Broken PipeBroken Pipes: “Wet Spots” can also be caused by broken pipes in the system. There are two types of lines in irrigation systems where pipe breaks can occur: Main (Constant Pressure) Lines and Lateral (Zone) Lines. In order to assess your situation, you will best be served by determining which type of line is broken. Main (Constant Pressure) Line: This pipe that leads from the backflow prevention device to the individual zone control valves and supplies the system with continuous water pressure. If you break or have a leak in a main line, the water will flow continuously whether the system is running or not. The flow may be large enough to erode a hole in the soil or cause a continuous leak or wet spot.
Lateral (Zone) Lines: These pipes feed the various individual zones of the sprinkler system that are under pressure only when the system is actually running. A lateral line break can be hard to spot because it only leaks while that particular zone or station of the system is active. No matter whether it is a small leak or a large break, it will eventually erode the soil and create a hole in the lawn or bed.
Line breaks waste water and can cause damage by erosion or over watering. Both Main Line and Lateral Line breaks should be repaired by an irrigation professional. Contaminants (dirt, rocks or mulch) could enter the line during repairs and clog or permanently damage downstream sprinklers and other components.