Broken Sprinkler Lateral Line Leak — Diagnostics

A lateral-line leak usually follows one zone’s schedule and creates wet ground or pressure loss between heads. Confirm the zone, timing, and pipe route before excavating.

Symptoms to compare

• A linear wet patch appears between two heads while one zone runs.
• The affected zone loses pressure while neighboring zones are normal.
• The wet area returns with the same zone and then dries.
• A greener stripe after one or two cycles, shallow sinking along the pipe path, or mushy soil without a puddle can mark a slow leak.

Free diagnostic checks

1. Run only the suspected zone and map where water surfaces.
2. Turn it off and compare wet-area growth with meter movement and other demand.
3. Inspect exposed ends, valve boxes, and head connections before treating the lateral as the source.
4. If pressure tests isolate one lateral but not the break, listen along its route with a ground microphone or mechanic’s stethoscope every two to three feet while the zone runs; mark the strongest hiss before digging.
5. Walk the known route during and after one or two cycles, mark any linear soggy or greener stripe, shallow depression, or mushy soil, and compare it with head and fitting locations.

What the result usually means

• A cracked pipe or separated fitting creates a schedule-linked wet path.
• Root, freeze, or landscape damage can split a lateral.
• A head, valve-box, utility, or groundwater leak can look similar.

Free diagnosis boundary. Call before you dig, isolate irrigation, and use a professional if a potable line may be involved. Use the matching Repair Guide for the protected repair procedure, parts list, testing, and verification.