A CSIRO report released into the Wye River and Separation Creek bushfires identifies ignition of extensive surface litter and domestic fuels within the township as the main contributors leading to house loss.
The review, commissioned by the CFA, identifies the factors that led to the loss of and damage to more than 100 houses and the survival of others following the bushfires on Christmas Day.
CSIRO experts conducted surveys of houses within the fire footprint from January 6-8 as part of the study which highlights a range of weaknesses in building design and materials, vegetation management and the storage of heavy fuels as the main factors impacting house loss.
Other key factors identified in the report as contributing to house loss include:
- No distinct border between the forest and urban areas of the township with widespread established tree coverage spread across residential properties
- Extensive surface litter provided a near continuous flammable fuel bed
- Ignition of heavy fuels such as plastic water tanks, building materials, small garden sheds, boats and kayaks stored under or adjacent to houses
- Strong evidence of house-to-house fire spread despite the generally large distances between buildings of up to 12m
- Timber retaining walls provided a direct threat to buildings and adjacent fuel elements
- Positioning and storage of LPG pressure vessels
Emergency Management Commissioner Craig Lapsley said the CSIRO report emphasised the life-threatening nature of the fire and the impact of fire on buildings and surrounding materials.
“The extensive number of houses that were on fire, combined with the terrain and fire behaviour created a high risk to life; to the residents, holiday-makers and firefighters in the area,’’ he said.
“Yes, there was considerable property loss but this report is a reminder of just how lucky we were that no-one was killed or seriously injured.
“There was no loss of life because the community heeded warnings to evacuate, they were highly organised and were able to manage the challenges; that’s the positive we can take from all of this.’’
Mr Lapsley said the report in finding that limitations in building design and materials contributed to house loss, reinforced the importance of constructing houses to Australian Standards.
“Building to Australian Standards provides a consistent national approach to assess fire behaviour and the design of houses to withstand the passage of fire, protect human life and build community resilience,’’ he said.
“What we can take from this report is the need to look holistically at a property. Building to the BAL rating is very important but these standards must extend to the surrounds of a property. Ongoing maintenance, vegetation management and the safe storage of outdoor furniture, building materials and water tanks are extremely practical, logical and achievable ways we can reduce risk.’’
Mr Lapsley said the CSIRO report would be shared with communities, agencies and planning authorities, as a learning tool for the future.
“The report provides a great case study that we can all learn from. These learnings are not just relevant to Wye River and Separation Creek; they apply to all bushfire areas in Victoria, across Australia and the world. We need to not only learn from this but take those learnings and turn them into actions,’’ he said.
“Fire is a natural part of our landscape, so the more prepared and resilient we are, the better we will recover.’’
Download the CSIRO report here.