Every year before the first freeze, blowing out your sprinkler system should be a priority for any and all irrigation systems that are located in a region where the frost levels can extend below the depth of the installed piping. 

 Why is this important? If there is any water left in your sprinkler pipes, they can freeze, expand, and crack your PVC piping. Freezing water left in the back flow assembly can damage the internal components and may possible crack the brass body. 

 To minimize any risk of damaging your sprinkler system, you will need to winterize your sprinklers. There are a few different methods but the most common and effective one generally tends to be the blowout.