Find and fix underground water leak

Underground water leaks need fast action, as they can cause damage and cost money if they aren’t addressed. We are going to discuss how to tell if one exists, how to test for one, and some useful tools for locating the leak.

An underground water leak can be located by looking for marshy ground, but usually, you will need to use specialist equipment to detect the problem. Once you have located the issue, you can dig down in that specific area to repair the pipework.

How To Tell If You Have An Underground Water Leak

The commonest sign that there is a leak underground will be the sudden increase in the home owner’s water bill, especially if they haven’t recently done anything that would increase their water usage.

A second sign could be marshy areas in the yard, especially if these are new and located near pipework. This might be accompanied by bushy and lush growth in that area, as plants are being heavily watered.

A third sign is a that the pressure of the water in the house may be decreased, because not enough water is getting through the pipes. This usually only occurs with major leaks.

Finally, the water meter may have a leak indicator, which is a small triangle (blue, white, or red). This will spin when water is being used, so if you have turned off all the water in the house, the triangle should be motionless. If it isn’t, there is likely a leak somewhere.

How To Test For An Underground Water Leak

To test for a leak properly, follow these steps:

Step One: Start by turning off the main water valve. This will stop any water from being used inside the home.

Step Two: Go to look at the small triangle described above. If the indicator is still spinning once the main water valve is off, there must be a leak somewhere; no water is being used inside the home, so it must be leaking underground.

Alternative Option: If the meter does not have one of these indicators, take a meter reading just after you shut off the valve, and then take another an hour later, leaving the valve shut off the entire time. If there is a difference between the two readings and the valve has not been turned back on, there must be a leak on the property.

Useful Tools For Detecting Underground Water Leaks

Locating an underground water leak is a challenge, and unless you want to be digging up a lot of pipework (or there is an obviously boggy area), you probably need some specialist equipment.

You will find many tools available here, although most cost over $1000, so it’s not a small investment to make! Most of these work by using very sensitive acoustic equipment that detects the vibrations created by the water when it is leaking.

You can use this equipment by walking to the start of the pipework, and placing the microphone on the ground. You will then use headphones to listen to the noise through the microphone, which will amplify the vibrations.

You can slowly work your way along the ground, following the line of the pipes. You should be able to hear if the sound suddenly changes; this indicates that the leak is nearby.

You can use this equipment to pinpoint the leak, and then dig down in a very small and localized area, minimizing the damage.

The great thing about this method is that most equipment will work regardless of what the material between the microphone and the leak is – even if it’s concrete or stone. If pipework runs under hard-standing of any kind, this is key to minimizing the damage done by the repair.

Good quality equipment should be able to detect a leak even several feet below the surface of the ground, no matter how small the leak is. You might find that large leaks are easier to hear, but you should be able to find small ones with good equipment too.


Dealing with underground water leaks is always problematic, because you don’t want to be digging up the ground (or flooring) to find the leak. With proper equipment, you can find leaks and fix them with far less disruption.


How to Find a Water Leak Underground

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