bushfire protection assessment · assessment is prepared in accordance with section 100b of the...

T h e S c o t s C ol l e ge , 4 5 3 C ul b ur r a R o a d, W o l l um b o o la

BUSHFIRE PROTECTION ASSESSMENT

Proposed Dormitory

The Scots College, 453 Culburra Road, Wollumboola

Prepared for

Presbyterian Church (NSW) Property Trust

27 June 2013


© E CO LO G ICA L A U S T RA L IA P T Y LT D i

DOCUMENT TRACKING

ITEM DETAIL

Project Name Bushfire Protection Assessment, Proposed Dormitory – The Scots College, 453 Culburra Road, Wollumboola

Project Number 12SGBBUS-0125

Project Manager Julie Holden

Reviewed by David Peterson

Approved by David Peterson

Status FINAL

Version Number V2

Last saved on 27 June 2013

ACKNOWLEDGEMENTS

This document has been prepared by Eco Logical Australia Pty Ltd.

Disclaimer

This document may only be used for the purpose for which it was commissioned and in accordance with the contract between

Eco Logical Australia Pty Ltd and Presbyterian Church (NSW) Property Trust. The scope of services was defined in consultation

with Presbyterian Church (NSW) Property Trust, by time and budgetary constraints imposed by the client, and the availability of

reports and other data on the subject area. Changes to available information, legislation and schedules are made on an ongoing

basis and readers should obtain up to date information.

Eco Logical Australia Pty Ltd accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this

report and its supporting material by any third party. Information provided is not intended to be a substitute for site specific

assessment or legal advice in relation to any matter. Unauthorised use of this report in any form is prohibited.


© E CO LO G ICA L A U S T RA L IA P T Y LT D ii

Contents

List of Figures ............................................................................................................................................ iii

List of Tables ............................................................................................................................................. iii

1 Property and proposal ............................................................................................................. 1

1.1 Description of proposal ............................................................................................................ 1

1.2 Location and description of subject land ................................................................................. 1

2 Bushfire threat assessment ..................................................................................................... 5

2.1 Vegetation types and slope ..................................................................................................... 5

3 Asset Protection Zones (APZ) ................................................................................................. 6

4 APZ maintenance plan ............................................................................................................ 7

5 Construction standard ............................................................................................................. 7

6 Water supply ............................................................................................................................ 8

7 Gas and electrical supplies ...................................................................................................... 8

8 Access ..................................................................................................................................... 8

9 Assessment of environmental issues ...................................................................................... 9

10 Summary of protection provisions and conformity with PBP ................................................... 9

10.1 Conclusion ............................................................................................................................... 9

11 References ............................................................................................................................ 10

12 Photographs .......................................................................................................................... 11

Appendix A .............................................................................................................................................. 12


© E CO LO G ICA L A U S T RA L IA P T Y LT D iii

List of Figures

Figure 1: Location ...................................................................................................................................... 2

Figure 2: Bushfire hazard assessment ....................................................................................................... 3

Figure 3: Development proposal ................................................................................................................ 4

List of Tables

Table 1: Threat assessment, APZ and category of bushfire attack ........................................................... 6

Table 2: Assessment of conformity with PBP ............................................................................................ 9


© E CO LO G ICA L A U S T RA L IA P T Y LT D 1

1 Property and proposal

Name: Presbyterian Church (NSW) Property Trust

Postal address: C/- Allen Price & Associates

PO Box 73, Nowra NSW 2541

Street or property Name: 453 Culburra Road

Suburb, town or locality: Wollumboola Postcode: 2540

Lot/DP no: Lot 2 DP 1017929

Local Government Area: Shoalhaven City Council

Type of development: School dormitory (SFPP facility)

1.1 Descript ion of proposal

Presbyterian Church (NSW) Property Trust commissioned Eco Logical Australia Pty Ltd (ELA) to

prepare a bushfire protection assessment (BPA) for a proposed school dormitory at The Scots College,

453 Culburra Road, Wollumboola (hereafter referred to as the subject land). As the development is a

school dormitory, it is assessed as a Special Fire Protection Purpose Development.

This assessment has been prepared by the ELA Senior Bushfire Consultant, Julie Holden (FPAA

BPAD-A Certified Practitioner No. BPAD-PA-23572) with quality assurance review by David Peterson.

Both Julie and David are recognised by the NSW Rural Fire Service as qualified bushfire consultants in

bushfire risk assessment. The subject land was inspected on 26 April 2013.

1.2 Location and description of subject land

The subject land is located on the northern side of Culburra Road in the south coast locality of Culburra

as shown in Figure 1. Figure 2 shows the subject land and the location of the proposed dormitory in

relation to the nearest bush fire prone vegetation which is Blackbutt Forest to the east, and Casuarina

Forest fringed with mangroves and saltmarsh to the north on the Crookhaven River.



Figure 1: Location

Subject land



Figure 2: Bushfire hazard assessment



Figure 3: Development proposal

Lot 2 DP 1017929



2 Bushfire threat assessment

The subject land is identified as Bush Fire Prone Land by Shoalhaven City Council. The following

assessment is prepared in accordance with Section 100B of the Rural Fires Act 1997 and ‘Planning for Bush

Fire Protection’ (RFS 2006), herein referred to as PBP.

The use of the building is defined as Special Fire Protection Purpose (SFPP) as it is a school and

accordingly a Bush Fire Safety Authority from the NSW Rural Fire Service is required for the development.

The Authority is sought based on the details of this Bushfire Protection Assessment prepared in accordance

with Section 100B of the Rural Fires Act 1997, Clause 44 of the Rural Fires Regulation 2008, and the

‘Planning for Bushfire Protection Guidelines 2006’ document (NSWRFS 2006).

2.1 Vegetat ion types and slope

In accord with PBP the predominant vegetation class has been calculated for a distance of at least 140 m

out from the proposed dormitory and the slope class ‘most significantly affecting fire behaviour’ has been

determined for a distance of at least 100 m in all directions. The predominant vegetation and effective slope

assessments are shown in Table 1 (p. 6).

The site is characterised by a flat, cleared area where the development is proposed, bordered to the north

and north-west by a steep embankment which drops down to a strip of remnant vegetation along the

Crookhaven River. The riparian vegetation to the north is mangroves fringed with a 5-15 m wide strip of

Casuarina Forest below the embankment on 0-5 degree downslopes. This vegetation is classified as

‘rainforest’ by PBP in recognition of the reduced fire behaviour in the lineal strip.

The riparian vegetation to the north-west is mangroves fringed with a 30 m wide strip of Casuarina Forest

below the embankment on a 2 degree downslope. This vegetation is classified as ‘forested wetland’ by PBP.

On top of the embankment to the east is Blackbutt Forest on 0-5 degree downslopes, classified as ‘forest’ by

PBP.

To the west, the canopy trees of this Blackbutt Forest vegetation community remains, with a managed

understorey, classified as ‘forest’ by PBP. Managed grazing lands are in all other directions.



3 Asset Protection Zones (APZ)

Table A2.6 of PBP has been used to determine the width of Asset Protection Zones (APZ) for the proposed

development using the vegetation and slope data identified above and replicated in Table 1. The proposed

APZ are also shown in Table 1.

The Acceptable Solution APZ cannot be achieved to the north-west. The vegetation in this direction is on a

very slight downslope and is only 30 m wide therefore the NBC Bushfire Attack Assessor v2.1 was used to

conduct an alternate solution by calculating the required APZ to achieve no more than 10kW/m2

of radiant

heat at the building face based on these above specific parameters. This was achieved by using the actual

slope of 2 degrees (rather than the PBP slope class of 0-5 degrees which produces an APZ based on 5

degrees) and the maximum fire width that could be achieved through the corridor, being no more than 30 m.

The model input parameters of slope and flame width (fire front) was adjusted in the model to calculate the

alternate solution and achieve the minimum APZ. Table 1 below outlines the APZ calculations and the

model report is attached in Appendix A.

Table 1: Threat assessment, APZ and category of bushfire attack

Direction from

dormitory

Slope1 Vegetation2 PBP required

APZ3

10kW/m2 Modelled

APZ 4

Proposed APZ

AS3959 Construction

Standard5

Comment

North 0-5 0

downslope Rainforest (Remnant)

40 m --- 55 m BAL 12.5

APZ with subject land.

Riparian strip of vegetation 10-15 meters wide, so rainforest setback applied.

East 0-5 0

downslope Forest 70 m --- 80 m BAL 12.5 APZ with subject land

West 0-5 0

downslope Forest 70 m --- 70 m BAL 12.5

APZ extends over adjoining lot to the west. This lot is within the same ownership and the APZ will be formalised in accordance with PBP requirements.

North-west

2 0

downslope Forested wetland

n/a 36m --- BAL 12.5 APZ with subject land

South Upslopes and flat

land

Managed land

BAL 12.5

APZ within managed landscaping around building including access road and car parking.

1 Slope most significantly influencing the fire behaviour of the site having regard to vegetation found. Slope classes are according to

PBP. 2 Predominant vegetation is identified, according to PBP and “Where a mix of vegetation types exist the type providing the greater

hazard is said to be predominate”. 3 Assessment according to PBP.

4 Modelled using NBC Bushfire Attack Assessor v 2.1

5 Assessment according to AS 3959-2009.



4 APZ maintenance plan

The proposed APZ is in place and no further vegetation clearance or tree removal is required to support the

proposed development. Ongoing maintenance of the APZ is required and fuel management within the APZ

is to be as follows:

No tree or tree canopy is to occur within 2 m of the development roofline;

The presence of a few shrubs or trees in the APZ is acceptable provided that they:

o Are well spread out and do not form a continuous canopy;

o Are not species that retain dead material or deposit excessive quantities of ground fuel in a

short period or in a danger period; and

o Are located far enough away from the building so that they will not ignite the building by

direct flame contact or radiant heat emission.

Any landscaping or plantings should preferably be local endemic mesic species or other low

flammability species;

A minimal ground fuel is to be maintained to include less than 4 tonnes per hectare of fine fuel (fine

fuel means ANY dead or living vegetation of <6 mm in diameter e.g. twigs less than a pencil in

thickness. 4 t/ha is equivalent to a 1 cm thick layer of leaf litter); and

Any structures storing combustible materials such as firewood (e.g. sheds) must be sealed to

prevent entry of burning debris.

The western APZ is partly over a neighbouring lot under the same ownership. This APZ should be

formalised in an easement.

5 Construction standard

In response to the predicted bushfire attack the proposed dormitory is to be constructed to a BAL-12.5

standard under Australian Standard AS 3959-2009 ‘Construction of buildings in bushfire-prone areas’

(Standards Australia 2009).

Furthermore, the provisions of Section 3 ‘Construction General’ of AS3959-2009 and the ember protection

provisions outlined on Page 10 of the 2010 Appendix 3 Addendum to PBP are also required for the proposed

dormitory where applicable.



6 Water supply

The subject land will be serviced by reticulated water network, which will be expanded to support the

proposed development. The furthest point from any future development to a hydrant will be less than 70 m.

The reticulated water supply will comply with the acceptable solutions within Section 4.1.3 of PBP.

7 Gas and electrical supplies

In accordance with PBP, electricity should be underground wherever practicable. Where overhead electrical

transmission lines are installed:

Lines are to be installed with short pole spacing, unless crossing gullies, and

No part of a tree should be closer to a powerline than the distance specified in ‘Vegetation Safety

Clearances’ issued by Ausgrid (NS179, December 2010).

Any gas services are to be installed and maintained in accordance with AS/NZS 1596:2008 (Standards

Australia 2008).

8 Access

A single property access road / driveway linked to an access and parking configuration to accommodate

buses provides access to the proposed dormitory. The PBP performance criteria for SFPP internal roads is

that ‘internal road widths and design enables safe access for emergency services and allow crews to work

with equipment about the vehicle’ and the intent of measures is ‘to provide safe operational access for

emergency services personnel in suppressing a bush fire while residents are accessing or egressing an

area’.

The property access road is 4 m wide for the first 50 m before it links to the large bitumen carpark provided

immediately south of the proposed dormitory. This section of road is short, on the non-hazard side of the

development, links directly to the public road and has opportunities for vehicles to pull off the road provided

by a large 58 space carpark directly accessible to the east and a hardstand area associated with existing site

shed directly accessible to the west. There will be no parking along the access roads as on-site parking is

provided for over 100 cars in dedicated car parks and the development is with an open space landscape (not

forest or woodland).

This enables the access to allow safe operational access with a 4m width in this section.

The access road is not located near the bush fire hazard; it travels through managed land from the public

Culburra Road, north through the subject land to the proposed dormitory building. In the event of bushfire

any fire-fighters operating from a vehicle are unlikely to do so off the access road as this is more than 90 m

from the closest bushfire hazard. A fire appliance can be located at either the existing dwelling or within the

hardstand provided in the carpark immediately to the south of the proposed dormitory. At these locations

crews can work with equipment around the vehicle in accordance with the performance criteria.



Being a school dormitory, the access configuration has been designed to accommodate large vehicles (i.e.

multiple buses) and provides road sizes and design which will facility fire vehicle access. As detailed above

the proposed access configuration can achieve the PBP SFPP access performance criteria and address the

intent of measures.

9 Assessment of environmental issues

At the time of assessment, there were no known significant environmental features, threatened species or

Aboriginal relics identified under the Threatened Species Conservation Act 1995 or the National Parks Act

1974 that will affect or be affected by the bushfire protection proposals in this report.

Shoalhaven City Council is the determining authority for this development; they will assess more thoroughly

any potential environmental and heritage issues.

10 Summary of protection provisions and conformity with PBP

Table 2 summarises the bushfire protection proposed for the dormitory and its conformity with PBP.

Table 2: Assessment of conformity with PBP

Bushfire Protection Provision Proposal Complies with

PBP

Asset Protection Zones Table 1 (p. 6) identifies the size of proposed APZ.

Alternate solution provided for NW APZ. See Section 3. Yes,

Construction Standards BAL-12.5 under AS 3959-2009; see p.6 Yes

Water supply Reticulated water is provided; see p. 7 Yes

Access Alternate solution provided for access road width, see section 8. Yes

10.1 Conclusion

In the author’s professional opinion the bushfire protection requirements listed in this assessment provide an

adequate standard of bushfire protection for the proposed dormitory, a standard that is consistent with

‘Planning for Bush Fire Protection’ (RFS 2006) and should be issued a Bush Fire Safety Authority.

Julie Holden

Senior Bushfire Planner

FPAA BPAD-A Certified Practitioner No. BPAD-PA-23572



11 References

Ausgrid. 2010. Network Standard NS 179 Vegetation Safety Clearances (updated from Energy Australia.

2002. Network Standard NS 179 (Vegetation Safety Clearances)). Ausgrid, Sydney.

NSW Rural Fire Service (RFS). 2006. Planning for Bush Fire Protection: A Guide for Councils, Planners, Fire

Authorities, Developers and Home Owners including the 2010 Appendix 3 Addendum. Australian

Government Publishing Service, Canberra.

Standards Australia. 2005. Fire hydrant installations - System design, installation and commissioning,

AS2419.1, Fourth edition 2005, SAI Global, Sydney.

Standards Australia. 2008. The storage and handling of LP Gas, AS/NZS 1596:2008, Fourth edition 2005,

SAI Global, Sydney.

Standards Australia. 2009. Construction of buildings in bushfire-prone areas, AS 3959-2009 1. SAI Global,

Sydney



12 Photographs

Photo 1: Looking south from below embankment up to dormitory site (to Photo 2)

Photo 2: Looking north from dormitory site towards riparian vegetation (to Photo 1)

Photo 3: Looking east across dormitory site Photo 4: Existing APZ to the west (looking south)



Appendix A

NBC Bushfire Attack Assessment Report V2.1

Assessment Date: 16/05/2013Print Date: 16/05/2013

Assessor: Mr Admin; admin

Local Government Area: Shoalhaven

Site Street Address: Scotts College, Culburra

Alpine Area: No

Transmissivity: Fuss and Hammins, 2002Flame Length: RFS PBP, 2001Rate of Fire Spread: Noble et al., 1980Radiant Heat: Drysdale, 1985; Sullivan et al., 2003; Tan et al., 2005Peak Elevation of Receiver: Tan et al., 2005Peak Flame Angle: Tan et al., 2005

Equations Used

AS3959 (2009) Appendix B - Detailed Method 2

Forested Weltand corridor

2 Degrees

36

30

7.34

68

15 20

95

5

25

30818600

0.807

15.83

9.93

2.07

LOW

BAL 12.5

1200

Downslope

Run Description:

Vegetation Slope:

APZ/Separation(m):

Veg./Flame Width(m):

Peak Elevation of Receiver(m):

Flame Angle (degrees):

Surface Fuel Load(t/ha): Overall Fuel Load(t/ha):

Flame Emissivity:

Moisture Factor:

Relative Humidity(%):

Ambient Temp(K):Heat of Combustion(kJ/kg)

Transmissivity:

Flame Length(m):

Radiant Heat(kW/m2):

Rate Of Spread (km/h):

Category of Attack:

Level of Construction:

Flame Temp(K)

Vegetation Slope Type:

Vegetation Group: Forest and WoodlandVegetation Type: Forest

Vegetation Information

Calculation Parameters

Program Outputs

Fire Intensity(kW/m): 21352

Site Information

Site Slope: 0 Degrees Site Slope Type: Level

Elevation of Receiver(m): Default

Fire Inputs

Maximum View Factor: 0.11

36Inner Protection Area(m):

Outer Protection Area(m): 0

FDI: 100



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