Diagnosing Soggy Yard Area: Irrigation Leak vs. Drainage Issues

A persistently wet/boggy zone in a 15-year-old Hunter system—despite that zone being off all season—requires systematic elimination of causes.

Top 4 Causes (Most to Least Likely)

1. Main line leak near the soggy area: Pressurized 24/7. Shut off irrigation main for 3–5 days. If area dries, it's the main line.
2. Poor soil drainage / low spot: Clay, compaction, or grading traps water. Test: dig 12" hole, fill with water. If >24 hrs to drain, soil is the issue. Fix: Flo-Well dry well, French drain, or regrade.
3. Low-head drainage: If zone is on a slope, water drains from lowest heads after each cycle. But you said zone is OFF—so only relevant if other zones share the slope. Fix: Hunter check-valve heads or inline check valves.
4. Lateral line leak: Only leaks when zone runs. Since zone is off, unlikely.

Controller Workaround (If Soil Drainage)

Use Cycle & Soak: e.g., 30 min total → three 10-min cycles at 4 AM, 5 AM, 6 AM with 60-min soaks. Program the zone on its own program with 3 start times.

Next Step

Shut off irrigation main for 5 days. Monitor. If it dries → main line leak. If stays wet → drainage/spring. Photos help confirm.