Flood Risk Assessment & Design Life of Structures

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Rhys Thomson, Leo Drynan, James Ball, Mark Babister, Brett Phillips, Ailsa Veldema

Tuesday 30 june 2015

12:00 - 12:15h at South America (level 0)

Themes: (T) Flood risk management and adaptation, (ST) Flood risk assessment

Parallel session: 5J. Floodrisk - Assessment

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Design criteria for flooding infrastructure vary considerably across the globe. The adopted standard within a local, state or national government may differ based on extent of flooding, historical practices, and risk preference. Many countries are shifting towards adopting risk assessment as the basis of determining appropriate level of flood protection. However, it is increasingly recognised that climate change, changes in land-use and development as well as other non-stationary factors have the potential to alter the flooding risks suffered by a project over the course of its operational life, bringing into question the legitimacy of design criteria based on current risk levels as an appropriate methodology. As a part of the revision of Australian Rainfall and Runoff, this study provides a review of current practice in regards to the establishment of design criteria, specifically focussing on identifying how both stationary and non-stationary risk elements are considered in this process. Based on adoption of a project’s Effective Service Life (i.e. the total period an asset remains in use, regardless of its Design Service Life), the study provides a potential risk assessment framework by which design criteria can incorporate both stationary and non-stationary risks that reflect the local context of a project and the associated risk profile of proponents and determining authorities.