Sprinkler winterization is the process of removing all water from your lines and equipment to ensure frozen water in the system doesn't cause any damage in the winter months. Failing to winterize can result in broken or cracked underground pipes, valve damage, backflow preventer damage, and broken sprinkler heads and fittings. Frozen water expands inside the sprinkler system creating crack, which can lead to leaks that you do not notice for some time. If you live in a climate that freezes regularly, it is strongly suggested that you winterize your sprinkler system.