Flooding within the Hawkesbury-Nepean River floodplain is complex, due to its large catchment area and confined sandstone gorges that serve as “choke points” resulting in large differences in flood levels between events.

An update to the Hawkesbury-Nepean Flood Study has been in development since 2020. As one of the largest flood studies currently being undertaken in NSW, it uses state of the art technical approaches to define the flood risk throughout the floodplain and builds upon the 2019 Hawkesbury-Nepean Regional Flood Study.

The seminar will provide an overview of the development of the updated Hawkesbury-Nepean River Flood Study, with a particular focus on Western Sydney. The overview will cover the overall approach and key characteristics of the floodplain.

The seminar will also cover the recent March 2021 and March 2022 events. This will include an overview of the events themselves, how they informed the development of the flood study, and key technical learnings from these events.

The recent flooding in March 2021 and again in March 2022 have provided renewed focus on the flood risk within Western Sydney in the Hawkesbury-Nepean River Floodplain. Understanding this risk, and the potential influence on communities in the floodplain, has been a key component of the Hawkesbury-Nepean Flood Strategy.

As part of this overall strategy, an update of the 2019 flood study has been in development since 2020. The March 2021 event in particular provided a unique opportunity to verify the modelling that was undertaken, using extensive data that was collected throughout the event.

The seminar will:

  • Provide a general overview of the Hawkesbury-Nepean flood study, and the general behaviour of flooding within the floodplain
  • Review some of the key characteristics of the floodplain that make the Hawkesbury-Nepean River unique
  • Provide an overview of the March 2021 event, and how this has informed the study, and how the more recent March 2022 event is being considered. This will include an overview of the events themselves, as well as how these events sit within the historical flood record and predicted flooding.

Event Date Time: 27 / 06 / 2022 06:00 pm–07:30 pm
Register at: https://www.engineersaustralia.org.au/event/2022/05/how-recent-floods-have-informed-one-australia%E2%80%99s-largest-studies-42666


Rhys Thomson
Director, Rhelm

Rhys is an engineer and economist with Rhelm, with significant experience in floodplain management. He has been involved in the preparation of numerous flood related projects throughout Australia, as well as the wider Asia Pacific.

Rhys has authored over 30 papers in national and international conferences, and was a key author of several chapters in Australian Rainfall and Runoff.

David Tetley
Director, Catchment Simulation Solutions

David is a civil engineer and Director of Catchment Simulation Solutions. He has over 20 years of experience in hydrologic and hydraulic modelling and leads Catchment Simulation Solutions’ flood modelling team in Sydney. He has been involved in the preparation of approximately 40 Government funded flood studies and floodplain risk management studies in addition to numerous site-specific flood studies and flood impact assessments. He has also authored several papers on hydrology, hydraulics and floodplain management and was a member of the consultant’s reference group involved in the update of the Floodplain Risk Management Manual.