Urban development and long-term flood risk and resilience: Experiences over time and across cultures. Cases from Asia, North America, Europe and Australia

Rivers are the lifeblood of many cities, but flood risk is projected to increase due to urbanisation and climate change. Better floodplain management in and near urban areas is required to produce the New Urban Agenda’s ‘just, safe, healthy, accessible, affordable, resilient and sustainable cities’. Many jurisdictions are looking to move or keep people out of human-constructed residential ‘niches’ on hazardous floodplains, but this has proved difficult to achieve. Our historical case studies of colonial societies in ancient Rome, as well as on the Yangtze, Mississippi and Brisbane rivers, show the deep roots of many contemporary flood risk issues, such as failures of risk perception related to recent settlement, the moral hazard of spending on flood defence infrastructure, the creeping nature of floodplain encroachment into ‘niches’ of perceived protection created by structural interventions, the need for a central, ‘whole of river’ approach, and the difficulties of implementing this approach locally. These case studies also suggest solutions, including the adoption of Indigenous perspectives, benefits to incentivise local actors and a historical education strategy to increase appetite for more sustainable flood risk mitigation.