Locating underground irrigations systems

Underground irrigation systems can be hard to find. When you have a leaking irrigation pipe or irrigation solenoid you need to find it fast . If you want to landscape or undertake excavations, you will need to know where your underground irrigation pipes and solenoid valves are so that you do not dig break them. You may want to find your buried irrigation pipes so that you can add an extra sprinkler head or zone.

Dial Before You Dig plans will not show the location of irrigation systems or valves. They will show the location of the water utility’s water mains and water inlet service up to the water meter.

I have been in this industry since for a very long time. Only on rare occasions will you find marker tape indicating that there is a buried irrigation system below. However, if you happen upon any marker tape while excavating, stop your excavations immediately. Marker tape indicates that you are possibly digging directly above an expensive underground Asset. If you find marker tape you must either expose the underground asset by shovel or hydrovac, or change the location of your excavation.

Some smart irrigations system installers will provide their customers with a plan that shows the layout of irrigation systems. These diagrams are more common for commercial irrigation systems, and will show the location of all pipes, solenoids other valves, wiring and control systems. Search the files that you keep for your home or building. It is not likely that your council or planning authority will keep a record on file. However, it would not hurt to ask.

Solenoid valves for irrigation systems can be easy to find. A metal detector could be used to locate the copper wires running from the controller to the solenoid valve. A Chatterbox can be connected to the selected wiring at the irrigation control box. This will cause the selected solenoid valve to click rapidly, thus making quite an audible noise. We induce an electronic signal into the wiring for the solenoid. We then use a receiver locator to trace that wire until we come to the end of the wire where the solenoid is usually located.

Underground irrigation pipes tend to be small diameter UPVC pressure pipes, with many sharp bends and Ts. They will not have a tracer wire. Wires running between the control box and the solenoid tend to be in the same trenches that the main water supply to each solenoid is in. Therefore tracing the solenoid wire helps to find the location of the irrigation pipes. The branch lines after the solenoid valves can be very hard to find. We would normally look for lineal depressions in the ground or a greener tinge of grass running in straight lines.

Irrigation isolation / stop valves are usually located on a branch line, not far off the water service pipe to the building. They may be in the main water meter box or in their own valve box close to the meter. If they are buried and the water service pipe is metal, a metal detector may suffice. We induce an electronic signal into the water service pipe. We then use a receiver locator to find that signal being emitted from the pipe. We may then use a spike to find a buried, hard and flat surface. This usually indicated the top of a valve box.