A couple of days ago I happened to be outside while the sprinklers in one zone were operating and noticed a dribble of water from a pop-up I didn't know existed. Even when the water was on, the pop-up barely reached the level of the top of the grass.
Now I am wondering whether there are other sprinkler heads that got buried even further down than this one. The neighbors on both sides (no fences) have been there only a few months longer than us, so asking, "Did you ever a notice another sprinkler head anywhere around here?" achieves nothing.
We don't have a plan of the sprinkler system that would show where they were installed originally. Nor is there anything to indicate by whom they were installed, so we can't go back to the installer (if it wasn't in fact a DIY job) for information.
Any bright ideas for a means of locating buried sprinkler heads?