The situation
Illustrative example. Not a real job or customer.
A homeowner on a sloped lot opens a water bill far higher than the same period last year. There are no warm floors, no damp carpet and no sounds in the house. A neighbor's slab leak is fresh in their mind.
- They run a meter test; the indicator spins steadily with everything off.
- They close the water heater inlet; nothing changes.
- They close the house main shutoff by the garage; the meter still moves.
- They walk the front slope and find the soil along the driveway edge soft and damp, with no sprinkler nearby.
Because the meter kept moving with the house main closed, the leak had to be on the line between the meter and the house, not under the slab.
What each check ruled out
| Check | Result | Ruled out |
|---|---|---|
| Everything off, meter watched | Moving | Nothing; confirmed a leak |
| Heater inlet closed | Still moving | The hot side under the slab |
| House main closed | Still moving | Everything inside the house, including the slab |
| Irrigation supply checked | Not on this branch | The sprinkler system |
What happened next
- Called the right people.They asked the city's water utility whether the meter side was involved and booked a plumber for the yard service line.
- Protected the slope.They avoided parking on the soft driveway edge until it was assessed.
- Plumber located the break.Testing pointed to the service line running under the front yard.
- Repair and recheck.After the line was repaired, the meter stayed still with everything off.
Lessons from the example
- The main valve is a test tool
- Closing it divides the problem into inside and outside the house.
- No heat, no sound
- The absence of indoor signs was a clue in itself.
- Ownership matters
- Meter and street side belong to the utility; the house side generally does not. Confirm with the city.
Why this matters for slab leak worries
A homeowner who skipped the main valve check might have paid for under-slab detection that found nothing. Five extra minutes with one valve pointed straight at the yard, and the conversation with the plumber started in the right place.
Common questions
Is this a real case?
No. It is invented to illustrate how to rule a slab leak in or out.
Can a service line leak and a slab leak happen at once?
It is possible. After fixing one, rerun the meter test to make sure the movement has fully stopped.
Who fixes the service line?
Generally a licensed plumber for the owner's side. Ask the city utility about anything at or beyond the meter.
General information for Anaheim Hills, not a quote or professional advice. In an emergency, call 911.