said by John97:
...a leak in the irrigation system.
Thanks for coming back here and letting us know.
If you learn any good methods for finding irrigation system leaks in the process, by all means tell us that too. I sometimes think I have a leak in my 2" rainwater transport pvc pipe(s), but haven't been able to find the issue despite that it rarely rains here and I oughta be able to find a wet spot in the soil!