Abstract: A device for detecting and warning of floodwater about a building structure, the device including a plurality of selectable remote alarm indicators, a matching plurality of alarm selector switches for selectively enabling and disabling the remote alarm indicators, means for detecting the presence of water, a power circuit with backup battery capability, a selectable intermittent alarm signal generator, a master remote alarm enabler switch, an automatic audio alarm indicator which emits different alarm noises depending on a floodwater condition and/or a low power condition, an alarm priority override circuit, a power status light indicator, and a selectively activatable self-test circuit for simulating a floodwater condition.