The Flood-Related Behaviour of River Users in Australia.

Abstract

Introduction: Flooding is a common natural disaster affecting 77.8 million people and claiming the lives of 4,731 people globally in 2016. During times of flood, drowning is a leading cause of death. Flooding is a known risk factor for river drowning in Australia. With little known about river usage in Australia, this study aimed to examine the links between person demographics and self-reported participation in two flood-related behaviours, driving through floodwaters and swimming in a flooded river.

Methods: A self-reported questionnaire was administered to adult river users at four high-risk river drowning locations; Alligator Creek, Townsville, Queensland; Murrumbidgee River, Wagga Wagga, New South Wales; Murray River, Albury, New South Wales; and Hawkesbury River, Windsor, New South Wales. Univariate and chi square analysis was undertaken with a 95% confidence interval (p<0.05). All river users surveyed, were also breathalysed to record an estimate of their blood alcohol content (BAC) on their expired breath. Results: 688 river users responded to the questionnaire; 676 (98.3%) answered the driving question and 674 (98.0%) answered the swimming in floodwaters questions. Of the respondents, 35.7% stated they had driven through floodwater and 18.7% had swum in a flooded river. Males were more likely (p<0.001) to report having undertaken both activities. Australian-born respondents were more likely to report having driven through floodwaters (p=0.006). Those aged 18-24 years old and those residing in outer regional areas were more likely (p<0.001) to have swum in a flooded river. Those who self-reported participating in both driving through floodwaters (p=0.001) and swimming in a flooded river (p<0.001) were significantly more likely to record contributory levels of alcohol (i.e. a BAC ≥0.05%) when breathalysed at the river.

Discussion: Ensuring the safe movement of people during floods is difficult, particularly for those living in regional Australia, due in part to long distances travelled and reduced investment in infrastructure such as bridges. With males and females equally exposed, more effective prevention strategies must target both sexes and may include improved education on when it is safe to drive through (low depth, still water, stable road base) and when it is not (e.g. deep water, moving water and unstable road base). This study identified one in five respondents had swum in a flooded river, most commonly young people aged 18-24 years, with participants signficantly more likely to have recorded contributory levels of alcohol when breathalysed. Further research should examine the reasons behind participation in this behaviour, including the role of alcohol.

Conclusion: Preventing drowning in floodwaters is an international challenge, made more difficult by people driving through or swimming in floodwaters. Strategies for driving through floodwaters should educate both males and females on when it is safe to drive through floodwaters and when it is not. Further research is required to improve knowledge of the poorly understood behaviour of swimming in flooded rivers.