AS 3959 Bushfire Attack Level (BAL) Compliance Report Stage 6 Ariella Estate, Brabham

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1 To: Preston O'Keefe Date: 22 August 2018 Company: Cedar Woods Properties Limited Project No: CED Inquiries: Zac Cockerill Stage 6 Ariella Estate, Brabham Site Details Address: 47 residential lots within Stage 6 Ariella Estate Suburb: Brabham State: Western Australia Local Government Area: Description of building works: City of Swan Residential development Class 1, 2 or 3 buildings with associated Class 10a buildings) Report details Report/Job number: CED Report reference: Assessment date: 26/10/17 and 27/07/18 Report date: 22 August 2018 Endorsement/Review Zac Cockerill BPAD Level 2: Introduction This Bushfire Attack Level BAL) compliance report has been prepared for 47 residential lots within Stage 6 Ariella Estate, Brabham hereon referred to as the project area), located in the City of Swan. Lots within Stage 6 are subject to WAPC subdivision approval WAPC Ref ). This report provides a post-subdivisional works update of the BAL ratings for individual lots within the project area and has been prepared for the benefit of the developer, future lot purchasers and decisionmakers. BAL certificates for each individual lot contained in Appendix 1) have been prepared based on the final site compliance check and are appended to this report for use at the building permit stage. The BAL assessment outlined in this report is the most up to date assessment relating to the project area and therefore supersedes any previous Strategen BAL assessments undertaken within the project area, including those documented in previously approved Bushfire Management Plans BMPs) to accompany both the original Ariella Private Estate subdivision 2015) and revised subdivision for Stages ). The approach for preparation of this BAL compliance report is consistent with Section 4.2 and Appendix 3 of Guidelines for Planning in Bushfire Prone Areas the Guidelines). The BAL compliance assessment has been completed by a Level 2 accredited Bushfire Planning and Design practitioner Zac Cockerill, BPAD37803) in accordance with Method 1 of AS Construction of Buildings in Bushfire-prone Areas AS 3959) and results are consistent with on-ground conditions observed at the time of inspection on 26 October 2017 and reassessment on 27 July Should subdivision design or the classified vegetation extent be further modified prior to building construction, then an updated BAL assessment for the affected lots may need to be undertaken to account for these changes. Level 1, 50 Subiaco Square Road, Subiaco, WA 6008 P.O. Box 243, Subiaco, WA 6904 Phone: 08) Fax: 08) Spencer Street, Bunbury, WA 6230 P.O. Box 287, Bunbury, WA 6231 Phone: 08) Fax: 08) info@strategen.com.au Web: ABN:

2 Site assessment and site plan The assessment of this site/development was undertaken initially on 26 October 2017, then reassessed on 27 July 2018 by a BPAD Accredited Practitioner for the purpose of determining the Bushfire Attack Level in accordance with AS Simplified Procedure [Method 1]). A site plan and site assessment results are depicted in Figure 1. Vegetation classification All vegetation within 100 m of the site/development was classified in accordance with Clause of AS and the Visual Guide for Bushfire Risk Assessment in Western Australia. Each distinguishable vegetation class with the potential to determine the Bushfire Attack Level is identified below in Table 1 and Figure 1. Future rehabilitation in the Resource Enhancement Wetland REW) and adjacent buffer to the south of the project area will result in the following vegetation classifications as per the approved landscape plan: rehabilitation consistent with a Class B woodland status within the REW rehabilitation consistent with a Class C shrubland status within the REW buffer. Subdivisional works have resulted in the following exclusions within and adjacent to the project area: the project area is in a cleared, managed low fuel state and is excluded from classification under Clauses e) and f) adjacent Stages 5 and 7 to the west are in a cleared, managed low fuel state and are excluded from classification under Clauses e) and f) built stages of Ariella Estate to the north are in a cleared, managed low fuel state and are excluded from classification under Clauses e) and f) adjacent development south of Woollcott Avenue Whiteman Edge) is in a cleared, managed low fuel state and is excluded from classification under Clauses e) and f) adjacent development to the east Flamewood Estate) is in a cleared, managed low fuel state and is excluded from classification under Clauses e) and f) the adjacent east Dampier to Bunbury Natural Gas Pipeline DBNGP) corridor is in a cleared, managed low fuel state and is excluded from classification under Clauses e) and f) in accordance with approved landscape plans. 22-Aug-18 2

3 Flamewood Estate Ambersun Av 5 Legend Development layout Surrounding subdivisions 100m assessment area 150m assessment area 7 Cadastre Vegetation class Watervalley Blv 309 Plot 1: Class B woodland, 0-5 degrees down-slope 308 REW Buffer 4 2 Plot 2: Class C Shrubland, 0-5 degrees down-slope Flannigan St Photo point and direction Project area DBNGP corridor Buckland Rd 371 Gunbower Rd Bromfield Av Woolshed Rd Rollston St Byenup Ln Arafura Wy Excluded under Clause e) and f) BAL contours REW BAL FZ BAL BAL 29 BAL 19 Woollcott Av BAL 12.5 BAL Low Whiteman Edge Estate Figure 1: BAL compliance assessment: Stage 6 Ariella Estate ± Scale 1:3,218 at A4 m Coordinate System: GDA 1994 MGA Zone 50 Date: 22/08/2018 Q:\Consult\2018\CED\CED18426\01_GIS_documents\CED18426_G001_RevB.mxd Whilst every care has been taken to prepare this map, Strategen & CED makes no representations or warranties about its accuracy, reliability, completeness or suitability for any particular purpose and cannot accept liability and responsibility of any kind whether in contract, tort or otherwise) for any expenses, losses, damages and/or costs including indirect or consequential damage) which are or may be incurred by any party as a result of the map being inaccurate, incomplete or unsuitable in any way and for any reason. Data source: Nearmap: Aerial image, flown 06/2018. Landgate: Cadastre, 11/2017. Client: Development layout, 08/2018. Created by: jcrute

4 Table 1: Vegetation classification Plot 1: Photo 1: Class B woodland within REW rehabilitation also to be consistent with Class B woodland) Trees 5-20 m in height, grassy understorey, lacking a shrubby middle layer Plot 1: Photo 2: Class B woodland within REW rehabilitation also to be consistent with Class B woodland) Trees 5-20 m in height, grassy understorey, lacking a shrubby middle layer 22-Aug-18 4

5 Plot 2: Photo 3: REW buffer to be rehabilitated to Class C shrubland Class B woodland REW in background) Currently weed regrowth, to be rehabilitated with shrubland vegetation as per landscape plan Plot 2: Photo 4: REW buffer to be rehabilitated to Class C shrubland Class B woodland REW right of shot) Currently cleared, to be rehabilitated with shrubland vegetation as per landscape plan 22-Aug-18 5

6 Photo 5: Excluded Non-vegetated & Low threat Clauses [e] and [f]) DBNGP corridor currently cleared, to be landscaped to non-vegetated and low threat state Photo 6: Excluded Non-vegetated & Low threat Clauses [e] and [f]) DBNGP corridor currently cleared, to be landscaped to non-vegetated and low threat state Flamewood Estate cleared land in background) 22-Aug-18 6

7 Photo 7: Excluded Non-vegetated & Low threat Clauses [e] and [f]) DBNGP corridor currently cleared, to be landscaped to non-vegetated and low threat state Flamewood Estate cleared land in background) Photo 8: Excluded Non-vegetated & Low threat Clauses [e] and [f]) Cleared land within Stage 5 Ariella Estate 22-Aug-18 7

8 Photo 9: Excluded Non-vegetated & Low threat Clauses [e] and [f]) Cleared land within Stage 5 Ariella Estate Photo 10: Excluded Non-vegetated & Low threat Clauses [e] and [f]) Cleared land within Stage 7 Ariella Estate 22-Aug-18 8

9 Relevant Fire Danger Index The fire danger index for this site/development has been determined in accordance with Table 2.1 of AS or otherwise determined in accordance with a jurisdictional variation applicable to the site. Fire Danger Index FDI 40 FDI 50 FDI 80 FDI 100 Table Table Table Table Potential bushfire impacts The potential bushfire impact to the site/development from each of the identified vegetation plots are identified in Table 2. Table 2: Method 1 BAL calculation Classified vegetation Effective slope BAL contour width m) BAL rating Comment Class B woodland Class C shrubland Downslope >0-5 degrees Downslope >0-5 degrees <13 BAL FZ No development is proposed in this area 13 <17 BAL 40 No development is proposed in this area 17 <25 BAL 29 No development is proposed in this area 25 <35 BAL 19 No development is proposed in this area 35 <100 BAL 12.5 Development will occur in this area <7 BAL FZ No development is proposed in this area 7 <10 BAL 40 No development is proposed in this area 10 <15 BAL 29 No development is proposed in this area as a result of mandatory R-code building setbacks 15 <22 BAL 19 Development may occur in this area 22 <100 BAL 12.5 Development will occur in this area Determined Bushfire Attack Level The Determined Bushfire Attack Level highest BAL) for the proposed development has been determined in accordance with Clause Simplified Procedure [Method 1]) of AS using the above analysis and documented in each of the BAL certificates in Appendix 1. No development will occur in areas of BAL-40 or BAL-FZ. BAL certificates BAL certificates are provided in Appendix 1 for all 47 residential lots within the project area as per the BAL compliance assessment outlined in Figure 1. Should a lower BAL rating be realistically achievable through an appropriate building setback, then the landowner can refer to detailed advice for recommended setbacks in Table 3. The lower BAL rating may be achieved if the recommended building setback is reflected on the building plan for that lot and a revised BAL certificate can be issued at that time. 22-Aug-18 9

10 Table 3: Recommended setbacks to achieve a lower BAL rating Lot number 308 Current separation distance Current BAL rating BAL-19 Recommended setback to achieve lower BAL 8 m front building setback New separation distance New BAL rating* BAL BAL-19 8 m front building setback BAL BAL-19 8 m front building setback BAL BAL-19 8 m front building setback BAL BAL-19 8 m front building setback BAL m including 415 BAL-19 8 m front building setback BAL m wide 22 m including 14m 424 Watervalley BAL-19 8 m front building setback wide Watervalley BAL-12.5 Boulevard road 472 Boulevard road reserve and at BAL-19 8 m front building setback BAL-12.5 reserve and an 8 m 473 least a 1 m BAL-19 8 m front building setback front building BAL-12.5 mandatory front setback) 474 R-code building BAL-19 8 m front building setback BAL-12.5 setback) 475 BAL-19 8 m front building setback BAL BAL-19 8 m front building setback BAL BAL-19 8 m front building setback BAL BAL-19 8 m front building setback BAL BAL-19 8 m front building setback BAL-12.5 *The new BAL rating in Table 3 can only be confirmed once the building plan for the relevant lot has been prepared to demonstrate compliance with the recommended setback. Once the setback has been confirmed, a new BAL certificate for the lower BAL rating can be prepared and issued to accompany the building permit application. Conclusion and recommendations This BAL compliance report has been prepared for Stage 6 Ariella Estate to provide a final BAL check for individual lots for use at the building permit stage. Assessment results are consistent with current onground conditions. Strategen can confirm that the existing BMPs over the site have been implemented as intended throughout the duration of subdivisional works for the relevant Stage 6 area and adjacent land to achieve the bushfire management outcomes as planned for in these documents. In the absence of any change in development design or post-development classified vegetation extent, Strategen considers that the BAL assessment and BAL certificates outlined in this report are accurate to inform individual lot building permit applications. Should the extent of classified vegetation change or new vegetation be introduced within 100 m of proposed development, then the BAL rating should be reassessed at the building permit stage to ensure accuracy with on-ground conditions. Should it be determined through demonstration on the building plan that compliance with the recommended building setbacks has been achieved and subsequently a lower BAL rating has been achieved as per Table 3), then the lower BAL rating should apply and be reflected in an updated BAL certificate prepared at that time. The BAL assessment outlined in this report is the most up to date assessment relating to the project area and therefore supersedes any previous Strategen BAL assessments undertaken within the project area. Ongoing requirements of the current City of Swan annual firebreak notice should continue to be implemented as required, particularly with regards to ongoing fuel management of vacant land and road reserves. 22-Aug-18 10