Water coming up through driveway cracks or joints in dry weather, a spot that never dries, or a sinking slab often means the water service line or an irrigation line is leaking underneath. Turn off all water and check the meter; then close the irrigation valve and the house shutoff to see which line it is. The leak can be pinpointed with line tracing, acoustic listening and tracer gas, so only a small section of concrete is cut, or the line is rerouted around the driveway.
Driveways often sit right on top of the water service line, and sometimes an irrigation line too. When one of those pipes leaks, the water has nowhere to go but up through cracks and joints, or out at the edge of the concrete. A wet driveway in dry weather is worth checking before it undermines the slab. Here’s how to confirm it’s a leak and find it without cutting up the driveway to look.
Signs of a leak under the driveway
- Water seeping through cracks or control joints when it hasn’t rained
- A wet or dark patch that never fully dries, often with moss or algae
- Water trickling out at the edge of the driveway or into the street gutter
- A sunken, cracked or tilting section of concrete
- A patch of lawn beside the driveway that stays soggy
- A meter that moves with everything off, a higher bill or lower water pressure
Is it a leak, or just groundwater?
| Clue | Points to |
|---|---|
| Wet in dry weather, day after day | A pressurized water line leak |
| Wet only during or after sprinklers run | An irrigation line or valve |
| Wet only after rain | Runoff or groundwater, a downspout, or drainage |
| Meter moves with all water off | A leak on your side of the meter |
Step 1: Meter test
- Turn off every faucet, appliance and the irrigation system.
- Watch the meter’s leak indicator for 15–30 minutes, or compare readings an hour or two apart.
- If it moves, a line is leaking.
Step 2: Which line is it?
- Close the irrigation shutoff. If the meter stops, the leak is in the sprinkler system. See how to find a sprinkler leak.
- Close the main shutoff in the house. If the meter keeps moving, the leak is in the service line between the meter and the house, which often runs under the driveway.
- If the meter stops with the house shutoff closed, the leak is inside the house, and the wet driveway may have another cause.
If the leak looks like it’s at the meter or on the street side, call your water utility first. In most Johnson County communities the utility owns the line up to the meter and the homeowner owns the rest.
Step 3: Pinpoint it before cutting concrete
Concrete is expensive to cut, remove and pour back. Guessing can mean several openings. With underground water leak detection, we:
- Trace the line so you know exactly where it runs under the slab
- Listen through the concrete with ground microphones; concrete carries leak noise well, and the loudest point marks the leak
- Use tracer gas on plastic lines, which escapes through joints and cracks at the leak
- Mark the spot on the driveway for the repair
Repair options
| Option | When it fits |
|---|---|
| Cut a small section and repair | Line is in good shape; one leak |
| Reroute around the driveway | Older line, repeated leaks, or you’d rather not cut concrete |
| Replace the whole service line | Old galvanized or lead line, several problems. See water line replacement cost |
After the repair, the base under the concrete should be checked. Water can wash out gravel and soften the clay soil common across central Indiana, and a void left under the slab can lead to cracking later.
Don’t wait
A leak under a driveway runs 24 hours a day, adds to your water bill, and slowly erodes what’s holding the concrete up. A freeze makes it worse: water in the base expands, and ice on the driveway surface becomes a slip hazard.
We find leaks under driveways, sidewalks and patios across Bargersville and Johnson County, including Greenwood, Center Grove and Whiteland. Once the meter test shows a leak, call us to find it and mark it.
Still can’t find it?
Our underground water leak detection pinpoints the leak without tearing things up, so the repair starts in the right spot.
Frequently asked questions
Why is water coming up through my driveway?
In dry weather, it's often a leak in the water service line or an irrigation line running under the concrete. After rain, it may just be groundwater or runoff. A meter test with everything off tells you whether a pressurized line is leaking.
Can a leak under the driveway be found without breaking concrete?
Yes. The line is traced, then acoustic listening and tracer gas pinpoint the leak through the concrete. Only a small section is cut for the repair, or the line is rerouted around the driveway.
Should I repair or reroute a water line under my driveway?
If the line is in good shape, a small cut and patch at the marked spot is often cheapest. If the line is old or has leaked before, rerouting a new line around the driveway avoids cutting concrete at all and replaces the weak section.
Can a leak under the driveway damage the concrete?
Yes. Water running under a slab can wash out the base and soften clay soil, which leads to cracking, settling and sunken sections. The sooner it's found, the less damage there is to the base.