Wet Spot in the Yard
A wet or lush spot in the yard that doesn't dry up can sometimes indicate an underground water line leak between the meter and the house. It could also be a sprinkler system issue or a sewer line leak. The meter test helps confirm whether it's a pressurized water line leak before you start investigating further.
- —Underground water service line leak (between the meter and the house)
- —Sprinkler system leak or broken head
- —Sewer line leak or break (usually wetter and smellier)
- —Natural groundwater or drainage issue
Try This First
Safe, simple steps you can try yourself. If any step feels beyond your comfort level, skip it and continue below.
- 1
Check for unexplained metered flow
Confirm fixtures, toilets, irrigation, appliances, water treatment, and other automatic users are off, then observe the meter without disturbing utility-owned equipment. Continued movement means water is being metered somewhere, but isolate automatic users before assuming an underground service-line leak.
- 2
Use the building-side shutoff to narrow the area
If you know the location of the home's customer-side main shutoff and can operate it safely, compare meter behavior before and after closing it. If the meter continues registering flow, the source may be upstream of that valve or on another metered branch; if it stops, the unexplained flow is likely downstream. The exact interpretation depends on the piping layout.
- 3
Check the sprinkler system
If you have irrigation, turn off the sprinkler system at its shutoff and see if the meter stops. A broken sprinkler head or underground pipe can cause a wet yard without a main line leak.
If the problem is resolved
If the meter stops after shutting off the sprinkler system, a sprinkler repair is the fix — not a main water line issue.
If the problem persists
If the meter continues to register flow with the building-side main shut off, a leak on the service line between the meter and building becomes a strong possibility. Responsibility boundaries vary by utility and meter configuration, so confirm the serving utility's rules before assuming who owns the affected section. Continue below.
Stop and Call a Plumber If…
- The meter continues to register unexplained flow after known water users are ruled out
- The wet area is growing or getting wetter
- Water is entering the crawlspace or basement
- The yard is sinking or eroding where it's wet
- Your water bill has increased significantly
- ✓Using acoustic, pressure/isolation, and site evidence as appropriate to narrow the likely underground leak location
- ✓Determining whether a spot repair or full line replacement is needed
- ✓Checking for a leak inside the house (slab leak, wall leak)
- ✓Evaluating the pipe material and age for the repair recommendation
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Reviewed by Paul Hall, Owner & Licensed Plumber
The Classic Plumber · Knoxville, TN · License #4268. This guidance is general — an onsite inspection may be required for a confirmed diagnosis.