PURPOSE: To obviate the manual work by connecting a liquid source and a sprinkler opening to each other via piping, and providing in the piping a valve device capable of being controlled by a timer.

CONSTITUTION: When accumulation of snow is expected a timer 4 is set to a proper time. At the time set by the timer 4 a solenoid valve 3 is opened by the timer 4 and water is transmitted through a water pipe 1, the solenoid valve 3 and piping 7 and is sprinkled from the sprinkler opening 10 of a sprinkler pipe 8 to prevent accumulation of snow. To drain the water from the piping 7 and the inside of the sprinkler pipe 8, a manually operated valve 6 is opened and the water is drained so as to prevent destruction of the piping 7, etc., due to freezing of the water.