Council archive · source document
Approved Document OPW18-0319 · OPW18/0319
Consult Arborist Pty Ltd
ARBORICULTURAL APPRAISAL
&
TREE RISK ASSESSMENT
Project Address: RACV Noosa Resort
94 Noosa Drive,
Noosa Heads, QLD, 4567
Real Property Description: Lot 203 SP 267424
Commissioned by: Darren McClenaghan
Resort Manager
Responsible Council: Noosa Council
Application No.: OPW18/0319 112007.135
Date: 24/01/2019
Prepared by:
Matthew Duncan
Director / Principal Arborist
AQF Level V, TRAQ, QMQAA
e: [email protected]
m: 0450 355 770
ABN: 68 153 548 531
-
NOOSA COUNCIL
APPROVED PLAN
OPW18/0319 31 JAN 2019
TODAY’S TREES FOR TOMORROW
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Consult Arborist
This document was prepared for the sole use of RACV Noosa Resort and any regulatory
agencies involved in this project. No other party should rely on this information without the
prior written consent of Consult Arborist and RACV Noosa Resort.
The findings laid out in this report are valid for 12 months from the date of the assessment.
If the advice and recommendations made in this report are not strictly adhered to, no
responsibility will be taken for the continuing health and condition of retained trees. Trees are
dynamic living organisms that respond to changes in their environs; repeat assessments are
key to maintaining tree vitality, structural integrity and to reduce any potential risk they may
pose.
C OPYRIGHT
This report/document is subject to copyright laws and penalties @280c per word per incident,
no part may be reproduced or used without the written permission of Consult Arborist Pty Ltd.
No responsibility will be accepted by Consult Arborist Pty Ltd for unauthorised or partial use
of this report.
General Permission of use as subject to Consult Arborist Pty Ltd copyrights:
1. Customer permission:
No more than three hard copies to exist at any one time.
2. Customer email permissions:
Must be original PDF format and limited to agreed Parties with a direct and vested
interest in the case.
D OCUMENT C ONTROL
The latest approved version of this 19_01_24_TRA_RACV Resort _Noosa_V3 should be
available to all personnel involved in consultation with Consult Arborist Pty Ltd.
Each new revision should be distributed to all key personnel for review and endorsement.
All individuals working near trees are to be made aware of this document and it is the
responsibility of the individual to implement and/or adhere to the recommendations and
guidelines.
Version Date Written Reviewed Approved
Draft 14/01/2019 MJD SCD MJD
One (1) 15/01/2019 MJD SCD MJD
Two (2) 22/01/2019 MJD SCD MJD
Three (3) 24/01/2019 MJD SCD MJD
D OCUMENTS R EVI EWED
Reference / Date Title / Details
14/12/2018 Noosa Council - OPW18-0319 Information Request
19/09/2018 RAS – Arborist Report
29/11/2017 Elevated Tree Removals Arborist Report
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T ABLE OF C ONTENTS
Copyright .............................................................................................................................. 2
Document Control ................................................................................................................. 2
Documents Reviewed ........................................................................................................... 2
1 Brief ............................................................................................................................... 4
2 Site Inspection ............................................................................................................... 4
3 Scope and Limitations .................................................................................................... 5
4 Site Description and Details ........................................................................................... 6
4.1 Site Location ........................................................................................................... 7
5 Visual Tree Risk Assessment Results ............................................................................ 8
5.1 Tree 1 – Swamp Mahogany .................................................................................... 8
5.2 Tree 2 - Corkwood ................................................................................................ 10
5.3 Tree 3 – Brush Box ............................................................................................... 11
5.4 Tree 4 – Cheese Tree ........................................................................................... 13
5.5 Tree 5 – Swamp Mahogany .................................................................................. 14
5.6 Tree 6 - Blackwood ............................................................................................... 16
5.7 Tree 7 – Soapy Ash .............................................................................................. 18
5.8 Tree 8 – Swamp Mahogany .................................................................................. 20
5.9 Tree 9 – Swamp Mahogany .................................................................................. 22
5.10 Tree 10 – Eucalypt Species .................................................................................. 24
6 Summary Table............................................................................................................ 26
7 Replanting / Habitat Restoration .................................................................................. 27
7.1 Planting List Suggestions ...................................................................................... 27
7.1.1 Understory and Shrubs .................................................................................. 27
7.1.2 Trees ............................................................................................................. 27
8 Plant Zone Enrichment................................................................................................. 28
8.1 Mulching ............................................................................................................... 28
8.2 Additional Plant Health Care ................................................................................. 28
9 Additional Information .................................................................................................. 29
9.1 Contractor Notes ................................................................................................... 29
9.2 Habitat Trees ........................................................................................................ 29
9.3 Wildlife Considerations ......................................................................................... 29
10 References: .............................................................................................................. 30
11 Assumptions and Disclaimer .................................................................................... 30
Appendix 1 - Tree Risk Assessment Methodology .............................................................. 31
Appendix 2 - Definition of ISA Terms .................................................................................. 31
Appendix 3 - Definition of Terms ......................................................................................... 32
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Consult Arborist 1 B RIEF This report was commissioned by Darren McClenaghan, RACV Resort Manager on the 8 January 2019. Consult Arborist Pty Ltd has been requested to carry out an independent Arboricultural Appraisal and Tree Risk Assessment on trees that have previously been submitted to Noosa Council as part of an application to remove protected vegetation. The aim of this report is to provide a tree risk assessment and information on the subject tree's current condition with recommendations offered regarding hazard mitigation works if required, and their suitability for retention and/or the option to maintain the tree in a suitable condition for its location. The information is to respond to a Noosa Council Information Request dated 14th December 2018. 2 S ITE I NSPECTION Matthew Duncan, Director and Principal Arborist of Consult Arborist, undertook the Visual Tree Assessment of the site from a ground level on Thursday, 10 January 2019. Matthew holds an AQF Level 5 (AHC50510) Diploma in Arboriculture from Sunshine Coast TAFE, an International Society of Arboriculture’s Tree Risk Assessment Qualification 2015 and has worked in the arboricultural industry since 1994. Since its establishment in 2011, Consult Arborist has been engaged to provide arboricultural advice and guidance on private, civil and capital works projects from cross-sector clients throughout SEQ. During the assessment, I was accompanied by an RACV representative and shown the specific subject trees. No further assessment of the other trees within the resort was undertaken at this time. Regular assessments of the mature trees are recommended on an annual basis. 19_01_24_TRA_RACV Resort _Noosa_V3 Page 4 of 32
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Consult Arborist 3 S COPE AND L IMI TATIO NS An International Society of Arboriculture’s (ISA) Tree Risk Assessment was performed on the subject trees to determine their health, structure, risk rating and suitability for retention within their current surroundings. The ISA “Tree Risk Assessment” and is designed to guide a systematic and structured approach to assessing tree risk and managing these risks. The level of assessment undertaken for this Arboricultural Appraisal was a Basic Level 2 visual assessment of the surrounding area and the subject tree’s structure and health, from a ground level. It is a qualitative risk assessment that includes the use of basic tools and techniques, i.e. cavity probing, minor root collar excavation, measuring tapes and devices and photography to gather information. The timeframe for this report is the inspection period; re-inspection should occur 1 year from this inspection. No additional specialist equipment was used, no conclusive comments on what may have or may be happening within the internal structure of the tree will be made. No tissue or soil samples have been collected or submitted for testing. The information contained in this report is based on a visual inspection of each tree and its location, species, health and condition at the time of inspection unless otherwise stated. It is the author's opinion and is a 'snapshot in time' of the specific tree's health and condition at the time of the inspection and no guarantee can be given that faults or issues may not arise in the future. The relevant tree information has been recorded to be used as a functional proactive tool to determine a safe management strategy for the trees, taking into account past works, past storm damage, site activities, age/condition, location and future use of the area. The trees were not tagged, see Site Plan and photographs for tree location within the site. 19_01_24_TRA_RACV Resort _Noosa_V3 Page 5 of 32
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Consult Arborist 4 S ITE D ESCRIPTION AND D ETAI LS The subject trees referred to in this report are located within a 10m vegetation Buffer Zone that was created and conditioned for retention during the original development procedures for this site. The aim of the Buffer Zone is to provide a wildlife and habitat for local fauna including the endangered Koala and Glossy Black Cockatoos. This Buffer Zone is protected under the development approval for the site and is included in the site's Approved Landscape Scheme. On assessing the site, it was apparent that the forest floor in many places is bare of vegetation and the soil condition is poor with little organic matter to form the required mulch/organic layer essential to supporting young plants in the site's sandy soil. The Buffer Zone has received little maintenance over the years and the poor sandy soils and a past weed management regime may have contributed to the prevention of the natural understory regeneration of native trees and plants; a few tube-stock had been planted, but with little success. These conditions are also likely to have contributed to the general tree decline. RACV intends to increase the maintenance to this area to improve the conditions throughout as part of the proposed general habitat restoration program of works. The treescape is a mix of Eucalyptus, Coastal Rainforest and a few weed species. Predominantly, the important Eucalyptus are aged Swamp Mahogany and a few early-mature Forest Red Gums. The presence of overhead power lines running north-south along the eastern boundary/fence line has resulted in the pruning of most of these trees with little canopy spread remaining to the east. This has caused depleted canopies, additional sunlight penetrating to the forest floor and little to no ground vegetation. On the western side of the Buffer Zone is the main resort with holiday units constructed at the base of the 1-3m high retaining wall. It appears that as part of the development the vegetation along the western side was all retained with pruning of side branches where conflict with the build occurred. Over the past 10 years, this has resulted in sections of dense vegetation directly encroaching and targeting constantly occupied holiday Units. Some encroachment pruning has occurred as a necessary requirement but predominantly the trees have been untouched since construction. Due to the increasing encroachment of all the trees along the western boundary over the Units they require some level of management and an assessment of this whole area is advised. The weather at the time of the inspection was clear with a light breeze and ground conditions underfoot were generally dry. Fair - good access was available to the site and subject trees with only minor restriction. 19_01_24_TRA_RACV Resort _Noosa_V3 Page 6 of 32
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4.1 SITE LOCATION
Plans are not to scale and is to be used in conjunction with the information within this
assessment results.
Figure 1: Google map overview with the protected 10m Veg Buffer Zone
where the subject trees are located.
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5 V ISU AL T REE R ISK A SSESSM ENT R ESULTS
The assessment commenced at the northern end of the Buffer Zone and preceded south along
the western edge. The subject trees were previously marked with flagging tape to aid
identification. To provide continuity, the trees were assessed in the same order as the previous
assessment, where possible with tree additional trees.
Tree attributes are approximately measured visually unless otherwise stated.
5.1 TREE 1 – SWAMP MAHOGANY
ID Genus & Species Common Name
1 Eucalyptus robusta Swamp Mahogany
Height Crown Spread [email protected] Age
18-20m 8-10m 600-700mm Over-mature
Health Structure
Fair to Poor with depleted canopy Fair to Poor with typical die-back in the main
branch structure
Target Occupancy Target Zone
Residential dwelling Constant Within 1 x height & Dripline
Comments
The tree is located within a bushland setting with no evidence of ground disturbance on the tree's
tension side. A main feature of the tree is a dominant lean to the main trunk, likely developed when
young and seeking light (phototrophic). No evidence of root plate failure/heave over the recent years
that would have contributed to the lean was confirmed.
The canopy displays typical decline for this species when in an advanced stage of life. Natural
retrenchment and regrowth creating twig/branch die-back and deadwood with responsive epicormic
growth creating new growth are evident throughout the main branch structure.
Tree 1 is directly targeting a Unit with the upper canopy encroaching over the roof.
This is a known Koala food tree and generally a good habitat tree.
The risk matrix has been calculated on branch failure as this has been deemed the most likely event
to occur within the next 12 months.
Likelihood of Failure Likelihood of Impacting Target Matrix 1 - Result
Probable High Likely
Consequence of Failure Matrix 2 – Overall Risk Rating Work Priority
Significant High Within 30 days
Recommendations
Canopy management is recommended to reduce the canopy away from the adjacent dwelling.
Pruning will likely exceed the recommended 20% removal of lost live foliage but will retain a more
stable tree and an acceptable height that will reduce the likelihood of further branch failure in the
near future and create a tree that can be managed into the future.
This species are known for being responsive to pruning with the creation of prolific regrowth formed
by epicormic shoots. These works will also reduce canopy sail area and, although unlikely, the
likelihood of total failure.
Re-inspect in 12 months.
Residual Risk on completion of Mitigation Options
Low
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Picture 1: Tree 1 pruning guide
Picture 2: Tree 1 leaning trunk
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5.2 TREE 2 - CORKWOOD
ID Genus & Species Common Name
2 Endiandra sieberi Corkwood tree
Height Crown Spread [email protected] Age
4-5m 1-2m 400-500mm Over-mature
Health Structure
Poor limited growth Poor recent mid-stem failure
Target Occupancy Target Zone
Residential dwelling Constant Within 1 x height & Dripline
Comments
Recent mid-stem failure due to fungal attack.
The remaining trunk has epicormic growth from its base. There is evidence of a hollow trunk at
ground level.
There is multi-stem Brush Box growing with it adjacent Tree 1 with side branches encroaching over
the neighbouring unit roof.
Likelihood of Failure Likelihood of Impacting Target Matrix 1 - Result
Possible High Somewhat Likely
Consequence of Failure Matrix 2 – Overall Risk Rating Work Priority
Minor Low Proactive maintenance within
6-12 months
Recommendations
• Removal of remaining defective trunk to ground level.
• General encroachment pruning to the Brush Box's side branches
• Re-inspect in 12 months.
Residual Risk on completion of Mitigation Options
Low
Picture 3: Remove defective trunk and prune encroachment
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5.3 TREE 3 – BRUSH BOX
ID Genus & Species Common Name
3 Lophostemon confertus Brush Box
Height Crown Spread [email protected] Age
12-14m 4-5m 200-250mm Early-mature
Health Structure
Good – Fair average vigour Fair - Asymmetrical canopy
Target Occupancy Target Zone
Residential dwelling Constant Within 1 x height & Dripline
Comments
Tree 3 is located within 2m of the adjacent Unit with a predominant phototrophic lean towards and
over the roof.
It is likely that it was retained as a young tree after the main site clearing. A fence has been
positioned next to the tree's lower trunk and, as it has increased in diameter contact is now starting
to occur.
No evidence was found to indicate ground or root plate movement on the tension side.
With no protection beneath the tree and the canopy protruding beyond the forest edge there is a
likelihood that this tree is over-exposed to wind loading that will increase as the canopy develops in
size and spread.
The risk matrix has been calculated on total tree failure.
Likelihood of Failure Likelihood of Impacting Target Matrix 1 - Result
Improbable High Unlikely
Consequence of Failure Matrix 2 – Overall Risk Rating Work Priority
Significant Low Proactive maintenance within
6-12 months
Recommendations
Although the tree appears in a suitable condition for retention its location directly adjacent to, and
directly targeting a Unit is not.
Tree 3 is not deemed as a High-risk tree at this time but its suitability for long-term retention beyond
2-3 years is untenable as the encroachment over the adjacent dwelling increases.
• Proactive removal within 6-12 months, prior to an increase risk rating due to encroachment
and size increase.
Residual Risk on completion of Mitigation Options
NA
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Picture 4: Tree 3 asymmetrical canopy encroaching over the roof
Picture 5: Lower trunk impacting fence
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5.4 TREE 4 – CHEESE TREE
ID Genus & Species Common Name
4 Glochidion ferdinandi Cheese Tree
Height Crown Spread [email protected] Age
8-10m 4-5m 150-250mm Early-mature
Health Structure
Fair with reduced vigour Fair - uneven form
Target Occupancy Target Zone
Residential dwelling Constant Within 1 x height & Dripline
Comments
This is an understorey edge tree with a phototropic lean over the adjacent dwelling. There is
evidence of past pruning and regrowth. No signs of ground or root plate movement were observed.
The risk matrix has been calculated on total tree failure.
Likelihood of Failure Likelihood of Impacting Target Matrix 1 - Result
Improbable High Unlikely
Consequence of Failure Matrix 2 – Overall Risk Rating Work Priority
Minor Low Proactive maintenance within
6-12 months
Recommendations
This tree is not deemed as a High-risk tree at this time but its suitability for long-term retention beyond
2-3 years is questionable as the encroachment over the adjacent dwelling increases.
Limited opportunity for suitable pruning.
• Proactive removal within 6-12 months, prior to an increase risk rating due to encroachment
and size increase.
Residual Risk on completion of Mitigation Options
NA
Picture 6: Edge tree with phototropic growth
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5.5 TREE 5 – SWAMP MAHOGANY
ID Genus & Species Common Name
5 Eucalyptus robusta Swamp Mahogany
Height Crown Spread [email protected] Age
6-8m 4-5m 200-300mm Early-mature
Health Structure
Fair with reduced vigour Poor - excessive lean
Target Occupancy Target Zone
Residential dwelling Constant Within 1 x height & Dripline
Comments
An edge tree growing at an excessive angle with a developing canopy and end-weight loading.
There is evidence of past pruning and responsive regrowth.
The tree is targeting the outdoor entrainment area and entrance way of the Unit beneath it.
The risk matrix has been calculated on total tree failure.
Likelihood of Failure Likelihood of Impacting Target Matrix 1 - Result
Possible High Somewhat Likely
Consequence of Failure Matrix 2 – Overall Risk Rating Work Priority
Minor Low Proactive maintenance within
6-12 months
Recommendations
Tree 5 is not deemed as a High-risk tree at this time but its suitability for long-term retention beyond
2-3 years is questionable as the encroachment over the adjacent dwelling increases.
There is limited opportunity for suitable pruning.
• Proactive removal within 6-12 months, prior to an increase risk rating due to encroachment
and excessive end-weight leading to failure.
Residual Risk on completion of Mitigation Options
NA
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Picture 7: Canopy with excessive end-weight
Picture 8: Acute angle to lower trunk
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5.6 TREE 6 - BLACKWOOD
ID Genus & Species Common Name
6 Acacia melanoxylon Blackwood
Height Crown Spread [email protected] Age
10-12m 4-5m 300-400mm Mature
Health Structure
Fair reduced vigour Poor strongly development of phototrophic lean
Target Occupancy Target Zone
Residential dwelling Constant Within 1 x height & Dripline
Comments
Tree 6 is located within 3m of the adjacent Unit with a predominant phototrophic lean towards and
over the roof. It presents a pronounced asymmetrical canopy with canopy connectivity to adjacent
trees.
There is evidence of defective/decay pockets on the tension side of the main trunk although no
active fungal or insect attack was noted at this time.
Blackwoods are a relatively short-lived species with limited ability to respond to decay once well-
established with a rapid decline in health ensuing.
The risk matrix has been calculated on total tree failure.
Likelihood of Failure Likelihood of Impacting Target Matrix 1 - Result
Possible High Somewhat Likely
Consequence of Failure Matrix 2 – Overall Risk Rating Work Priority
Significant Moderate Within 6 months
Recommendations
While the tree looks healthy and in a suitable condition for retention the defects noted and location
directly adjacent to and targeting a Unit renders the tree unsuitable for retention.
• Proactive removal within 6 months.
Residual Risk on completion of Mitigation Options
NA
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Picture 9: Lower trunk
Picture 10: Phototrophic lean over adjacent dwelling
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5.7 TREE 7 – SOAPY ASH
ID Genus & Species Common Name
7 Alphitonia excelsa Soapy Ash
Height Crown Spread [email protected] Age
6-8m 4-5m 200-250mm Early-mature
Health Structure
Good with average vigour Poor - major phototrophic growth
Target Occupancy Target Zone
Residential dwelling Constant Within 1 x height & Dripline
Comments
Tree 7 is located within 3m of the adjacent Unit with a prominent phototrophic lean towards
the entrance doorway.
The trunk is at an excessive angle with a weighted canopy leading to additional loading on
the root plate.
The risk matrix has been calculated on total tree failure.
Likelihood of Failure Likelihood of Impacting Target Matrix 1 - Result
Probable High Likely
Consequence of Failure Matrix 2 – Overall Risk Rating Work Priority
Minor Moderate Within 6 months
Recommendations
Failure is likely to occur due to overloaded root plate.
• Proactive removal prior to failure.
Residual Risk on completion of Mitigation Options
NA
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Picture 11: Excessive end-weighted canopy
Picture 12: Over-loaded root plate
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5.8 TREE 8 – SWAMP MAHOGANY
ID Genus & Species Common Name
8 Eucalyptus robusta Swamp Mahogany
Height Crown Spread [email protected] Age
10-12m 5-6m 200-300mm Early-mature
Health Structure
Fair with reduced vigour Fair - uneven form
Target Occupancy Target Zone
Residential dwelling Constant Within 1 x height & Dripline
Comments
Tree 8 is an edge tree with a phototropic lean over the adjacent Unit.
There is evidence of past pruning and regrowth.
No signs of ground or root plate movement were found at the time of the inspection.
The risk matrix has been calculated on total tree failure.
Likelihood of Failure Likelihood of Impacting Target Matrix 1 - Result
Possible High Somewhat Likely
Consequence of Failure Matrix 2 – Overall Risk Rating Work Priority
Minor Low Proactive maintenance within
6-12 months
Recommendations
This is not deemed as a High-risk tree at this time but its suitability for long-term retention beyond 2-
3 years is questionable and it will need to be reassessed.
• Prune branches on dwelling side to reduce general encroachment.
Re-inspect in 12 months.
Residual Risk on completion of Mitigation Options
LOW
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Picture 13: Canopy encroachment over dwelling
Picture 14: Lower trunk with developing lean
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5.9 TREE 9 – SWAMP MAHOGANY
ID Genus & Species Common Name
9 Eucalyptus robusta Swamp Mahogany
Height Crown Spread [email protected] Age
12-14m 8-10m 500-600mm Over-mature
Health Structure
Fair to Poor with depleted canopy Fair to Poor with typical die-back in the main
branch structure
Target Occupancy Target Zone
Residential dwelling Constant Within 1 x height & Dripline
Comments
Tree 9 is positioned adjacent to the retaining wall and structural root disturbance on the compression
side is evident to facilitate the construction of the wall. With a canopy that favours the resort side,
the tree has compensated by over-developing structural and buttress roots on the tension side that
are visible at on the surface adjacent to the tree. This is a typical response for this species.
With the upper canopy in a retrenchment state, there is an increase in twig/small branch dead wood
and epicormic growth through the canopy. This is typical for this species and a natural method of
reducing the canopy size at this stage of its life cycle.
With no major faults noted that would indicate an increased likelihood of total failure within the
timeframe of this assessment, the risk matrix has been calculated on branch failure as this has been
deemed the most likely event to occur within the next 12 months.
Likelihood of Failure Likelihood of Impacting Target Matrix 1 - Result
Possible High Somewhat Likely
Consequence of Failure Matrix 2 – Overall Risk Rating Work Priority
Minor Low Proactive maintenance within
6-12 months
Recommendations
While tree 9 is not deemed as a High-risk tree at this time there are options to undertake canopy
management to assist the tree with its natural retrenchment process and reduce unpredictable
branch drop while retaining the tree for future habitat value.
• Prune branches on dwelling side to reduce general encroachment and end-weight
• Re-inspect in 12 months.
Residual Risk on completion of Mitigation Options
LOW
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Picture 15: Canopy encroachment over dwellings and pruning guide
Picture 16: Lower trunk with developed surface buttress/structural roots
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5.10 TREE 10 – EUCALYPT SPECIES
ID Genus & Species Common Name
10 Eucalypt species Unidentified
Height Crown Spread [email protected] Age
12-14m 5-6m 200-300mm Mature
Health Structure
Poor / dead Hazardous dead top
Target Occupancy Target Zone
Residential dwelling Constant Within 1 x height & Dripline
Comments
Edge tree with a dead top directly targeting the Unit dwelling.
The risk matrix has been calculated on dead canopy failure.
Likelihood of Failure Likelihood of Impacting Target Matrix 1 - Result
Imminent High Very Likely
Consequence of Failure Matrix 2 – Overall Risk Rating Work Priority
Significant High Within 30 days
Recommendations
• Remove the upper dead branch to the main trunk and retain the live low branch.
• Reinspect in 12 months.
Residual Risk on completion of Mitigation Options
LOW
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Picture 17: Dead Canopy encroachment over dwelling
Picture 18: Lower trunk next to the retaining wall
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6 S UMM ARY T ABLE
Tree
Name Comments Recommendation
ID
• Canopy Management to
Swamp Aged tree to the rear of the reduce branches on
1
Mahogany dwelling. property side.
• Re-inspect in 12 months.
2 Corkwood Defective trunk. • Remove
Unsuitable location for long-
3 Brush Box • Proactive removal
term retention.
Unsuitable form and location
4 Cheese Tree • Proactive removal
for long-term retention.
Swamp Unsuitable form and location
5 • Proactive removal
Mahogany for long-term retention.
Developing defect in main
6 Blackwood • Proactive removal
trunk.
7 Soapy Ash Unsuitable form for retention. • Proactive removal
Swamp Encroachment over adjacent
8 • Encroachment pruning
Mahogany dwelling.
• Canopy Management to
Swamp Aged tree with encroachment reduce branches on the
9
Mahogany over the adjacent dwelling. property side.
• Re-inspect in 12 months.
Eucalypt Dead section in the upper • Remove dead section
10
Species canopy. • Re-inspect in 12 months
Replacement planting for removed trees will be at a 1-5 ratio of suitable Eucalyptus species
as recommended in 7 Replanting / Habitat Restoration.
A total of 30 replanted trees will be incorporated into the first stage of a longer-term planting
scheme to restore appropriate flora within the Buffer Zone.
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Consult Arborist 7 R EPL ANTI NG / H ABI TAT R ESTOR ATI ON With a general lack of either natural regeneration or a successful replacement planting programme, many areas of the 10m Buffer Zone are lacking in both understory and tree cover particularly along the eastern boundary fence line. Noosa Council has conditioned that restoration planting is undertaken to re-establish the lost vegetation density to ensure on-going tree and vegetation cover. Key, locally indigenous plants are to be used in the habitat restoration with an emphasis on Koala and Black Glossy Cockatoo feeder trees whilst also improving the general amenity of the area for the resort guests. Prior to planting it is recommended that exposed areas of ground devoid of leaf litter are covered with a layer of mulch, 100mm in depth and that it is allowed to begin to compost into the soil. This action will help improve soil quality and plant establishment. Plants are to be tube stock of 'local providence' plants, planted at 1-2m spacings preferably in a mixed group of plants. Specific locations for larger tree species are to be considered prior to planting. It is estimated that 400-500 tube stock plants would be required for the re- establishment of the Buffer Zone. This quantity allows for some trees not to take, but hopefully, the ground improvements will also encourage natural regeneration. This planting can be staged in sections of the Buffer Zone and completed over 4-5 years to help with site preparation and establishment of the plants. 7.1 PLANTING LIST SUGGESTIONS 7.1.1 UNDERSTORY AND SHRUBS Pale Flax lily – Dianella longifolia Native Blue Tongue - Melastoma malabathricum subsp. Malabathricum Hovea - Hovea acutifolia Bitter pea – Daviesia umbellulate Baeckea - Babingtonia bidwillii 7.1.2 TREES Blueberry Ash - Elaeocarpus reticulatus Banksia integrifolia – Coastal Banksia Banksia – Banksia serrata Lemon scented tea tree - Leptospermum petersonii Soapy Ash - Alphitonia excelsa Black She-oak - Allocasuarina littoralis Moreton Bay Ash - Corymbia tessellaris Swamp Mahogany – Eucalyptus robusta Forest Red Gum – Eucalyptus tereticornis Black wattle – Acacia leiocalyx 19_01_24_TRA_RACV Resort _Noosa_V3 Page 27 of 32
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Consult Arborist 8 P L ANT Z ONE E NRI CHMENT There are a number of steps that may be taken when planting new plants and/or to improve existing plants, to better the establishment rate and increase the plant’s vigour, which will, in turn, benefit the plant’s health and the amenity that it provides. The use of chemical herbicides should be avoided where possible and alternative means used to manage undesirable plants, (e.g. hand removal). 8.1 MULCHING Spread decaying forest mulch over as large an area as possible around the tree to a depth of 100-150mm. There are numerous benefits that mulch provides to the soil beneath and the tree roots growing within it including moisture retention, an increase in beneficial fungal growth as the mulch slowly decays and forms a layer of compost providing an ideal environment for soil life and positive growing conditions. 8.2 ADDITIONAL PLANT HEALTH CARE Regular applications of a seaweed-based soil conditioner/plant food will feed the soil life and the trees and plants, promoting healthy growth for stronger safer trees that add amenity value to the local area and the associated benefits that come with having a healthy plantscape. www.nutri-tech.com.au In really poor soils – NTS Black Gold and NTS Liquid Humus On new plantings – NTS Root and Shoot 19_01_24_TRA_RACV Resort _Noosa_V3 Page 28 of 32
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Consult Arborist 9 A DDI TION AL I NFO RM ATION 9.1 CONTRACTOR NOTES Recommended arboricultural works are to be carried out by an arborist holding a minimum of a Level 3 AQF qualification in Arboriculture. It is expected that the Arborist may encounter anomalies within the tree as they climb/work and as such may use their discretion to remove any further branches or limbs which they may deem could pose an immediate risk. Additional removals outside the recommendations or defects noted whilst in the tree are to be recorded and reported to the author. All works must be undertaken in accordance with Australian Standards, AS 4373 – 2007 Pruning of amenity trees, and industry best practice. 9.2 HABITAT TREES When undertaking remedial tree works on habitat trees please be aware of the fauna and their habitat. Creation of future habitat whilst undertaking remedial works is to be considered. When mitigating hazardous deadwood, hollow sections and large branches, minimal pruning or reduction of weight is required rather than total removal. Hollow sections take many years to be created and are a highly valuable habitat. Coronet cuts should be facilitated where appropriate to mimic natural branch failure. Additional habitat can be created with the installation of a selection of nesting boxes. It is recommended that guidance on the specific type and positioning is received prior to installation. https://www.hollowloghomes.com/ 9.3 WILDLIFE CONSIDERATIONS The DEHP (Department of Environment and Heritage Protection) should be consulted regarding regulations concerning tree removal. The Nature Conservation Act 1992 provides statutory protection for most species of native animals and any tree work which affects them may constitute an offence. A qualified Fauna Spotter-Catcher should be consulted prior to tree works being carried out where protected wildlife may be active. 19_01_24_TRA_RACV Resort _Noosa_V3 Page 29 of 32
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Consult Arborist
10 R EFERENCES :
• Australian Standards AS 4373 – 2007 Pruning of amenity trees
• ISA Tree Risk Assessment
• Wild Plants of Greater Brisbane – Queensland Museum
• Noosa’s Native Plants – Stephanie Haslam, Second Edition
• Evaluating Tree Defects – A Field Guide by Ed Hayes, Second Edition
• Body Language of Trees - Research for Amenity Trees, Claus Mattheck
• Smiley E. Thomas, Nelda Matheny and Sharon Lilly April 2012. Tree Risk Assessment: Levels of Assessment
• Matheny Nelda and Jim Clark Feb 2009. Tree Risk Assessment: What we know (and What we Don’t Know)
11 A SSUMPTIONS AN D D ISCL AIM ER
This information contained in this report has been prepared on an independent basis, free of any bias and represents the honest
opinion of the consulting arborist.
All data is based on visual inspection of the tree/s and its/their location at the time of writing, unless otherwise stated, and contains
opinions, advice and recommendations based on information and data gathered from site inspections carried out by the author
and information supplied by the Client (RACV Noosa Resort).
All information received from the Client shall be deemed to be true, accurate and up to date.
To the extent permitted by law, you agree Consult Arborist Pty Ltd is not liable to you or any person or entity for any loss of or
damage caused or alleged to have been caused (including loss or damage resulting from negligence) either directly or indirectly,
by your use of the information made available in this report. In no event will the author be liable to you for any lost revenue or
profits, or for special, indirect, consequential or incidental damage (however caused and regardless of the theory of liability)
arising out of or related to your use of that information, even if the author has been advised of the possibility of such a loss or
damage.
Consult Arborist cannot be held responsible for the effects of non-conformance works performed, by unsuitably qualified staff or
without the supervision of Consult Arborist.
Unless otherwise stated this report cannot be used within a court of law or any legal situation without the prior consent of Consult
Arborist Pty Ltd. The author shall not be required to give testimony or to attend court by reason of this report unless subsequent
contractual arrangements have been made.
The information contained in this report refers only to the tree/s that were inspected on 10/01/2019 and reflects the condition of
the tree/s at the time of the inspection.
There is no warranty or guarantee, expressed or implied, that the problems or deficiencies of the plants or property in question
may not arise in the future. Likewise, remedial treatments cannot be guaranteed.
Arboriculturalists cannot detect every condition that could possibly lead to the structural failure of a tree. Trees are living
organisms that fail in ways we do not fully understand. Conditions are often hidden within trees and below ground. Consult
Arborist Pty Ltd and the author cannot guarantee that a tree will be healthy or safe under all circumstances, or for a specified
period of time.
This report does not take into consideration the possibility of extreme weather or other events over which Consult Arborist Pty
Ltd has no control.
Treatment, pruning and removal of trees may involve considerations beyond the scope of the Arboriculturalists services, such as
property boundaries and ownership, disputes between neighbours, sight lines, landlord-tenant matters and related. Consult
Arborist Pty Ltd cannot take such issues into account unless the complete and accurate information is given to them. Likewise,
Consult Arborist Pty Ltd cannot accept any responsibility for the authorization or non-authorization of any recommended treatment
or remedial measure.
Arboriculturalists are tree specialists who use their education, knowledge, training and experience to examine trees, recommend
measures to enhance the beauty and health of trees and attempt to reduce the risk of living near trees. Trees can be managed,
but they cannot be controlled. To live or work near a tree involves some degree of risk. The only way to eliminate all risks
associated with a tree is to eliminate the tree.
Clients may choose to accept or disregard the recommendations of Consult Arborist Pty Ltd or to seek additional advice.
19_01_24_TRA_RACV Resort _Noosa_V3 Page 30 of 32
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Consult Arborist
A PPENDIX 1 - T REE R ISK A SSESSM ENT M ETHODOLOGY
The methodology of rating risk used in this report is based on the following International Society of Arboriculture’s Tree Risk
Assessment and is calculated through the use of qualitative risk matrix tables.
Initially, the Likelihood Matrix is used to estimate how likely a failure will be to impact a target. This is calculated by categorising
how likely failure is to occur and combining that with how likely that failure is to impact a target, as per Table 1.
Matrix 1 – Likelihood Matrix
Likelihood of Impacting Target
Likelihood of Failure
Very low Low Medium High
Imminent Unlikely Somewhat Likely Likely Very likely
Probable Unlikely Unlikely Somewhat Likely Likely
Possible Unlikely Unlikely Unlikely Somewhat Likely
Improbable Unlikely Unlikely Unlikely Unlikely
Table 1: Matrix 1 – Level likelihood of impact to a target.
Once the Likelihood of Failure & Impact level is determined a final level of Risk Rating can be calculated by combining the
Likelihood with the Consequences of Failure for each identified risk. This ascertains an overall Risk Rating for the tree, determined
in Table 2.
Matrix 2 – Risk Rating Matrix
Likelihood of Failure Consequences of Failure
& Impact Negligible Minor Significant Severe
Very Likely Low Moderate High Extreme
Likely Low Moderate High High
Somewhat Likely Low Low Moderate Moderate
Unlikely Low Low Low Low
Table 2: Matrix 2 – Level of Risk
Where multiple risks are noted these tables will be used for each risk and the highest level will be taken as the overall risk rating
for the tree. In this scenario, multiple mitigation options may be offered to the tree manager to return the risk to an acceptable
level within a reasonable timeframe.
A PPENDIX 2 - D EFINITION OF ISA T ERMS
Likelihood of Failure
Improbable: The tree or branch is not likely to fail during normal weather conditions and may not fail in many severe weather
conditions within the specified time frame.
Possible: Failure could occur, but it is unlikely during normal weather conditions within the specified time frame.
Probable: Failure may be expected under normal weather conditions within the specified time frame.
Imminent: Failure has started or is most likely to occur in the near future, even if there is no significant wind or increased load.
This is an infrequent occurrence for a risk assessor to encounter and may require immediate action to protect
people from harm.
Likelihood of impacting a target
Very low: The likely hood of the failed tree or part impacting the specified target is remote. Occupancy rates are rare with
no protection or occasional with moderate protection.
Low: It is not likely that the failure will impact the target. The occupancy rates are frequent with partial protection or
constant with significant protection.
Medium: The failure is as likely as not to impact the target. The occupancy rates frequent with single side exposure or
constant with partial protection.
High: The failure is most likely to impact the target. Occupation is constant with no protection.
Occupancy rates
Constant: 24 hours a day, 7 days a week.
Frequent: A large portion of the day/week.
Occasional: The zone is occupied by people or targets infrequently or irregularly.
Rare: Not commonly used.
Consequences of Failure
Negligible: Low-value property damage or disruption that can be replaced or repaired, no personal injury.
Minor: Low to moderate property damage, small disruptions to traffic or infrastructure, or very minor injury to persons.
Significant: Property damage of moderate to high value, considerable disruption, or personal injury.
Severe: Serious personal injury or death, damage to high-value property or disruption of important activities.
Levels of risk
Extreme: Failure is imminent with a high likelihood of impacting the target, and the consequences are severe.
High: Failure is very likely or likely with significant consequences, or failure is likely with severe consequences.
Moderate: Failure is very likely or likely with minor consequences, or failure is somewhat likely with significant or severe
consequences.
Low: Failure is unlikely with negligible consequences or failure is somewhat likely with minor consequences.
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Consult Arborist
A PPENDIX 3 - D EFINITION OF T ERMS
The following criteria have been used in the report to gather information and determine the required management
options on the grounds of public health and safety. Measurements are approximate and made visually by eye
unless otherwise stated.
Age Class:
Young: Early stage of growth, immature size
Early Mature: Fast growing well-established tree which has not yet reached mature size
Mature: The tree reached its mature size, exhibits slowing growth rates with early stages of naturally forming dead
or dysfunctional wood.
Over Mature: Tree has reached mature size and is unlike to increase significantly in height or mass. Retrenchment of the
upper crown with increased vegetative vitality in lower crown, increased fungal activity and wood decay,
increase colonisation by flora and fauna.
Veteran: Tree with advanced retrenchment, a reduced crown size and annual increment growth, extensive hollowing,
crown collapse, low vigour, advance heartwood decay, advanced colonisation by fauna and flora.
Health:
Good: Tree with no defects or disorders which are notable. Full canopy with good colour foliage. Minimal pathogen
damage.
Fair: Tree with minor defects or disorders which are notable. Some deadwood within what can be an unbalanced
canopy, foliage generally with good colour although some discolouration may be present typical of species
in location. Minor pathogen damage.
Poor: Tree with major defects or disorders which are notable. Tree has considerable deadwood present,
discoloured or distorted leaves indicating further decline of the tree. Detrimental pathogen damage.
Dead: Dead or dysfunctional moribund tree.
Structure:
Good: Tree with good unions and no branch defects. Sound trunk with no / minor defects. Good buttress and root
structure.
Fair: Tree with minor defects or disorders which are notable. Small areas of bark missing. Small cavities or minor
unfavourable branch unions may be present. Minor damage to roots.
Poor: Tree with major defects, large hollows, weak unions and/or problematic damaged roots.
Hazardous: This implies a tree with a major defect that may fail at any time
Tree Retention Value:
This retention value comes from the Institute of Australian Consulting Arborists (IACA), 2010, IACA Significance of a Tree,
Assessment Rating System (STARS), Institute of Australian Consulting Arboriculturists, Australia, www.iaca.org.au -
http://www.iaca.org.au/home/index.php/publications/71-stars
The process uses the Retention Value – Priority Matrix by assessing the Tree Significance Assessment Criteria and crossing
it with the Estimated Life Expectancy to determine the following ratings:
High: Priority for Retention
These trees are considered important for retention and should be retained and protected. Design
modification or relocation of building/s should be considered to accommodate the setbacks as prescribed by
the Australian Standard AS4970 Protection of trees on development sites. Tree sensitive construction
measures must be implemented e.g. pier and beam etc. if works are to proceed within the Tree Protection
Zone.
Medium: Consider for Retention
These trees may be retained and protected. These are considered less critical; however, their retention
should remain a priority with removal considered only if adversely affecting the proposed building/works and
all other alternatives have been considered and exhausted.
Low: Consider for Removal
These trees are not considered important for retention, nor require special works or design modification to
be implemented for their retention.
Remove: Priority for Removal
These trees are considered hazardous, or in irreversible decline, or weeds and should be removed
irrespective of development.
Timeframe to complete works based on Risk Rating:
Low Low-risk potential / proactive management Within 6-12 months
Moderate Medium risk potential / reactive management Within 6 months
High High-risk potential / reactive management Within 30 days
Severe Severe risk potential / Risk management ASAP - Urgent
Definitions & Abbreviations:
DBH: Diameter at Breast Height - The approximate diameter of the trunk is measured visually in millimetres at a
height of 1.4m.
Works Definitions:
Canopy Combination of dead wooding and selective pruning to benefit the tree’s future health and canopy structure.
Management: End-weight reduction of longer lateral branches, with the creation of future growth points to sustain canopy
growth and mimic natural canopy retrenchment.
19_01_24_TRA_RACV Resort _Noosa_V3 Page 32 of 32
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