Gardiner v Bisley

On site hearing

1. The retaining wall is located within the applicant's property, close to his rear boundary, and the trees are located within a strip of land, about six metres wide, in an adjacent neighbouring property, owned by Mr Bisley. Beyond the row of trees is the respondent's old tennis court, the side of which is roughly parallel to the boundary wall which separates the two properties, along a north-south axis.
2. Though the respondent's tennis court is about four metres higher than the ground level at the rear of the applicant's property, the land slopes down markedly towards the common boundary wall. Close to the wall, on the respondent's side, soil has been excavated down a further 500mm or more, and removed. Though accumulated leaf and stick litter made the depth of this excavation difficult to quantify, the net effect of the slope down from the tennis court, and this excavation, has resulted in only the lower part of the tall boundary wall retaining soil in the respondent's property. Having said this, it is reasonable for the applicant to consider this wall a retaining wall and refer to it as such.
3. In addition to the large Blackbutt, the trees comprise one Eucalyptus botryoides (Southern mahogany), three mature Callitris sp. (Australian Cypress) and various Cinnamomum camphora (Camphor laurel) and Pittosporum undulatum (Sweet Pittosporum or Mock Orange).

Proposed orders

1. The applicant seeks the following orders: "Removal of all trees in the application due to damage to property and likely to cause serious injury or death - 13 in total. Replacement of block retaining wall due to structural damage being caused by tree roots and constant pressure."
2. The respondent reiterated that his original offer to Mr Gardiner of "no objection to the overhanging branches of trees being lopped back to level of your concrete retaining wall", still remained open, though remained subject to the conditions noted in his letter of 28 February 2019. Mr Bisley advised that he had received no reply to his letter, but that at no point had Mr Gardiner disputed anything in that letter.
3. Mr Gardiner appeared annoyed because Mr Bisley provided his reply to Mr Gardiner's correspondence on his legal firm's letterhead, and attached a range of conditions as requirements for any pruning works. At Q32 of his application, he noted that "Max Bisley then sent legal documents from his own law firm trying to bully, make the process harder and assert his authority".
4. While Mr Bisley may have been trying to exploit a power imbalance in the context of this legal dispute, the conditions included in his response to Mr Gardiner all appeared to be relatively straightforward and justified, so as to prevent damage to his property, and address requirements regarding access via a right of way owned by a third party.
5. The applicant's annoyance appeared to exacerbate his fervour in his pursuit of removal of all the trees, and likely influenced his objection to the submission, by the respondent, of a late arborist report that may have assisted the Court, notwithstanding that it was the applicant's right to do so. I accepted this objection, and the report was not tabled.

Jurisdictional requirements

1. With respect to s 7, an owner of land may apply to the Court for an order to remedy, restrain or prevent damage to property on the land, or to prevent injury to any person, as a consequence of a tree to which this Act applies that is situated on adjoining land.
2. The Court's ability to make orders is limited, at s 10 of the Act. 10 Matters of which Court must be satisfied before making an order (1) The Court must not make an order under this Part unless it is satisfied: (a) that the applicant has made a reasonable effort to reach agreement with the owner of the land on which the tree is situated, and (b) if the requirement to give notice has not been waived, that the applicant has given notice of the application in accordance with section 8. (2) The Court must not make an order under this Part unless it is satisfied that the tree concerned: (a) has caused, is causing, or is likely in the near future to cause, damage to the applicant's property, or (b) is likely to cause injury to any person.
3. If the jurisdictional tests at s 10 of the Act are satisfied, the Court can make orders such as those at s 9 to remedy, restrain or prevent damage to property, or to prevent injury to a person, as a consequence of the tree. Before determining the nature of any orders, the Court must consider a range of matters set out at s 12. The record of correspondence and conversations between the parties demonstrates that Mr Gardiner has made reasonable effort, and this is not disputed. Therefore, the principal jurisdictional test in this matter is at s 10(2).

Retaining wall damage and engineering evidence

1. Both parties provided engineering reports, though neither engineer noted the requirement of expert witnesses to read and comply with the Expert Witness Code of Conduct in sch 7 of the Uniform Civil Procedures Rules 2005. Nonetheless, I considered each report.
2. The applicant's report, dated 23 September 2020, was provided by Mr Goran Ugrinovski of ATB Consulting Engineers Pty Ltd. It noted that the line of trees "have caused structural damage to the retaining wall along the western boundary and have left a significant amount of debris (leaves, branches, twigs etc) upon the roofs, yard and pool". Mr Ugrinovski identified the tree species correctly in the main, and added that "the smallest tree kind grows to 15m with the largest up to 70m". In reality, none of these trees were taller than about 25 metres, and the majority were less than 10 metres.
3. With reference to photos 7-8 which displayed cracks in the retaining wall, Mr Ugrinovski noted that "Considering the vicinity of trees adjacent to the property, this is caused by the outgrowing tree roots which place additional pressure along the retaining wall than it is capable."
4. Beyond the proximity of the trees to the wall, Mr Ugrinovski provided no evidence to support this presumption. There is no mention of any testing or excavation being undertaken or considered, so as to confirm a causal relationship between the wall damage and the trees. He mentioned no other possible causes for this damage. As such, Mr Ugrinovski's findings are speculative.
5. In reference to nine other photos, Mr Ugrinovski highlights tree debris in the pool, yard, gutters, and on roofs, and the frequent maintenance required to remedy this. He describes the respondent's refusal to remove the trees, then says "In our opinion, the adjacent trees will need to be removed as soon as possible as they have already caused structural damage to the property and are a safety concern."
6. The remainder of the report largely expands on the applicant's concerns about his children's safety from dropping branches, and references the gravitational acceleration, and force on impact, of a branch dropping from a height of 70 metres, notwithstanding that the tallest tree is around one third of this height, and unlikely to grow much taller. He also highlights the trees' contribution to bushfire risk.
7. Mr Ugrinovski has displayed little objectivity, but rather, appears to have written his report predominantly to amplify the various concerns of the applicant. In doing so, he has provided opinions outside of his field of expertise of "Senior Civil and Structural Engineer". Where he has addressed the retaining wall, i.e. the engineering issue, his conclusions are not based on evidence that may have been gained from excavation to locate tree roots, or any other testing, and thus are mere speculation. There was no mention by Mr Ugrinovski, nor by the applicant, of any request made to the respondent for access to undertake such investigation. Based on all these considerations, this report has not assisted the Court, nor the applicant.
8. Mr Ali Sooreh, a Civil/Structural Engineer of Aegis Civil & Structural Engineering, provided a report, dated 9 January 2021, for Mr Bisley (the Aegis report). Based on his inspection and measurements taken on 6 January 2021, he noted that the rear retaining wall is constructed from core-filled blocks with a natural batter of about five degrees, which had sustained lateral shift of around 20mm at the base of the wall and significant stepped cracking.
9. Mr Sooreh noted multiple mechanisms contributing to wall damage: 1. The proximity of the Blackbutt and other trees, exerting excessive surcharge pressure on the wall, with signs of "differential stem deflection which has caused cracking". 2. Though no destructive investigation was undertaken to find a free draining layer behind the wall, he notes an absence of "any weep holes, or suitable drainage system such as sub-soil tail-outs". 3. Mr Sooreh added that "hydrostatic pressure on a retaining wall can be more significant than soil pressure and this water pressure can put excessive pressure on a wall causing it to fail". 4. No vertical expansion joints were observed in the wall. Mr Sooreh noted that a wall of 20 metres long (like this one), would normally have two to three, to minimise the impact of thermal changes (i.e. expansion and shrinkage). He said, "This could exacerbate internal cracking." 5. Mr Sooreh noted difference in level across the length of the wall, with subsidence of 50mm at the northern end. He explained this as "likely due to global ground movement over time and/or initial construction error, which has contributed to cracking". 6. Mr Sooreh made the following observation: "For a cantilevered wall it is unusual that the wall has sustained lateral shift of around 20mm at the base of the wall. Normally a wall of this size would be reinforced with vertical 12mm or 16mm steel bars and cantilevered into a footing. This would mean that if the wall was to begin to fail, it would fail by rotation, not by lateral shift of the stem of the wall. We could not determine the size of the cantilever footing however the above observations lead us to conclude that the wall may have been inadequately constructed." 1. Mr Sooreh noted that the expected service life of a wall structure such as this one is 40-50 years and thus it may be "approaching end of useful life, and/or a period where maintenance is required to extend service life".
10. He concluded that the applicant's property is currently safe to occupy, but these "issues pose risk to long-term structural strength of the retaining wall without mitigation works".
11. The report recommended staged remediation works, considering "condition, with respect to the age of the asset".
12. Remediation Action 1 recommended the removal of the boundary trees to reduce surcharge and the damage to the wall, with the option of a staged approach, where some "significant" trees are initially removed, and the remaining trees pruned in the interim. Residual stumps are to be retained, or, if removed, a cementitious fill installed behind the wall. The object of these two alternative measures was to maintain stability on the sloping bank and behind the wall, a function which the network of tree roots are likely to currently perform, so as to minimise risk of subsidence damage to the respondent's tennis court and surrounds.
13. Remediation Action 2 recommended the installation of a 100mm diameter Agline with minimum 20mm coarse aggregate or blue metal, behind the wall, to allow the free flow of water and thus minimise hydrostatic pressure. This Agline would be connected to the existing hydraulic system.
14. Remediation Action 3 provided specifications for crack stitching of identified masonry cracks in the retaining wall, to be undertaken by a specialist qualified in the use of the 'HeliFix' system.
15. Remediation Action 4 is ongoing monitoring of the wall, and reporting should the cracking worsen. Soil nailing is said to be an appropriate future option, should this eventuate. The adoption of this recommendation is noted to be at the client's discretion.
16. Due to the implicit relationship between trees and structures, with the arboricultural expertise and experience I bring to the Court, I have considered many retaining walls near trees. The seven mechanisms noted as contributing to wall damage in the Aegis report are all reasonable, and it is likely that a combination of many, or even all of these factors are at play here.
17. It is regrettable that, as with Mr Ugrinovski, Mr Sooreh did not undertake or recommend excavation, to clarify whether there was a causal link between roots of the Blackbutt or any other of the trees, and the wall damage.
18. In Smith & Hannaford v Zhang & Zhou [2011] NSWLEC 29 at [62], Craig J said "something more than a theoretical possibility is required in order to engage the power under the Trees (Disputes between Neighbours) Act to make an order to remedy, restrain or prevent damage".
19. In Stevens v Russell [2016] NSWLEC 1233 at [40], Commissioner Fakes notes that: "it is a common assumption that the mere presence or proximity of a tree is sufficient to conclude that the tree is the cause of the damage. It is not. It is necessary to find evidence to substantiate the assumption that the tree has caused the damage. In the case of alleged root damage, some excavation is usually required."
20. Notwithstanding this, based on the characteristics of the cracking, and the proximity of the base of the Blackbutt to the cracks, I am satisfied on the balance of probability, though barely, that the Blackbutt is one of various causes of past or current wall damage, and the jurisdiction of s 10(2) of the Act is therefore engaged.
21. With respect to the applicant's request for orders for removal of all 13 trees, along with replacement of the block retaining wall, there are many elements to be considered, some of which were mentioned in the Aegis report.
22. Mr Bisley advised that he had inherited his property from his parents, and had lived there, or had been associated with it, for about 60 years. He claimed that the Blackbutt was well established when his father bought the property, and estimated that it was about 80 years old. I concur with this estimate.
23. I am therefore satisfied that the Blackbutt was in situ long before the construction of the retaining wall, which was built just inside the respondent's rear yard, about 50 years ago.
24. In Black v Johnson (No 2) [2007] NSWLEC 513 (Black), the Court has published a tree dispute principle which says, in summary, that the fact that the tree was there first should not impact on whether or not some order should be made about the tree but, subject to a range of matters discussed in the principle, the prior existence of the tree may be a relevant matter to be considered when deciding who should meet the cost of carrying out any orders which the Court might make.
25. The Aegis report noted an absence of "any weep holes, or suitable drainage system such as sub-soil tail-outs". Some weep holes were, in fact, identified between blocks, but, given that the Court inspects many retaining walls, they appeared to be very small and far too few, to accommodate water discharging down the considerable slope behind the wall, in an escarpment location likely subject to quite high rainfall.
26. The applicant conceded that there were no vertical expansion joints in the wall, noted in the Aegis report as mechanism 4, contributing to wall damage.
27. The engineer's comment in the Aegis report about mechanism 6 was compelling: "For a cantilevered wall it is unusual that the wall has sustained lateral shift of around 20mm at the base of the wall. Normally a wall of this size would be reinforced with vertical 12mm or 16mm steel bars and cantilevered into a footing. This would mean that if the wall was to begin to fail, it would fail by rotation, not by lateral shift of the stem of the wall. We could not determine the size of the cantilever footing however the above observations lead us to conclude that the wall may have been inadequately constructed."
28. Upon seeing the lateral shift at the base of the wall, I was satisfied that it was unlikely to have been reinforced with "vertical 12mm or 16mm steel bars", thus its construction methodology was likely to have been inadequate, and unlikely to have met required building standards in force at the time of construction.
29. The applicant did not challenge the engineer's mechanism 7 in the Aegis report, which noted "the expected service life of a wall structure such as this one is 40-50 years and thus it may be approaching end of useful life, and/or a period where maintenance is required to extend service life". I have no reason not to accept this finding.
30. I also accept the conclusion of the engineer in the Aegis report "that the applicant's property is currently safe to occupy, but these issues pose risk to long-term structural strength of the retaining wall without mitigation works".
31. I am not satisfied that any significant change in the nature of the damage, or increased risk with respect to the wall, is likely in the near future. In a guidance decision published in Yang v Scerri [2007] NSWLEC 592, as a rule of thumb, the 'near future' is deemed to be a period of 12 months from the date of the determination. Any claim for damage in the near future, beyond that which has been acknowledged to have already occurred, is thus set aside.
32. Orders will be made, based on Remediation Action 2 and 3 of the Aegis report, for installation of Agline behind the wall, and crack stitching of identified masonry cracks in the retaining wall.
33. Orders related to Remediation Action 1 of the Aegis report, which recommended "the removal of the boundary trees" shall be addressed after considering the following factors related to the trees.

Risk of Injury

1. The large Blackbutt tree overhanging the applicant's yard and house is the primary issue in his claim, with respect to risk of injury. As noted in this judgment's 'Background', in a letter dated 28 November 2016, Mr Gardiner said he has been "advised that these trees are very brittle, and commonly large branches can snap off without warning". He added "if and when this happens, it is likely to fall through the roof of the children's bedrooms", or "injure anyone in its path".
2. Such advice is inflammatory, and not based on facts, nor on evidence exhibited by the tree. Neither the genus Eucalyptus, nor this species, Eucalyptus pilularis, are inherently 'very brittle', and nor do large branches 'commonly' snap off without warning. Very occasionally, large branches may break from large trees. In most cases this relates to wood strength being compromised by cracks and/or fungus and/or termite damage. In many situations, such propensity for branch failure could have been identified prior, during an arborist's aerial inspection.
3. Mr Bisley submitted that one such live branch broke from the tree about 40 years ago, and damaged the rear of the applicant's house. Mr Gardiner provided photographic evidence of a large limb which fell harmlessly into the void behind his retaining wall about two years ago. No evidence was provided as to whether either or both occurred in calm, or stormy, weather conditions. The likelihood of such occurrences increases in windy, stormy conditions, but occupation of the zone around trees by people or animals is far less likely during such events, and thus the risk may be less, rather than greater than normal, during these events.
4. The tree appears to be healthy, and, from my ground-based inspection, structurally sound. The wound from the branch breakage two years ago was not apparent, and possibly hidden by an adjacent Callitris sp. The wound from the breakage forty years ago, would have disappeared long ago, after wound-wood occlusion. No other major or mid-size limb breakage were reported by either party, nor were there obvious wounds on the tree's trunk or branch scaffold, suggestive of other similar events. Two such instances over a forty-year period cannot be considered a 'common' occurrence, and the likelihood of injury from such events, in the context of this tree, and the likely frequency of occupation of the site, is relatively low.
5. In his letter of 15 October 2018, Mr Gardiner noted that "we have spoken to different tree companies who have told us that the tree is extremely dangerous" and "that gums like that can just drop a limb out of nowhere on a hot day".
6. Again, this is unsubstantiated, poor, incorrect advice, in the context of this tree. There is a well-known phenomenon (not yet fully understood) called summer, or sudden branch drop, whereby branches fall unexpectedly. It can affect a wide range of genus and species, but it occurs very rarely. Advice such as that quoted at [54] can only be viewed as fear mongering. There is no evidence to justify a suggestion that this tree is 'extremely dangerous'. There are no apparent signs of structural weakness in the trunk, nor indications of faults at branch junctions. Notwithstanding this, because of the limitations of my ground-based inspection, particularly with respect to faults that may be visible only on the top of branches, an aerial inspection by a suitably qualified arborist, shall be ordered.
7. Beyond this poor advice from various tree companies, no tree risk assessment, or any other evidence from a qualified arborist, was provided by the applicant so as to substantiate his position. It is common for human perception and reality to vary greatly with respect to tree risk, but it is necessary for the response to be based on evidence, and to be proportional to the situation.
8. This trees' main risk issue appears to relate to medium sized deadwood, quite a few examples of which were visible in the currently drained pool. Other similar dead branches were present in the canopy overhanging the applicant's property, and this risk can be mitigated by normal tree maintenance. There was no suggestion or indication that any dead-wooding had previously been undertaken on this tree.
9. Orders will be made for pruning of dead branches, and the branch size specification applied will be smaller than that in similar cases, due to a premium duty of care which reasonably applies for children, who may occupy the pool and surrounds for sustained periods.
10. Trees optimise foliage cover to maximise photosynthesis, and thus carbohydrate, upon which all their functions are reliant. Heavy pruning causes tree stress. A common stress response from excessive pruning is rapid growth of poorly attached epicormic foliage (sucker growth). Ironically, this often increases the frequency of branch breakage. Mr Bisley's proposal to allow pruning up to the shared property boundary is therefore not appropriate, either in terms of health and longevity, or tree risk. Given that the tree's live branch structure appears sound, only minor pruning of the live canopy overhanging the applicant's property is warranted.
11. Orders will be made for pruning of two low branches extending over the swimming pool, and for minor reduction pruning of part of the canopy growing over the children's bedrooms. Allowance will be made for minor additional pruning that may be specified by the arborist who undertakes the aerial inspection, but the maximum total volume of foliage to be pruned from the canopy shall be 10%.
12. Though the cost of this inspection and the pruning, shall be shared equally by the parties, Mr Bisley shall organise this aspect of the works, and ensure that they are completed in compliance with the orders. The aerial inspection shall be completed initially, by an arborist with AQF level 5 (Diploma) qualifications, while the pruning shall be completed by an arborist with at least AQF level 3 (Certificate 3 (climbing)) qualifications, under the supervision of the level 5 arborist. There are arborists in the Illawarra region who hold both qualifications, who may provide improved efficiency by completing both aspects of these works.
13. Once these works are completed, the tree will pose a low, and acceptable risk. The applicant's claim with respect to risk of injury from this tree will thus be resolved.
14. Deadwood will likely re-accumulate, and may require occasional removal to maintain low risk. An order shall be made to provide future access to the tree for such works, by an AQF level 3 qualified arborist, for the pruning of deadwood only.
15. Some of the other trees in the application, which are growing close to and/or over the applicant's property, are dead, dying, or, in the case of the Eucalyptus botryoides, exhibiting phototropism, with an extreme lean over the applicant's property. Considered as a group, they do present a moderate level of risk to the applicant and his family, and insufficient benefit to either party, so removal will be ordered. Though the applicant did not provide reliable evidence to support his concerns regarding bushfire threats, the removal of these dead and dying trees will reduce risk in this respect.
16. The structure and pendant form of branches of one healthy Camphor laurel, overhanging the applicant's shade cloth and swimming pool at the northern end, appears sufficiently brittle and suspect, that pruning and ongoing maintenance of its canopy, to remove and prevent growth over the applicant's property, shall be ordered.

Dropping debris

1. To support their claim for removal of the trees, the applicant stressed the issue of ongoing maintenance required to clean up leaves and sticks continuously dropping onto his hard surfaces, shade cloth and pool below the tree, along with having to clear gutters and roofs of dead leaves.
2. In Robson v Leischke (2008) 72 NSWLR 98; (2008) 159 LGERA 280 (Robson) at [171], with respect to "annoyance or discomfort to the occupier of the adjoining land occasioned by nuisances of the third kind", Preston CJ states that this is not "damage to property on the land" within s 7 of the Act, and that "leaves, fruits, seeds, twigs, bark or flowers of trees blown onto a neighbours land might cause annoyance or discomfort to a neighbour, but unless they also cause damage to property on the neighbour's land they will not be actionable under s 7."
3. In Robson, at [56], discussing the issue of nuisance, his Honour states that "mere encroachment is insufficient to complete a cause of action."
4. The issue of the maintenance impost from falling tree debris is addressed in Barker v Kyriakides [2007] NSWLEC 292 (Barker), which, at [20], establishes the tree dispute principle: "… For people who live in urban environments, it is appropriate to expect that some degree of house exterior and grounds maintenance will be required in order to appreciate and retain the aesthetic and environmental benefits of having trees in such an urban environment. In particular, it is reasonable to expect people living in such an environment might need to clean the gutters and the surrounds of their houses on a regular basis. The dropping of leaves, flowers, fruit, seeds or small elements of deadwood by urban trees will not ordinarily provide the basis for ordering the removal of or intervention with an urban tree."
5. In the context of this grounds maintenance expectation with respect to this tree, none of the applicant's submissions with respect to falling leaves, fruits, seeds, twigs, bark or flowers, onto the ground, the shade-cloth, into the swimming pool, onto roofs, or into gutters, invokes the Act's jurisdiction.
6. Additionally, regardless of whether tree debris drops into the applicant's pool, resulting in more cleaning and addition of chemical or other ameliorants to stabilise water requirements than may be the case in their absence, upon purchasing the property about five years ago, it should have been obvious to the applicant that the tree was large and well established, that its canopy extended over the pool, and that such additional maintenance would be required. In such a scenario, it is unreasonable to expect that the tree be removed or severely pruned, to eliminate or reduce this debris, when the tree long predated the pool's installation.

Discretionary matters - s 12

1. In making an order, the Court considers relevant matters in s 12 of the Act.

• The Blackbutt is located in the respondent's property about three metres from the common side boundary (s 12(a)).
• Pruning or removal of the Blackbutt would require consent from Council under the Environmental Planning and Assessment Act 1979 (s 12(b)).
• Pruning should not occur as part of 'normal' maintenance, but should be undertaken only when necessary to achieve a required purpose, and thus not compromise tree health. It should be selective, and heavy pruning of overhanging branches should be avoided. By restricting the volume of pruned material to no more than 10% of the canopy, and requiring it be undertaken by an AQF level 3 qualified arborist, at the least, negative impacts from pruning can be minimised. All works shall comply with AS 4373:2007 Pruning of amenity trees (subs 12(b2)).
• All trees to be retained, and the Blackbutt in particular, contribute to privacy, to protection from the sun, and from wind, to the amenity of the respondent's property, to the natural landscape, and the scenic value of the land on which it is situated. (subss 12(b3), (e)).
• Particularly when viewed from the street in front of the applicant's property, one can appreciate the significant intrinsic public amenity that the Blackbutt provides, and also how healthy it appears. Given its advanced age, it may also have historical value (subss 12(c), (f)).
• Being a large example of a species endemic to the region, its flowers and fruit, trunks and branches could be expected to provide food and or shelter for local fauna, and therefore it is likely to make a significant contribution to local biodiversity (subs 12(d)).
• Given the slope of the land of both properties, and the different levels on which their houses and yards are located, the trees are highly likely to be providing benefit to soil stability, and to the absorption of water and the reduction of run off. For the trees that are removed, stump bases and roots should thus be retained (subs 12(g)).
• Subsection 12(i) considers anything, other than the tree, that has contributed, or is contributing, to any damage or likelihood of damage, including any act or omission by the applicant and the impact of any trees owned by the applicant. The advanced age of the retaining wall, and inadequacies in its construction have been considered in this respect, within the judgment.
• The fact that 'the tree was there first' is considered within the judgment, and falls under subs 12 (j), as a matter that the Court considers relevant in the circumstances of the case.
• Conclusion

1. Based on all evidence adduced, I have reached the following conclusions:
2. Noting the unchallenged comment in the Aegis report, that "the expected service life of a wall structure such as this one is 40-50 years", it is likely that the retaining wall was beyond, or close to the expiration of its safe useful service life, at the time of the applicant's property purchase.
3. I am satisfied that the Blackbutt is one of many causes of wall damage, and that the other causes relate to various inadequacies in the wall construction, natural movement of reactive clays over the long life of the wall, and the wall reaching or approaching the end of its service life. These considerations render it unreasonable for the respondent to be responsible for the cost of wall replacement. This element of the applicant's claim is thus dismissed.
4. Crack stitching, per the Aegis report, is likely to restore and maintain retaining wall strength and stability in the short to medium term. The pool gate opening problem could be ameliorated by cutting a rebated channel into the masonry, or by some other means to be determined by a builder, along with these wall repair works. It would also be prudent for the undersized drainage weep holes to be made larger.
5. The Blackbutt is a large, mature example of a long-lived Eucalyptus species endemic to the region, which provides a significant contribution to local biodiversity, various important benefits to the respondent, and a significant contribution to public amenity. These factors, which, according to s 12 of the Act, must be balanced against any damage or risk of injury which the tree causes, are considered with respect to any orders made.
6. Given that the Blackbutt was long established when the wall was constructed, the tree dispute principle in Black applies. This element, in conjunction with those considered at [76], results in the majority of the cost for wall repair falling on the applicant.
7. The Blackbutt has been growing in close proximity to the wall for about 50 years. Characteristics of the bark suggest stable, relatively slow growth in girth, and this is likely to reduce further as the tree ages. The configuration and location of major structural roots has likely been established since early in the tree's life. Having interacted with the wall for all these years with only minor damage, and with its growth rate likely to be gradually slowing, the situation is unlikely to change much in the near future.
8. When the wall is replaced, engineering modifications including pier and beam rather than strip footings, or cantilevering, in proximity to roots, should allow for minimal root disturbance around the Blackbutt, and minimal likelihood of subsequent wall damage.
9. Risk associated with the Blackbutt will be mitigated by selective pruning of two long branches over the pool, removal of moderate sized deadwood from the section of the canopy overhanging the applicant's property, and reduction pruning of part of the canopy area overhanging the applicant's house.

Orders

1. The orders of the Court are: 1. Crack stitching of identified masonry cracks in the retaining wall, shall be undertaken, using the 'HeliFix' system, by a licenced builder, who holds all appropriate insurances, and is qualified in the use of the 'HeliFix' system. The pool gate which adjoins the wall shall be repaired and made safe by this licenced builder, so as to comply with current relevant pool fence safety standards. These works shall be contracted and paid for by the applicant, and completed within 120 days of the date of these orders. Upon completion of these works, the respondent shall pay the applicant an amount equivalent to 40% of the cost of these works, within 14 days of receipt of a paid invoice. 2. The respondent shall, within 60 days of the date of these orders, install, at his expense, a 100mm diameter Agline with minimum 20mm coarse aggregate or blue metal, behind the entirely of the retaining wall, to allow the free flow of water and thus minimise hydrostatic pressure. This Agline shall be connected to the existing hydraulic system, by a licenced plumber, who holds all appropriate insurances. 3. The respondent shall organise and pay for an aerial inspection of the Blackbutt by an AQF level 5 arborist, who also holds climbing qualifications. This inspection shall comprise a climbing inspection to assess the structural integrity of the entirety of the trees' trunk, and all branches which extend over the applicant's property. This inspection shall be completed within 60 days of the date of these orders. 4. Following this inspection, the respondent shall organise and pay for an AQF level 3 climbing arborist (or, an arborist who holds both AQF level 3 (climbing), and AQF level 5 qualifications) to remove the two long, lowest branches overhanging the applicant's swimming pool back to their branch collars, plus any other branches, that may have been deemed potentially dangerous from the findings of the aerial inspection. The area of the canopy which overhangs the applicant's children's bedrooms shall next be 'reduction pruned' to branch collars, to reduce (but not necessarily eliminate) the extent of the canopy overhanging the house. The extent of this aspect of the pruning shall be limited, such that the total volume of live vegetation removed from the sum of all this pruning shall not reduce the overall leaf mass of the tree by more than 10%. All deadwood larger than 10mm at the branch collar, in the area of the canopy overhanging the applicant's property, shall also be removed. All pruning refuse shall be removed from site as part of these works. All pruning refuse that is lowered or dropped onto the applicant's property shall be removed via the applicant's access. All pruning refuse that is lowered or dropped onto the respondent's property shall be removed via the respondent's access. This pruning shall be completed within 30 days, after the completion of the inspection in Order (3). 5. All arborists subject to Orders (3) and (4) shall carry all appropriate insurances, and all pruning work must comply with AS 4373:2007 Pruning of Amenity Trees. 6. Upon completion of the inspection in Order(3) and these pruning works specified in Order (4), the applicant shall pay the respondent an amount equivalent to 50% of the cost of the works, within 14 days of receipt of a paid invoice. 7. The respondent shall remove, at his expense, and within 60 days of the date of these orders, all dead and dying Sweet Pittosporum and Camphor laurel trees which grew, or are growing, in the subject area behind the entire length of the applicant's retaining wall, which was inspected at the hearing. All stumps shall be cut to near ground level and retained. All above ground refuse from these works shall be removed from the site via the respondent's access. 8. The respondent shall, at his expense, and within 60 days of the date of these orders, remove the Eucalyptus botryoides, growing almost horizontally over the applicant's swimming pool, to near ground level, and, shall prune foliage from the healthy Camphor laurel, overhanging the northern end of the applicant's shade cloth and swimming pool, back to the shared property boundary. Alternatively, this Camphor laurel, can be removed to near ground level, and have its stump poisoned. All tree refuse shall be removed from site as part of these works. All tree refuse that is lowered or dropped onto the applicant's property shall be removed via the applicant's access. All tree refuse that is lowered or dropped onto the respondent's property shall be removed via the respondent's access. The residual stump of the Eucalyptus botryoides shall not be poisoned. 9. Should the Camphor laurel, referred to in Order (8), be pruned only, the respondent shall, at his expense, maintain the canopy so that it does not re-grow across the boundary into the applicant's property at any time in the future. All tree refuse from such future works shall be removed via the respondent's access. 10. All tree work must comply with the Safe Work Australia Guide to Managing Risks of Tree Trimming and Removal Work, 2016. 11. Each party shall provide access to their property, should it be required, for any of the contractors to undertake the works specified in Orders (1), (2), (3), (4), (7), (8), and (9), upon receipt of at least 48 hours' written notice from the other party, which details the dates and approximate times that works are to commence. 12. Should pruning be required in future (not including that covered by Order (4)), to remove additional deadwood overhanging the applicant's property from the Blackbutt, the respondent shall allow AQF level 3 qualified arborists contracted by the applicant, who carry all appropriate insurances, to access the tree, so as to complete such works, upon receipt of at least 48 hours' written notice from the applicant, which details the dates and approximate times that works are to commence. Such works shall be completed at the applicant's expense, and all refuse shall be removed via the applicant's access. 13. All works shall be carried out during reasonable working hours.

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