Causal Pathways of Flood Related River Drowning Deaths in Australia

Introduction: Globally, flooding is the most common of all natural disasters and drowning is the leading cause of death during floods. In Australia, rivers are the most common location of drowning and experience flooding on a regular basis. Methods: A cross-sectional, total population audit of all known unintentional river flood related fatal drownings in Australia between 1-July-2002 and 30-June-2012 was conducted to identify trends and causal factors. Results: There were 129 (16.8%) deaths involving river flooding, representing a crude drowning rate of 0.06 per 100,000 people per annum. Half (55.8%) were due to slow onset flooding, 27.1% flash flooding and the type of flooding was unknown in 17.1% of cases. Those at an increased risk were males, children, driving (non-aquatic transport) and victims who were swept away (p<0.01). When compared to drownings in major cities, people in remote and very remote locations were 79.6 and 229.1 times respectively more likely to drown in river floods. Common causal factors for falls into flooded rivers included being alone and a blood alcohol content ≥0.05% (for adults). Non-aquatic transport incident victims were commonly the drivers of four wheel drive vehicles and were alone in the car, whilst attempting to reach their own home or a friend’s. Discussion: Flood related river drownings are preventable. Strategies for prevention must target causal factors such as being alone, influence of alcohol, type/size of vehicle, and intended destination. Strategies to be explored and evaluated include effective signage, early warning systems, alternate routes and public awareness for drivers.