A blue plastic pipe in the ground which is broken and surrounded by water and mud.

Underground water leaks can be rather tricky to locate because they can go undetected for quite some time. Homeowners often do not even know they have a leak until they start to see physical signs of it. By then, the leak could have caused significant water damage that must also be repaired after the leak is fixed.

What are some common signs of water leaking underground?

There are several common signs of leaking water underground you need to know to help determine if you have a leak, including the following:

  • Soggy patches of grass or other vegetation in the yard.
  • Discolored areas on floors inside the home.
  • Unexplained increases in water bills and usage statistics from your water provider.
  • A strong, musty odor coming from the crawl space, slab foundation, or basement.
  • Warped, peeling, blistering, or cracked flooring.
  • Soft, squishy, or sloshy flooring.
  • Wet carpeting that never dries out.
  • Increased mildew growth indoors due to high humidity levels caused by underground moisture seepage into living spaces within the home.
  • Puddles appear after rainfall and do not seem to dry up quickly despite good drainage conditions outdoors.
  • The sound of dripping or running water coming from your crawl space, slab, or basement foundation.
  • The basement floor is damp or wet.
  • The slab is damp, wet, or you notice water trickling out from around the sides of the slab foundation on the home’s exterior.

Have you noticed one or more common signs of a water leak? Call the water leak detection experts at Larkin Plumbing in Las Vegas today.  

How do I determine if there really is a water leak underground?

The best way to determine if you have a water leak is to use the water meter test. Start by verifying all water throughout the house is shut off. Do not forget to shut off your automatic ice maker. 

Next, locate your water meter and take a look at the meter display. There are different displays depending on when the meter was installed. Some newer meters have built-in leak detection, so all you have to do is look at the meter’s display. 

However, if your water meter doesn’t have this feature, you want to write down whatever is on the meter’s display. Now, wait an hour with all the water turned off and then reread the water meter display. If the number has increased or the needle has moved, it indicates a water leak somewhere. 

What causes underground leaks?

Corroded metal pipe with valve leaking water.

Underground water leaks can be caused by a variety of things, including:

  • Faulty installation of the plumbing system during construction.
  • Corroded pipes or joints.
  • Tree roots that have grown into and damaged the pipe system.
  • Soil movement due to freeze/thaw cycles or land shifts.
  • Settling ground.

How do you find the source of an underground water leak?

Finding the source of an underground water leak requires using one or more of the following methods:

Pressure Test

Pressure testing is a method of finding underground water leaks. It utilizes specially designed equipment to pressurize the plumbing system and detect where pressure is lost, indicating a potential leak. Pressure tests are relatively quick and easy to perform, making them an effective way to pinpoint the source of a suspected leak without having to excavate any area.

Trace Gas Test

Trace gas leak detection is a method of finding underground water leaks that uses specialized equipment to detect the presence of gasses. This type of testing involves injecting an inert gas such as nitrogen or helium into the plumbing system and detecting any escaping gas with a sniffer device. Trace gas leak detection can be an effective way to locate small leaks in inaccessible areas since it does not require excavation or visual inspection.

Thermal Imaging

Thermal imaging is a non-invasive way to detect water leaks. It involves using an infrared camera to locate areas of higher temperature, which can indicate moisture seeping into the ground or structures due to leaking pipes. Thermal imaging can be used in both residential and commercial settings and helps pinpoint the source of the leak quickly and accurately without having to excavate any area.

Noise Correlation Test

Leak noise correlation is a method of finding underground water leaks that uses specific technical equipment to detect and locate the sound of escaping water. This type of testing involves placing two or more listening devices in different locations around the suspected leak area and correlating the sounds detected by each device to pinpoint the exact location of the leak. Leak noise correlation can be useful for inaccessible areas or difficult terrain.

Acoustic Test

Acoustic leak detection is a method of finding underground water leaks that use specialized listening devices to detect the sound of escaping water. These devices are able to pick up on the high-frequency noise generated by leaking pipes and provide an accurate indication of where the leak is located. Acoustic leak detection can be used both above and below ground.

Out of all these methods, thermal imaging and pressure testing are used the most often. However, the other methods can be beneficial in certain situations, like when there are multiple water leaks. 

How is a leak underground fixed?

Man using a large wrench on blue water pipes.

Underground plumbing water leaks can be fixed by either repairing or replacing the damaged pipe. The leak repair process typically involves digging up the area around the leak and patching or sealing it with epoxy resin. In some cases, replacement requires excavating a larger area to access and remove the old pipe before installing a new one.

In addition, other factors, such as accessibility and severity of the damage, will determine the most effective repair or replacement option. Regardless of the repair or replacement option used, getting professional assistance from qualified plumbers is highly recommended.

Do you think you have a water leak in Las Vegas?

If you suspect you have an underground water leak at your Las Vegas home or business, scheduling a water leak detection test with the trusted and experienced plumbers at Larkin Plumbing is a good idea. We use the latest technology and leak detection equipment to pinpoint the leak quickly so it can be fixed. 

Schedule an underground leak detection service by contacting Larkin Plumbing in Las Vegas today. 


Does Homeowners Insurance Cover Slab Leaks? (2022).
Leak Detection With a Thermal Camera: What We Need to Know.
Wallender, L. (2023). How Much Does Slab Leak Repair Cost in 2023?