bloomfield sports precinct

Bloomfield Sports Precinct

Significant Tree Protection Management Plan

D21/56945

Executive Summary The following provides recommendations to minimise the potential construction impacts on significant cultural and heritage trees identified for retention and contained within the Proposed Bloomfield Sports Precinct and those on the adjacent Institutional Parkland/North Bloomfield site. This Tree Protection Management Plan (TPMP) has been prepared to address the Heritage Council of NSW – Bloomfield Sub-Committee – Bloomfield Hospital (SHR No 01745) recommendation of its meeting held on the 20 August 2021.

‘A management strategy prepared by an arborist to ensure that the significant trees to be retained will be protected from the impacts associated with proposed develop.’

The report provides recommended tree protection measures to ensure the viable, long-term health and vigour of trees identified as being retained. The site has been inspected by Nigel Hobden, Manager City Presentation with Orange City Council, a Qualified Horticulturalist, Arborist and Environmental Scientist. The site inspection was undertaken to determined appropriate Tree Protection Zones (TPZ) and undertake a visual inspection to gauge the health, structure and condition of trees identified for retention.

1. Introduction This report has been commissioned by Scott Maunder, Director of Community, Recreation and Cultural Services, Orange City Council. The TPMP is compiled in accordance with AS4970 - 2009 Protection of trees on development sites and AS4373 – 2007 Pruning of amenity trees for the care and management of significant trees to be retained within the Bloomfield Sport Precinct. This TPMP is designed to provide information about the trees that may be affected within the site (Sports Precinct) and on those adjacent (Bloomfield Institutional Parklands / Bloomfield North) and provide recommendations to minimise negative impacts. The trees that this report covers are those as identified in the Taylor Brammer Landscape Architects – Orange Sporting Precinct Landscape Master Plan, page 11 dated 6th August 2021 and presented to Heritage NSW on 14th July 2021. Tree protection measures are to be as specified and installed prior to commencement of tree felling operations and earth works. In general tree protection measures include:

Installation of tree protection fencing

Mulching of the tree protection zone

Amenity tree pruning Any work to be carried out within the Tree Protection Zone (TPZ) shall be undertaken under the supervision of an AQF Level 5 Arborist/ Council’s Manager City Presentation. Reference is made to Orange City Council’s ‘Bloomfield Golf Course – Tree Assessment and Protection Measures – Northern Precinct Future Sports Hub’ 12 February 2021.

2. Scope Inspect the health and condition of site trees and those on the adjoining properties that may be affected by the proposed construction activities (tree demolition and earth works). Determine from the assessment a description of the measures required to ameliorate the impact of construction activities on those trees identified to be retained.

3. Methodology To undertake a Visual Tree Assessment (VTA) from ground level. This VTA consisted of:

Tree health, structure and vigour

Site conditions

Assessment of construction impacts

Amenity pruning requirements

Tree Protection Measure are based upon the measurement of the trunk at 1400mm above ground level using a tree diameter measuring tape in accordance with AS4970 – 2009 Protection of trees on development sites. The radius of the TPZ is calculated for each individual tree and cluster of trees by multiplying the Diameter at Breast Height (1400mm above ground level) (DBH) by 12. TPZ radius = DBH x 12 In the event that the crown spread of the tree extends beyond this offset or merges with other trees (clusters) the TPZ may be adjusted to the outer extent of the crown spread or combined crown spread.

4. Site

Image 1: Taylor Brammer Landscape Architects - Bloomfield Hospital Primary Heritage Curtilage and Sir Jack Brabham Park

The Bloomfield Sport Precinct site is shaded red in the above image. Noting the immediately adjoining Institutional Parkland and Bloomfield North sites within the Bloomfield Hospital Primary Heritage Curtilage (red outline).

Image 2: Taylor Brammer Landscape Architects – Significant Tree Protection Management Plan

5. Discussion The Tree Protection Zone (TPZ) is the specified area, measured as a radius from the centre of the trees stem, above and below the ground for the protection of the tree’s roots and crown to provide for the viability and stability of a tree to be retained.

Image 3: AS4970 – 2009 Protection of trees on development sites

The above image demonstrates the normal structure of tree roots in an open landscape setting where there is no civil or hard infrastructure surfaces within the growing environment. Note the shallow depth of the root system. Establishment of Tree Protection Measures (TPM) to ensure that the root system and canopy are secure from potential damage incurred as a result of construction activities with ensure the long-term health, stability and viability of each tree to be retained. Incursions within the TPZ such as excavation, modification of the existing ground levels, trenching may damage part of all off the root system or affect the trees ability to survive and therefore its long-term health and viability.

An encroachment of 10% or less within the TPZ is considered to be a minor provided it is outside of the Structural Root Zone (SRZ). The SRZ is the area ‘around the base of a tree required for the tree’s stability in the ground. The woody root growth and soil cohesion in this area are necessary to hold the tree upright. The SRZ is nominally circular with the trunk at its centre and is expressed by its radius in metres.’ A major encroachment within the TPZ is considered to greater than 10%. Exploratory excavation work shall be undertaken using non-destructive methods such as hydro-vacuum or hand digging to evaluate the potential damage to the root system and determine whether the tree will remain viable. The area lost to the encroachment shall be compensated for elsewhere and be contiguous to the TPZ.

Image 4: AS4970 – 2009 Tree Protection Fencing

Image 5: AS4970-2009 Tree Protection Zone signage

Access within the Tree Protection Zone shall be restricted to the project arborist and only for undertaking tasks relevant to tree health such as mulching and amenity tree pruning work.

6. General Recommendation The TPMP outlines tree protection measures (TPM) to ensure that trees identified for retention are protected and maintained in a healthy and ‘as is’ condition (structurally). Compliance inspections by the ‘project arborist’ or delegated Council Officer shall be undertaken at regular intervals to ensure that TPM are maintained and to inspect the health and vigour of trees identified for retention. Should the health (or structure) of a tree require attention due to environmental influences the project arborist or delegated Council Officer will arrange / implement changes to improve health and vigour or undertake remedial action (eg pruning). Compliance inspections are recommended to be undertaken on a monthly to bi-monthly basis throughout the tree demolition and bulk earth works phases of the project.

Table 1: Tree Protection Zone Fencing Fencing shall be erected in accordance with the TPZ Radius identified within the table below.

Tree ID # Botanic Name Common Name DBH TPZ(m) TPZ Radius (m)

1 Ulmus procera English Elm 0.94 11.3

2* Ulmus procera English Elm 1.2 14.4

3 Ulmus procera English Elm 1.27 15




7* Ulmus procera English Elm 1.3 15










17 Platanus x hybrida London Plane 0.87 10.4

18 Fraxinus sp Ash 0.51 6.1

19 Eucalyptus sp Gum (Smooth barked) 0.49 5.9

20* Eucalyptus nicholii Narrow-leaved Black Peppermint

0.96 11.5

21 Eucalyptus nicholii Narrow-leaved Black Peppermint

0.73 8.8


0.69 8.3

23 Pinus radiata Monterey Pine 0.88 10.6

24 Eucalyptus mannifera Brittle Gum 0.85 10.2



27 Eucalyptus sideroxylon Ironbark 0.39 4.7

28 Eucalyptus scoparia Willow-Gum 0.41 4.9

29 Eucalyptus sideroxylon Ironbark 0.47 5.6


1.0 12


1.0 12

32 E. bridgesiana Apple-box 1.8 15**

33 E. bridgesiana Apple-box 1.04 15**

34 Curpessus torulosa Cypress 2.1 15**




38* Eucalyptus viminalis Ribbon Gum 0.9 10.8

39 Eucalyptus viminalis Ribbon Gum 1.1 13.2

40 Eucalyptus viminalis Ribbon Gum 1.2 14.4

*Tree containing a significant and structural defect ** Maximum TPZ AS4970-2009 cannot be greater than 15metres radii (except where crown protection is required)

Once erected TPZ fencing must not be removed or altered without approval from the project arborist. TPZ fencing shall be secured to restrict access. As per AS4970-2009 TPZ fencing shall be 1800mm in height and be freestanding. The area within the TPZ shall be mulched, once material becomes available from onsite grinding operations. Only non-Pinus radiata mulch shall be used ie mulch from the grinding of native eucalypts and exotic trees other than Pinus radiata may be used. Mulching to a depth of 100mm from 1000mm from the trunks junction with the ground shall be undertaken to the edge of the TPZ radius. Should any earth works be required to be undertaken within the TPZ the project arborist shall oversee such works, be satisfied that such works will not compromise the health of the tree and immediately upon conclusion of such works a layer of mulch 100mm thick shall be applied to bare earth within the TPZ. The project arborist shall induct all site workers during the construction phase onto the site specify ‘no go’ areas of this TPMP. At the completion of the project the protect arborist is to certify that tree protection measure comply with the TPMP.

Table 2: Tree images and existing defects

Tree 1

Tree 2

Significant defect in Tree 2 - major split between codominant leaders (consider cable and bracing or removal)

Tree 3

Tree 4

Defect in Tree 4 trunk – large branch scare

Tree 5

Tree 6

Tree 7

Canopy reduction has been performed on Tree 7

due to bifurcation of trunk – major split

Tree 8

Tree 9

Tree 10

Tree 11

Tree 12

Tree 13

Tree 14

Tree 15

Tree 16

Tree 17

Decay and cavity formation at the root crown of tree

17

Photinia

Photinia

Cypress, Silver Birch and Silver Birch (image a)

Small Eucalypts and Oleanders marked for retention (image b)

Radiata pine – marked for retention proposed road

impacts upon retention capacity

Tree 18

Tree 19

Defect – branch detachment scare to Tree 19

Tree 20

Tree 21

Tree 22

Tree 23

Tree 24

Tree 25

Tree 26

Tree 27

Tree 28 and 29

Tree 30 and 31

Tree 32

Tree 33

Trees 34, 35, 36 and 37 Cypress Pines (Riverside)

Tree 38

Bracket fungus in lower trunk

Tree 39

Tree 40

7. References Standards Australia, AS4373 – 2007: Pruning of amenity trees

Standards Australia, AS4970 – 2009: Protection of trees on development sites

Taylor Brammer Landscape Architects; Presentation to NSW Heritage – Orange Sporting Precinct Landscape Master Plan (2021)

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