Abstract: A water leak detection and active surveillance system applied to one or more single or multiple-story buildings that timely alerts and contacts a decision maker(s) of the leak so that that corrective intervention may be implemented. The system includes multiple water detection endpoints and a base station that is connected by wireless transmission or other communication means. The system also includes a central server which augments the alarms with text messaging and emails as well as maintains a customer database of all water incidents and alarming procedures. The system also monitors the functionality (operating health) of all detection components. The system also provides proprietary access to the database by qualified users through an internet portal. The system includes the capability to implement a water shutoff action to the water source of the affected building. The system can also operate in mixed mode detection where it can detect a combination of alarm conditions such as smoke, motion, etc.