Abstract: A system and method for controlling the flow of water through a water supply line into a building. The system has a valve that connects to the water supply line of the building. The system also includes a flow meter that connects to the water supply line, wherein the flow meter produces a water flow signal indicative of the volume of water flowing through the water supply line. A systems controller is provided that is connected to both the valve and the flow meter. The systems controller is configurable between a first operations mode and a second operations mode. The systems controller reads the water flow signal from the flow meter and closes the valve at a first flow rate when it is in its first operations mode. Similarly, the systems controller closes the valve at a second flow rate when it is in its second operations mode. When the flow meter detects an excessive volume flow, the systems controller only closes the valve if the excessive flow persists beyond a predetermined period of time.