A water supply control apparatus for use in homes or other structures is provided that incorporates a radio frequency transmitter and a receiver regulating the open or closed state of an electrical solenoid valve in fluid communication with a structure's water supply. A by-pass switch enabling manual regulation of the solenoid valve is mounted on the valve itself. Also provided is a method of controlling the flow of water supplied to a structure utilizing radio frequency pulse broadcasts to regulate the open or closed state of the solenoid valve.