Attachment 5 - Bushfire Hazard Assessment & Management Plan

Bushfire Hazard Assessment & Management Plan v1                                  NCES REF: J000542
Lot 9 on RP225312 – 100 Cooyar Street, Noosa Heads



                  society will not accept this risk and measures are to be put in place to reduce
                  risks to at least a tolerable level.
Section 9.4 of the QFES Bushfire Resilient Communities 2019 references radiant heat flux
exposure of <10kW/m² on the development footprint plan as generating an Acceptable to
Tolerable level of risk for vulnerable uses.
AS/NZS ISO 31000:2018 defines ‘Likelihood’ as the chance that something might happen.
Likelihood can be defined, determined, or measured objectively or subjectively and can be
expressed either qualitatively or quantitatively (using mathematics). The following ‘likelihood’
categories for the probability of the assessed bushfire attack mechanisms impacting the
assessment area have been adopted within this assessment:
          Likely - Will probably occur
          Unlikely - Could occur but doubtful
The determination of whether a bushfire event is likely or unlikely to occur (i.e., impact the
site) has been based on the relative position of hazardous vegetation to the site. Hazardous
vegetation located upwind of the site under typical south-east Queensland (SEQ) seasonal
fire winds from the north to north-west to west to south-west are deemed to be exposed to a
‘likely’ probability of impact. Hazardous vegetation located downwind of the site under typical
SEQ seasonal fire winds are deemed to be exposed to an ‘unlikely’ probability of impact.

4.2       Risk from Identified Hazardous Vegetation
Hazardous vegetation is positioned to the north, south, and east of the development. The
likelihood of a fire head approaching from these directions is typically considered unlikely,
given dominant regional fire weather winds are typically derived from the north-west to west
to south-west in SEQ. A fire front being directed by such winds could be expected to burn
eastward away from the site with the site exposed to the flanks of any such fire front rather
than the fire head. Nonetheless fire movement and wind patterns during a fire can be
unpredictable and given the extent of bushland to the north, south and east of the site and
forecast increases in bushfire weather severity as a result of climate change, a conservative
approach should be adopted, and the Likelihood risk assigned as Likely meaning that a fire
impacting the site will probably occur at some time in the future.
The degree of separation offered to the adjoining vegetation is the primary driver of the
assigned level of consequential risk and was determined with consideration to the Flamesol
modelling output presented in Section 3.3.
The following minimum separation distances are required to the identified hazardous
vegetation to ensure the proposed development (edge of the building) is exposed to <10kW/m²
radiant heat flux as per the Flamesol modelling presented herein:
          47.1m to SUB UNIT 1 (VHC 22.1);
          38.4m to SUB UNIT 2 (VHC 29.2); and
          31.6m to SUB UNIT 3 (VHC 34.5).
Figure BF04 – Setback Requirements has been prepared to depict the position of the
<10kW/m2 RHF contour emanating from the edge of the NSC firebreak surrounding the site
vs. the footprint of the proposed development. The majority of the proposed development
occupies the existing building footprint with only the southern extent of the proposed building
extending slightly beyond the existing development footprint. The proposed development
footprint intercepts the vulnerable use <10kW/m2 RHF setback requirement/contour to the to
the south by a maximum of approximately 7.8m and to the east by a maximum of
approximately 6m. The proposed degree of separation therefore exposes the future building
to >10kW/m2 RHF to the east and south.
Consequently, further modelling was undertaken to identify the specific radiant heat flux acting
on the building to facilitate an assessment of the acceptability of the degree of encroachment.
The modelling (refer Appendix 4 for full transcripts) identified the proposed separation exposes
the building to:


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