Frequency of flooding events worldwide has increased significantly over the past decades, and with it so has the need to raise citizen’s awareness of potential dangers within local flood zones. Smart phones provide a feasible means with which to educate the public in this way. We present a working smart phone app to engage the public with local flood zones by visualising potential flood levels. An interactive augmented reality (AR) tool provides in situ modeling of simple prototype 3D building models (cuboids) along a riverside, which are used to “occlude” an augmented flood plane within the scene. Flood plane height may be adjusted by the user. We discuss related AR work, tools for real-time in situ geometry modeling, app operation and present and on site demonstration.