Response to Information Request - OPW13/0669

                                                                                                  Tree Inspection Report   -

                                                                                                                               Manyaii Chan
                                                                                              Site Address: 4 Habitat Place, Noosa Heads




                Identifying and managing risks associated with trees is a subjective process. Tree evaluation involves
                examining a tree for structural defects and associating those defects with a known pattern of failure and
                rating the degree of risk. By definition, a hazard requires the presence of both a defective tree and a
                target. Unless a target is present a tree cannot be hazardous. As a result, assessing hazard is not
                limited to evaluating failure potential on its own. Hazard evaluation must consider the potential
                presence of a target and its consequence.

                Tree Hazard Assessment involves three components
                   .     A tree with the potential to fail
                         An environment that may contribute to that failure
                         A person or object that would be injured or damaged


                ArborCare Queensland has used the above rationale in establishing an overall perceived risk that this
                Eucalyptus tereticornis (Forest Red Gum)currently exhibits.

                The Australian Standard AS4970 -2009 Trees on Development Sites outlines minimum requirements to
                maintain tree stability and health. ArborCare Queensland considers this standard to be industry best
                practice in arboriculture.

                An indicative Tree Protection Zone (TPZ)and Structural Root Zone (SRZ)of each tree is established
                from the tree diameter measurements measured at 1.4m above ground level for a single leader tree.

                The Structural Root Zone (SRZ)is an area required for tree stability and is constantly moving and
                flexing as a result of wind and tree dynamics. A larger area is required to maintain a viable tree. There
                are many factors that affect the size of the Structural Root Zone (e.g.tree height, crown area, soil type,
                soil moisture). The following formula is used to determine the Structural Root Zone


                                                         SRZ radius = (D )C 50)0.42 )C 0.64

                The Tree Protection Zone (TPZ)is a combination of root area and crown area which contains vital roots
                which collect nutrients and moisture for the tree, and must be protected in order for the tree to survive
                The TPZ is an exclusion zone which protects trees during construction related activities and is an area
                isolated from construction disturbance, so that the tree remains viable. The following formula is used to
                define the Tree Protection Zone,


                                    The radius of the TPZ is calculated for the tree by multiplying its DBH )( 12.
                                                                  TPZ = DBH )C 12


                Please refer to the following table below which provides an indicative SRZ and TPZ requirements for
                three different tree diameter sizes.


                        Tree Diameter (m)                    Structural Root radius (m)       Tree Protection Zone radius
                                                                                                               em)
       I    I                        .4                                2.25                                    5.0
            ’--_.-      --    ..-




                                     .5                                2.45                                    6.0

                                     .6                                2.65                                    7.0


                ArborCare Queensland consulted with Charlie Gilbert Plumbing & Draining Coolum Beach, who
                installed and repaired in ground rain water harvesting tanks at 4 Habitat Place.


                Photographs of key interest areas are contained within this report for your perusal

Cons       ting Arborist: Phillip Best
                         Dip. Arb, Nat. Cert. Hort                                                                             Page 3/10