ARBORICULTURAL ASSESSMENT REPORT

Transcription

1 EARTHSCAPE HORTICULTURAL SERVICES Arboricultural, Horticultural and Landscape Consultants ABN ARBORICULTURAL ASSESSMENT REPORT PROPOSED 132kV FEEDER REPLACEMENT LINDFIELD STS to CASTLE COVE ZS July 213 Prepared for: Glen Isbester Environmental Officer, Environmental Services Ausgrid GPO Box 49 SYDNEY NSW 21 Ph: Prepared by: Andrew Morton Dip. (Arboriculture) [AQF Level 5] B. App. Sci. (Horticulture) A. Dip. App. Sci. (Landscape) EARTHSCAPE HORTICULTURAL SERVICES Ph: Member of Arboriculture Australia Member International Society of Arboriculture - Australian Chapter (ISAAC) Member Local Government Tree Resources Association (LGTRA) PO Box 364, BEROWRA NSW 281 Ph: (2) Mobile: Fax: (2) earthscape@iinet.net.au

2 EARTHSCAPE HORTICULTURAL SERVICES TABLE OF CONTENTS 1 INTRODUCTION THE SITE SUBJECT TREES HEALTH AND CONDITION ASSESSMENT Methodology Health, Vigour and Condition Maturity Class Safe Useful Life Expectancy (SULE) LANDSCAPE SIGNIFICANCE Methodology for Determining Landscape Significance Environmental Significance Heritage Significance Amenity Value TREE RETENTION VALUES TREE PROTECTION ZONES Structural Root Zone (SRZ) Depth of the Root Plate Acceptable Incursions to the Canopy PROPOSED DEVELOPMENT IMPACT ASSESSMENT Acceptable Incursions to the Tree Protection Zone Minimum Setback Distance (to trenching) Assessment of Potential Impact of proposed trenching works INCURSIONS EXCEEDING 1% OF THE TPZ EXPLORATORY EXCAVATION AND ROOT INVESTIGATION Ground Penetrating Radar (GPR) Vacuum Device Air Spade ALTERNATIVE INSTALLATION METHODS Sub-surface boring Tunneling SUMMARY OF IMPACTS AND RECOMMENDATIONS APPENDIX 1 - CRITERIA FOR ASSESSMENT OF LANDSCAPE SIGNIFICANCE APPENDIX 2 ACCEPTABLE INCURSIONS TO THE TREE PROTECTION ZONE (TPZ) APPENDIX 3 TREE ASSESSMENT SCHEDULE APPENDIX 4 IMPACT ASSESSMENT SCHEDULE APPENDIX 5 - TREE LOCATION PLANS Arboricultural Assessment Report Proposed 132kV Feeder 2 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

3 EARTHSCAPE HORTICULTURAL SERVICES 1 INTRODUCTION This report was commissioned by Parsons Brinckhoff on behalf of Transmission Cable Alliance (TraCA) to assess the health and condition of three-hundred and forty (34) trees located along the route of proposed 132kV Feeders between the Lindfield Sub-transmission Substation (LSTS) and the Castle Cove Zone Substation (CCZS). The report has been updated at the request of Ausgrid to include an alternative route through Sydney Road, Carnarvon Street, Merlin Street and Roseville Avenue, Lindfield which includes an additional seventy-eight (78) trees. The report has been prepared to assist in the preparation of a Review of Environmental Factors (REF) as required under Part 5a of the Environmental Planning and Assessment Act The purpose of this report is to assess the potential impact of the proposed development on the subject trees, together with recommendations for amendments to the design or construction methodology where necessary to minimise any adverse impact. The report also provides recommended tree protection measures to ensure the long-term preservation of the trees to be retained where appropriate. 2 THE SITE The proposed route extends from the Lindfield STS located at 2B Carlyle Road, East Lindfield to the Castle Cove Zone Substation located at Victoria Avenue, Chatswood. The route traverses the Ku-ring-gai and Willoughby City Local Government Areas (LGAs). The alignment of the route is indicated in blue in Figure 1. The Alternate Route is indicated with a green line on this drawing is entirely within the Ku-ring-gai LGA The landscape and soils of along the route vary. The location of the route relative to Soil Landscapes is shown in Figure 2. Initially the route traverses soils typical of Hawkesbury Sandstone (Hawkesbury and Gymea Soil Landscape) [ha & gy], then transitional soils, between sandstone and shale (Lucas Heights Soil Landscape) [lh], then to clay soils more typical of Wianamatta Shale (Glenorie [gn] and Blacktown Soil Landscapes [bt]). The Alternate Route is located entirely within Gymea Soil Landscape. The soil landscape in each street is indicated in the following table (Table 1) and expected soil depth is discussed in Section Most of the locally-indigenous vegetation within the alignment of the route has been cleared for residential development. However, there are some areas of locally indigenous tree species and some remnant trees, representative of the original vegetation of the area. The original vegetation communities would also be variable based on the underlying soil conditions. However, typically, Gymea and Lambert Soil Landscapes would have supported open forest and woodland typical of Hawkesbury Sandstone areas, Lucas Heights Soil Landscapes would have supported forest typical of transitional soils (Turpentine-Ironbark Forest) and Glenorie and Blacktown Soil Landscapes would have supported tall open forest (Blue Gum High Forest) The majority of the streetscapes in the Ku-ring-gai LGA contain a mixture of planted non-local native and exotic (introduced) species, with some remnant and planted locally indigenous species. There few formally planted avenues, with exception of Clermiston Avenue [predominantly Lophostemon confertus (Brushbox)]. The streetscapes within the Willoughby LGA contain a number of formal avenues, but also contain streets with mixed exotic and non-local native plantings. The dominant species in each street are shown in the following table (Figure 3). 3 SUBJECT TREES The subject trees along the route were inspected by (EHS) during February and March 212. Trees along the Alternate Route were inspected in July 213. Each tree has been provided with an identification number for reference purposes denoted on the Arboricultural Assessment Report Proposed 132kV Feeder 3 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

4 EARTHSCAPE HORTICULTURAL SERVICES attached Tree Plan (Appendix 4), based on the cadastral drawings for Ku-ring-gai and Willoughby Local Government Areas. The numbers used on this plan correlate with the Tree Assessment Schedule (Appendix 3). Trees along the Alternate Route have been numbered with a A suffix for differentiation. Figure 1 Showing proposed cable transmisson route (blue line) and Alternate Route (green line) Arboricultural Assessment Report Proposed 132kV Feeder 4 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

5 EARTHSCAPE HORTICULTURAL SERVICES Figure 2 Extract from the Soil Landscapes of the Sydney 1:1, Sheet, showing proposed cable transmisson route (blue line) the alternate route (shown with a green line) is highlighted with an arrow. Arboricultural Assessment Report Proposed 132kV Feeder 5 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

6 EARTHSCAPE HORTICULTURAL SERVICES TABLE 1 DOMINANT TREE SPECIES IN EACH STREET ALONG THE PROPOSED ROUTE Street/Place Name Dominant Tree Vegetation Type Note Melaleuca quinquenervia (Broad-leaved L M Paperbark) Carlyle Road Eucalyptus haemastoma (Scribbly Gum) N M, SM Liquidambar orientalis (Turkish Sweetgum) E M Melaleuca quinquenervia (Broad-leaved N M Paperbark) Pleasant Avenue Jacaranda mimosifolia (Jacaranda) E M Fraxinus Raywood (Claret Ash) E M Jacaranda mimosifolia (Jacaranda) E SM Allambie Avenue Prunus serrulata (Japanese Flowering Cherry) E M Eucalyptus saligna x botryoides (Hybrid Blue Gum) N M Adelaide Avenue Angophora costata (Sydney Red Gum) L M Eucalyptus resinifera (Red Mahogany) L M Eucalyptus punctata (Grey Gum) L M Jacaranda mimosifolia (Jacaranda) E M, SM Liquidambar styraciflua (Liquidambar) E M Angophora costata (Sydney Red Gum) L M Sydney Road Eucalyptus resinifera (Red Mahogany) L M Syncarpia glomulifera (Turpentine) L M Jacaranda mimosifolia (Jacaranda) E M Woodlands Road Eucalyptus sp. (mixed) L, N M Thuja orientalis (Chinese Arborvitae) E M Soil Type ha > gy gy > lh > gy gy gy > lh lh > gy gy > lh Archbold Road Lophostemon confertus (Brushbox) N M lh > gy Earl Street Moore Street Barcoo Reserve Barcoo Street Barambah Road Jacaranda mimosifolia (Jacaranda) E M, SM Bauhinia variegata (Orchid Tree) E M Ulmus glabra 'Lutescens' (Golden Elm) E M, SM Tristaniopsis laurina (Water Gum) N M Melaleuca styphelioides (Prickly Paperbark) N M Melaleuca quinquenervia (Broad-leaved Paperbark) N M Lophostemon confertus (Brushbox) N M Eucalyptus grandis (Flooded Gum) N M, SM Angophora costata (Sydney Red Gum) L M Eucalyptus pilularis (Blackbutt) L M Lophostemon confertus (Brushbox) N M, SM Jacaranda mimosifolia (Jacaranda) E M Flindersia australis (Crows Foot Ash) N M, SM Lophostemon confertus (Brushbox) N M lh lh gy gy gy > gn > gy Arboricultural Assessment Report Proposed 132kV Feeder 6 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

7 EARTHSCAPE HORTICULTURAL SERVICES Street/Place Name Dominant Tree Vegetation Type Note Soil Type Populus balsamifera (Balsam Poplar) E M Ashley Street Callistemon viminalis (Weeping gy N M Bottlebrush) Barcoo Street Harpephyllum caffrum (Kaffir Plum) E M Liquidambar styraciflua (Liquidambar) E M gy Scotts Creek Ficus rubiginosa (Port Jackson Fig) L M gy Jacaranda mimosifolia (Jacaranda) E M High Street Syzygium luehmannii (Small-leaf Lillypilly) N M gy > bt Eucalyptus haemastoma (Scribbly Gum) L M, SM Mann Street Afrocarpus falcatus (Outeniqua Yellowwood) E M bt Alleyne Street Callistemon sp. (Bottlebrush) N OM bt Corymbia maculata (Spotted Gum) N M Victoria Avenue Corymbia ficifolia (WA Flowering Gum) N M gy Acer negundo (Box Elder) E M Castle Cove Zone Jacaranda mimosifolia (Jacaranda) Substation E M gy ALTERNATE ROUTE Street/Place Name Dominant Tree Sydney Road Carnarvon Street Merlin Street Callistemon viminalis (Weeping Bottlebrush) Eucalyptus haemastoma (Scribbly Gum) Vegetation Type Note Soil Type N SM gy L M, SM Jacaranda mimosifolia (Jacaranda) E M Jacaranda mimosifolia (Jacaranda) E M, SM Syzygium luehmannii (Small-leaf Lillypilly) N M Melaleuca quinquenervia (Broad-leaved Paperbark) N M Roseville Avenue Jacaranda mimosifolia (Jacaranda) E M gy LEGEND Vegetation Type Soil Landscapes E = Exotic species gy = Gymea Soil Landscape (Hawkesbury Sandstone) N = Non-local Native gn = Glenorie Soil Landscape (Wianamatta Shale) L = Locally-indigenous la = Lambert Soil Landscape (Hawkesbury Sandstone) bt = Blacktown Soil Landscape (Wianamatta Group & Hawkesbury Shales) Maturity Class lh = Lucas Heights Soil Landscape (Transitional M = Mature between Wianamatta Shale & Hawkesbury Sandstone) SM = Semi-mature gy gy Arboricultural Assessment Report Proposed 132kV Feeder 7 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

8 EARTHSCAPE HORTICULTURAL SERVICES 4 HEALTH AND CONDITION ASSESSMENT 4.1 Methodology An assessment of each tree was made using the Visual Tree Assessment (VTA) procedure. 1 All of the trees were assessed in view from the ground. No aerial inspection or diagnostic testing has been undertaken as part of this assessment. The assessment has been limited to mature and semimature trees of 2mm diameter or greater measured at 1.4 metres, on the basis that trees of less than this dimension are unlikely to be adversely affected by the proposed trenching works The following information was collected for each tree:- Tree (Botanical & Common Name); Approximate height; Canopy spread; Trunk diameter (measured at 1.4 metres from ground level); Health & vigour; using foliage size, colour, extension growth, presence of disease or pest infestation, canopy density, presence of deadwood, dieback and epicormic growth as indicators, where Condition; using visible evidence of structural defects, instability, evidence of previous pruning and physical damage as indicators, where This information is presented in a tabulated form in Appendix Health, Vigour and Condition The following codes have been used for the Health & Vigour and Condition columns:- VG G F P HEALTH & VIGOUR Very good health and vigour - exhibiting no apparent or minor pest/disease, good extension growth, normal foliage size, colour & density. Good health and vigour - exhibiting minor pest/disease, fair extension growth, minor abnormalities in foliage size, colour or density. Fair health and vigour - may exhibit moderate (non-life threatening) pest/disease, fair extension growth, small foliage size, abnormal colouration, thin foliage cover Poor health and vigour - exhibiting extensive or untreatable pest/disease, poor extension growth, significant deadwood and dieback, evidence of rapid decline, sparse foliage cover, abnormal foliage colour or size. CONDITION (STRUCTURE, STABILITY & DAMAGE) Very good structure - stable and free from, or with minor visible defects and damage. Appears stable with no visible evidence of instability Good structure - may contain minor defects and/or damage that can be successfully remediated or do not require treatment with an acceptable level of risk. Fair structure - containing defects and/or damage that may me able to be remediated to provide an acceptable level of risk. Evidence of instability or contains defects and/or damage which render the tree potentially hazardous/ prone to failure or cannot be successfully remediated. Arboricultural Assessment Report Proposed 132kV Feeder 8 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

9 EARTHSCAPE HORTICULTURAL SERVICES 4.3 Maturity Class The Maturity Classification of each tree has been divided into the following categories:- OM Over Mature (Senescent) Greater than 8% of the life expectancy for the species. These trees are senescent, being in a state of gradual decline M Mature 5-8% of the life expectancy for the species SM Semi-mature 2-5% of the life expectancy for the species I Immature or Young 4.4 Safe Useful Life Expectancy (SULE) less than 2% of the life expectancy for the species The remaining Safe Useful Life Expectancy(SULE) 2 of the tree is an estimate of the sustainability of the tree in the landscape, calculated based on an estimate of the average age of the species in an urban area in Sydney, less its estimated current age. The life expectancy of the tree has been further modified where necessary in consideration of its current health and vigour, condition and suitability to the site. The estimated SULE of each tree is shown in Appendix The following ranges have been allocated to each tree:- L Long Trees having a remaining SULE of more than 4 years M Medium Trees having an estimated remaining SULE of 15 4 years S Short Trees having an estimated remaining SULE of 5-15 years T Transient Trees having an estimated remaining SULE of less than 5 years D Dead Dead or immediate hazard (defective or unstable) 5 LANDSCAPE SIGNIFICANCE 5.1 Methodology for Determining Landscape Significance The significance of a tree in the landscape is a combination of its amenity, environmental and heritage values. Whilst these values may be fairly subjective and difficult to assess consistently, some measure is necessary to assist in determining the retention value of each tree. To ensure in a consistent approach, the assessment criterion shown in Appendix 1 have been used in this assessment A rating has been applied to each tree to give an understanding of the relative significance of each tree in the landscape and to assist in determining priorities for retention, in accordance with the following categories:- 1. Significant 2. Very High 3. High 4. Moderate 5. Low 6. Very Low 7. Insignificant Arboricultural Assessment Report Proposed 132kV Feeder 9 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

10 EARTHSCAPE HORTICULTURAL SERVICES 5.2 Environmental Significance Tree Preservation Order A Tree Preservation Order (TPO) applies to all land within the Municipality of Ku-ring-gai, made under Clause 42 of the Ku-ring-gai Planning Scheme Ordinance and adopted by Council on 25 th January 27. The TPO generally protects all trees of a height of five (5) metres or greater or with a trunk diameter of 15mm or greater. Some exemptions apply. The following trees are exempt (not protected) under the provisions of Ku-ring-gai Council s Tree Preservation Order:- Tree Exemption T36, 33 Acer negundo (Box Elder) Environmental Weed T228, T229, T23 23, A24 A5 A26 A2 Alnus jorullensis (Evergreen Alder) Liquidambar styraciflua (Liquidambar) Erythrina crista-galli (Cocks Comb Coral) Erythrina sykesii (Indian Coral) Cinnamomum camphora (Camphor Laurel) Nuisance Environmental Weed (less than 12 metres in height) Environmental Weed Environmental Weed Environmental Weed (less than 15 metres in height) The remainder of the trees within the Ku-ring-gai LGA are protected under Ku-ring-gai Council s TPO and are afforded some protection under Section 138 (c) of the Roads Act (NSW) 1993 and Section 629 of the Local Government Act (NSW) 1993, being located within the Road Reserve. A Tree and Bushland Preservation Order (TBPO) exists within the City of Willoughby, pursuant to the Willoughby Local Environment Plan (LEP) 1995 and Sydney Regional Environmental Plan (SREP) 5 made by resolution of Council dated 26 th March 26. The TBPO generally protects all trees with a height of four (4) metres or greater and/or with a trunk circumference exceeding 6 mm (i.e. 2 mm diameter) and/or a canopy spread exceeding three (3) metres. Some exemptions apply. The following trees are exempt (not protected) under the provisions of Willoughby Council s TBPO:- Tree Exemption T275, T276, T277 Populus balsamifera (Balsam Poplar) Nuisance The remainder of the trees within the Willoughby LGA are protected under Willoughby Council s TPO and are afforded some protection under Section 138 (c) of the Roads Act (NSW) 1993 and Section 629 of the Local Government Act (NSW) 1993, being located within the Road Reserve Wildlife Habitat Acacia decurrens (Black Wattle) [A73], Acacia binervia (Coastal Myall) [T285], Allocasuarina littoralis (Black She-oak) [2] Angophora costata (Sydney Red Gum) [T63, T81, T82, T84, T85, T88, T89, T98, 1, 18, 24, 38, 43, 55, 73, T238, T242, T243, T244, T245, T246, T248 & T332], Angophora floribunda (Rough-barked Apple) [57 & T24], Eucalyptus globoidea (White Stringybark) Eucalyptus haemastoma (Scribbly Gum) [A18, A19, A22,, T2, Arboricultural Assessment Report Proposed 132kV Feeder 1 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

11 EARTHSCAPE HORTICULTURAL SERVICES T59, T294, T298 & T3], Eucalyptus paniculata (Grey Ironbark) [35], Eucalyptus pilularis (Blackbutt) [A7, A71, T52, T75, 41, 84 & T247], Eucalyptus punctata (Grey Gum) [A9, T68, T69 & T7], Eucalyptus racemosa (Scribbly Gum) [T233], Eucalyptus resinifera (Red Mahogany) [T67, T87, T93, T94,, 5, 22 & 29], Eucalyptus saligna (Sydney Blue Gum) [T22 & 4], Ficus rubiginosa (Port Jackson Fig) [T287], Pittosporum undulatum (Sweet Pittosporum) [A25] and Syncarpia glomulifera (Turpentine) [A12, A21, A31, A76, 9, T97, 12, 13, 14, 15, 16, 7, 19, 2, 21, 25, 3 & 47] are all locallyindigenous species, representative of the original vegetation of the area and would be of benefit to native wildlife. However, none of the trees contain cavities suitable as nesting hollows for arboreal mammals or birds or other visible signs of wildlife habitation Noxious Plants & Environmental Weeds Cinnamomum camphora (Camphor Laurel) [A2 & T289] is scheduled as a Class 4 Noxious Weed under the meaning of the Noxious Weeds Act (NSW) 1993 within both the Ku-ring-gai and Willoughby LGAs. The growth and spread of this plant must be managed in a manner that reduces its numbers, spread and incidence and continuously inhibits its reproduction and the plant must not be sold, propagated or knowingly distributed. It should be noted that A67 & A68 are protected under Ku-ring-gai Council s TPO being greater than fifteen (15) metres in height. Acer negundo (Box Elder) [T333 & T334] whilst protected under the provisions of Willoughby Council s TBPO is considered an Environmental Weed in many LGAs within the Sydney Metropolitan Area Threatened & Ecological Communities Eucalyptus scoparia (Willow Gum) [A8 & T77] is listed as Endangered in Schedule 2 of the Threatened Conservation Act 1995 (NSW) and listed as a Vulnerable under the Environmental Protection and Biodiversity Conservation Act Whilst this species is listed as endangered & vulnerable, it is a commonly planted ornamental tree in parks, gardens and streetscapes. The species is not endemic to this area and therefore does not have any ecological significance in the context of this area. Eucalyptus nicolii (New England Peppermint) [T49, T51, 74 & T28] is listed as a Vulnerable in Schedule 2 of the Threatened Conservation Act 1995 (NSW) and listed as a Vulnerable under the Environmental Protection and Biodiversity Conservation Act Whilst this species is listed as vulnerable in its native habitat, it is a commonly planted ornamental tree in parks, gardens and streetscapes. The species is not endemic to this area and therefore does not have any ecological significance in the context of this area. Syzygium paniculatum (Magenta Cherry or Lilly Pilly) [T311] is listed as a Vulnerable on Schedule 2 of the Threatened Conservation Act 1995 (NSW) and a nationally vulnerable species under the Environmental Protection and Biodiversity Conservation Act Whilst this species is listed as vulnerable, it is a commonly planted ornamental tree in parks, gardens and streetscapes. The species is not endemic to this area and therefore does not have any ecological significance in the context of this area. The National Parks and Wildlife Service (NPWS) 1:25 Mapping Series (Native Vegetation of the Cumberland Plain) 3 indicates that there is one area of remnant native vegetation community transected by the transmission route (refer to Figure 3), near the intersection of Adelaide Avenue and Sydney Road, Lindfield. This area is classified as Turpentine-Ironbark Margin Forest (TIMF). Turpentine-Ironbark Margin Forest is a sub-group of Sydney Turpentine Ironbark Forest (STIF). STIF is listed as an Endangered Ecological Community (EEC) under the Threatened Conservation Act 1995 (NSW) and a Critically Endangered Ecological Community under the Environmental Protection and Biodiversity Conservation Act It should be noted that the portion of the Route along Carlyle Road, Pleasant Avenue, Crana Avenue, Allambie Avenue and Arboricultural Assessment Report Proposed 132kV Feeder 11 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

12 EARTHSCAPE HORTICULTURAL SERVICES the eastern part of Adelaide Avenue are outside the NPWS Study Area. However, the assemblage of species in this area is more typical of Sandstone Ridgetop Woodland, which is not listed as an EEC. Figure 2 Extract from the National Parks and Wildlife Service (NPWS) 1:25 Mapping Series (Native Vegetation of the Cumberland Plain, showing the proposed cable transmisson route (blue line) and Alternate Route (green line). Note that the first section of the Route (Carlyle Road, Pleasant Avenue, Crana Avenue, Allambie Avenue and the eastern part of Adelaide Avenue) are outside the Study Area (as defined by the red line). Within the area identified as TIMF, several species typical of the assemblage of species for vegetation community were identified, most of them remnant trees. Syncarpia glomulifera (Turpentine) [T97, 12, 13, 14, 15, 16, 17, 19, 2, 21, 25 & 3], Angophora costata (Sydney Red Gum) [T63, T81, T82, T84, T85, T88, T89, T98, 1, 18 & 24] and Eucalyptus resinifera (Red Mahogany) [T67, T87, T93, T94,, 5, 22 & Arboricultural Assessment Report Proposed 132kV Feeder 12 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

13 EARTHSCAPE HORTICULTURAL SERVICES 29] are all Positive Diagnostic 4 for this Vegetation Community. Eucalyptus pilularis (Blackbutt) [T75] and Eucalyptus punctata (Grey Gum) [T68, T69 & T7] are associated canopy species of this Community. As such, these trees are considered to form part of the EEC. Whilst not specifically indicated on the NPWS maps, a number of locally indigenous trees in Woodlands Avenue, including Eucalyptus paniculata (Grey Ironbark) [35], Angophora costata (Sydney Red Gum) [38 & 43], Eucalyptus globoidea (White Stringybark) [39], Eucalyptus saligna (Sydney Blue Gum) [4], Eucalyptus pilularis (Blackbutt) [41], and Syncarpia glomulifera (Turpentine) [47] and Barcoo Reserve, including Eucalyptus racemosa (Scribbly Gum) [T233], Angophora costata (Sydney Red Gum) [T238, T242, T243, T244, T245, T246, T248] and Eucalyptus pilularis (Blackbutt) [T247] are also considered to form part of this EEC. Within the Alternate Route Eucalyptus punctata (Grey Gum) [A9] and Syncarpia glomulifera (Turpentine) [A21 & A76] are also considered to form part of the TIMF EEC. Both A9 and A76 appear to be remnant trees. Two other Turpentines along the alternate route [A12 & A31] whist typical of this vegetation community have been planted within the last 1 years. None of the other trees are listed as Threatened or Vulnerable or form part of Endangered Ecological Communities under the provisions of the Threatened Conservation Act 1995 (NSW) or the Environmental Protection and Biodiversity Conservation Act Heritage Significance Heritage Items None of the trees along the route within the Ku-ring-gai LGA are listed as Heritage Items under Schedule 7, Part 2 of the Ku-ring-gai Planning Scheme Ordinance (as amended to 26 th August 211). None of the trees along the route within the Ku-ring-gai LGA have any known or suspected heritage significance. None of the trees along the route within the Willoughby LGA are listed as Heritage Items under Schedule 5, of the draft Willoughby Local Environment Plan 29 (WLEP). None of the Route is located within a designated Heritage Conservation Area within the Willoughby LGA. Mann Street contains a mature avenue of Afrocarpus falcatus (Outeniqua Yellowwood), probably planted Whilst not specifically listed as a Heritage Items on the WLEP, this street planting is an intact, uniform avenue, fairly characteristic of this era and is therefore considered to be of some heritage value None of the other trees along the route within the Willoughby LGA have any known or suspected heritage significance Significant Tree Register Ku-ring-gai Council does not maintain a Register of Significant Trees Willoughby City Council maintains a Natural Heritage Register, listing natural heritage places and items (including trees, natural vegetation and geological features not otherwise listed on the WLEP). At this stage the Register is incomplete and does not cover a large portion of the Route. However, none of the trees along the Route are listed on the Register thus far. 5.4 Amenity Value Criteria for the assessment of amenity values are incorporated into Appendix 1. The amenity value of a tree is a measure of its live crown size, visual appearance (form, habit, crown density), visibility and position in the landscape and contribution to the visual character of an area. Arboricultural Assessment Report Proposed 132kV Feeder 13 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

14 EARTHSCAPE HORTICULTURAL SERVICES Generally the larger and more prominently located the tree, and the better its form and habit, the higher its amenity value. 6 TREE RETENTION VALUES The Retention Values shown in Appendix 3 have been determined on the basis of the estimated longevity of the trees and their landscape significance rating, in accordance with Table 2. Together with guidelines contained in Section 7 (Tree Protection Zones) this information should be used to determine the most appropriate position of building footprints and other infrastructure within the site, with due consideration to other site constraints, to minimise the impact on trees considered worthy of preservation. TABLE 2 TREE RETENTION VALUES ASSESSMENT METHODOLOGY Estimated Life Expectancy Long - Greater than 4 Years Medium- 15 to 4 Years Short - 5 to 15 years Transient - Less than 5 Years Dead or Potentially Hazardous Landscape Significance Rating High Retention Value Moderate Retention Value Low Ret. Value Very Low Retention Value 7 TREE PROTECTION ZONES The Tree Protection Zone (TPZ) is a radial distance measured from the centre of the trunk of the tree as specified in Appendix 3. These have been calculated in accordance with AS (Protection of Trees on Development Sites). 5 The intention of the TPZ is to ensure protection of the root system and canopy from the potential damage from construction works and ensure the long-term health and stability of each tree to be retained Incursions/ encroachments to the root zone may occur due to excavations, changes in ground levels, (either lowering or raising the grade), trenching or other forms or soil disturbance such as ripping, grading or inverting the soil profile. Such works may cause damage or loss of part of the root system, leading to an adverse impact on the tree. 7.2 Structural Root Zone (SRZ) The Structural Root Zone (SRZ) provides the bulk of mechanical support and anchorage for a tree. This is also a radial distance measured from the centre of the trunk as specified in Appendix 3. The SRZ has been calculated in accordance with AS (Protection of Trees on Development Sites). Incursions within the SRZ are not recommended as they are likely to result in the severance of woody roots which may compromise the stability of the tree or lead to its decline and demise. 7.3 Depth of the Root Plate The soil conditions along the cable route vary considerably. In Gymea (gy) and Hawkesbury (ha) soil landscapes in the first and last sections of the route (refer Figure 2), soil depth is estimated to be relatively shallow [approximately.3-.8 metres to weathered sandstone and approximately.5 Arboricultural Assessment Report Proposed 132kV Feeder 14 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

15 EARTHSCAPE HORTICULTURAL SERVICES metres to the D Horizon (gy4), which is a yellowish-brown sand clay sub-soil material]. It is likely that the majority of the roots of the subject trees will be located above this layer (i.e. in the top.5-.8 metres) The soil depth within transitional areas (Lucas heights Soil Landscape) is variable, but it is estimated to be approximately metres to weathered shale/sandstone and approximately.6-1. metres to the D Horizon (lh4), which is a sandy clay to heavy clay sub-soil material. It is likely that the majority of the roots of the subject trees will be located above this layer (i.e. in the top.7-1. metres) The soil depth in in the central section (within Glenorie and Blacktown Soil Landscapes) is likely to be more uniform, but it is estimated to be approximately metres to weathered shale and approximately metres to the D Horizon (gn4), which is a heavy clay sub-soil material or (bt4) which is a light grey plastic mottled clay sub-soil material.. It is likely that the majority of the roots of the subject trees will be located above this layer (i.e. in the top metres) It should be noted that under these soil conditions the root plates of the subject trees are likely to spread laterally through the soil profile and more or less radially from the trunk as shown in Figure 4, and will often spread well beyond the canopy drip line in natural soil conditions. Figure 4 Showing the typical root plate of a mature tree under the prevailing soil conditions However, it should be noted that the conditions for root growth beneath the road pavement will be poor due to the level of previous soil compaction (for the pavement sub-grade) and the low permeability of the road surface (asphalt or concrete). In many instances roots will be deflected by the kerb and gutter and footing thereof. This does not mean that roots will not be encountered beneath road pavements, but more so that the actual intensity and distribution of roots is difficult to predict. Adequate precautions should therefore be instigated where excavating closer than the minimum setback distances to trenching to avoid adverse impact on existing trees. 7.4 Acceptable Incursions to the Canopy The removal of a small portion of the crown (foliage and branches) is generally tolerable provided that the extent of pruning required is less than 1% of the total foliage volume of the tree and the removal of branches does not create large wounds or disfigure the natural form and habit of the tree. All pruning cuts must be undertaken in accordance with AS 4373:27. This generally involves reduction of the affected branches back to the nearest branch collar at the junction with the parent branch, rather than at an intermediate point. The latter is referred to as lopping and is no longer an acceptable arboricultural practice. Generally speaking, the minimum pruning as Arboricultural Assessment Report Proposed 132kV Feeder 15 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

16 EARTHSCAPE HORTICULTURAL SERVICES required to accommodate any proposed works is desirable. Extensive pruning can result in a detrimental impact on tree health and may lead to exposure of remaining branches to wind forces that they were previously sheltered from, leading to a greater risk of branch failure Clearance to between the building line and canopy should take into account any projecting structures, such as balconies, awnings and the roofline and any requirement for temporary scaffolding to be erected during construction (typically metres wide). High structures should preferably be located outside the canopy dripline (as shown indicatively on the attached plans) in order to avoid or minimise canopy pruning. 8 PROPOSED DEVELOPMENT The proposed development includes the installation of underground electrical cables (132kV Feeder) between the Lindfield Sub-transmission Substation and the Castle Cove Zone Substation at Chatswood. It is understood that the cables and associated joint bays will generally be installed by open trenching within the road pavement area The trench detail (width, depth and cable arrangement) varies depending on the surface treatment and road type, by in most instances the trench will be in the order of mm wide and 14-18mm deep (refer to Typical Trench Details plan prepared by TraCA). The conduits will typically be covered with a layer of Thermally Stabilised Backfill (TSB) before restoring the road pavement surface or other pre-existing surface treatment The offset distance between the cable trench and kerb also varies from street to street and sometime varies within the same street, depending on the nature and position of existing underground services and other constraints. Generally speaking, the cable trench will be sited close to the centreline of the roadway, but in some instances the position of the trench may vary between 1.5 and 5. metres from the face of the kerb. 9 IMPACT ASSESSMENT 9.1 Acceptable Incursions to the Tree Protection Zone Where encroachment to the TPZ is unavoidable, an incursion to the TPZ of not exceeding 1% of the area of the TPZ and outside the SRZ may be acceptable. Examples of acceptable incursions are shown in Appendix 2. Greater incursions to the TPZ may result in an adverse impact on the tree Where incursions greater than 1% of the TPZ are unavoidable, exploratory excavation using nondestructive methods may be required to evaluate the extent of the root system affected and determine whether or not the tree can remain viable. Encroachments of greater than 2% of the TPZ or within the SRZ are not recommended without first undertaking careful exploratory excavation or using alternative methods of cable installation, such as Horizontal Directional Drilling (sub-surface boring). It should be noted that AS limits the maximum size of TPZs to 15 metres radius and minimum size to 1.5 metres radius, regardless of tree size Appendix 3 provides the TPZ, SRZ and minimum offset to trenching (Minimum Setback Distance) for each tree along the route as calculated in accordance with AS Minimum Setback Distance (to trenching) The Minimum Setback Distance as shown in the above table is not defined in AS497:29. However, this distance, if measured at tangent to the root plate, is equivalent to an incursion of 1% of the TPZ, as indicated in the following diagram (Figure 5). This distance should be measured from the centre of the trunk to the edge of the trench closest to the tree as indicated in Figure 5. Trenches excavated at this distance or beyond (further from the tree) should not require Arboricultural Assessment Report Proposed 132kV Feeder 16 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

17 EARTHSCAPE HORTICULTURAL SERVICES any exploratory works or special excavation methods and can be excavated using standard excavation equipment 9.3 Assessment of Potential Impact of proposed trenching works An assessment of the potential impact of proposed trenching works on each tree along the proposed route is shown in Appendix 4, using the above mentioned principles. The offset distance between the tree and the edge of the trench has been estimated by measuring the distance between the kerb and the trench centre line (obtained from TraCAs GIS Mapping Series), adding the distance between the tree and kerb (obtained by field measurements) and subtracting half the width of the trench (obtained from Construction Detail Plans). This offset distance has then been compared with the calculated TPZs, Minimum Setback Distances and SRZ s to evaluate the potential impact on each tree. TPZ Canopy Drip-line SRZ Trunk Kerb Minimum Setback Distance Cable Trench 1% Incursion to TPZ Figure 5 showing Minimum Setback Distance to open trenching. 1 INCURSIONS EXCEEDING 1% OF THE TPZ Where incursions to the TPZ are greater than 1% (closer to the tree than the recommended Minimum Setback Distance, but outside the Structural Root Zone), exploratory excavation should be undertaken to verify the presence and size of any woody roots within the trench alignment prior to any mechanical excavation occurring. This can be undertaken using a variety of methods described following. Alternatively (and preferably) the alignment of the cable trench should be adjusted where possible to avoid an encroachment of greater than 1% of the TPZ Incursions to the SRZ are not recommended as trenching within these zones using conventional methods may lead to severance or damage of woody roots. Mechanical excavation at can result in severe damage to woody roots and such damage cannot be repaired once incurred. In the worst case scenario, trees that have suffered extensive root damage may need to be removed as a result Arboricultural Assessment Report Proposed 132kV Feeder 17 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

18 EARTHSCAPE HORTICULTURAL SERVICES of compromising their stability. Where cable installation within SRZs cannot be avoided, consideration should be given to alternative installation methods (such as sub-surface boring). If alternative methods are not considered feasible and exploratory excavations or root investigation indicates that the stability of the tree may be compromised, consideration may need to be given to the removal of nominated trees. 11 EXPLORATORY EXCAVATION AND ROOT INVESTIGATION Exploratory excavation can be undertaken (where necessary) using a variety of techniques. The aim of exploratory excavation and root investigation is to determine the presence, size and location of any woody roots within the trench alignment prior to mechanical excavation. Once the presence, size and location of any woody roots has been verified, a qualified arborist can make a more informed judgement about the potential impact on any trees and determine the best course of action Ground Penetrating Radar (GPR) GPR is a non-destructive technique that provides high resolution reflection profiles of the subsurface. The technique works by pulsing electro-magnetic energy in the form of radio waves into the subsurface material with a transmitting antenna. This energy propagates through the subsurface material as a function of its electrical properties which are in turn a function of its physical and chemical properties. Reflection of energy occurs at boundaries between media which have contrasting electrical properties such as tree roots within soil which are detected by a receiving antenna. Conversely, a zero reflection (where the amplitude of reflections is close to zero) occurs from a homogenous material where there are no internal reflectors. By building a continuous profile of scans along a traverse and analysing the recorded reflections for shape, amplitude, location and two-way travel time, a profile of the depth and extent of any subsurface anomalies can be produced The GPR method can map root position and depth and can give an idea of size (by comparison of reflection size). However, the technique will not find roots smaller than 5 mm in diameter and as such can be used in locating the larger structural root system. Profiles collected over disturbed ground, thick undergrowth, some paving materials or reinforced concrete slabs adversely affects the data collected, and hence the reliability of the information obtained may be compromised in such situations. However, GPR can still be a useful method for quickly determining the presence of any large underlying roots without disturbing the surface. This technique can also be used in parallel with mechanical excavation (under supervision) as the depth and approximate position of large woody roots can be verified on the surface prior to mechanical excavation taking place Vacuum Device This device can be used effectively in some soil types by extracting soil around woody roots without incurring any damage in order to verify their presence, size and location. This device can be used in some situations to excavate portions of the trench around woody roots (and leave them intact), allowing conduits to be sleeved beneath woody roots and avoid damage or severance that might otherwise be incurred using conventional mechanical methods. The device can be used more effectively with the aid of water or air pressure to displace soil Air Spade The Air Spade uses pneumatic (air) pressure applied via an air compressor and specialised lance and nozzle to displace soil from around roots without causing any mechanical damage. The drawback of this method is that it is fairly labour intensive in heavy (clay) soils and cannot always achieve the required depths and can produce a significant amount of dust. However, it is effective method of exploratory excavation in combination with the vacuum device. Arboricultural Assessment Report Proposed 132kV Feeder 18 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

19 EARTHSCAPE HORTICULTURAL SERVICES Water Knife The Water Knife uses water pressure to displace soil from around roots. It can be an effective tool for exploratory work providing that the water pressure is not too high and used by an experienced operator. High pressure water improperly applied can abrade or even ringbark or sever woody roots. The drawback of the Water Knife is the production of soil slurry that can be difficult to dispose of, but can be used more effectively in combination with a vacuum device. 12 ALTERNATIVE INSTALLATION METHODS Where cable installations within the SRZ cannot be avoided and root investigation determines that woody roots are present and their removal will adversely affect the health or compromise the stability of a tree, alternative installation methods (rather than conventional trenching methods) should be considered Sub-surface boring Sub-surface boring involved use of a Horizontal Direct Drilling (HDD) machine to bore holes beneath the root plate and then draw the conduits through. It is generally more expensive than open trenching and is usually only undertaken in exceptional circumstances. Where directional drilling is the only option, the invert level of the conduit, plus the conduit diameter should be installed below the root plate depth (refer Section 7.3) Tunneling Where sub-surface boring is not considered feasible, tunnelling beneath any woody roots using a variety of non-destructive methods (Air Spade, Water Knife, Vacuum Device) or a combination of these to excavate around and tunnel beneath woody roots and sleeve conduits beneath may be a feasible alternative. This is more labour intensive than HDD, but may be an option in one-off or special circumstances for significant trees. Generally woody roots of 4mm in diameter or greater should be retained and protected from damage during excavations and installation of conduits. 13 SUMMARY OF IMPACTS AND RECOMMENDATIONS For the majority of the proposed route the proposed setback distances to trenching are acceptable, being either outside the TPZ or beyond the Minimum Setback Distance. In these instances the proposed trenching should not result in any adverse impact on the subject trees In some instances the proposed trench will be located within the Minimum Setback Distance and as such the potential encroachment to the TPZ is greater than 1%. In these instances, there is the potential for the proposed trenching to result in an unacceptable level of root loss or damage that may result in an adverse impact on the subject trees. The key areas identified where this is the case include:- The southern end of Carlyle Road, adjacent 2A Carlyle Road and 88 Wellington Road (T8-1). It is recommended that this section of trench adjacent these properties be relocated 3 metres west adjacent these trees if possible The eastern section of Pleasant Avenue, between Carlyle Road and Sylvan Avenue. It is recommended that this section be located 2 to 3 metres further south (away from trees T22, T23, T24, T27, T28 & T29). The western section of Pleasant Avenue, between Sylvan Avenue and Crana Avenue. It is recommended that this section be located 2 to 3 metres further north (away from T47, T48, T49 and in particular T52). Note that even at the amended position may require exploratory excavation to be undertaken within the TPZ of T52, given the size of this tree. Arboricultural Assessment Report Proposed 132kV Feeder 19 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213

20 EARTHSCAPE HORTICULTURAL SERVICES Sydney Road, between the intersections of Chelmsford Avenue and Woodlands Road. This section of the street contains a significant stand of Turpentines (refer to Section 5.2.4). As such it is recommended that the cable trench be relocated at least 2 metres east away from trees The eastern section of Earl Street, between the intersections of Oroya Parade and Moore Street. This section of the trench should be relocated 2 metres further south (away from trees 74, 79, 82, 83 & 84) Barcoo Reserve. Due to the random positions of the trees it is not possible to calculate the exact distance between the trench and subject trees, however a number of trees may be adversely affected. It is recommended that the positions of the tree be surveyed and the position of the trench adjusted where required to minimize adverse impact on existing trees. Notwithstanding this, it is likely that T238 (Sydney Red Gum) & T239 (Flooded Gum) will need to be removed to accommodate the works. T247 is a very large remnant Blackbutt tree. Special measures (as per Sections 1 & 11) should be adopted within the TPZ of this tree Barambah Road. The cable trench runs close to the centerline of the road, so adjustment to the alignment is not recommended. However, special measures (as per Sections 1 & 11) should be adopted within the TPZ s of trees T259, T26, T261, T265, T267, T268, T269, T27, T273 & T274. Scotts Creek Crossing. Two large Kaffir Plums (T281 & T282) may require removal to accommodate the proposed trenching works. ALTERNATE ROUTE Sydney Road adjacent A9 (Grey Gum) this is a remnant tree and an associated canopy species of TIMF. The tree was probably in existence prior to the construction of the road and is growing in close proximity to the kerb (6mm to the trunk centre). The potential encroachment to the root zone is approximately 15% of the TPZ. Whilst this exceeds acceptable limits under AS497:29, it is not considered to be a significant encroachment. Despite its ecological significance, the subject tree exhibits poor health and condition and has a Moderate Retention Value. Notwithstanding this, precautionary measures during excavation as specified in Section 11 should be implemented to avoid any adverse impact on this tree. Carnarvon Road adjacent A15 (Monterey Pine). This tree was probably self-sown and is growing in fairly close proximity to the road edge. The potential encroachment to the root zone is approximately 2% of the TPZ. Whilst this exceeds acceptable limits the subject tree should tolerate the extent of encroachment. The precautionary measures during excavation as specified in Section 11 can be implemented to avoid any adverse impact on this tree. Merlin Street adjacent A35 & A36 (Hill s Figs). These trees are significantly larger that the majority of the trees along the route. They are not generally planted as a street tree in Kuring-gai and were probably planted by a local resident. Trenching has previously been undertaken close to the eastern kerb (1.5-2 metres from the trunks) within the SRZs of these trees and there is evidence that roots were previously severed and have regrown back across the trench. Whilst this is a very resilient species to root loss, the precautionary measures specified in Section 11 should be adopted adjacent these trees to minimize any adverse impact. Andrew Morton EARTHSCAPE HORTICULTURAL SERVICES 12 th July 213 Arboricultural Assessment Report Proposed 132kV Feeder 2 Lindfield STS to Castle Cove Zone Substation Version 4 12 th July 213