2: Acoustic listening across the likely route
A listening device follows the sound of the escape along the supply pipe's probable path, narrowing the search area significantly.
Step 3: Tracer gas to pinpoint the exact spot
Where the ground is particularly saturated or the acoustic signal is unclear, introducing a safe 5% hydrogen and 95% nitrogen gas mix into the pipe and detecting where it surfaces gives an exact fix.
This full non-invasive process is covered in more depth in our guide to how to find a water leak underground, and it's exactly what our underground water leak detection service is built around.
What happens once the leak is found
Once the leak's exact position is marked, any excavation needed is limited to that spot rather than a trench across the whole garden. A plumber or groundworker can then repair the specific section of pipe, and the surrounding lawn or driveway can be reinstated with minimal disruption.
If the leak sits on a shared supply pipe serving a tenement or a row of houses, it's worth notifying your insurer of an escape of water and checking whether the common block policy covers the repair, per the tenement advice service Under One Roof. Where a leak is causing ongoing damage, our water mains leak detection service can prioritise the survey.
Getting a written report at this stage is worth doing even if you're not planning an insurance claim yet. If the same patch reappears somewhere else along the same pipe run in a year or two, which happens on older supply pipes, having a record of exactly where the last leak was found makes the next survey faster.
Frequently Asked Questions
The clearest test is timing. A drainage issue dries out within a few days of dry weather, while a leak-fed patch stays damp regardless. Checking your water meter for movement with everything off is the quickest confirmation either way.
It's best avoided. Water often surfaces some distance from where a pipe has actually failed, so digging at the wet patch can miss the real problem and damage the pipe further if you strike it by accident.
Scottish Water is responsible for the mains pipe up to your property boundary. Everything from the boundary or stopcock into your home is your responsibility, per Citizens Advice Scotland, so most garden leaks fall to the property owner.
No. Acoustic listening and tracer gas both work from the surface without any digging. Only once the leak's exact position is confirmed does any excavation happen, and it's kept to that specific spot.
If your property is metered, yes, a constant leak will show up as increased usage. Most Scottish households pay via council tax rather than a meter, so a garden leak there usually shows up as damage rather than a bill increase, per mygov.scot.
As soon as you notice a persistent wet patch that doesn't match the weather. A supply pipe leak left running can undermine paving, wash out soil, and in the worst cases affect foundations nearby, so earlier is always better.
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