A little history: Elementary school is about 16 years old. First principal had a group of scouts come in and pour a concrete sidewalk across an irrigated zone so there'd be better access to the office without people having to get their feet wet walking through the grass. Problem is, he never notified anyone that the sidewalk was going in. On a Friday there was no sidewalk and on a Monday there was. They poured the sidewalk right over the sprinklers and along a wall that creates a patio for the staff lounge. A couple of years later water started appearing between the cracks of the sidewalk and inside the patio planter (following electrical conduit) every time the zone fired and it started traveling to the exterior wall of the office. This site's buildings are block wall that was neither sealed nor is there any interior vapor barrior. Needless to say mold has been appearing over the years on the interior wall. Over the past 10 years I've "investigated" this situation at least five times. The valve sets right next to the sidewalk and the lateral line immedaitely goes under the concrete. No chance to cut and cap a lateral supplying the concrete-covered sprinkler heads by the wall. Each time I've recommended: (1) turn the zone off, (2) abandon the existing zone, come off the valve and install completely new sprinklers, or (3) remove the concrete and fix the problematic areas. The answer has always been, "Maybe" or "It's not causing much problems", or "It's too expensive to fix", etc. and nothing has ever been done. Now the problem has to be fixed because it has come to the attention of district administrators (BTW... the original principal is now an "area administrator" in charge over this site) and we all know what runs downhill. We went out and cut off the lateral line, shut down the Flow Control, cut the solenoid wires and zeroed out the zone on the controller so the valve can neither be manually nor automatically actuated. Now I'll just hold my breath until Maintenance can get out there and saw-cut the concrete so we can remove it and fix the problem once and for all as that's the course of action my boss has elected. We'll see.