How to Find a Water Leak Underground

Underground leaks are some of the hardest to detect, since there’s often no visible sign until the damage is significant — wet patches on your lawn, sinkholes, or a spiking water bill.

Signs to look for

• An unusually lush, soggy, or sunken patch of lawn or garden with no obvious cause
• A noticeably higher water bill with no change in household usage
• Reduced water pressure throughout the property
• The sound of running water near a garden tap or meter when everything indoors is switched off
• Cracks appearing in a driveway or paved area above a pipe run

Test your water meter

Turn off every tap and appliance, note the meter reading, wait an hour without using any water, and check again. If it’s moved, water is flowing somewhere — and if there’s no indoor leak, that points to an underground pipe.

Why you shouldn’t just start digging

Underground pipe runs aren’t always where you’d expect, and digging in the wrong spot causes unnecessary damage to your garden or paving without finding the actual leak. Acoustic leak detection equipment listens for the specific sound signature of water escaping under pressure, and can pinpoint a leak’s location to within a small area before any digging starts.

Why speed matters

Underground leaks often get worse gradually — what starts as a small crack can erode surrounding soil over time, sometimes undermining paving or even foundations. Left long enough, it also means paying for water that’s never reaching a tap.

If you suspect an underground leak, getting it properly located rather than guessing saves both money and unnecessary excavation.