The system detects and prevents water leaks. When the leak is detected, the system disconnects the water supply, activating the Shut Off unit. The system is designed to minimize potential flooding damages by shutting down the water supply when the site is inactive and/or when a leak indication is received. Each unit is comprised of a Shut Off unit (valve) installed on the main water supply pipe and leak detector overseeing the closing of the valve. Also, the Shut Off unit can be deactivated manually. The water system is designed for internal use and should be installed by an authorized technician.