(Undated) -- It's about time to put your lawn sprinklers away for the winter. Experts say they should be disconnected and emptied to prevent freezing damage over the winter. Leaving the water in the lines could cause serious illnesses if it starts to flow back into the home. That doesn't normally happen when the city's water pressure is as high as it should be. But in the event of a pressure drop, malfunctioning lawn sprinklers could let pesticides into the water mains.