There is little disagreement that entering floodwater is risky, whether in a vehicle or on foot. There is usually little or no visibility of what is under the surface and even shallow water with moderate flow can make vehicles unstable or sweep people off their feet. In addition, floodwater will often contain contaminants and debris. Therefore, the safest course of action is to avoid entering floodwater. Indeed, the most pervasive risk communication message is 'If it's flooded, forget it'. This clear, unambiguous message is good at getting people's attention, but it is unclear whether it actually changes behaviour. Research with Australian public, floodplain management professionals, State Emergency Services (SES) personnel, and other emergency management experts has identified a number of challenges to floodwater safety and risk communications. Using a combination of research evidence and expert opinion, this paper discusses four pressing challenges and highlights some of the approaches being taken to help address them.