2022-08-09 Services & Organisation Committee Agenda

SERVICES & ORGANISATION COMMITTEE MEETING AGENDA   9 AUGUST 2022




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SERVICES & ORGANISATION COMMITTEE MEETING AGENDA                                                                    9 AUGUST 2022

                                                                                                           Noosa Shire Council
                                                                                       Guiding Principles for Tree Management
                  Appendix B — Risk Management Options for Existing Trees
                   Table2 3 Example Risk Management Approaches for Existing Trees
                     APPROACH               DESCRIPTION
                     Monitor trip points      Where no other practical method can be employed to prevent this occurring, a
                                              regular trip point inspection program should be instigated and pavement replaced
                                              or repaired as necessary.
                     Flexible pathways        Use of flexible material such as bitumen, paving, or rubber compounds for
                                              footpaths and tree surrounds, will reduce the occurrence of trip points and may be
                                              less expensive and easier than concrete to maintain or replace when necessary.
                   BOGS PSN              |       ay als be bene        reduce the nent    ected paivay with                |
                     Re-direct pathways       Where space allows, pathways should be re-directed away from trees/tree roots.

                                              raise pathways above the roots, allowing for root expansion without damaging the
                                              pavement. Timber bridges are an effective option

                                              guidance of a qualified arborist. This practice could be combined with installation
                                              of root barriers where appropriate.
                     Root barriers            In some circumstances root barriers may be useful in deflecting roots away from
                                              pavement or services.
                     Directional or           Directional boring rather than open trenching for underground services will greatly
                     Horizontal Boring        reduce public risk as well reducing injury to tree roots. If located deeply, root
                    Services                  contact with the pipeline may be minimised as the majority of roots of most
                                              species will remain within the top 1 metre of soil (based on a soil with medium
                                              texture).
                     PVC Welded Piping        Replacement of old porous clay pipe mains with PVC or polyurethane mainlines
                                              will significantly reduce the potential for tree root entry.
                     Preventative tree        Trees in public areas should be regularly inspected and maintenance, such as
                     maintenance              dead-wooding and developmental pruning carried out as prescribed. Pruning
                                              should always be specified and undertaken in accordance with AS 4373-2007.
                     Raising pathways         Where appropriate, pathways could be raised to reduce direct root pressure on
                                              the pavement. Care must be taken not to build up soil against the trunk of a tree.
                                              Aeration piping, in conjunction with geo-textile fabric and gravel should be
                                              installed between root zone and new pavement to aid with gas exchange to roots.
                                              Care should be taken to shape the new surface to drain water away from the
                                              trunk of the tree.
                     Insulated cabling        Replacement of uninsulated overhead power lines with insulated & bundled
                                              cables will reduce both the clearance needed and the pruning costs and severity.
                     Underground power        The initially high cost of installing power underground may in fact be a practical
                     and                      option when compared with the projected cost of repeated pruning, the risk that
                     communications           this work involves to operators, the negative impact on trees, loss of public
                     networks                 amenity and of urban forest economic contributions.

                                              a valuable stand of trees is present. To make this option more attractive to
                                              service providers, Councils may wish to consider waiving road opening fees.
                      kerb/gutter             from the trunk, creating an island around the tree.
                       zone                   enlarged/created to accommodate surface roots. Rather than turf, this area could
                                              be formed into a garden bed, mulched or covered with a suitable tree grate.
                       pruning                Refer to AS4373 Pruning of Amenity Trees.
                                              rather than to remove a tree in order to abate a hazard.
                      defect                  stems.
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                       Tree engineering       In some cases cabling may be used to support tree structure or to control the
                       Tree removal           In some situations it may be preferable to remove a tree and replace with a more
                                              suitable species, perhaps in an alternative location. In all cases of tree removal it
                                              is necessary to ensure that the removal is mitigated in order to ensure the future
                                              integrity of the urban forest.

                  Noosa Shire Council                                                                           10

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