Bushfire Risk Assessment and Bushfire Risk Management Plan

Bushfire Risk Assessmentand

Bushfire Risk Management Planfor

12-14 Clearview Court, Buderim

Lot 606 on RP805273

Revision 1

Ecological Natural Area Management

April 2015

E c o l o g i c a l N a t u r a l A r e a M a n a g e m e n t

Document details

Author details

The author of this bushfire risk assessment and bushfire risk management plan is Adrian Hansen, proprietor of Ecological Natural Area Management. Note that the author is a Fire Protection Association of Australia Accredited Practitioner Level 3 in Bushfire Planning and Design.

Please see Appendix 3: Qualifications and experience of the author on page 28 of this report for demonstration that Adrian Hansen is “a competent person [and] is an appropriately qualified and experienced consultant with appropriate and proven technical expertise in the preparation of bushfire hazard assessment reports”.

Document history

Revision Date Reviewed

Revision 1 16 October 2015 Adrian Hansen

Document certification

16 October 2015……………

Adrian Hansen Date

Bushfire Risk Assessment and Management Plan – 12-14 Clearview Court, Buderim October 2015

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Table of Contents1 Executive Summary.............................................................................................................................5

2 Introduction...........................................................................................................................................82.1 The reasons for the Bushfire Risk Assessment and Management Plan....................................82.2 Commissioning of the Bushfire Risk Assessment and Management Plan.................................82.3 The aim of the Bushfire Risk Assessment and Management Plan............................................82.4 Legislative considerations..........................................................................................................82.5 Other regulatory considerations.................................................................................................8

3 Site description....................................................................................................................................93.1 Location......................................................................................................................................93.2 Zoning.......................................................................................................................................103.3 Building Code of Australia building class..................................................................................103.4 Applicable development codes.................................................................................................103.5 Topography...............................................................................................................................103.6 Assessed Bushfire Status.........................................................................................................103.7 Area of the lot...........................................................................................................................103.8 Assessment criteria..................................................................................................................103.9 Climate.....................................................................................................................................10

4 Site vegetation....................................................................................................................................114.1 Site aerial photo........................................................................................................................114.2 Mapped Remnant Regional Ecosystems.................................................................................124.3 Visually assessed vegetation communities .............................................................................134.4 Map of visually assessed vegetation communities..................................................................14

5 Conservation significance of the vegetation...................................................................................155.1 Enhanced conservation significance of the Remnant Regional Ecosystems derived from the Queensland Vegetation Act...............................................................................................................155.2 Enhanced conservation significance of the vegetation derived from the Sunshine Coast Planning Scheme 2014.....................................................................................................................15

6 Bushfire risk assessment..................................................................................................................166.1 Assessment of the Severity of the Bushfire Hazard using the protocol of Planning scheme policy for the bushfire hazard overlay code.......................................................................................166.2 Tabulation of the Severity of the Bushfire Hazard....................................................................176.3 Assessment of the Bushfire Attack Level using the Method 2 protocol of Australian Standard AS3959..............................................................................................................................................186.4 Modelled bushfire attacks.........................................................................................................186.5 Bushfire parameters used in the bushfire behaviour modelling of the west bushfire attack....186.6 Results of bushfire attack modelling.........................................................................................19

7 Bushfire risk management solutions and recommendations.......................................................207.1 Bushfire hazard mitigation recommendations: Legislative drivers...........................................207.2 Bushfire risk mitigation recommendations to address the requirements of Sunshine Coast Planning Scheme: Bushfire Hazard Overlay Code...........................................................................207.3 Recommendations in respect of Part E: Natural hazards of the Queensland State Planning Policy 2014........................................................................................................................................217.4 Bushfire mitigation recommendations in respect of the assessed bushfire attack level (BAL)217.5 Recommendations in respect of siting, landscaping etc..........................................................22


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7.6 Recommendations in respect of lodgement points for burning debris.....................................227.7 Recommendations in respect of on-going management of the buildings and landscaping.....237.8 Recommendations in respect of vegetation clearing...............................................................24

8 References..........................................................................................................................................25

9 Appendices.........................................................................................................................................269.1 Appendix 1: Regional Ecosystem full descriptions...................................................................269.2 Appendix 2: Software report from the bushfire behaviour modelling.......................................279.3 Appendix 3: Qualifications and experience of the author.........................................................28

List of FiguresFigure 1: Proposed site plan......................................................................................................................9

Figure 2: Aerial photograph showing Lot configuration, location of the house in the lot, nearby native vegetation, suburban areas, 5 m contours and watercourses.................................................................11

Figure 3: Map of the Queensland Vegetation Management Act conservation status of the mapped Remnant regional Ecosystems on and contiguous with the lot................................................................12

Figure 4: View of batter batter west of the built up area of the building block showing low weed growth and does not have features of native forest.............................................................................................13

Figure 5: View of the built up area of the building block across to the rear batter...................................13

Figure 6: View of the open forest vegetation community west of the lot..................................................13

Figure 7: Map showing the locations of the visually assessed vegetation communities.........................14

Figure 8: Map of the areas in the lot and contiguous areas with enhanced conservation significance as they are mapped as Native Vegetation areas or Waterway Buffer for a Stream Order 1-2.....................15

Figure 9: Diagram showing the methodology to create a bushfire resistant buffer zone around the house..................................................................................................................................................................22

Figure 10: Methodologies for minimising the lodgement points for burning debris around the house....22

Figure 11: Map showing the area recommended for bushfire risk mitigation in this plan. (Highlighted in orange).....................................................................................................................................................24

List of TablesTable 1: Regional Ecosystems near the lot..............................................................................................12

Table 2: Conservation significance of the Remnant Regional Ecosystems derived from the Queensland Vegetation Act..........................................................................................................................................15

Table 3: Assessment of the severity of the bushfire Hazard on the lot and on contiguous lots...............17

Table 4: Assessed Bushfire Attack Levels (BAL) for the modelled bushfire attacks................................19


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1 Executive SummaryIntroduction

The location of a house, proposed to be constructed at 12-14 Clearview Court, Buderim is mappedas being in an area of Medium Bushfire Hazard Buffer the on Sunshine Coast Plan 2014: Bushfire hazard Overlay Map OVM32D and is also mapped as being in an area of Potential High Bushfire Intensity Buffer on the Queensland State wide bushfire hazard mapping. Therefore, the location of the building is deemed to be in a Bushfire Prone Area and an assessment of the bushfire risk to thebuilding and a bushfire risk management solution is to be prepared.

Site specific assessment of the Severity of the Bushfire Hazard

A site specific assessment of the Severity of the Bushfire Hazard using the protocol of Sunshine Coast planning scheme 2014: Planning scheme policy for the bushfire hazard overlay code confirms that:

• The western end of the lot is assessed as being Medium Severity of the Bushfire Hazard,

• The proposed location of the house is assessed as being in a Medium Severity of the Bushfire Hazard

Assessment of Bushfire Prone Area status

The assessment of Medium Severity of the Bushfire Hazard confirms that:

• The location of the house is deemed to be a Bushfire Prone Area.

Assessment of the Bushfire Attack Level

The Bushfire Attack Level (BAL) using the the Method 2 protocol of Australian Standard AS3959 (2009) Construction of buildings in bushfire prone areas using bushfire behaviour modelling was assessed as:

• Bushfire Threat Category: MODERATE

• Bushfire Attack Level: BAL 19

Recommendations

Recommendations in respect of Sunshine Coast Planning Scheme 2014

These recommendations are based on Self Assessable development of a single dwelling house and that the level of bushfire hazard shown on the Bushfire Hazard Overlay Map is confirmed as Medium Severity of the Bushfire Hazard through the preparation of a site-specific bushfire hazard assessment under the requirements of the Sunshine Coast Planning Scheme: Bushfire Hazard Overlay Code.

It is recommended that:

• The requirements or fire fighting have been met as the premises are connected to the reticulated water supply infrastructure network for fire fighting purposes,

• 375m2 of additional clearing of vegetation mapped as Native Vegetation or Remnant Regional Ecosystem needs to be conducted to achieve the bushfire risk mitigation recommendations in this bushfire risk management plan,

(Note: See Section 7.8: Recommendations in respect of vegetation clearing on page 24 of this report for the specific clearing recommendations and demonstration that this level of vegetation clearing is acceptable under the requirements of Sunshine Council planning Scheme 2014 Biodiversity Overlay Code and Queensland vegetation Management Act)


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• It is sited in a location of low hazard in the lot,

• It achieves setbacks of greater than 1.5 times the height of the predominant vegetation,

• It is greater than 10 m from retained vegetation strips,

• The location maximises setbacks from hazardous vegetation and,

• there is efficient emergency access to the building or fire fighting purposes.

Recommendations in respect of part E: Natural hazards of the Queensland State Planning Policy 2014

It is recommended that, even though the proposed building location is in an area of Potential Bushfire Hazard:

• The building siting, construction, firefighting resources etc outlined in Section 7.2 appropriately mitigates the potential bushfire Hazard as required by Part E: Natural Hazards of the SPP

• The development does not unduly burden emergency services as there is good access for firefighting appliances, good fire fighting space, good water supply and contributes only oneextra building in the emergency services area

• The building and the cleared and hard-standing areas significantly decreases the severity of a bushfire on the lot and therefore does not increase severity of the bushfire Hazard as required by Part E: Natural Hazards of the SPP

• There will be no hazardous material stored on the lot

• the development does not impinge on a natural waterway and the vegetation associated with the natural waterway and therefore maintains the protective function of landforms and vegetation to mitigate the risks associated with the natural Hazard and maintains biodiversity values.

Recommendations in respect of Australian Standard AS3959 (2009)


• The building solution to address the Deemed to Satisfy requirements of Sections 3 and 6 of Australian Standard AS3959 -2009: Construction of buildings in bushfire-prone areas

Other recommendations in respect of building siting, landscaping etc


• The building to have a bushfire fuel free zone around the house. See Section 7.5 : Recommendations in respect of siting, landscaping on page 22 of this report.


• The building be constructed with a minimum of lodgement points for burning debris. See Section 7.7 : Recommendations in respect of lodgement points for burning debris on page 22 of this report.


• On-going maintenance of the building be conducted. (See Section 7.8 : Recommendationsin respect of on-going management of the buildings on page 23 of this report)


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375m2 of additional clearing of vegetation mapped as Native Vegetation needs to be conducted to achieve the bushfire risk mitigation recommendations in this bushfire risk management plan.

The recommended vegetation clearing includes:

• Removal of the two medium sized Corymbia intermedia trees at the top of the batter in the area identified for house construction,

• Clearing and mowing the low growing herbaceous species, mainly weed species, along the batter and at the base of the batter.

Note:

The large Corymbia intermedia tree at the base of the batter can be left in-situ as long as the herbaceous weeds underneath it are cleared and mown so that the tree is not involved in any bushfire behaviour.

This level of vegetation clearing is acceptable under the Sunshine Coast Planning scheme 2014 Biodiversity Overlay Code as it is:

• Less than 600m2,

See Figure 9 on page x of this report which shows the areas recommended for bushfire risk mitigation in this plan.


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2 Introduction

2.1 The reasons for the Bushfire Risk Assessment and Management Plan

The location of a house, proposed to be constructed at 12-14 Clearview Court, Buderim is mappedas being in an area of Medium Bushfire Hazard Buffer the on Sunshine Coast Plan 2014: Bushfire hazard Overlay Map OVM32D and is also mapped as being in an area of Potential High Bushfire Intensity Buffer on the Queensland State wide bushfire hazard mapping. Therefore, the location of the building is deemed to be in a Bushfire Prone Area and an assessment of the bushfire risk to thebuilding and a bushfire risk management solution is to be prepared.

2.2 Commissioning of the Bushfire Risk Assessment and Management Plan

Ecological Natural Area Management has been commissioned to prepare a Bushfire Risk Assessment and Bushfire Risk Management Plan to fulfil the above requirements. See Appendix 3 for demonstration that the author is a “qualified and experienced consultant with appropriate and proven technical expertise in the preparation of bushfire hazard assessment reports and management plans”.

2.3 The aim of the Bushfire Risk Assessment and Management Plan

The aim of this bushfire impact assessment report is to achieve appropriate levels of bushfire protection for the developed properties while maintaining ecological sustainability.

Bushfire protection for buildings in bushfire prone areas is best achieved using a mix of:

• Fire resistant building technologies in the structures.

• Fire resistant methodologies in the structures such as minimising ember lodgement points

• Providing and appropriate fire break between the developed properties and flammable vegetation.

• Appropriate building siting for bushfire protection

• Fuel management in the flammable vegetation near the developed properties while maintaining ecological values of the vegetation habitat.

• Fuel management between the flammable vegetation and the developed properties.

• Maintenance of ecological and habitat values of any vegetation subject to vegetation management for bushfire risk management.

To achieve the aim, the Plan will conduct bushfire assessments against the applicable legislative requirements and make recommendations that address the requirements of these legislative instruments.

2.4 Legislative considerations

• Queensland Sustainable Planning Act,

• Queensland Vegetation Management Act,

• Sunshine Coast Planning Scheme 2014: Bushfire Hazard Overlay Code,

• Sunshine Coast Planning Scheme 2014: Planning scheme policy for the bushfire hazard overlay code

2.5 Other regulatory considerations

• The Building Code of Australia: Volume 2 and

• Australian Standard™ AS 3959—2009: Construction of buildings in bushfire-prone areas.


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3 Site description3.1 Location

The site, described as Lot 606 on RP805273 is situated at 12-14 Clearview Court, Buderim in the Sunshine Coast Regional Council jurisdiction.


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Figure 1: Proposed site plan


3.2 Zoning

The Zoning Class of the site is Medium Density Residential Zone on the Sunshine Coast Planning Scheme 2014: Zone map ZM32.

3.3 Building Code of Australia building class

The building is a Class 1a building under the Building Code of Australia. That is: a detached house.

3.4 Applicable development codes

Development codes addressed in this report are:

• Sunshine Coast Planning Scheme 2014: Bushfire Hazard overlay code,

• Sunshine Coast Planning Scheme 2014: Biodiversity and wetlands overlay code.

3.5 Topography

Site topography is “Rolling hills”: 10% to 20% slope.

3.6 Assessed Bushfire Status

The location of a house, proposed to be constructed at 14 Dawson Parade, Buderim is mapped as being in an area of:

• Medium Bushfire Hazard Buffer the on Sunshine Coast Plan 2014: Bushfire hazard OverlayMap OVM32D and

• Potential High Bushfire Intensity Buffer on the Queensland State wide bushfire hazard mapping.

3.7 Area of the lot

The Lot area = 1,472m2.

3.8 Assessment criteria

This development is subject to Self Assessment.

3.9 Climate

The climate is subtropical. That is, the area is influenced by monsoonal climate systems in summerbut also from temperate climate systems in winter. Mean rainfall is approximately 1500.mm per year. (Bureau of Meteorology, 2004) The “wet” season runs from December to April.

Severe bushfire weather can occur. This is characterised by:

• Dry windy days

• Winds north to north west for 2-4 days

• Temperatures 350C or over

These conditions occur from September to December; worst month, November. (Webster J, 2000)


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4 Site vegetation4.1 Site aerial photo

Aerial photography indicates that there is considerable native forest vegetation to the south and west of the proposed house with roads and suburban areas to the north. Figure 2 below shows the proposed house location in relation to native vegetation.


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Figure 2: Aerial photograph showing Lot configuration, location of the house in the lot, nearby native vegetation, suburban areas, 5 m contours and watercourses


4.2 Mapped Remnant Regional Ecosystems

Large areas of the vegetation near the lot shown Figure 2 on the previous page has been mapped as Remnant Regional Ecosystems.

Table 1: Regional Ecosystems near the lot

Regional Ecosystem Description

RE 12.9-10.7a Eucalyptus siderophloia, Corymbia intermedia +/- E. tereticornis and Lophostemon confertus open forest on sedimentary rocks

Non-remnant Vegetation that has species representative of the Remnant Regional Ecosystems but does not meet all of the criteria of Remnant Regional Ecosystem

(Source: Department of Environment and Heritage Protection, 2014) See Appendix 1 for the full descriptions of these Regional Ecosystems.


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Figure 3: Map of the Queensland Vegetation Management Act conservation status of the mapped Remnant regional Ecosystems on and contiguous with the lot


4.3 Visually assessed vegetation communities

The vegetation on the lot and contiguous areas was visually assessed. The vegetation is confirmedas Eucalyptus siderophloia, Corymbia intermedia open forest which concurs with the the Remnant Regional Ecosystem mapping. The lot has been levelled with a large amount of fill material and a retaining wall to be installed which has produced a tall, steep batter. This batter will afford vertical separation of the house from the hazard as well as shielding some of the house from the radiant heat surface of a bushfire flame.


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Figure 4: View of batter batter west of the built up area of the building block showing low weed growth and does not have features of native forest

Figure 5: View of the built up area of the building block across to the rear batter

Figure 6: View of the open forest vegetation community west of the lot


4.4 Map of visually assessed vegetation communities

Based on the visual assessment of the vegetation shown in the photographs on the previous page,inspection of the NearMap aerial photograph and field verification, the map below shows the locations of the visually assessed vegetation communities. The visually assessed vegetation communities are:

• Eucalyptus siderophloia, Corymbia intermedia open forest (height of the canopy = 15 m),

• An area along the batter as mainly low growing herbaceous weed species without the features associated with native open forest vegetation (see 4 above) and

• Suburban areas with roads, houses and gardens etc

These visually assessed vegetation communities will be used for subsequent bushfire risk assessments in this report.


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Figure 7: Map showing the locations of the visually assessed vegetation communities


5 Conservation significance of the vegetation

5.1 Enhanced conservation significance of the Remnant Regional Ecosystems derived from the Queensland Vegetation Act

Some of the vegetation on the lot derives enhanced conservation significance from the Queensland Vegetation Act as it is mapped as Remnant Regional Ecosystem.

Table 2: Conservation significance of the Remnant Regional Ecosystems derived from the Queensland Vegetation Act

RegionalEcosystem

Regional Ecosystem short description VMA conservationclass

VMA biodiversitystatus

RE 12.9-10.7a Eucalyptus siderophloia, Corymbia intermedia +/- E. tereticornis and Lophostemon confertus open forest on sedimentary rocks

Of concern Of concern

5.2 Enhanced conservation significance of the vegetation derived from the Sunshine Coast Planning Scheme 2014

Some of the vegetation on the lot derives enhanced conservation significance from the Sunshine Coast Planning Scheme 2014 as it is mapped as:

• A Native Vegetation Area on the Biodiversity, Waterways and Wetlands Overlay Map (i)


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Figure 8: Map of the areas in the lot and contiguous areas with enhanced conservation significance as they are mapped as Native Vegetation areas or Waterway Buffer for a Stream Order 1-2.


6 Bushfire risk assessmentAs the house location is mapped as as being in an area of Medium Bushfire hazard the on Sunshine Coast Planning Scheme Bushfire hazard Overlay Map OVM32D, this report will detail bushfire hazard assessments against:

• Sunshine Coast Planning Scheme - Bushfire Hazard Overlay Code,

• Sunshine Coast Planning Scheme: Planning scheme policy for the bushfire hazard overlay code and

• Australian Standard™ AS 3959 as referenced by The Building Code of Australia: Volume 2

6.1 Assessment of the Severity of the Bushfire Hazard using the protocol of Planning scheme policy for the bushfire hazard overlay code

This section is a site specific bushfire Hazard assessment using the protocol of Sunshine Coast planning scheme 2014: Planning scheme policy for the bushfire Hazard overlay code.

The methodology uses “loadings” to assess the threat. The loadings are based on:

1. Vegetation community

The vegetation community influences bushfire behaviour and thus parameters such as bushfire rate of spread, bushfire intensity, flame length etc. Eg grass fire vs forest fire. The vegetation communities used for the assessment are based on the visual assessed vegetation shown on Figure 7 on page 14 of this report.

2. Slope in the vegetation

Slope influences the forward rate of spread and therefore, the intensity of a bushfire, for example bushfires travel faster up slope, increasing bushfire intensity and more slowly down slope, decreasing intensity.

3. Aspect

Aspect influences bushfire intensity through the bushfire fuel being drier on a northerly aspect than a southerly aspect allowing a greater proportion of the heat release rate of the bushfire fuel being available for bushfire intensity. In addition, north westerly aspects provide an increased slope for a bushfire coming from the normal direction of severe bushfire weather (Webster, 2000) so has a greater impact on the bushfire threat to a community,

4. Disaggregation

Each component of the landscape needs to be disaggregated and assessed individually,

5. Buffers

If an area of the bushfire hazard is assessed as Medium Severity of the Bushfire Hazard, a buffer area extends out 50m from the edge of the hazard which also has Medium Severity of the Bushfire Hazard or if an area of the bushfire hazard is assessed as High Severity of the Bushfire Hazard, a buffer area extends out 100m from the edge of the hazard which also has High Severity of the Bushfire Hazard.

6. Fragmentation of the bushfire hazard

The planning scheme policy recognises that bushfires will not generally reach their full intensity where bushfire fronts [are] narrow strips of vegetation [or] units of vegetation are less than 50 hectares in area” and this may allow for a reduction in the assessed severity ofthe bushfire Hazard.


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6.2 Tabulation of the Severity of the Bushfire Hazard

The assessment of the Severity of the Bushfire Hazard on the lot and on contiguous lots using the protocol of Sunshine Coast Planning Scheme 2014: 6.1 Planning scheme policy for the bushfire hazard overlay code is tabulated in table 3 below.

Table 3: Assessment of the severity of the bushfire Hazard on the lot and on contiguous lotsVegetation Community Hazard Score for

impacting vegetationHazard Score for

slope in thevegetation

Hazard Scorefor aspect in the

vegetation

Sum of HazardScores

Severity of the Bushfirehazard of vegetation

Eucalyptus siderophloia,Corymbia intermedia

open forestAspect west to south

6eucalypt forest with dry-shrub ladder ladder fuelsReduced 1 level from 8to 6 as the hazardous

vegetation <50ha in area

3Rolling Hills

10% to 20% slope

2West to south

11 Medium

Suburban areasAspect west to south

2Grazed grasslands

2Rolling Hills

10% to 20% slope

2West to south

6 Low

Note:

Areas assessed as Medium Severity of the Bushfire Hazard have a 50m buffer extending from the edge of the hazard which is also considered to be Medium Severity of the Bushfire Hazard.

From the above tabulation of the Severity of the bushfire Hazard and the required 50m buffer:

• The western end of the lot is assessed as Medium Severity of the Bushfire Hazard and

• The location of the proposed house is assessed as Medium Severity of the Bushfire Hazard

This confirms that the proposed house location is in a:

• Bushfire Prone Area

As the proposed house location is assessed as being in a Bushfire Prone Area, an assessment of the Bushfire Attack Level using the protocol of Australian Standard AS3959 (2009): Construction ofbuildings in bushfire prone areas is required as specified by the Queensland Building Act and the Building Code of Australia.

Subsequent sections of this report will assess the Bushfire Attack Level (BAL) using the Method 2 protocol Australian Standard AS3959 (2009).


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6.3 Assessment of the Bushfire Attack Level using the Method 2 protocol of Australian Standard AS3959

The Building Code of Australia references Australian Standard AS3959-2009: Construction of buildings in bushfire-prone areas for Deemed to Satisfy building requirements for bushfire risk management construction of buildings. This section assesses the Category of Bushfire Attack and an equivalent construction Bushfire Attack Level (BAL) for the proposed building using the Method 2 protocol of Australian Standard AS3959 -2009: Construction of buildings in bushfire-prone areas to determine a level of construction required to achieve the objective of the Standard which is to “prescribe particular construction details for buildings to reduce the risk of ignition from a bushfire while the fire front passes”. (Standards Australia, 2009). This report uses software developed by Newcastle Bushfire Consulting which models the Bushfire Attack Level using Method 2 of Australian Standard AS3959-2009.

6.4 Modelled bushfire attacks

The main potential direction for a bushfire attack is from the west. Accordingly, the west bushfire attack was modelled using Method 2 of Australian Standard™ AS 3959—2009: Construction of buildings in bushfire-prone areas. Bushfire attack parameter attenuation will be included in the bushfire attacks as:

• A shorter fire run as in this case precludes a bushfire reaching its full quasi-steady state rate of spread (Cheney & Gould, 1997) and bushfire attack attenuation with this rate of spread reduction will be incorporated in this BAL assessment with the modelling using the method of Tan (2006).

6.5 Bushfire parameters used in the bushfire behaviour modelling of the west bushfire attack

This modelled fire burns up-slope through Eucalyptus spp open forest to attack the building from the west.

Fuel loads used for the modelling are the “woodland” fuel loads of Australian Standard AS3959 (2009) of 15t/ha surface fuel & 25 t/ha total fuel.

Separation of the house from the hazard: 20m

Slope in the vegetation = 10.90.

Site slope = 27.70

Fire run = 450m which leads to a bushfire rate of spread of 0.76 of the full quasi-steady state rate of spread


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6.6 Results of bushfire attack modelling

The results of the bushfire attack modelling are tabulated in Table 4 below (see Appendix 2 for full software reports on the bushfire behaviour modelling). Note that the Forest Fire danger index used in the modelling was FFDI 50 as required by the Sunshine Coast Planning Scheme: Planning scheme policy for the bushfire hazard overlay code.

Table 4: Assessed Bushfire Attack Levels (BAL) for the modelled bushfire attacks

From Table 4 above the Bushfire Attack Level outputs from bushfire behaviour modelling are:

• Bushfire Threat Category: MODERATE

• Bushfire Attack Level: BAL 19

See Appendix 2 for a detailed software reports from which the above table was generated.


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Modelled bushfire attack

Modelled bushfire parameter West bushfire attackSeparation from the hazard 20Vegetation WoodlandModelled surface fuel load 15Modelled total fuel load 25Vegetation slope (degrees) 10.9Site slope (degrees) 27.5Fire run 450Proportion of QSS ROS 0.76QSS ROS 1.91 km/hRadiant heat 17.56Modelled rate of spread 1.45 km/hModelled fire line intensity 18729Modelled flame length 12.42Bushfire threat category MODERATELevel of construction (BAL) BAL 19

m

t/hat/ha0

0

m run

kW/m2

kW/mm


7 Bushfire risk management solutions and recommendations

7.1 Bushfire hazard mitigation recommendations: Legislative drivers

As shown above, the proposed house:

• Is located in an area mapped as being in an area of Medium Bushfire Hazard Buffer the on Sunshine Coast Plan 2014: Bushfire hazard Overlay Map OVM32D,

• Is located in an area mapped as being in an area of Potential High Bushfire Intensity Buffer on the Queensland State wide bushfire hazard mapping and

• Is in an area assessed as Medium Severity of the Bushfire Hazard as assessed using the protocol of Appendix SC6.7A Methodology for undertaking bushfire hazard assessment of the Sunshine Coast Planning Scheme: Planning scheme policy for the bushfire hazard overlay code

• Is confirmed as being in an area deemed to be a Bushfire Prone Area,

• Is assessed as being subject to a bushfire risk to the building of MODERATE and

• is assessed as having a building construction requirement of BAL 19.

Accordingly, this section will recommend bushfire mitigation requirements for the above assessments with reference to legislative requirements detailed in:

• Sunshine Coast Planning Scheme 2014: Bushfire Hazard Overlay Code and

• Australian Standard AS 3959, 2009 Construction of Buildings in Bushfire Prone Areas

• State Planning Policy 2014.

7.2 Bushfire risk mitigation recommendations to address the requirements of Sunshine Coast Planning Scheme: Bushfire Hazard Overlay Code

These recommendations are based on Self Assessable development of a single dwelling house and that the level of bushfire hazard shown on the Bushfire Hazard Overlay Map is confirmed as Medium Severity of the Bushfire Hazard through the preparation of a site-specific bushfire hazard assessment under the requirements of the Sunshine Coast Planning Scheme: Bushfire Hazard Overlay Code.


• The requirements or fire fighting have been met as the premises are connected to the reticulated water supply infrastructure network for fire fighting purposes,

• 375m2 of additional clearing of vegetation mapped as Native Vegetation or Remnant Regional Ecosystem needs to be conducted to achieve the bushfire risk mitigation recommendations in this bushfire risk management plan,

(Note: See Section 7.8: Recommendations in respect of vegetation clearing ob page 24 for the specific clearing recommendations and demonstration that this level of vegetation clearing is acceptable under the requirements of Sunshine Council planning Scheme 2014 Biodiversity Overlay Code and Queensland vegetation Management Act))

• The proposed house is sited in a location of low hazard in the lot,

• The proposed house achieves setbacks of greater than 1.5 times the height of the predominant vegetation,


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• The proposed house is greater than 10 m from retained vegetation strips,

• The proposed house location maximises setbacks from hazardous vegetation and,

• There is efficient emergency access to the building or fire fighting purposes.

7.3 Recommendations in respect of Part E: Natural hazards of the Queensland State Planning Policy 2014

It is recommended that, even though the proposed building location is in an area of Potential Bushfire Hazard:

• The building siting, construction, firefighting resources etc outlined in Section 7.2 above appropriately mitigates the potential bushfire Hazard as required by Part E: Natural Hazards of the SPP

• The development does not unduly burden emergency services as there is good access for firefighting appliances, good fire fighting space, good water supply and contributes only oneextra building in the emergency services area

• The buildings and the cleared and hardstanding areas significantly decreases the severity of a bushfire on the lot and therefore does not increase severity of the bushfire Hazard as required by Part E: Natural Hazards of the SPP

• There will be no hazardous material stored on the lot

• the development does not impinge on a natural waterway and the vegetation associated with the natural waterway and therefore maintains the protective function of landforms and vegetation to mitigate the risks associated with the natural Hazard and maintains biodiversity values.

7.4 Bushfire mitigation recommendations in respect of the assessed bushfire attack level (BAL)

Australian Standard AS3959 -2009: Construction of buildings in bushfire-prone areas specifies Deemed to Satisfy bushfire resistant methodologies based on the assessed Bushfire Attack Level.

The assessed Bushfire Attack Level = BAL 19

The Deemed to Satisfy construction building requirements for a BAL 12.5 are specified by:

• Sections 3 and 6 of Australian Standard AS3959 -2009: Construction of buildings in bushfire-prone areas


• The building solution address the Deemed to Satisfy requirements of Sections 3 and 6 of Australian Standard AS3959 -2009: Construction of buildings in bushfire-prone areas.


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7.5 Recommendations in respect of siting, landscaping etc

It is recommended that:the building to have a bushfire fuel free zone around the house. The fuel free zone to have no overhanging tree branches that can:

• Break off in the high winds associated with bushfire weather and damage property or causeinjury to residents or fire fighting personnel

• Be a lodgement point for wind blown burning debris from the fire front which can then drop burning debris onto the buildings

It is further recommended that landscaping around the building such as planting low, fire resistant shrubs or building permanent barriers such as low stone or masonry walls to:

• Create barriers which slow down and cool the fire front.

Such methodologies help to protect buildings from possible attack by burning debris, heat radiationand direct flame contact. See Figure 10 below for an example of the creation of a buffer zone.

7.6 Recommendations in respect of lodgement points for burning debris

The Queensland Fire and Rescue Service recommend that buildings be constructed with a minimum of lodgement points for burning debris.

(Source: Queensland Government, 2000)


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Figure 9: Diagram showing the methodology to create a bushfire resistant buffer zone around the house

Figure 10: Methodologies for minimising the lodgement points for burning debris around the house


7.7 Recommendations in respect of on-going management of the buildings and landscaping

On-going maintenance procedures will ensure that the buildings will maintain the highest levels of bushfire protection afforded by the siting, landscaping and construction recommendations in this report. Maintenance strategies include:

Cleaning the roof and gutters of all flammable material on a regular basis, especially in the lead up to the fire season

• Keeping the lawn buffer zone mown and watered

• Keeping the lawn buffer zone clear of all flammable material

• Clearing away any flammable material lodged against the structure

• Repairing and close any exposed lodgement points for burning debris

• Ensuring all painted surfaces are in good condition

• Maintaining drive ways

• Maintaining screens in good condition

• Maintaining roof in good condition

• Maintaining doors in good condition

• Keeping flammable material away from the buildings


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7.8 Recommendations in respect of vegetation clearing

375m2 of additional clearing of vegetation mapped as Native Vegetation needs to be conducted to achieve the bushfire risk mitigation recommendations in this bushfire risk management plan.

The recommended vegetation clearing includes:

• Removal of the two medium sized Corymbia intermedia trees at the top of the batter in the area identified for house construction,

• Clearing and mowing the low growing herbaceous species, mainly weed species, along the batter and at the base of the batter.

Note:

The large Corymbia intermedia tree at the base of the batter can be left in-situ as long as the herbaceous weeds underneath it are cleared and mown so that the tree is not involved in any bushfire behaviour.

This level of vegetation clearing is acceptable under the Sunshine Coast Planning scheme 2014 Biodiversity Overlay Code as it is:

• Less than 600m2,

The map below shows the areas recommended for bushfire risk mitigation in this plan.


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Figure 11: Map showing the area recommended for bushfire risk mitigation in this plan. (Highlighted in orange)


8 ReferencesCheney, N.P. and Gould, J.S. (1997). Letter to the editor – fire growth and acceleration. International Journal Wildland Fire 7(1):1-5

Couch, P, (2010). The Urban Fringe Under Pressure, in Proceedings of Fire Australia 2010, Fire Protection association of Australia, Melbourne.

Department of Environment and Heritage Protection, (2014). Regional ecosystem descriptions. Available from http://www.ehp.qld.gov.au/ecosystems/biodiversity/regional-ecosystems, accessedOctober 2015

Department of Environment and Heritage Protection, (2014). Regional Ecosystem Maps / Regrowth Vegetation Maps and PMAVs, Available from <http://www.ehp.qld.gov.au/ecosystems/biodiversity/regional-ecosystems/maps/index.php>, accessed October 2015

Sunshine Coast Council, (2014). Sunshine Coast planning scheme 2014, Sunshine Coast Council, Nambour, Queensland.

McCarthy, GJ, Tolhurst, KG & Chatto K, (1999), Overall Fuel Hazard Guide: 3rd Edition, Department of Natural Resources and Environment, Victoria

Queensland Government, (1994). Queensland Vegetation Management Act 2003, The Office of the Queensland Parliamentary Counsel, Brisbane, Queensland

Queensland Government, (2000). Protecting your home against bushfire attack, Queensland Government

Queensland Government, (2003). State planning policy 1/03 guideline: Mitigating the adverse impacts of flood, bushfire and landslide, Department of Local Government and Planning, Brisbane

Standards Australia, (2009). Australian Standard™ AS 3959-2009: Construction of buildings in bushfire-prone areas, Standards Australia, Sydney

Tan, Z, (2006). Effect of fire run distance on bushfire behaviour and its implications for bushfire hazard rating and prescription of asset protection zones, NSW Rural Fire Service Technical Paper002/2006, NSW Rural Fire Service, Sydney.

Webster J, (2000). The complete bushfire safety book, Random House Australia Pty Ltd, Milsons Point, NSW


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9 Appendices

9.1 Appendix 1: Regional Ecosystem full descriptions


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9.2 Appendix 2: Software report from the bushfire behaviour modelling


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9.3 Appendix 3: Qualifications and experience of the author

This appendix to demonstrate that the author is an “appropriately qualified and experienced consultant with appropriate and proven technical expertise in the preparation of bushfire hazard assessment reports and management plans” (Sunshine Coast Regional Council, 2014b).

Author: Adrian Hansen

Relevant qualifications:

• Graduate Diploma in Design for Bushfire Prone Areas

• Diploma in Community Natural Resource Management

• Certificate IV Applied Environmental Management

• Certificate II in Bush Regeneration (with distinction)

Relevant certifications:

• FPAA Accredited Practitioner Level 3 in Bushfire Planning and Design.

(See FPAA website (http://www.fpaa.com.au/bpad.aspx) for details of the certification)

Other relevant qualifications

• Certificate II in Public Safety (Fire fighting Operations)

• Certificate in Bushfire Management

• Certificates in Fire Fighting - Advanced skills & Crew leadership

• Certificate in Property Fire Management Planning

• Certificate in Fire and Biodiversity Monitoring

• Certificate in Regional Ecosystems Frameworks

• Bachelor of Applied Science (Majors in botany and ecology)

• Candidate for Queensland Fire and Emergency Services FBAN (Bushfire Behaviour Analyst)

• Nearing completion of Master of Environmental Science (focusing on fire, vegetation disturbance and restoration ecology).

Relevant experience:

• 10 years experience preparing bushfire risk assessments and bushfire risk management plans (Plans have included individual lots, sub-divisions, eco-cabins developments, schoolsetc including both deemed to satisfy and alternate solutions)

• 11 years experience in bush fire fighting

• 11 years experience in bushfire ecology (includes fire and biodiversity monitoring and ecological fire management plans for conservation areas)

• 12 years experience in natural resource management, ecology, ecological restoration, environmental management planning etc


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Documents

Bushfire Risk Assessment and Bushfire Risk Management Plan