Wet Spots or Slow Leakage Out of Sprinklers When System is Off

Troubleshooting (see the Troubleshooting Charts)

The purpose of automated irrigation systems is to water your landscape according to the program schedule with even application. If you find that you have areas that are overly wet between or after watering cycles, you should look into this right away. “Wet spots” can be caused by a number of things; here are a few of most common causes.
leaky zone valve

Leaky Zone Control Valves:

Think of each valve in your irrigation system as a faucet – they turn on and shut off water flow. They can also leak, just like any of the faucets in your home. This is usually caused by an obstruction in the mechanism that operates the valve, but it can also be a sign that the valve is worn out and needs to be replaced. Leaky valves are easy to spot as water will keep flowing out of the sprinkler even after the system has been shut off for a long time. However, such a leak can also be a symptom of low-head drainage.
Install a check valve

Low-Head Drainage:

Low-head drainage  occurs when water siphons out of the lowest sprinkler in a given zone once the program is complete. After watering, any water remaining in the system line drains downhill to the lowest point in the zone. If you have a sprinkler head in that area, the water will continue to flow until it reaches equilibrium or the zone’s pipes have been emptied.

Hunter Check Valve
It’s normal for the water in irrigation systems  to seek equilibrium due to gravity flow. Usually, this isn’t a problem; however, if the drainage creates puddles or water flows over sidewalks or driveways, it needs to be addressed. You can usually solve this problem by making adjustments to your irrigation system or installing devices called drain check valves. If you’re unable to do this yourself, the professional and friendly staff at Hydro-Scape can assist you.

Broken Pipes:

Broken pipes are another source of wet spots in your landscape. Irrigation systems have two types of water lines in which pipe breaks can happen – Main or Constant Pressure Lines and Lateral or Zone Lines. In order to repair your problem, you first need to determine which type of line is broken.

Main or Constant Pressure Lines: These are the pipes that lead from the Backflow Prevention Device to each individual zone control valve. They supply your irrigation system with continuous water pressure. If one of these pipes is broken, water flow will continue uninterrupted whether the system is actively running or not. Due to the nature of this type of break, the flow may be strong enough to create a hole in the soil, constant leaks, or wet spots.

If your main line is broken, shut off the water supply immediately! See “WHEN A ZONE WON’T SHUT OFF.”

Lateral (Zone) Lines: Lateral lines supply each individual zone and are only under pressure when the irrigation system is running. Unfortunately, this makes lateral line breaks difficult to find. Large or small, breaks in lateral lines can cause soil erosion and holes in your lawn or flowerbeds.

Both types of line breaks waste water and damage your landscape through over-watering or erosion. These line breaks need to be repaired by an irrigation professional, who will ensure that contaminants, such as dirt, rocks or mulch don’t get in the line during repairs. Such contaminants could clog or permanently damage sprinklers and other sections of your system.

However, you can continue to use your irrigation system with a lateral line break. Simply turn off the zone in which the break is located until the system has been repaired. This prevents further damage to your landscape.

Images courtesy of Hunter Irrigation