Abstract: A water protection system apparatus for detecting and stopping a flow of water which includes a power supply, a water ionization switch, and a controlled valve assembly. The water ionization switch selectively conducts electricity when exposed to water and includes an initially dry non-conductive crystallized compound. The compound ionizes when exposed to water to form an electrolyte which conducts electricity. This switch is connected to a controlled valve assembly to stop the flow of water in response to the detection of water by the switch. Other refinements include modifications to the switch housing and condition indicators for monitoring the system and signaling water detection and shutdown operations.