Bushfire Report

                         Ecological Natural Area Management

North bushfire attack
This modelled fire burns up-slope through Notophyll Vine Forest to attack from the north.
   • Fuel loads used are the “Rainforest” fuel loads of Australian Standard AS3959 of 10t/ha
       surface fuel & 125t/ha total fuel.
•      Separation of the house from the hazard: 17m
   • Slope in the vegetation = 13.50
   • Site slope = 12.50
   • Fire run = 500m leading to a 0.78 reduction of the bushfire rate of spread from the full
       quasi-steady state ROS
7.6       Results of bushfire attack modelling
Table 3: Assessed Bushfire Attack Levels for the modelled bushfire attacks
                                                            Modelled bushfire attack
Modelled bushfire parameter                   South bushfire attack             North bushfire attack
Separation from the hazard                            30 m                               23 m
Vegetation                                    Rainforest                         Rainforest
Modelled surface fuel load                            10 t/ha                            10 t/ha
Modelled total fuel load                              12 t/ha                            12 t/ha
Vegetation slope (degrees)                          13.7 0                             13.5 0
Site slope (degrees)                                10.7 0                             12.5 0
Fire run                                          >1000 m run                           500 m run
Proportion of QSS ROS                               1.00                               0.78
QSS ROS                                             1.61 km/h                          1.58 km/h
Modelled rate of spread                             1.61 km/h                          1.23 km/h
Flame width                                          100 m                              100 m
Radiant heat                                       11.14 kW/m 2                       12.14 kW/m 2
Modelled fire line intensity                        9957 kW/m                          7626 kW/m
Modelled flame length                              11.88 m                             9.44 m
Level of construction (BAL)                     BAL 12.5                           BAL 12.5

From above the worst case Bushfire Attack Level from the bushfire behaviour modelling is BAL 12.5
See Appendix 2 for a detailed software reports from which the above table was generated.
7.7       Bushfire Attack Levels for each building elevation
Australian Standard AS3959 Construction of buildings in bushfire-prone areas specifies that the
building elevation opposite the assessed bushfire attack direction can be reduced on BAL level due
to shielding by the building but BAL 12.5 cannot be reduced further so the Bushfire Attack Levels
for each of the building elevations are:
      •    BAL 12.5 for all building elevation.
7.8       Assessment of vegetation clearing
No clearing of vegetation with conservation significance is required for bushfire risk mitigation in
this plan




Bushfire Risk Assessment and Management Plan for a house at 411 Black Pinch Rd, Cootharaba              December 2021

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