proposed development - municipality of strathfield · useful life expectancy (sule), landscape...

0 Preliminary Tree Assessment Report. Melville Community Hall, Hampstead Rd, Homebush West – Leon Limberiou (TMO)

Proposed Development: Melville Community Hall and car park Hampstead Rd, Homebush West. Tree Assessment Report

07.04.2017 Prepared by: Leon Limberiou Position: Tree Management Officer AQF Level 5 in Arboriculture Cert 4 Training and Assessment. Phone: 9748 9999

07.04.2017 Reviewed and approved: Peter Bowmer Position: Management Service Delivery Phone: 9748 9999

Executive Summary:

At the request of Architect/Urban and Public Domain Officer for Strathfield Municipal Council, I was

requested to assess 99 trees at Melville Reserve on Hampstead Road in Homebush West to ascertain

which trees may be affected by a proposed new development for the demolition and rebuild of the

Melville Community Hall and extended car park - Site Map DWG No.02, dated 03.03.17. I was asked

to give my recommendations to highlight and reduce the impact the proposed plans may have on

trees to be retained. Primarily my assessment was to measure the Tree Protection Zones (TPZ) and

Structural Root Zones (SRZ) for all trees on site and evaluate where incursions by the proposed

development may occur.

There is an operating childcare centre (Integricare Children’s Centre) and a community hall existing

on site and these are separated by a stand of mixed plantings. The majority of trees on site consisted

of relatively young trees estimated to be less than 50 years of age.

A tree assessment schedule and site plan has been included in this report. Several trees have been

highlighted for removal by Council’s Infrastructure and Planning Architects to allow for the

development on the current preliminary site plan. 99 trees were tagged and numbered. Only trees

directly affected by the proposed development as per current plans, with the addition of four other

trees which were identified for removal due to significant structural faults, have been allotted a Safe

Useful Life Expectancy (SULE), Landscape significance rating and Tree retention Value.

In addition to this:

20 trees from the 99 trees that were assessed will be directly affected by the proposed

development. Incursion into the TPZ for these trees is considered too great for these trees

to be retained.

Four additional trees outside of the building footprint are recommended for removal due to

significant structural defects.

It is recommended that the remaining 75 of the 99 trees on the site be retained and TPZ’s

afforded to these trees in accordance with Australian Standard (AS) 4970-protection of trees

on development sites.

10 trees may require root mapping prior to demolition and development.

Subject to the development being approved, 5 trees would require pruning.

Measures have been outlined to reduce the impact the development process may have on retained

trees. These include but are not limited to:

• Sturdy Tree Protection Zone barriers

• Mulching or placing a removable aggregate on the main thoroughfare or roadway to

limit compaction.

• Having designated roads in and out of the site.

• Placing site amenities close to TPZ on pillars so as to reduce the available room for heavy

traffic near retained trees.

• Driveway, car park, curbs and gutters being constructed on existing grade with no

further excavation being undertaken.

• Stockpiling fill in designated areas away from retained trees.

• Utilising retaining walls outside the TPZ to raise the soil levels for the future grade of the

site where applicable.

• Using piers or cantilever construction methods.

• Curving utility services trenches so as to lay these around trees for retention or having

these placed above ground where possible.

• Consideration should also be given to the role of trees growing in a stand or grove and

the removal of external trees exposing internal trees to changed wind dynamics.

It is recommended that an AQF level 5 project Arborist be appointed to oversee the protection of

trees to be retained on site for the duration of construction works, initiating “hold points” to ensure

compliance from all contractors. All pruning and removal works must be under the supervision of an

AQF Level 5 arborist for works including root mapping.

It is recommended tree replacement is based on Strathfield Municipal Councils Recommended tree

list and specimens used to revegetate this site be in accordance with NATSPEC specifications and

guidelines as per landscape DWG No.02 dated 03/03/201, Melville Community Hall Project,

Hampstead Rd, Homebush west.

Table of Contents:

1 Introduction and scope: .................................................................................................................. 1

1.1 History of Melville Reserve: .................................................................................................... 2

2 Method and limitations of assessment: ......................................................................................... 2

3 Observations: .................................................................................................................................. 3

3.1 Tree Assessment Schedule:..................................................................................................... 7

3.2 Site Plan: ............................................................................................................................... 10

4 Discussion: .................................................................................................................................... 11

4.1 Trees as a grove: ................................................................................................................... 11

4.2 Tree Protection Zones (TPZ) .................................................................................................. 11

4.3 Structural Root Zone (SRZ) .................................................................................................... 13

4.4 SULE, Landscape Significance and Tree Retention Values: ................................................... 13

4.5 Maintaining native vegetation corridors .............................................................................. 14

4.6 Conclusion: ............................................................................................................................ 16

5 Recommendations: ....................................................................................................................... 17

5.1 Trees impacted by development: ......................................................................................... 17

5.1.1 Additional trees noted for removal: ............................................................................. 17

5.1.2 Protection of remaining trees: ...................................................................................... 17

5.1.3 Mitigating disturbance of remaining trees: .................................................................. 17

5.2 Root Mapping: ...................................................................................................................... 18

5.3 Trees recommended for removal due to structural defects: ............................................... 18

5.4 Trees recommended for pruning: ......................................................................................... 19

5.5 Exempt Species: .................................................................................................................... 20

5.6 Root pruning: ........................................................................................................................ 20

5.7 Stump grinding: ..................................................................................................................... 20

5.8 Site considerations: ............................................................................................................... 20

5.9 Limiting compaction:............................................................................................................. 21

5.10 Tree maintenance: ................................................................................................................ 21

5.11 Tree removal specs: .............................................................................................................. 21

5.12 Tree replacement and habitat retention .............................................................................. 22

6 References: ................................................................................................................................... 23

7 Appendix A: Safe Useful Life Expectancy Data Sheet ................................................................... 24

8 Appendix B: Determining Landscape Significance ........................................................................ 26

9 Appendix C: Determining Retention Values: ................................................................................ 27

10 Appendix D: Strathfield Council Recommended Tree List ........................................................ 28

Table of Figures:

Figure 1: Google Earth image of Melville Reserve .................................................................................. 1

Figure 2: Hampstead Road entry into Melville Community Hall site car park. ....................................... 1

Figure 3: Melaleuca sp. and water pooling after rain. ............................................................................ 3

Figure 4: Storm water canal and Casuarinas with younger individuals from root stock. ....................... 4

Figure 5: Grove of Casuarina sp. ............................................................................................................. 5

Figure 6: Trees growing in garden beds within car park. ........................................................................ 5

Figure 7: Mixed plantings separating childcare centre and community hall. ......................................... 6

Figure 8: Melville Community Hall site centre site plan ....................................................................... 10

Figure 9: Structural defect – Tree 41. ................................................................................................... 19

Preliminary Tree Impact Assessment Report. Melville Community Hall, Hampstead Rd, Homebush West - Leon Limberiou (TMO) 1

1 Introduction and scope: The objective of this report is to establish which trees on site may be affected by a proposed new

development for the demolition and rebuild of the Melville Community Hall and car park at

Hampstead Rd, Homebush West.

Architect – Urban and Public Domain Officer for Strathfield Council, engaged me to assess 99 trees

growing on site to ascertain the relevant Tree Protection Zones (TPZ) and Structural Root Zones (SRZ)

for trees that are located within or close to the proposed development footprint – Site Map DWG

No.02, dated 03.03.17. I was also requested to provide Arboricultural advice and recommendations

relating to tree sensitive construction measures that could be utilised to minimise disturbances to

the trees on site.

Figure 1: Google Earth image of Melville Reserve

Figure 2: Hampstead Road entry into Melville Community Hall site car park.

Community Hall

Water Canal

Childcare Centre


1.1 History of Melville Reserve: Melville Reserve was opened in 1937 and named for solicitor Alexander Melville, an Alderman

[1925-1940] and Mayor of Strathfield [1939-40]. Following Melville’s death in 1940, Council

dedicated a water bubbler in Melville Reserve to his memory. The reserve contains many items of

interest including WWI War Memorials. The iron gates on Hampstead Rd and the bridge were

dedicated by the ‘people of Flemington’ to commemorate the Great War 1914-1918. These items

are included on Council’s Heritage Register (Jones, 2004).

2 Method and limitations of assessment: My assessment is based on measurements taken from the ground only. No Ariel or below ground

investigations were undertaken. Trees were not assessed for health or structural defects however,

notes were included for some specimens that had obvious defects or that compromised the

retention of adjoining trees if removed. Further hazard assessment separate to this report is

recommended.

The heights of the tallest trees were calculated using a SUUNTO Clinometer for accuracy and the

heights of remaining trees were estimated. This was considered a feasible approach due to the fact

that many of the trees located on site were of similar estimated age and overall size, many of which

were located growing in stands of trees. Photographs for report were taken at a later date from

original findings as weather would not permit at the time.

The diameter of trees was measured with a METRI diameter tape for trees of greatest size and /or

greatest risk of anticipated incursions into Tree protection Zones (TPZ) or Structural Root Zones

(SRZ). The diameters of the remaining trees were estimated due to the above mentioned

constraints. All measurements for diameter of trees were taken at breast height (DBH) at 1.4m and

at the root flare (DRF) of trees. A screwdriver was used to determine soil compaction. Site maps

were supplied by Marco Marin, Architect – Urban and Public Domain Officer for Strathfield Council.

Only trees marked for removal to facilitate the proposed development and those with significant

structural defects have been allotted a Safe Useful Life Expectancy (SULE), Tree retention Value and

Landscape significance rating. Trees were tagged and numbered to identify trees on site.

Neighbouring trees not part of the proposed site map were not assessed or tagged.

This report is to serve as a report for this site and further assessments, recommendations and

amendments to this report may be require.


3 Observations: The treescape of the site consists of a mixed planting of:

Syncarpia glomulifera (Turpentine ),

Lophostemon confertus (Brush Box),

Eucalypyus microcorys (Qld Tallowood),

Corymbia maculata (Spotted gum),

Callistemon salignus (Willow Bottlebrush),

Callistemon viminalis (Bottlebrush),

Jacaranda mimosifolia (Jacaranda),

Eucalyptus tereticornis (Forest Red Gum),

Eucalyptus sideroxylon (Mugger Ironbark),

Casuarina glauca (Swamp She-oak),

Allocasuarina torulosa (Forest She-oak),

Leptospermum petersonii (Tea tree),

Melaleuca quinquenervia (Broad leaved paperbark),

Melaleuca styphelioides (Prickly leaved paperbark),

Banksia spinulosa (Hairpin Banksia),

Celtis australis (hackberry) which is considered an exempt species within Strathfield Council

DCP under 8m.

Figure 3: Melaleuca sp. and water pooling after rain.

The site was inspected during heavy rain and it was noted that puddles had accumulated extensively

in various areas where soil was presumably not as free draining. Typical soil types for Strathfield

include a high portion of clay content however, it is unclear as to how much fill or changes to the soil

profile have occurred on this site previously. The soil is classified as a class 3 and 5 Acid Sulfate soil

according to Strathfield Local Environmental Plan (LEP) 2012 for this site. A soil map of this area can


be found at https://www.strathfield.nsw.gov.au/development/strathfield-local-environmental-plan-

2012/strathfield-lep-2012-maps/

At the Northern end of the site there is a large storm water canal separating the site from adjacent

recreational Melville Reserve parkland. It was noted that the pooling of water accumulated at the

lowest point of the site following the canal. Access from the site to the Melville Reserve parklands is

achievable by a foot bridge over the canal. Soil was probed with a screwdriver using downwards

force to determine its relative compaction at various locations indicating that the soil was

moderately to extremely compacted in areas despite the moisture content in the soil at the time of

inspection. At the time of writing no plans were made available of the number and location of storm

water drains currently used for this site.

Figure 4: Storm water canal with Casuarinas sp.

Casuarina sp. (She-oak) is well represented in the area that was assessed. Two distinct groves or

stands of casuarinas were observed comprising of distinctly older specimens surrounded by several

younger individuals that likely have suckered from parent root stock. This is reflected by trees

growing closely together of uniform height and slenderness. There is also a row of Casuarinas sp.

that were planted between the storm water canal and the community hall between 1995 and 2000.

https://www.strathfield.nsw.gov.au/development/strathfield-local-environmental-plan-2012/strathfield-lep-2012-maps/



Figure 5: Grove of Casuarina sp. showing younger trees suckering from root stock.

Allowing for the different growth rates of various species as well as growing conditions and

limitations, the majority of trees on site consisted of relatively young trees estimated to be between

5 and 50 years of age with the exception of a few specimens.

Many of the trees assessed are located within garden islands and beds bordering an existing carpark

and walkways consisting of bitumen and concrete.

Figure 6: Trees growing in garden beds within car park.

There is an operating childcare centre (Integricare Children’s Centre) and a community hall existing

on site and these are separated by a stand of mixed plantings, predominantly Melaleuca

styphelioides (prickly leaved paperbark), Casuarina glauca (Swamp She-oak) and Syncarpia

glomulifera (Turpentine).


Figure 7: Mixed plantings separating childcare centre and community hall.

At the time of inspection a group of three Calyptorhynchus funereus (Yellow tailed black cockatoos)

were observed feeding within the Casurinas sp. located within the island stand in the middle of the

car park. A Podargus strigoides (Tawny frogmouth) was also noted to be sheltering in one of the

Melaleuca styphellioides (prickly leaved paperbark) 20m from the entrance to the child care centre.


3.1 Tree Assessment Schedule:

Tree # Genus & Species Common Name Height (m) Spread (m) DBH (mm)

TPZ (m)

radial

SRZ (m)

radial SULE

Landscape

Significance

Retention

Value

Identified for

removal on

development plan

Other trees

recommended for

removal

Trees

recommended for

root mapping Comments

#1 Lophestemon confertus Brushbox 10 5x5 500 6 2.67 Not impacted from development

#2 Casuarina glauca Swamp She-Oak 15 5x3 300 3.6 2.25 Not impacted from development

#3 Casuarina glauca Swamp She-Oak 18.61 4x5 570 6.84 2.92 Not impacted from development

#4 Casuarina glauca Swamp She-Oak 8 3x3 200 2.4 2 Not impacted from development



#7 Casuarina glauca Swamp She-Oak 14.5 4x4 380 4.56 2.61 Not impacted from development

#8 Eucalyptus microcorys QLD Tallowood 9 5x5 400 4.8 2.47 Yes

Located at the edge of proposed building footprint. Root mapping

required

#9 Eucalyptus microcorys QLD Tallowood 8 5x4 250 3 2.13 Yes


required

#10 Casuarina glauca Swamp She-Oak 16.5 6x5 510 6.12 2.87 Yes


required

#11 Allocasuarina torulosa Forest She-oak 4.5 2x2 150 2 2 Yes


required

#12 Casuarina glauca Swamp She-Oak 11 3x4 300 3.6 2.25 Within proposed building footprint

#13 Casuarina glauca Swamp She-Oak 10.5 3x2 300 3.6 2.25 Yes


required

#14 Casuarina glauca Swamp She-Oak 4 2x2 180 2.16 2 remove low very low Yes Within proposed building footprint

#15 Casuarina glauca Swamp She-Oak 3.5 2x2 150 2 2 remove low very low Yes Within proposed building footprint

#16 Casuarina glauca Swamp She-Oak 3 2x3 100 2 2 transient low very low Yes Within proposed building footprint

#17 Casuarina glauca Swamp She-Oak 8.5 2x3 260 3.12 2.13 long moderate moderate Yes Within proposed building footprint

#18 Allocasuarina torulosa Forest She-oak 5 2x3 250 3 2.13 transient low very low Yes Within proposed building footprint

#19 Allocasuarina torulosa Forest She-oak 3 1.5x1.5 150 2 2 transient low very low Yes Within proposed building footprint

#20 Allocasuarina torulosa Forest She-oak 4 1.5x2 150 2 2 remove very low very low Yes Within proposed building footprint

#21 Allocasuarina torulosa Forest She-oak 8 3x4 430 5.16 2 medium moderate moderate Yes Within proposed building footprint

#22 Casuarina glauca Swamp She-Oak 4 2x2 140 2 2 remove very low very low Yes Within proposed building footprint

#23 Casuarina glauca Swamp She-Oak 3.5 1.5x1.5 100 2 2 remove very low very low Yes Within proposed building footprint

#24 Casuarina glauca Swamp She-Oak 11.5 4x4 640 7.68 2.73 remove very low very low Yes

Included stems. Splitting at base. Within proposed building

footprint.

#25 Casuarina glauca Swamp She-Oak 4.5 1x1 100 2 2 remove very low very low Yes Within proposed building footprint

#26 Casuarina glauca Swamp She-Oak 3.5 2x2 100 2 2 remove very low very low Yes Within proposed building footprint

#27 Casuarina glauca Swamp She-Oak 11 4x3 260 3.12 2.13

Located between canal and current scout hall - Further

assessment required post removal of Hall

#28 Casuarina glauca Swamp She-Oak 16.24 5x4 275 3.3 2.15






#30 Casuarina glauca Swamp She-Oak 14.25 4x4 200 2.4 2



#31 Casuarina glauca Swamp She-Oak 13 3x4 260 3.12 2





assessment required post removal of Hall. Pruning at site of

inclusion required.

Tree Assessment Schedule - Melville Community Hall Project, Homebush West











#36 Eucalyptus tereticornis Forest Red Gum 7.5 2x3 250 3 2.13 remove very low very low Yes

Growing on fence line of childcare center and regrowth from old

stump - remove

#37 Melaluca styphelioides Prickly Leaf Paperbark 9.5 5x5 300 3.6 2.25 Yes

Would require crown raising to accommodate roof line of

proposed structure. Root mapping required for preperation for

pier and beam construction to mitigate root damage

#38 Melaluca styphelioides Prickly Leaf Paperbark 9 6x5 410 4.92 2.32 Yes




#39 Melaluca styphelioides Prickly Leaf Paperbark 8.5 6x5 600 7.2 2.85 Yes




#40 Syncarpia glomulifera Turpentine 9 5x2 320 3.84 2.2 remove very low very low Yes Structural defects - located near childcare center - Removal

#41 Syncarpia glomulifera Turpentine 10 5x3.5 340 4.08 2.2 remove very low very low Yes Open inclusion at 4.5m - Removal

#42 Melaluca styphelioides Prickly Leaf Paperbark 10 6x6 590 7.08 2.71 Yes




#43 Leptospermum petersonii

Lemon Scented Tea

Tree 4

#44 Pittosporum sp. Pittosporum 5 3x3 150 2 2 Not impacted from development

#45 Grevillia robusta Silky Oak 10.5 4x5 350 4.2 2.37 Not impacted from development

#46 Callistamon viminalis Bottle Brush 4.5 3x4 150 2 2 Not impacted from development

#47 Callistamon viminalis Bottle Brush 4.5 3x4 250 3 2.13 Not impacted from development

#48 Casuarina glauca Swamp She-Oak 18 4x4 400 4.8 2.47 medium moderate moderate Yes Within proposed building footprint

#49 Casuarina glauca Swamp She-Oak 5 3x4 370 4.44 2 remove very low very low Yes

In small garden bed closest to main enterance to childcare center -

Poor union, multiple stem inclusion. Within building footprint.

#50 Syncarpia glomulifera Turpentine 8.5 6x5 400 4.8 2.47 Yes

Located enterance to childcare center in separate garden bed,

sparce canopy. Drain and soil grade change noted - Possible root

damage. Located at edge of proposed building footprint. Root

mapping required.

#51 Syncarpia glomulifera Turpentine 8 4x3 350 4.2 2.37 Not impacted from development

#52 Callistamon salignus White bottlebrush 6 3x1 200 2.4 2 Not impacted from development

#53 Melaluca styphelioides Prickly Leaf Paperbark 8 5x5 470 5.64 2.43 Not impacted from development

#54 Melaluca styphelioides Prickly Leaf Paperbark 5 4x4 300 3.6 2.25 Not impacted from development

#55 Allocasuarina torulosa Forest She-Oak 9 6x6 500 6 2.67 Located on edge of proposed development

#56 Syncarpia glomulifera Turpentine 8 5x5 400 4.8 2.47 Not impacted from development

#57 Syncarpia glomulifera Turpentine 7 4x5 350 4.2 2.37

Located inside childcare center - Broken canopy, poor taper,

Further assessment needed. Pruning required

#58 Callistamon salignus White bottlebrush 6 5x5 300 3.6 2.25 Minor deadwood. No impact.

#59 Jacaranda mimosifolia Jacaranda 4 3x3 230 2.76 2 remove very low very low Yes Heavily decayed at base, no retention value - Remove.

#60 Melaluca styphelioides Prickly Leaf Paperbark 6.5 4x5 300 3.6 2.25 Not impacted from development

#61 Corymbia maculata Spotted Gum 23.1 8x7 890 10.68 3.27 Not impacted from development

#62 Corymbia maculata Spotted Gum 21 5x7 550 6.6 2.76 Not impacted from development

#63 Callistamon salignus White bottlebrush 5.5 3x4 400 4.8 2.47 Not impacted from development

#64 Callistamon salignus White bottlebrush 5 3x4 350 4.2 2.37

Phototropic, minor deadwood, further testing for decay at base.

Not impacted by development

#65 Acmena smithii Lillypilly 3 2x2 150 2 2 Not impacted from development

#66 Acmena smithii Lillypilly 4.5 3x3.5 200 2.4 2 Not impacted from development

#67 Syncarpia glomulifera Turpentine 11 6x5 450 5.4 2.57 Phototropic. No impact if carpark is constructed on grade.

Not significant


#68 Syncarpia glomulifera Turpentine 7 3.5 x 3 250 3 2.13 Phototropic. No impact if carpark is constructed on grade.

#69 Syncarpia glomulifera Turpentine 10 5x4 400 4.8 2.47

Included at approx 4m. No impact if carpark is constructed on

grade.

#70 Syncarpia glomulifera Turpentine 7 2x3 150 2 2 No impact if carpark constructed on grade.

#71 Syncarpia glomulifera Turpentine 8.5 4x5 390 4.68 2.37 No impact if carpark constructed on grade.

#72 Syncarpia glomulifera Turpentine 8.5 4x4 300 3.6 2.25

inclusion with little reaction wood - further assessment. No

impact if carpark is constructed on grade.

#73 Eucalyptus sideroxylon Mugga Ironbark 20.32 6x7 530 6.36 2.73 medium moderate moderate Yes Within proposed building footprint for carpark.

#74 Jacaranda mimosifolia Jacaranda 7 4x4 300 3.6 2.25 transient low very low Yes In proposed footprint for new car park.

#75 Corymbia maculata Spotted Gum 12 4x5 400 4.8 2.47 Located at the edge of proposed building footprint.

#76 Eucalyptus microcorys QLD Tallowood 5 3 X 3.5 200 2.4 2

No impact if carpark constructed on grade. Possible branch

reuction to allow machinery access.

#77 Casuarina glauca Swamp She-Oak 12 1.5x1.5 160 2 2 No impact if carpark is constructed on grade

#78 Casuarina glauca Swamp She-Oak 5 2x1 150 2 2

Previously lopped at approx 7 ft. No impact if carpark constructed

on grade.

#79 Casuarina glauca Swamp She-Oak 9 3x2 190 2.28 2 Included at base. No impact if drive way constructed on grade.

#80 Casuarina glauca Swamp She-Oak 13.5 3x4 300 3.6 2.25 Prominent specimen. No impact from proposed development.

#81 Casuarina glauca Swamp She-Oak 5 2x1 150 2 2 Not impacted from development

#82 Casuarina glauca Swamp She-Oak 4 3x1.5 150 2 2 Not impacted from development


One of the larger specimines in the grove. Cavity at breast height -

further assessment required. No impact if carpark is constructed

on grade

#84 Casuarina glauca Swamp She-Oak 8.5 3x2 200 2.4 2 No impact if drive way constructed on grade.

#85 Casuarina glauca Swamp She-Oak 8 3x2 200 2.4 2 No impact if drive way constructed on grade.

#86 Casuarina glauca Swamp She-Oak 11 3x2 200 2.4 2 Check impact for additional car spaces.


Tallest tree in grove - located at edge of proposed development

footprint.

#88 Casuarina glauca Swamp She-Oak 8 1.5x1.5 150 2 2 Located at edge of proposed development.

#89 Casuarina glauca Swamp She-Oak 12 3x4 300 3.6 2.41 long moderate moderate Yes Within building footprint

#90 Casuarina glauca Swamp She-Oak 12.5 3x3.5 300 3.6 2.25 long moderate moderate Yes Within building footprint

#91 Syncarpia glomulifera Turpentine 6 3x2 250 3 2.2 short very low very low Yes

Within proposed building footprint. Included at base - poor eg

specimen

#92 Casuarina glauca Swamp She-Oak 6 1x2.5 150 2 2

Likely an epicormic from an old stump. No impact if carpark is

constructed on grade.

#93 Casuarina glauca Swamp She-Oak 12 3.5x4 300 3.6 2.25

Possible impact from additional car spaces. Car park to be

resurfaced on grade.

#94 Casuarina glauca Swamp She-Oak 7.5 3x3 200 2.4 2 No impact if carpark is constructed on grade

#95 Melaluca quinquenervia

Broad Leaved

Paperbark. 6.5 3x2 180 2.16 2 No impact if carpark is constructed on grade

#96 Casuarina glauca Swamp She-Oak 6 2x2.5 150 2 2 No impact if carparkis constructed on grade


Included at head height - fungal fruiting body noted. Further

assessment required. No impact if driveway constructed on grade.

#98 Syncarpia glomulifera Turpentine 8.5 2x2.5 250 3 2.13 Located at edge of proposed building footprint

#99 Melaluca quinquenervia

Broad Leaved

Paperbark. 5 3x3 180 2.16 2 Locatedat edge of proposed building footprint.


3.2 Site Plan:

Figure 8: Melville Community Hall site plan


4 Discussion:

4.1 Trees as a grove: A grove of trees can be considered an important factor when looking at Retention Values. No tree is

in perfect condition however, trees growing together i.e. sharing root plates; crown space and

buffering each other from prevailing winds need to be classified as one tree. According to Mattheck

(2007, p.3 – 4) and his study into the axiom of uniform stress and tree slenderness as a hazard; a

tree requires broadening at the base so as to cope with wind bending the tree downwards and be

able to cope with the structural stresses this presents. However, trees in a forest (or group) setting

tend to have internal trees that lack this obvious basal flare and this is due to these trees relying on

the surrounding group and external trees to take the force of wind loading. This is a normal in a

group or forested setting but the issue arises when external trees are removed and expose slender

internal trees to forces they have otherwise not encountered. The loss of one or more significant

trees within a grove can cause detrimental effects to the stability of the remaining trees. The result

can be total tree failure as they lack the required flaring at the base to keep them in the ground.

At the area assessed at the Melville Community Hall site, many of these internal trees within group

plantings can be observed to be growing with little to no trunk taper or basal flare. The lack of

secondary thickening and laying down of reaction wood at branch unions is also due to trees

growing within grouped conditions. Consideration into the changes in wind dynamics must be given

for the correct management of these trees to ensure that incidents from snapped out branches or

total tree failure do not occur particularly in high target areas such as the carpark or children’s play

area within the childcare centre.

4.2 Tree Protection Zones (TPZ) Tree Protection Zones are used to protect the root system of a tree from mechanical damage and

compaction in the development process. These zones are divided into two classes; The Tree

Protection Zone and The Structural Root Zone.

Tree Protection Zones (TPZ) have been calculated and allocated to each tree on the Site. This

measurement represents the maximum distance that soil disruption can occur to the trunk of any

one tree before too much of the root system is compromised. Some species can tolerate more root

disturbance than others, for example Ficus sp. compared to many Eucalypt sp. As most of the roots

can be found in the top 0.6m – 1m of soil, even shallow excavation within the TPZ can cause


significant damage to the tree (Harris, Clark & Matheny 2004, p.261). Harris, Clark and Matheny

(2004) go on to say that a tree could be just as compromised by excavating the top layer of soil as far

down to 0.6m as by excavation that goes much deeper. Root uniformity, extension or direction is

difficult to know prior to digging however some suggest that a tree can cope with as much as 50% of

the root system removed, although this may cause instability if this percentage is taken from one

side only (Harris, Clark & Matheny 2004, p.261). This would also depend greatly on the lean of the

tree, the soil type, soil water holding capacity, any decay in pane of lean and crown symmetry

and/or end weight. In addition, a common limit for the amount of root disturbance allowed at

development sites has been to the drip line of a tree. In leaning trees however, as well as trees with

very narrow canopies, group plantings or trees growing near structures the drip line method does

not work and by following this rule, can often still lead to reduction of the root zone by 50%

depending on the species (Harris, Clark & Matheny 2004, p.261).

Giving allowance for a TPZ based on the Australian Standards (2009 p.13), utilises the DBH to get an

accurate measurement specific to each individual tree. Harris, Clark and Matheny (2004) explain

that tree roots vary greatly in respect to age, species, vigour and size, that the drip-line technique is

not a dependable method of estimating a TPZ and agree that a more reliable measure is based on

calculating the DBH.

Any amount of development where heavy machinery is used is going to cause significant alterations

to the soil. This includes compaction, changes in water tables, damage to roots, changes in

microbiology and aeration (Harris, Clark & Matheny 2004, p.263). Above ground; trees on

development sites can also succumb to poor pruning, machine damage and accidental breakage

which can allow decay to progress throughout the tree. Throughout the construction phase,

chemical runoff and changes to the soil pH contribute to decline in trees which often shows up as

excessive deadwood, tip or crown die back and can often lead to death. This however, does not

tend to show up straight away and in some cases trees can take many years to show symptoms of

decline due to poor development practices and tree protection methods.

Some measures can be taken to reduce the impact the development process can have on trees.

These include but are not limited to:

1. The TPZ

2. Mulching or placing a removable aggregate on the main thoroughfare or roadway to limit

compaction.


3. Having designated roads in and out of the site.

4. Placing site amenities close to TPZ on pillars so as to reduce the available room for heavy


5. Stockpiling fill in designated areas away from retained trees.

6. Utilising retaining walls outside the TPZ to raise the soil levels for the future grade of the site

where applicable

7. Using piers or cantilever construction methods.

8. Curving utility services trenches so as to lay these around trees for retention or having these

placed above ground where possible.

4.3 Structural Root Zone (SRZ) Lateral roots that develop from the base of the trunk of a tree and grow horizontally outwards are

considered the Structural Roots, of which, the largest five comprise of approximately three quarters

of the entire root system (Gilman, 1997, p.95). Gilman (1997) goes on to say that these roots will

remain the largest and most dominant roots that form a part of any one root system. Due to the

nature of these roots it can be inferred that these are the most important factor in the stabilisation

of a tree. Disruption or removal of the structural roots could cause significant instability and cause

the tree to become a major hazard. This is especially relevant on Development sites due to the

intended use of the land and the economic value that is associated with it.

Providing a tree for retention with a Structural Root Zone measurement ensures that disruption of

the key structural roots is minimised in the development process. It provides a workable

measurement from the centre of the tree outwards and is a visual indicator as to where these roots

lie in proximity to the trunk of a tree and helps ensure that development remains outside of this

zone. When planning, the structural Root Zone needs to be adjusted in accordance with known local

growing conditions which includes; size, species, degree of lean, soil type and soil moisture content

(Gilman, 1997, p.95). One example would be; a tree with a significant lean would more than likely

have more crucial structural roots on the tension side than the compression side.

4.4 SULE, Landscape Significance and Tree Retention Values: At the Melville Community Hall site; 24 Trees were allocated a SULE, Landscape Significance rating

and a Tree Retention value (See Appendix A, B and C). The SULE and landscape significance rating is

used to work out the tree retention value of any given tree and this value can have an impact on the


proposed shape, size and building techniques of a development depending on the importance or

significance of the tree(s) assessed.

Trees that have a moderate retention value and fall within the proposed building footprint are as

follows: [T17, T21, T48, T73, T89 and T90]. According to the recommended action for Tree Retention

Values (Morton, 2011) a moderate tree retention value states that the retention of trees is desirable

however if these trees must be removed, replacement planting should be considered in accordance

with councils tree replacement policy to compensate for the loss of amenity.

The remaining trees that fell within the proposed building footprint were allocated a low or very low

retention value. These trees are as follows: [T14, T15, T16, T18, T19, T20, T22, T23, T24, T25, T26,

T49, T74 and T91]. According to the recommended action for Tree retention Values (Morton, 2011) a

low tree retention value states that these trees are not worthy of any special measures to ensure

their current health and should not be considered a restraint. Additionally; very low retention value

states that removal is recommended.

Trees [T36, T40, T41 and T59] have been allocated a SULE due to each being noted for removal

because of structural defects. All four trees have a very low retention value. Currently there are no

major restrictions on removal of the assessed trees listed above where a retention value has been

allotted however consideration should be given to retaining all trees where possible to manage the

impact of urban development. (Refer to Tree Assessment Schedule for further information).

4.5 Maintaining native vegetation corridors Given the rate of development throughout the greater Sydney region and current trends to

maximise the building envelope on available land in urban areas, the preservation of native corridors

for local fauna and flora communities has never been more important. At the time of inspection two

species of locally indigenous birds, Calyptorhynchus funereus (Yellow tailed black cockatoos) and a

Podargus strigoides (Tawny frogmouth) were observed feeding and roosting in the trees on site at

Hampstead Rd. Many trees that were identified on site, notably Casuarina sp., contribute

significantly to providing a source of food and available habitat for many species of local wildlife.

Strathfield Council has several well managed large parklands and reserves serving, amongst other

things, as refuges for these species within its LGA and has proven to be one of its greatest assets for

the greater community and indigenous wildlife alike. The area of trees assessed for the Melville


Community Hall site project within Melville Reserve merges into the adjoining Saleyard Creek which

in turn connects with Powells Creek before finally leading into the Mason Park Wetlands, thus

providing a native vegetation corridor.

Strathfield Municipal Council is still referred to as “The Oasis in The West” and all efforts should be

undertaken to not only maintain these parklands and reserves, but increase the number of locally

indigenous trees within these areas to extend existing native vegetation corridors and provide a

suitable source of food and habitat for local wildlife for future generations.


4.6 Conclusion: In conclusion, the proposed demolition and development at the Melville Community Hall site will

require tree sensitive building techniques to be utilised where proposed development conflicts with

incursions into the TPZ’s and SRZ’s for existing trees.

Areas where trees have been planted or are growing as a group or grove need to be carefully

managed to avoid tree or branch failure of inner trees which may become exposed to external forces

they are not used to.

Utilising a portion of the Site being cleared for the new development for stockpiling, refuelling and

storage will ultimately reduce the likelihood of trees being negatively impacted by development on

this Site. Initiating strategies to minimise compaction and mechanical damage to trees such as

erecting sturdy TPZ’s for trees which are to be retained, and implementing various tree sensitive

building techniques will also aid in reducing the impact by the proposed development.

It can be seen in the tree assessment schedule that four trees on the Site should be considered for

removal due to structural faults as well as 20 trees that will be directly affected by the proposed

development with Incursions into the TPZ for these trees considered too great for retention.

Currently there are no significant restraints on the proposed development however, replacement

species must be considered for trees with a moderate retention value.

By maintaining Strathfield Council parkland assets and being sensitive to the importance of insitu

stands of native vegetation as well the role this plays in maintaining habitat for local wildlife

communities; development and landscape designs should complement one another and add value

to the existing treescapes of Strathfield Municipal Council.


5 Recommendations:

5.1 Trees impacted by development: There are 20 trees within the direct building envelope and these have been proposed for removal in

accordance with the current ground floor plans, prepared by Council’s Department of Infrastructure

and planning, DWG No.02, dated 03.03.17 for the Melville Community Hall Project, Hampstead Rd,

Homebush West. These trees are located within the direct building envelope of proposed

construction and the incursions into each tree TPZ in accordance with the Australian Standard (AS)

4970 –Protection of trees on development sites would be considered too excessive for the retention

of these trees. These trees can be found on the Tree impact Assessment Schedule within this

document and are also outlined as follows: [T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24,

T25, T26, T48, T49, T73, T74, T89, T90 and T91].

5.1.1 Additional trees noted for removal:

In addition four trees have been recommended for removal and these fall outside current incursion

zones. These four trees have been ‘flagged’ for removal due to their significant structural faults.

These trees are as follows: [T36, T40, T41 and T59].

5.1.2 Protection of remaining trees:

It is recommended that the remaining 75 of the 99 trees on the site be retained and sturdy TPZ’s

erected and maintained in accordance with Australian Standard (AS) 4970-protection of trees on

development sites.

5.1.3 Mitigating disturbance of remaining trees:

Root disturbance and damage to remaining trees on site can be mitigated and trees be retained

subject to the carpark , curbs and gutters being constructed on existing grade and no further

excavation is undertaken. This work should be supervised by a project AQF level 5 Arborist. Trees

[T48, T89 and T90] fall within the development footprint for the proposed extended car park,

however, consideration should be given to the role that these trees contribute to the remaining

grove of trees (see discussion: Trees as a grove). Additionally, the design of the extended carpark

space that conflicts with TPZ of trees [T48, T89 and T90] may need to be adjusted or modified to

develop an elevated, cantilevered ramp that will accommodate for the abrupt change in soil grade at

this end of the carpark as well as potentially mitigate issues with trees currently at this location.


5.2 Root Mapping: It is recommended that root mapping is undertaken prior to commencement of site works (under

the supervision of an AQF level 5 consulting Arborist) for 10 trees located on site. Trees [ T37, T38,

T39, T42, T50] provide shade for the children of the child care centre and offer a visual screen from

the Community Hall. Root mapping would be required for trees [T8, T9, T10, T11 and T13] to

determine if incursions into TPZ for these trees would occur with proposed pathways. Non-

destructive methods must be utilised (pneumatic, hydraulic or ground penetrating radar) to

determine the location and distribution of roots to avoid damaging trees in preparation for the

installation of piers to support the development of the proposed Community centre. Regardless of

the method, roots must not be cut, bruised or frayed during the process. It is imperative that

exposed roots are kept moist and the excavation back filled as soon as possible. Photographs must

be taken and a root zone map prepared before any excavation for development commences.

Nine additional trees [T27, T28, T29, T30, T31, T32, T33, T34, and T35] would need further

assessment to make a determination for these trees should the demolition of the existing

community hall be approved to ascertain if supporting roots are using the current slab for

anchorage. Investigations should be undertaken (under the supervision of an AQF level 5 consulting

Arborist) by trenching alongside the slab using pneumatic, hydraulic or ground penetrating radar

methods or by gently digging by hand to locate roots (if any). Regardless of the method used, roots

must not be cut, bruised or frayed during the process. It is imperative that exposed roots are kept

moist and the excavation back filled as soon as possible. Photographs must be taken and a root

zone map prepared before any excavation for development commences.

5.3 Trees recommended for removal due to structural defects: Trees [T36, T40, T41 and T59] are recommended for removal due to structural defects. Three trees,

[T36, T40 and T41] identified as Syncarpia glomulifera (Turpentine) and Eucalyptus tereticornis

(Forest red gum) form part of a stand of trees that separate the child care centre from the current

Community Hall. The removal of these three trees will be quickly filled in by the canopies of

surrounding Melaleuca styphelioides (prickly leaved paperbark) without adversely affecting the rest

of the grove. Given the location of these three trees, should they fail, there would be the potential

of damage to infrastructure (including the proposed new community centre) and or injury to

children or staff from the child care centre. T59 identified as a young Jacaranda mimosifolia

(Jacaranda) was noted to have decay at base and provided little to the surrounding landscape.


If stumps are to be ground using a stump grinder, they must only be taken down to just below

ground level to avoid damaging the roots systems of adjoining trees. Stumps must not be removed

using excavators or backhoes or other such machinery.

Figure 9: Structural defect – Tree 41.

5.4 Trees recommended for pruning: Subject to the development being approved, trees [T37, T38, T39 and T42] would require moderate

crown raising in accordance with (AS) 4373-pruning of amenity trees to avoid conflict with the

proposed roof and gutter lines of the new community centre. It is also recommended that

appropriate gutter guards are considered as part of the design of the construction and routine

maintenance for these is scheduled.

In addition; it is recommended that remedial pruning work is undertaken for [T57] due to a large

snapped branch observed in the upper canopy as well as remedial pruning for [T32] that will require

one upright branch to be removed at site of inclusion.


All pruning work must be undertaken by a minimum AQF level 3 Arborist.

5.5 Exempt Species: It is recommended that all exempt or weed species listed on Council’s register be removed. At the

time of inspection at least 8 Celtis australis (Hackberry) were identified growing at the Southern end

of the carpark. Some of these trees are within the proposed building envelope and should pose no

constraint on the site development.

5.6 Root pruning: Any significant roots that require pruning should be done so with a root pruning saw (Harris, Clark &

Matheny 2004, p277) and under the supervision of an appointed AQF level 5 consulting Arborist.

Using the correct equipment minimises the damage that can be caused by excavators, axes and

other machines used for purposes other than root pruning. The use of stump grinders must not be

used to prune roots. Poor pruning at any stage in a tree’s life can lead to decay entering the root

tissue and cause issues with stability long after the development stage is over.

5.7 Stump grinding: Should the need for tree stumps to be removed with a stump grinder in close proximity to where

there are trees to be retained (e.g. a stand of trees), stumps must not be taken down more than

100mm below ground level to avoid damaging the roots from adjoining trees.

5.8 Site considerations: It is recommended that a AQF level 5 project Arborist be appointed to oversee the protection of

trees to be retained on site for the duration of construction works, initiating “hold points” to ensure

compliance from all contractors. All pruning and removal works must be under the supervision of an

AQF Level 5 arborist for works including root mapping.

Some measures can be taken to reduce the impact the development process can have on trees.

These include but are not limited to:

Mulching or placing a removable aggregate on the main thoroughfare or roadway to limit

compaction.

Having designated roads in and out of the site.


Placing site amenities close to TPZ on pillars so as to reduce the available room for heavy


Stockpiling fill in designated areas away from retained trees.

Utilising retaining walls outside the TPZ to raise the soil levels for the future grade of the site

where applicable.

Using piers or cantilever construction methods.

Curving utility services trenches so as to lay these around trees for retention or having these

placed above ground where possible.

5.9 Limiting compaction: It is recommended that a 15cm layer of mulch or crushed gravel aggregates on top of a geotextile

fabric be utilised in areas of high traffic to minimise the impact of compaction on remaining root

systems (Harris, Clark & Matheny 2004, pp.277-278). By using a geotextile fabric it ensures that

mulch or other aggregated material can be lifted and removed easily from the site after

development, with little disturbance to the root systems of retained trees.

5.10 Tree maintenance: It is recommended that trees which have had a portion of their roots removed or damaged during

development should be irrigated to supplement the loss in moisture absorption. Additionally, where

required and based on the nutritional quality of the retained trees, it is recommended that a

fertiliser and maintenance program be started prior and until the end of construction. According to

Harris, Clark & Matheny (2004, p.76), applying fertiliser to retained trees the season prior to the

commencement of development , throughout and for up to one year post development may be

beneficial in their overall health and performance of trees of retention.

5.11 Tree removal specs: All tree removal must be carried out by a minimum AQF level 3 Arborist(s). Current certificates of

currency must be produced by the nominated contractor on request. All work is to be in accordance

with (AS) 4373-pruning of amenity trees and (AS) 4970-protection of trees on development sites.

Suitable contractors must demonstrate WH&S compliance and be transparent with their coverage of

relevant insurances.


5.12 Tree replacement and habitat retention Subject to the trees being identified for removal being approved for this Site, it is recommended that

a replacement program be put in place dependant on the Landscape Architect’s vision and intended

use for the area. The following species are recommended for replacement and are largely based on

Strathfield Municipal Councils Recommended tree list (Appendix C). These trees have been selected

for their diversity, ability to survive endemic soil types and for their potential ecological value in

sustaining habitat corridors as well as their varied landscape use.

The majority of the trees proposed for removal are young or insignificant trees that are easily

replaced within the landscape and represent a small portion of trees currently situated on site.

It is recommended that several advanced sized specimens (500-1000L) are used to revegetate this

site in conjunction with other plantings to offset the trees proposed for removal and continue with

Strathfield Council’s strategies of increasing canopy cover and extending native vegetation corridors.

It is recommended that the trees purchased for replacement adhere to NATSPEC specifications and

guidelines. When planting advanced stock specimens, it is recommended that a reputable company

that is familiar with landscape design, stock selection and planting equipment required for

transporting and installing larger trees is engaged to undertake the work.


6 References:

Barrell, J, 2009, SULE: Its use and status into the new millennium - Paper presented to the NAAA

Conference in Sydney in April 2001

Gilman, E. F. 1997. Trees for urban and suburban landscapes. Delmar Publishers, Albany, NY

Harris, W, Clark, J.R, Matheny, N.P, 2004, Arboriculture: integrated management of landscape trees,

shrubs and vines, 4th edn, Pearson Education, Australia.

Jones. C., 2004. Parks, Reserves & Memorials of Strathfield.

Mattheck, C, 2007, Updated Field Guide for Visual Tree Assessment, Karlsruhe Research Center.

Morton, A, 2011, Determining the retention value of trees on development sites, TAFE notes.

Standards Australia, 2009, Australian Standards – Protection of trees on development Sites, AS4970-

2009, Sydney Australia.

Standards Australia, 2007, Australian Standards pruning of amenity trees, AS4373 -2007, Sydney

Australia.

Strathfield Municipal Council Local Environmental Plan, 2012. Acid Sulfate Soils Maps. Viewed

06.04.17 at https://www.strathfield.nsw.gov.au/development/strathfield-local-environmental-plan-

2012/strathfield-lep-2012-maps/

Strathfield Municipal Council, 2007. Recommended Tree List. Viewed 06.04.17 at

https://www.strathfield.nsw.gov.au/assets/Files/Documents/Information-

Sheets/Tree/Recommended-tree-list.pdf

Treetec, 2017, DBH, TPZ, AND SRZ CALCULATOR, Viewed online 16.01.17 at www.treetec.net.au



https://www.strathfield.nsw.gov.au/assets/Files/Documents/Information-Sheets/Tree/Recommended-tree-list.pdf

https://www.strathfield.nsw.gov.au/assets/Files/Documents/Information-Sheets/Tree/Recommended-tree-list.pdf

http://www.treetec.net.au/


7 Appendix A: Safe Useful Life Expectancy Data Sheet


8 Appendix B: Determining Landscape Significance


9 Appendix C: Determining Retention Values:

(Adapted from Morton, A, Dec 2011, Determining the Retention Value of Trees on Development

Sites)


10 Appendix D: Strathfield Council Recommended Tree List