What Do You Do When Your Irrigation System Freezes & Bursts?

Turn Off Water Supply

• Because irrigation valves are not typically buried under the earth, they are often more vulnerable to freeze damage than other parts of the irrigation system. If the water supply to the valves was not disconnected before a hard freeze, they -- or the supply lines that feed them -- are likely to break, resulting in water gushing out all over the ground. There should be a shut-off valve near where the irrigation supply line ties into the main water line for the house, often in a basement or crawlspace. In an emergency, start by closing this valve to stop the flow of water.

Check Zone-by-Zone

• Most irrigation piping is underground, making it difficult to pinpoint the exact location of a leak. If you turn on each zone one by one and there is noticeably less water coming through the sprinklers of one zone, this line is likely to be leaking. If some sprinklers in the zone have more water pressure than others, the leak is probably somewhere in the pipe between these two sprinklers. Walk the area between the two sprinkler heads, looking for wet earth that indicates the vicinity of the broken pipes. If all the sprinklers in a zone have low pressure, the leak is probably between the valve and the first sprinkler.

Repair the Pipes

• It may take a lot of digging to find the location of a broken pipe underground. Dig in the location of any area of wet soil that is found, using the degree of wetness as a clue to guide you in the direction of the leak. PVC pipe is the most common material used for underground irrigation lines. The broken area must be fully exposed and the pipe cut on both sides of the break. Two couplings and a new length of pipe are all that is needed to splice it back together. Just be sure to clean the surfaces thoroughly and use PVC primer on all parts that will be glued.

Winter Damage Prevention

• All water must be removed from the irrigation system before freezing weather occurs to prevent the possibility of freeze damage. Some systems have drains installed, but these are rarely effective in removing all the water from the lines with gravity alone. Instead, use an air compressor to blast pressurized air though the system, ensuring all the water is removed. Higher-quality irrigation systems are equipped with a fitting to attach an air hose to for this purpose. The amount of pressure you use depends on the material the system is made out of. Systems made from PVC piping endure higher air pressure than those made from black flexible piping. It's always best to check your owners installation manual to know the ideal pressure needed. The procedure is best carried out by a professional irrigation company, since damage can occur if the air pressure is not calibrated correctly.