During December 2010 and January 2011 many regions of Australia suffered major flooding. Flood waters affected several of Queensland’s coastal cities; a multitude of inland towns in Queensland, NSW, Victoria and Tasmania; and numerous rural farming and mining properties. The massive scale of this flood event has led to the fifth most costly natural disaster affecting Australia since 1967. The worst affected state, Queensland, had 58,600 insurance claims which topped $2.4 billion in insured losses. Many of these costs were due to inadequacies in Australian residential building practices which leave houses vulnerable to damage and possible structural failure when exposed to floodwaters. Proposed changes to these practices recommend new construction follows development controls including floor heights above expected flood levels, and the use of flood-resistant building materials and secure footing systems. However, controls are not retrospective and therefore do not decrease the flood risk to existing buildings or significantly reduce residual community risk.

This project investigated how flood actions affect buildings differently depending on elevation, structural shape, building materials, water transferability, and surrounding structures and terrain. By identifying a building’s specific vulnerabilities to different flood impacts, appropriate measures can be taken to reduce the future likelihood of their occurrence. This fact sheet synthesises information on flood impacts on buildings, addressing flood risk to new and existing structures, and recommendations for structure design.

This photo “Flood in Gympie” is copyright ©1989 Brian Yap and made available under an Attribution-Noncommercial-Share Alike 2.0 license