APPENDIX D BORR Northern and Central Sections Vegetation and Flora Assessment (BORR IPT 2019c) – Part 1 (part 1 of 8) Bunbury Outer Ring Road Northern and Central Sections Vegetation and Flora Study 20 May 2019 Executive Summary The Commissioner of Main Roads Western Australia (Main Roads) is proposing to construct and operate the Northern and Central sections of the Bunbury Outer Ring Road (BORR) project (Figure 1, Appendix A). The BORR is a planned Controlled Access Highway linking the Forrest Highway and Bussell Highway, and will provide a high standard route for access to the Bunbury Port. The completed BORR will also provide an effective bypass of Bunbury for inter‐regional traffic and freight, reducing traffic on the local road network, and facilitate proposed development to the east of the city of Bunbury. BORR forms a major component of the planned regional road network for the Greater Bunbury area. The concept for the road was originally developed by Main Roads in the early 1970s. The proposed BORR comprises three sections: ‘BORR Northern Section’ – Forrest Highway to Boyanup‐Picton Road ‘BORR Central Section’ – Boyanup‐Picton Road to South Western Highway (south), an existing 4 km section which was completed in May 2013, along with a 3 km extension of Willinge Drive southwards to South Western Highway ‘BORR Southern Section’ – South Western Highway (near Bunbury Airport) to Bussell Highway. This document refers to BORR Northern and Central Sections only. Main Roads commissioned the BORR IPT to undertake a biological assessment for BORR Northern and Central Sections (the Project). The purpose of the assessment was to delineate key flora and vegetation values within the survey area. This report is subject to, and must be read in conjunction with, the limitations and assumptions contained throughout the report. Key findings Vegetation Seventeen vegetation types as well as cleared areas, planted vegetation and rehabilitated areas were identified and described for the survey area. The majority of the survey area was rated Completely Degraded in condition (81 %). The road reserves and patches of vegetation within private land holdings had some areas rated as Good to Very Good (10.61 ha / 1.88 % of the survey area); these areas showed few weed species, had structural layers present and few signs of disturbance. These occurred along sections of Forrest Highway, near the South Western Highway, near the current BORR Central termination and the Boyanup Picton Road and along the Preston and Collie rivers. The remainder of the road reserves and agricultural lands were rated as Degraded to Completely Degraded in condition. Three conservation significant ecological communities were identified: Banksia Woodlands of the Swan Coastal Plain Threatened Ecological Community (TEC) – listed as Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) Banksia dominated woodlands of the Swan Coastal Plain IBRA region Priority Ecological Community (PEC) – listed as Priority 3 by DBCA Claypans of the Swan Coastal Plain / Herb rich shrublands in claypans (SCP08) (TEC) – listed as Critically Endangered under the EPBC Act and Vulnerable under the BC Act. This community may occur, however further studies are required to determine the floristics and condition. Although not considered to be a TEC or PEC, the vegetation unit along the Preston River is an example of a riverine community that has largely disappeared on the southern Swan Coastal Plain and is regionally significant. 20 May 2019 | Rev 0 Page i Flora Three hundred and sixty four flora species (including subspecies and varieties) were recorded during the field assessments. This comprised of 207 native species and 157 introduced / planted flora species. Of the introduced species, four are listed as Declared Pests under the Biosecurity and Management Act 2007 and/or as a Weeds of National Significance. No EPBC Act or Biodiversity Conservation Act 2016 (BC Act) listed flora were recorded within the survey area. Three DBCA Priority‐listed flora species were recorded Chamaescilla gibsonii (Priority 3), Acacia semitrullata (Priority 4) and Caladenia speciosa (Priority 4). The likelihood of occurrence assessment post‐field survey for conservation significant species concluded that three species are known to occur (including one species not identified in the desktop assessment), three species are likely to occur, 26 species possibly occur and 16 species are unlikely to occur within the survey area. 20 May 2019 | Rev 0 Page ii CONTENTS 1 INTRODUCTION 6 1.1 Project background 6 1.2 Purpose of this report 6 1.3 Project location 6 1.4 Scope of works 7 1.5 Relevant legislation 7 1.6 Limitations and assumptions 7 2 METHODOLOGY 9 2.1 Desktop assessment 9 2.2 Field assessment 9 2.3 Desktop and field assessment limitations 14 3 DESKTOP ASSESSMENT 18 3.1 Climate 18 3.2 Province 18 3.3 Landform and soils 18 3.4 Hydrology 19 3.5 Vegetation and flora 20 4 SUMMARY OF PREVIOUS VEGETATION AND FLORA SURVEYS 31 4.1 Survey areas and methodology 31 5 VEGETATION AND FLORA FIELD SURVEY RESULTS 35 5.1 Vegetation types 35 5.2 Vegetation condition 50 5.3 Conservation significant ecological communities 52 5.4 Other significant vegetation 59 5.5 Flora diversity 59 5.6 Conservation significant flora 60 5.7 Introduced flora 63 6 REFERENCES 64 20 May 2019 | Rev 0 Page iii TABLE INDEX Table 2‐1 Flora and vegetation survey timing and effort .................................................................................. 9 Table 2‐2 Data collected during the field survey ............................................................................................. 10 Table 2‐3 List of SWA quadrats used in PRIMER analysis ................................................................................ 12 Table 2‐4 Field survey limitations .................................................................................................................... 15 Table 3‐1 Geology and landform information for the survey area (Geological Survey of WA 2009) ............. 19 Table 3‐2 Extents of vegetation associations mapped within the survey area (GoWA 2018b) ...................... 21 Table 3‐2 Extent of vegetation complexes on the Swan Coastal Plain mapped within the survey area (GoWA 2018c) .............................................................................................................................................................. 22 Table 3‐3 Extent of vegetation complexes within Local Government Areas mapped within the survey area (GoWA 2018c) ................................................................................................................................................. 22 Table 3‐4 SWA dataset FCTs within 5 km of the survey area .......................................................................... 24 Table 3‐5 Threatened and Priority Ecological Communities identified in the desktop searches ................... 25 Table 4‐1 Summary of Previous Surveys ......................................................................................................... 31 Table 4‐2 Summary of the key findings of previous flora surveys .................................................................. 33 Table 5‐1 Recorded vegetation types .............................................................................................................. 38 Table 5‐2 Extent of vegetation condition ratings mapped within the survey area ......................................... 50 Table 5‐3 Diagnostic characteristics and condition thresholds to determine Banksia Woodlands TEC (TSSC 2016) ................................................................................................................................................................ 53 Table 5‐4 Summary of field assessment for Banksia Woodland TEC .............................................................. 55 FIGURES INDEX Figure 1 Project locality ............................................................................................................................ 67 Figure 2 Survey area and sample locations .............................................................................................. 67 Figure 3 Soil‐landscape types within the survey area .............................................................................. 67 Figure 4 Hydrological aspects within the survey area .............................................................................. 67 Figure 5 Vegetation association mapping within the survey area ............................................................ 67 Figure 6 Vegetation complex mapping within the survey area ................................................................ 67 Figure 7 Biological constraints within the survey area ............................................................................. 67 Figure 8 Vegetation types ......................................................................................................................... 67 Figure 9 Vegetation condition and significant weeds ............................................................................... 67 Figure 10 Conservation and other significant ecological communities and flora ...................................... 67 APPENDICES Appendix A Figures Appendix B Conservation Codes Appendix C Desktop Searches Appendix D Quadrat and Photo Point Data Appendix E Vegetation Statistics Appendix F Flora Species List Appendix G Flora Likelihood of Occurrence Assessment 20 May 2019