A domestic water leak and humidity detection and control apparatus to monitor and detect water leaks and to alert a user by an aural buzzer and by illuminated green, red, or yellow LEDs of an operative state of the apparatus incorporates one or more sensor sets, each sensor set having one or more leak detectors connected to a central controller; the central controller having for each sensor set a respective comparator set and a respective LED set, and the central controller connected to and controlling the aural buzzer and controlling a water valve to control water leaks originating from a domestic water supply by electrically controlling the water valve.