Growing Peri-Urban Developments Downstream of Farm Dams: Exploring How to Best Manage Increasing Dam Safety and Cumulative Flood Risks

Inadequately managed farm dams pose significant individual and cumulative threats that can cause considerable human, property, and environmental costs to growing downstream communities in a climate of increasing rainfalls and floods. Hence, ensuring adequate management of these structures that considers population growth downstream of dams—which can lead to hazard creep and a higher standard of requisite flood safety—is critical. We highlight the interrelated engineering, policy, responsibility, and cost sharing issues associated with the hidden farm dam hazard creep phenomenon. Key insights into the design of best practice integrated farm dam safety and land use planning policy are provided based on (1) review of policy and practice in Australia and internationally, underpinned by empirical comparative case study evidence, and (2) consideration of relevant theoretical principles and available low-cost flood safety review/design tools to help policy makers and stakeholders address the risk and cost sharing issues more equitably. The novel guidance and tools presented can help jurisdictions worldwide address the cumulative flood threats associated with farm dams and both existing and future downstream peri-urban land developments.