Natural Flood Management (NFM): Using all the geomorphological tools in the toolbox to achieve nature-based flood mitigation. - Part 2

The 2021-2022 floods across eastern Australia highlighted the vulnerability of rivers to changing climate extremes. They are the costliest natural disaster in Australia’s recorded history with insured losses of ~$6.41 billion, well ahead of the 2019-20 ‘black summer’ bushfires (ICA 2022). By 2050, Australia’s annual extreme weather cost is likely to be $32.5 billion (ICA, 2022).

The 2022 New South Wales (NSW) Government inquiry into the floods calls for implementation of “nature-based flood mitigation … using floodplains as assets … and letting watercourses largely flow naturally rather than implementing engineering barriers such as flood levees and mitigation schemes to stop floods” (O’Kane and Fuller, 2022). In this context we must urgently re-examine how to live with rivers and build nature-based flood mitigation capacity and resilience into them, to prepare for an inevitable future where floods are forecast to be more intense and extreme. So, how do we achieve this?

Natural Flood Management (NFM) uses natural processes to slow floods down, reduce their erosive power, and reduce flood risk. In this presentation Kirstie will describe how an understanding of geomorphic, vegetative and hydrological recovery can be used to determine the NFM potential of rivers and catchments. Kirstie will then consider how we realise NFM on-the-ground by using and applying all the nature-based tools we have in the toolbox to enhance river recovery and deliver flood mitigation to communities. Kirstie will use the 2021-2022 catastrophic floods in Eastern NSW as a case study to demonstrate the potential for delivering geomorphologically-informed NFM and river recovery in 21st Century river management (Fryirs et al., 2023).

Presenter: Professor Kirstie Fryirs, Macquarie University

Kirstie’s research focusses on how rivers work, how they have evolved, how they have been impacted by anthropogenic disturbance, and how to best use geomorphology in river management. Kirstie also researches how rivers and catchments may respond to future disturbances, particularly floods and droughts. Kirstie is probably best known as the co-developer of the River Styles Framework and professional short courses, and more recently delivery of microcredential courses for industry. Kirstie works in multi-disciplinary, collaborative teams that include ecologists, hydrologists, social scientists, industry practitioners and citizens. Kirstie has co-written three books and published over 150 journal papers. Kirstie is on the Specialist Environmental Advisory Committee (SEAC) for the Certified Environmental Practitioner (geomorphology) program. Kirstie is passionate about rivers, their health, their geodiversity and how to use best available science in conservation and rehabilitation practice.

Fryirs, K., Zhang, N., Ralph, T., Arash, A.M. 2023. Natural flood management: Lessons and opportunities from the catastrophic 2021-2022 floods in eastern Australia. Earth Surface Processes and Landforms. 48, 1649-1664. https://doi.org/10.1002/esp.5647

ICA (Insurance Council of Australia) 2022. Catastrophe Resilience Report. Available at: https://insurancecouncil.com.au/

O’Kane, M., Fuller, M. 2022. 2022 Flood Inquiry Volume One: Summary Report. 29th July 2022. New South Wales Government, Sydney. Available at: https://www.nsw.gov.au/nsw-government/projects-and-initiatives/floodinquiry