Underground pipe leaks on Lanzarote — what to watch for
A pipe buried half a metre under your drive can crack and pour hundreds of litres a day into the volcanic gravel while you walk over it. Underground leaks are the kind we get called to most by customers who notice the bill before they notice anything else.
This is the Leakbusters Lanzarote checklist of signs that a buried pipe on your property is leaking. If you spot any of these, the next thing to do is the overnight meter test below — that confirms it.
What you might see on the surface
A wet patch that won't dry
Lanzarote barely rains. If a part of your garden, patio, or drive stays damp for days when nothing else does, water is coming from underneath. Specifically watch for:
- Soil or gravel that's darker than the surrounding area
- A puddle that comes back after you've dried it
- Paving slabs that stay wet while everything around them dries off
These usually sit directly over the leak, or slightly downhill if the water is migrating sideways through the gravel.
One area suddenly greener than the rest
Plants follow water. A buried leak can make:
- A strip of grass much greener than the rest
- Weeds growing in a spot where nothing was before
- Tree or shrub roots visibly drawn towards a buried pipe route
In Lanzarote's arid climate this contrast is hard to miss once you've spotted it.
Ground starting to move
Water under pressure washes the fine volcanic particles out from underneath structures. Look for:
- Small sinkholes or depressions that weren't there
- Cracks in drives, paths, or patios
- Paving that's gone uneven or started to drop
- Gravel apparently washing away from one specific spot
On volcanic substrate this erosion happens faster than on clay or sandy soil — picón drains water easily, so a leak can carry surrounding material with it.
Sound
Lanzarote nights are quiet. In the early morning or late evening, walk near the main supply route on your property and listen for:
- A hiss near outdoor taps or the meter box
- Water trickling or rushing when no taps are open
- Gurgling in places where there's no plumbing nearby
Stand still for a minute or two. It's easy to miss in daytime noise.
The overnight meter test
This is the cleanest way to confirm a leak.
- Before bed, turn off every water appliance and fixture in the house. Pool pump too if you have one.
- Read the meter and write it down — every digit including the small ones.
- Don't use any water overnight.
- Read it again first thing in the morning.
If anything has changed, water has been flowing somewhere it shouldn't. For an underground leak, this is often the first solid evidence.
A small overnight change could be a slow drip inside the house — a leaking toilet, a tap left on. Several litres or more suggests something bigger, often buried. A meter wheel that doesn't stop spinning when nothing is on is the clearest sign of an active leak.
Why Lanzarote properties are particularly vulnerable
Volcanic ground
The substrate moves. Not earthquakes, just settlement. Properties built on fill or reclaimed land move more than ones on bedrock. That movement stresses pipe joints over years.
Picón and basalt fragments have sharp edges. Pipes resting against them get abraded over decades until eventually the pipe wears through.
Temperature changes too. The top half-metre heats up during the day and cools at night. Pipes there expand and contract every 24 hours — eventually that fatigues a joint.
Older infrastructure
A lot of Lanzarote was developed between 1970 and 2000. Supply pipes from that period are getting to end-of-life:
- Galvanised steel — corroding internally, especially with mineral-rich desalinated water
- First-generation PVC — brittle now from UV where pipes emerge above ground
- Compression fittings — designed for shorter lifespans than they've now been in service
Properties in older urbanisations like La Concha, Los Mojones, or the original Costa Teguise developments before 1990 benefit from a buried-pipe check every few years.
Desalinated water
Lanzarote tap water is desalinated. It's clean and safe, but the mineral composition is slightly different from natural fresh water. Over decades certain pipe materials react to that and corrode from inside faster than they would on mainland fresh water supply.
When to suspect a buried leak
Get it investigated when you've got:
- Water bills creeping up over three or more billing periods
- Meter movement with everything off
- A damp patch outside that won't dry
- Pressure down across the whole property
- A property built before 1995
Any one of these on its own isn't conclusive. Two or three together, and it's very likely a buried leak.
How Leakbusters Lanzarote finds buried leaks
- Acoustic listening — specialised equipment amplifies the sound of water escaping a pressurised pipe. We follow the sound along the pipe route and narrow it to centimetres. Works particularly well on metal pipes and in rocky ground.
- Ground microphones and correlators — two access points along the same pipe, sound captured at both, position calculated mathematically. Accuracy is usually good enough that the repair team digs one small hole rather than a trench.
- Thermal imaging — escaping water changes ground temperature. Infrared shows where water has spread below the surface. Best done early morning or late evening when the ground temperature is settling.
- Tracer gas — for leaks that don't make detectable sound (slow weeps, hairline cracks). We introduce a safe hydrogen-nitrogen mix into the pipe and the gas escapes through any leak. A surface detector picks up where it comes up.
Protecting your property
Prevention:
- For properties over 20 years old, get the supply pipes inspected every 5-7 years
- Note your meter reading at the start of each season and compare against the previous year
- Don't ignore pressure changes — they're often the early warning
- Consider relining the worst stretches of pipe rather than waiting for the failure
If you suspect a leak:
- Photograph everything — dates, location of wet patches, anything visible
- Do the overnight meter test
- Call a leak detection specialist before you dig anywhere
- Don't try to find it by exploratory digging — it almost never works and you end up paying twice
The cost reality
Professional underground leak detection costs a fraction of exploratory excavation. Once we've pinpointed it, the repair trench is small, the materials are minimal, and you don't have to relay half the patio afterwards. Worth the detection cost every time.
Bottom line
Underground leaks get worse, not better. Every day the bill goes up, the volcanic gravel under your structure gets a bit more washed out, and the eventual repair gets bigger. The signs above give you the early warning. Call Leakbusters Lanzarote when you've confirmed one. No find, no fee — if we don't locate the leak, you pay nothing.