Attachment 4 - Tree Management Report (002) · 51987.3004.01

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Brief:
  •   Identify trees impacted by the proposed construction of replacement retaining walls.
  •   Determine Tree Protection Zones of these trees using the Australian standards 4970-
      2009, Protection of trees on development sites
  •   Recommend any treatments or ongoing monitoring or maintenance.

Methods and Procedures:
  •   Discussions on site with Josh De Wit to determine the extent of works and
      methodology.
  •   Visual inspection of the standing stock at ground level and light probe investigation of
      the root plate of the trees to determine the extent and health of sub-canopy structures.
  •   No scientific analysis was conducted during the preparation of this report.
  •   Australian standards 4970-2009, Protection of trees on development sites, AS 4373-
      2007 pruning of amenity trees and AS2870-2011 have been referenced to prepare this
      report.
  •   International Society of Arboriculture Tree Risk Assessment Manual was used to
      provide recommendations in this report
  •   The weather on the day of the inspection was fine, low wind and a warm temperature

Summary
  •   This site located at Noosa Heads is a residential dwelling. This dwelling has been
      constructed on a steep embankment in an area classed as high slip risk.
  •   As this site is classed as a high slip risk area it is essential to maintain the integrity of
      the existing retain walls to manage water runoff and for erosion control.
  •   During the inspection it was determined that all existing sleeper style retaining walls
      have failed from the effects of tree trunk expansion, root ingress and rotting of the
      sleeper wall material. These walls need to be replaced to ensure the stability of the
      site, protect the foundations of the existing dwelling, mitigate the effects of water
      runoff and for erosion control.
  •   The influence of roots from the mature trees on site will be causing soil moisture
      suction (migration of moisture towards the trees.) this abnormal moisture condition at
      the foundations of the dwelling and retaining walls cause shrinkage and subsidence.
  •   The Australian Standard AS2870-2011 recommends large growing trees and tree
      groups should be grown at least one and a half times their mature height from
      foundations. All trees listed have portions of the existing dwelling within their
      Structural Root Zones.
  •   Trees appear to be in poor to average condition with some demonstrating issues
      arising from poor prior pruning practices. This prior pruning does not meet the
      Australian Standards and has created epicormic regrowth and branch defects which
      have rendered these trees as unstable.
  •   All proposed works to reconstruct the retaining walls, falls well within the Structural
      Root Zones and Tree Protection Zones of the trees per the Australian standards 4970-
      2009, Protection of trees on development sites.
  •   It is impossible to gain access or clearance zones away from the trees to carry out the
      essential reconstruction works which will render the trees as not viable.
  •   The only way to sufficiently mitigate these effects to protect the foundations of the
      existing dwelling and new retaining walls is to remove these trees.
  •   I recommend the removal of these trees.

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Site Plan


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                                        Tree 1
                     Cupaniopsis anacardioides 7m x 6m Cal .330m

                           Tree Protection Zone 3.96m Radius
                                   Structural Root Zone 2.08m Radius

Description:
   • This tree is not suitable for this confined environment as it is a large tree to 15 meters.
   • Tree health is considered poor. The trunk has developed through the face of the
       existing retaining wall and the tree lists heavily over the existing dwelling.
   • The proposed retaining wall replacement work is within the SRZ of the trees as set
       out in the Australian standards 4970-2009, Protection of trees on development sites,
       which will render the trees unviable.

Recommendations:
   • I recommend to remove this tree and replace with more appropriate species.

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                                       Tree 2
                   Syzygium cormiflorum 8m x 4m Cal .200m .200m

                           Tree Protection Zone 3.96m Radius
                                   Structural Root Zone 2.08m Radius
Description:
   • This tree is not suitable for this confined environment as it is a large tree to 15 meters.
   • Tree health is considered average and the tree lists over the existing dwelling.
   • The proposed retaining wall replacement work is within the SRZ of the trees as set
       out in the Australian standards 4970-2009, Protection of trees on development sites,
       which will render the trees unviable.

Recommendations:
   • I recommend to remove this tree and replace with more appropriate species.

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                                       Tree 3
                   Aleurites rockinghamensis 10m x 10m Cal .330m

                           Tree Protection Zone 3.96m Radius
                                   Structural Root Zone 2.08m Radius
Description:
   • This tree is not suitable for this confined environment as it is a large tree to 15 meters.
   • Tree health is considered average and the tree lists over the existing dwelling.
   • The proposed retaining wall replacement work is within the SRZ of the trees as set
       out in the Australian standards 4970-2009, Protection of trees on development sites,
       which will render the trees unviable.

Recommendations:
   • I recommend to remove this tree and replace with more appropriate species.

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                                         Tree 4
                              Acacia sp 6m x 3m Cal .200m

Description:
   • This tree is dead and listing heavily over the existing dwelling

Recommendations:
   • I recommend to remove this tree

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                                        Tree 5
                        Corymbia intermedia 8m x 5m Cal .350m

                             Tree Protection Zone 4m Radius
                                   Structural Root Zone 2.10m Radius

Description:
   • This tree is not suitable for this confined environment as it is a large tree to 15 meters.
   • Tree health is considered average and the tree lists heavily over the existing dwelling.
   • The proposed retaining wall replacement work is within the SRZ of the trees as set
       out in the Australian standards 4970-2009, Protection of trees on development sites,
       which will render the trees unviable.

Recommendations:
   • I recommend to remove this tree and replace with more appropriate species.

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                                         Tree 6
                              Acacia sp 6m x 4m Cal .400m

Description:
   • This tree is dead and lists towards the existing dwelling and is supported by the
       adjoining Corymbia.

Recommendations:
   • I recommend to remove this tree

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                                         Tree 7
                          Dypsis lutescens 5m x 4m Cal .100m

                           Tree Protection Zone 1.5m Radius
                                   Structural Root Zone 1 m Radius
Description:
   • This palm is not suitable for this confined environment.
   • Plant health is considered poor, and it is growing in a heavy shaded area.
   • The proposed retaining wall replacement work is within the SRZ of the plant as set
       out in the Australian standards 4970-2009, Protection of trees on development sites,
       which will render the plant unviable.

Recommendations:
   • I recommend to remove this tree and replace with more appropriate species.

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                                    Trees 8 & 9
                      Syzygium cormiflorum 8m x 4m Cal .350m

                            Tree Protection Zone 4m Radius
                                  Structural Root Zone 2.10m Radius

Description:
   • These trees are not suitable for this confined environment as they are a large tree to 15
       meters.
   • Tree health is considered poor. Poor prior pruning practices, which do not meet the
       Australian Standards, have created epicormic regrowth and branch defects which have
       rendered these trees as unstable.
   • The proposed retaining wall replacement work is within the SRZ of the trees as set
       out in the Australian standards 4970-2009, Protection of trees on development sites,
       which will render the trees unviable.

Recommendations:
   • I recommend to remove these trees and replace with more appropriate species.

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                                   Trees 10 to 20
                      Syzygium erythrocalyx 5m x 2m Cal .200m

                          Tree Protection Zone 2.4m Radius
                                 Structural Root Zone 1.68 m Radius

Description:
   • These trees have been grown as a hedge and are not suitable for this confined
       environment as they are a large tree to 10 meters.
   • Tree health is considered poor. Poor prior pruning practices, which do not meet the
       Australian Standards, have created epicormic regrowth and branch defects which have
       rendered these trees as unstable.
   • The proposed retaining wall replacement work is within the SRZ of the trees as set
       out in the Australian standards 4970-2009, Protection of trees on development sites,
       which will render the trees unviable.

Recommendations:
   • I recommend to remove these trees and replace with more appropriate species.

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                                            Tree 21
                                           Pandanus
Description:
   • This large plant has one extend branch which will block crane access required to
       complete works.
Recommendations:
   • I recommend to remove this branch


Implementation of tree protection measures during construction

All work is to be carried out in accordance with the Australian Standard AS4970-2009-
Protection of trees on development sites

Care is required to minimize the impact on trees located within the property and the adjoining
properties. Exclusion, with fencing and supervision while working within the identified
TPZ’s will allow the retaining walls replacement work to be carried without unduly affecting
the continued health of the adjoining trees.

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Protection of trees to be retained:

To preserve the retained trees within this site tree exclusion zones must be determined. To
calculate these zones the formula has been used from the Australian Standard AS4970-2009
Protection of trees on development sites. This is the “Tree Protection Zone”.

Any encroachment, disturbance, or compaction of the soil within the Tree Protection Zone
can damage or destroy the fine absorbing roots. Injury caused by cutting, crushing,
suffocation, poisoning, or moisture stress by inundation or dehydration can result in damage
to a tree. The effects of some Injuries may not be apparent for some time.

The following guidelines are minimum standard I recommended for the preservation of these
trees. These guidelines should be incorporated in construction contracts, and the details made
available to all parties involved with work on the site, including equipment operators. Other
guidelines and protective measures may also be appropriate, in addition to those listed below.

     1. Protection Barrier: A suitable protection barrier is to be installed around the trees to
         be preserved. The barrier shall be constructed of durable fencing material, such as
         plastic construction fencing or chain-link fencing. The barrier shall be installed at
         the Tree Protection Zone perimeter. The fencing is to be maintained in good repair
         throughout the duration of the project, and should not be removed, relocated, or
         encroached upon without permission of the consulting arborist.
     2. Storage of Materials: There is to be no storage of materials or supplies of any kind
         within the area of the protection barriers. Concrete and cement materials, block,
         stone, sand and soil are not being placed within any Tree Protection Zones.
     3. Fuel Storage: Fuel storage will not be permitted within 30 meters of any tree to be
         preserved. Refueling, servicing and maintenance of equipment and machinery will
         not be permitted within 30 meters of protected tree.
     4. Debris and Waste Materials: Debris and waste from construction or other activities
         cannot be permitted within the Tree Protection Zones. Wash-down of concrete or
         cement handling equipment, in particular, will not be permitted within 30 meters of
         protected tree.
     5. Altered Site Hydrology: No changes in soil surface hydrology, any grade changes
         proposed that will impact on the Tree Protection Zones should be approved by the
         consulting Arborist before construction begins.
     6. Damages: All precautions should be taken to mitigate any potential injuries to the
        protected trees and any damages or injuries should be reported to the project arborist
        as soon as possible. Severed roots shall be pruned cleanly to healthy tissue, using
        sharp clean pruning tools. Broken branches or limbs are to be pruned in accordance
        with the Australian Standard AS4373-2007 Pruning of Amenity Trees.




Assessed by: David Hawthorne                                              Dip Arb AHC50510
Consulting Arborist AQF5                                                  Dip Hort/Arb RTF50203
                                                                          Dip Hort RTF50103
                                                                          MQAA / ISA QTRA
                                                                          AIH RH0150