Canberra Bushfires 2003 & Ember Protection
On the 8th January 2003 in Canberra, with temperatures around 370C, low humidity and strong gusty winds, lightning strikes caused multiple bushfires to break out in the Kosciuszko and Namadgi National Parks surrounding Canberra.
By the 18th January these fires combined to create a 25 km fire front and with wind gusts of up to 65 km/h, the fire raged towards the outer suburbs of Duffy at around 3pm on that afternoon.
Four people lost their lives, more than 500 houses were lost, 5,000 people were evacuated and more than 160,000 ha of area was burnt.
The following link to a video on you tube made on that day, while long shows the ferocity of a bushfire. Take particular note of the ember attack (around the 12 minute mark) as opposed to the direct flame impact. Also note that the time was mid afternoon during the video, it was not night time.
An investigation of the Duffy fire ground found that whilst no houses were directly impacted by flames, 219 houses were lost. 50% of the houses were affected by ember attack only, and 35% were via embers and radiant heat from surrounding vegetation of other structures adjoining.
The review highlighted that elements such as timer decks, eave fascia & gutters, exposed beams, timber window & door frames, and external cladding were critical entry points for ember ignition. This reinforces the importance of ember protection, even in low risk areas.
The best way to minimise the risk of house loss through ember attack is to minimise the areas where debris and other flammable material accumulate, or embers can enter a house. If this cannot be done through design, then the use of gutter and valley guards, enclosing under decking, ensuring garage doors have ember traps installed etc. Use of metal fly screens will minimise the risk of melting and embers entering into houses. The use of construction standards specified in AS 3959-2009 are aimed to minimise ember attack impacts on houses in bushfire prone areas.
The video is confronting and I often ask people that haven’t experienced bush fires before to watch it. This is not to scare them but so they are a little more aware of the potential impacts a bushfire can have.
What have been your experiences?
Please tell us your thoughts on the video or your experiences with bush fires in your areas.
We’ll review a few more of Australia’s historic bushfire events in the weeks to come. What happened, what we learned and how that has been implemented into policy to minimise the risk to people in bushfire prone areas.