PURPOSE: To simplify the city water management without changing the charge system by opening forcibly a solenoid valve, based on an output from a controller at the time point when the balance amount by the controller reaches a prescribed value or below.

CONSTITUTION: As for a display of a calendar, by depressing a time limit switch 33 provided on a case main body 29 of a controller 3, a display of the balance amount in a display part 9 is switched. As for an emergency button 34, even if a solenoid valve 5 is closed, when the emergency button 34 is pushed in the case water is necessary, the solenoid valve 5 is opened, and closed when the water quantity of 5m2 flows, therefore, it is impossible to use it illegally from the outside. When a program is set in advance to an arithmetic processing part of the controller 3 so as to execute a start and a stop of feed water by opening and closing the solenoid valve 5, based on a period, the city water management of a villa is simplified.