RFI - Attachment 7A - Response to Bushfire Issues and BMP.pdf

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Table 3: - Noosa Springs - Minimum Distance Calculator - AS3959-2018 (Method 2)
Calculated October 9, 2020, 4:49 pm (MDc v.4.8)

             Inputs                                                  Outputs
 Fire Danger Index  48                  Rate of spread                            1.75 km/h
 Vegetation              Forest         Flame length                              14.28 m
 classification
 Surface fuel load       17.5 t/ha      Flame angle                               54 °, 64 °, 72 °, 76 °,
                                                                                  78 ° & 83 °
 Overall fuel load       24.2 t/ha      Elevation of receiver                     5.57 m, 6.14 m, 6.39
                                                                                  m, 6.36 m, 6.31 m &
                                                                                  5.47 m
 Vegetation height       n/a            Fire intensity                            21,888 kW/m
 Effective slope         8°             Transmissivity                            0.872, 0.854, 0.828,
                                                                                  0.803, 0.79 & 0.728
 Site slope              1°             Viewfactor                                0.599, 0.4456, 0.3007,
                                                                                  0.2045,    0.1663   &
                                                                                  0.0451
 Flame width             100 m          Minimum distance to < 40 kW/m²            11.7 m


 Windspeed               n/a            Minimum          distance to <       29   15.7 m
                                        kW/m²
 Heat of combustion      18,600         Minimum distance to < 19 kW/m²            23 m
                         kJ/kg
 Flame temperature       1,090 K        Minimum distance to < 12.5 kW/m²          32.4 m

                                        Minimum distance to < 10 kW/m²            38.4 m

Rate of Spread - McArthur, 1973 & Noble et al., 1980
Flame length - NSW Rural Fire Service, 2001 & Noble et al., 1980
Elevation of receiver - Douglas & Tan, 2005
Flame angle - Douglas & Tan, 2005
Radiant heat flux - Drysdale, 1999, Sullivan et al., 2003, Douglas & Tan, 2005

The setback distance required to achieve a radiant heat flux of less than 29kW/m2 is 15.7m
from the potentially hazardous vegetation to the north. Figure 5 below designates the setback
edge of hazardous vegetation where the distance to the proposed building is 21.9m from the
north-eastern most corner, and 24.4m from the north-western most corner. This will achieve
a Radiant Heat Flux within 19-29kW/m2 which is within the sates acceptable level of risk.
Compliance with AS3959-2018 for a Class 3 Structure will be required.




Bushfire Management Plan | Noosa Springs | RFA17-040                                        24 September 2021

                                     Rob Friend & Associates Pty Ltd