Yes, and fence installation is among the most reliable ways to damage an irrigation system, because post holes go deeper than irrigation pipe is usually buried and fence lines follow property boundaries — exactly where perimeter pipe and wire runs tend to go. A post auger through a mainline or a common wire is a routine call after fencing work, and it is largely preventable with flags and a walk-through before digging.
Why fencing is worse than most landscaping
Two reasons: depth and route.
Post holes are dug deeper than almost anything else that happens in a residential yard, and they are dug with equipment — augers and post-hole diggers — that gives no useful feedback when it meets a pipe. A shovel operator often feels the pipe before cutting it. An auger does not.
The route compounds it. Fences run along property lines, and irrigation perimeter laterals, common wire runs and sometimes the mainline run along the same boundaries, following the same logic about staying out of the middle of the lawn. Then the posts are set at regular intervals along that line, so it is not one chance of a strike but a dozen.
What typically gets hit
The concrete case is the one that turns a modest repair into an expensive one. A post hole that clipped a pipe and was then filled with concrete encases the damage, and reaching it means breaking out the footing and often resetting the post. It is worth far more effort to prevent than to fix.
| What was hit | Symptom |
|---|---|
| Lateral line | One zone has poor pressure at the heads; water surfaces near the fence while that zone runs |
| Mainline | Water flows continuously with the controller off; system pressure down everywhere |
| Station wire | One zone stops working entirely |
| Common wire | Several zones, or every zone, stop working at once |
| Pipe encased in concrete footing | A leak that cannot be repaired without breaking out the footing |
| Pipe crushed but not severed | Reduced flow on one zone with no visible leak — the hardest version to find |
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Diagnostic-first visits across North Georgia. Call 770.335.8595 or request service — you get an estimate before any work begins.
Preventing it: the walk-through that costs nothing
- Locate and flag every valve box before the crew arrives. Boxes on or near the fence line are at risk from both the digging and the equipment traffic.
- Run each zone and flag every head. Heads along the fence line map roughly where the perimeter laterals run, since pipe generally runs near the heads it feeds.
- Have the irrigation line route marked if you do not know it. A wire locator follows the field wire from the controller across the property, and the wire generally runs with the pipe. This is worth doing before a fence goes in rather than after.
- Tell the fence contractor explicitly. In writing if possible, with the marked route. Note that utility locate services mark public utilities — they do not mark private irrigation, so this is on you to provide.
- Ask for hand digging where the route crosses the fence line. A few posts dug by hand at known crossings is cheap insurance against a mainline break in concrete.
- Run every zone the day the fence is finished. Before final payment, ideally. Damage found immediately is attributable and repairable; damage found in April is neither.
If the fence is already up
Run each zone one at a time and note the symptom pattern. Nothing works at all, several adjacent zones dead, one zone dead, or one zone weak — each points somewhere different, and the distinction between one zone and several is the most informative thing you can establish before the appointment.
Diagnosis starts at the controller with voltage and resistance measurements on every station, which identifies an open circuit from a cut station wire or a compromised common wire in minutes without any digging. If the fault is a wire, an inductive locator puts a signal on the wire and follows it to the point where the signal stops, so the excavation is one targeted hole rather than a trench along the fence.
Where the break turns out to be inside a concrete footing, you will be told that before anything is broken out, along with what the alternatives are — sometimes re-routing the pipe around the post is less invasive and less expensive than reaching the original break.
Related answers
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