Signs of a leak
- A soggy or muddy spot, or water standing in the same place after watering
- A strip of grass that’s greener than the rest, or a sinking spot in the lawn
- Heads on one zone that barely pop up, or weak spray
- A valve box that fills with water
- A water bill that’s higher than usual
Mainline or zone line?
The mainline runs from the water supply to the valves and stays under pressure all the time, so a mainline leak keeps leaking even when no zone is on. A zone line (lateral) only has water in it while its zone runs, so it only leaks during that zone.
To check, turn off every faucet and water-using appliance in the house and keep the sprinklers off, then look at your water meter. If the meter keeps moving, water is leaving somewhere. That could be the house plumbing or the irrigation mainline, so close the irrigation shutoff and check the meter again.
Test one zone at a time
Run each zone by itself and walk it while it runs. Look for bubbling water, a geyser, a head that won’t rise, or water seeping up through the soil. Note which zone and where, then let it dry and look for the soft spot.
Before you dig
Call 811 before digging so buried utility lines get marked. Dig carefully by hand near the wet spot, since sprinkler lines are often shallow. A cracked fitting or pipe can be cut out and repaired; a leak at a valve may need the valve rebuilt or replaced.
When to call us
If you can’t find it, the leak is on the mainline, or the break is under a walkway, call us. Our free 21-point inspection checks for line leaks and soggy areas zone by zone. For repairs, see sprinkler repair in Fresno and Clovis.
Safety first: if you can’t stop the water, close the shutoff valve for the irrigation system, or the main shutoff to the house. Before you dig anywhere, call 811 to have buried utility lines marked.
Written by ACRE Landscape Co., Fresno & Clovis. Updated October 26, 2026.