Anthony Natoli Enterprises Pty Ltd v Hornsby Shire Council

[2021] NSWLEC 1435

Land and Environment Court

New South Wales

Medium Neutral Citation:

Anthony Natoli Enterprises Pty Ltd v Hornsby Shire Council [2021] NSWLEC 1435

Hearing dates:

20 and 21 April 2021

Date of orders:

30 July 2021

Decision date:

30 July 2021

Jurisdiction:

Class 3

Before:

Douglas AC

Decision:

The Court orders that:

(1) The appeal is dismissed.

Catchwords:

APPEAL – application to remove vegetation (a Sydney Red Gum) – appeal against refusal of application – whether evidence provided substantiates that the tree presents a genuine risk of damage and/or injury – whether sufficient relevant information has been provided by applicant to support appeal

Legislation Cited:

Environmental Planning and Assessment Act 1979, s 4.2

Hornsby Local Environmental Plan 2013, cl 1.2

Land and Environment Court Act 1979, s 39

State Environmental Planning Policy (Vegetation in Non-Rural Areas) 2017, Pt 1 cl 6, Pt 2 cll 7, 8, Pt 3 cll 9,10,11,12

Uniform Civil Procedure Rules 2005

Texts Cited:

Australian Standard AS4970-2009 - Protection of trees on development sites

Hornsby Development Control Plan 2013

Jacobs MR, Growth habits of the eucalypts, Forestry and Timber Bureau, Canberra, 1955

Johnson J and Hadlington P, Australian trees: their care and repair, UNSW Press, 1977

Category:

Principal judgment

Parties:

Anthony Natoli Enterprises P/L(Applicant)
Hornsby Shire Council (Respondent)

Representation:

Counsel:
A Johnson (Solicitor) (Applicant)
A Pickup (Solicitor) (Respondent)

Solicitors:
Albert A Macri & Co (Applicant)
Local Government Legal (Respondent)

File Number(s):

2020/247106

Publication restriction:

No

Judgment

1. COMMISSIONER: Anthony Natoli Enterprises P/L owns a property on Dangar Island, in the Hawkesbury River. In April 2020, Mr Natoli applied to Hornsby Shire Council (Council), on behalf of Anthony Natoli Enterprises P/L, pursuant to cl 11 of the State Environmental Planning Policy (Vegetation in Non-Rural Areas) 2017 (the Vegetation SEPP), to remove an Angophora costata (Sydney Red Gum) (the tree) that is growing on a sandstone shelf, above the dwelling. On 27 July 2020, Council issued a Notice of Determination refusing the proposed removal of the tree. Anthony Natoli Enterprises P/L has appealed the refusal, pursuant to cl 12 of the Vegetation SEPP.

2. Mr Natoli claims that the tree is moving in the ground, and thus is structurally unstable, and represents significant risk of damage to his dwelling, and risk of death or injury to occupants of his dwelling. Council’s reasons for refusing to grant a permit were based on the tree’s good health and sound structural condition, the inadequacy of evidence provided to substantiate tree risk, and their own quantified risk assessment, which resulted in the risk being determined as broadly acceptable.

Framework for this decision

3. The Land and Environment Court Act 1979 establishes the Court’s power on appeals at s 39. In making this decision, the Court has all the relevant functions and discretions of the body that made the original decision now being appealed – that is, Council (s 39(2)). Fresh or additional evidence may be given on the appeal (s 39(3)). At s 39(4), the Court is required to consider “… any other relevant Act, any instrument made under any such Act, the circumstances of the case and the public interest.”

4. The Environmental Planning and Assessment Act 1979 (the EPA Act) provides the overarching jurisdiction. At s 4.2 of the EPA Act:

(1) General    If an environmental planning instrument provides that specified development may not be carried out except with development consent, a person must not carry the development out on land to which the provision applies unless—

(a) such a consent has been obtained and is in force, and

(b) the development is carried out in accordance with the consent and the instrument.

Maximum penalty—Tier 1 monetary penalty.

(2) …

(3), (4) (Repealed)

(5) …

(6)–(9) (Repealed)

Tree removal – general

5. The primary relevant planning instrument is the Vegetation SEPP, Pt 2 of which establishes at cl 7(1) that: “A person must not clear vegetation in any non-rural area of the State to which Part 3 applies without the authority conferred by a permit granted by the council under that Part.”

6. There is a general exemption from any consent requirement at cl 8 (Pt 2) of the Vegetation SEPP:

8 Clearing that does not require authority under this Policy

…(3) An authority is not required under this Policy for the removal of vegetation that the council is satisfied is a risk to human life or property.

7. The framework for vegetation removal is set out in Pt 3. Permit requirements for vegetation removal vary between local government areas. According to cl 9 (Pt 3) of the Vegetation SEPP, a development control plan will usually declare vegetation to which Pt 3 of the Vegetation SEPP applies:

9 Vegetation to which Part applies

(1) This Part applies to vegetation in any non-rural area of the State that is declared by a development control plan to be vegetation to which this Part applies.

(2) A development control plan may make the declaration in any manner, including by reference to any of the following—

(a) the species of vegetation,

(b) the size of vegetation,

(c) the location of vegetation (including by reference to any vegetation in an area shown on a map or in any specified zone),

(d) the presence of vegetation in an ecological community or in the habitat of a threatened species.

8. Tree removal falls within the Hornsby Development Control Plan 2013 (the HDCP) at Section 1B.6 Tree and Vegetation Preservation.

“This section is made in accordance with State Environmental Planning Policy (Vegetation in Non-Rural Areas) 2017 (the Vegetation SEPP) and prescribes the trees and vegetation to which the Vegetation SEPP and/or Clause 5.10 of the HLEP applies and the applicable approval process.”

9. In this case, although the Vegetation SEPP post-dates the earlier Hornsby Local Environmental Plan 2013 (the HLEP), the HDCP still refers to the HLEP. Clause 5.10 of the HLEP considers Heritage Items and Heritage Conservation Zones, neither of which relate to this tree, but the Aims of the HLEP are relevant, in particular, cl 1.2(2)(b) and (2)(h).

(2)  The particular aims of this Plan are as follows—

…

(b)  to guide the orderly and sustainable development of Hornsby, balancing its economic, environmental and social needs,

…

(h)  to protect and enhance the scenic and biodiversity values of environmentally sensitive land, including bushland, river settlements, river catchments, wetlands and waterways,

…

10. Section 1B.6.1.a of the HDCP defines which trees are Prescribed;

“a. The prescribed trees that are protected by the Vegetation SEPP and/or Clause 5.10 of the HLEP and this Section of the DCP includes:

● all tree species except exempt tree species in Hornsby Shire, as listed in Table 1B.6 (b) or subject to the Biodiversity Offset Scheme,

● trees on land within a heritage conservation area described within the HLEP, and

● trees on land comprising heritage items listed within the HLEP.

b. To damage or remove any tree protected under this DCP is prohibited without the written consent of Council, except in accordance with the exemptions prescribed in this part (under the heading ‘Exempt Tree Work’).

…

Exempt Tree Work

d. The following exemptions to this part apply as set out below:

● The removal of or pruning to a tree where Council is satisfied the tree is dying or dead and is not required as the habitat of native fauna.

● The removal of species listed under the NSW Biosecurity Act 2015 for Hornsby Shire.

● Pruning of a tree by less than 10% of the foliage area in accordance with Australian Standard Australian Standard AS 4373 Pruning of Amenity Trees AS4373-2007 not more than once annually.

● The removal of or pruning of a tree where the base of the trunk of the tree at ground level is located within 3 metres of the foundation of an approved building (excluding detached garages, carports and other buildings ancillary to a dwelling house).

● The removal of a tree less than 3 metres in height not located within native vegetation.

● Trees deemed by Council in writing and shown by recorded photographic evidence or written evidence provided by a qualified Arborist (AQF.5) as an imminent risk to human life or is causing or likely to cause substantial damage to property.

● The removal of or pruning to a tree located on Council owned or managed land provided the works are undertaken by Council or Council authorized agents.

e. The exemptions at (d) above do not apply to:

● all lands mapped as Biodiversity on the HLEP Terrestrial Biodiversity Map, or

● threatened species or land that contains native vegetation which is habitat for threatened species, populations or ecological communities listed in Schedule 1and 2 of the Biodiversity Conservation Act 2016, or

● work that is contrary to a development consent that requires trees to be retained, or

● Any work to a tree that is or forms part of a heritage item or heritage conservation area, requires approval from the Council pursuant to the provisions of Clause 5.10 of the HLEP.”

11. The Vegetation SEPP then gives Council the power to grant a permit at cl 10:

10 Council may issue permit for clearing of vegetation

(1) A council may issue a permit to a landholder to clear vegetation to which this Part applies in any non-rural area of the State.

(2) A permit cannot be granted to clear native vegetation in any non-rural area of the State that exceeds the biodiversity offsets scheme threshold.

(3) A permit under this Part cannot allow the clearing of vegetation—

(a) that is or forms part of a heritage item or that is within a heritage conservation area, or

(b) that is or forms part of an Aboriginal object or that is within an Aboriginal place of heritage significance,

unless the council is satisfied that the proposed activity—

(c) is of a minor nature or is for the maintenance of the heritage item, Aboriginal object, Aboriginal place of heritage significance or heritage conservation area, and

(d) would not adversely affect the heritage significance of the heritage item, Aboriginal object, Aboriginal place of heritage significance or heritage conservation area.

(4) A permit may be granted under this Part subject to any conditions specified in the permit.

In short, Council can issue a permit, although a permit cannot be granted in certain situations. If issued, the permit can be subject to any conditions.

12. Section 1B.6.1.f. of HDCP notes that;

“An application is required to be completed and forwarded to Council for all work to protected trees where an exemption does not apply. Table 1B.6(a) identifies what type of application is required to be completed for work to trees.”

As the site is neither a Heritage item, within a Heritage Conservation Area, nor subject to the Biodiversity Offset Scheme (BOS), a Tree Permit, as used by the applicant, is identified as the appropriate form.

13. The applicant’s capacity to appeal Council’s decision is established at cl 12 of the Vegetation SEPP:

12 Appeal to Land and Environment Court

(1) An applicant for a permit may appeal to the Land and Environment Court against the refusal by a council to grant the permit.

(2) Any such appeal is to be made within 3 months after the date on which the applicant is notified of the decision or within 3 months after the council is taken to have refused the application (whichever is the later).

14. Where there is any inconsistency with the HLEP, the Vegetation SEPP, at cl 6(2), prevails:

6 Relationship to other planning instruments

(1) This Policy does not affect the provisions of any other State Environmental Planning Policy or any provisions of a local environmental plan that are mandatory provisions under the Standard Instrument (Local Environmental Plans) Order 2006.

(2) This Policy prevails to the extent of any inconsistency with any provisions of a local environmental plan that are not mandatory provisions under the Standard Instrument (Local Environmental Plans) Order 2006.

The hearing

15. The hearing was conducted on site on 20 April 2021, and continued on MS Teams on 21 April 2021.

16. Antony Johnson, Solicitor, represented the applicant. Council was represented by their Solicitor, Anthony Pickup. Russel Kingdom, consulting arborist engaged by the applicant, and Gareth Hambridge, Council’s Tree Management Officer, provided expert arboricultural evidence. Troy Crozier, Geotechnical engineer engaged by the applicant, and Peter Wright, Geotechnical engineer engaged by Council, provided expert engineering evidence. Mr Natoli, and Council’s Tree Management Coordinator, Mr Scott Wilkie, also attended. Initial reports by Mr Kingdom and Mr Crozier (Crozier report) were filed with the Court.

17. Mr Kingdom and Mr Hambridge prepared a joint report outlining their points of agreement and outstanding areas of differences, as did Mr Crozier and Mr Wright. For the majority of issues/points of contention, the engineers were not conclusive, but sought additional opinion/input from the arborists. The arborists therefore provided a supplementary joint statement in response.

18. All four experts acknowledged having read and prepared their statements in accordance with the NSW LEC Practice Note, Division 2, Part 31 of the Uniform Civil Procedure Rules 2005 (UCPR), and the Expert Witness Code of Conduct in Schedule 7 to the UCPR.

The applicant is able to appeal

19. Mr Natoli appealed within three months of Council’s determination, as per cl 12 of the Vegetation SEPP.

A permit is required to remove the tree

20. Pursuant to cl 8(3) of the Vegetation SEPP, consent is not required if Council is satisfied the tree is a risk to human life or property. Based on the adduced evidence, Council was not satisfied that this was the case, having found that consent was required, and denying such consent. I also find that cl 8(3) does not exclude the need for consent to remove the tree. Where people or property assets are near trees, within the target zones of branch, stem or root failure, or within their root zones (for property damage) there is inherently some level of risk. Risk standards generally promote a qualitative description of risk levels, using terms such as low, medium, high and very high, or a quantified assessment, where a numerical probability based on likelihood of failure and likely resulting consequences is determined. It would be absurd if cl 8(3) was referring to the entire range of risk levels when providing such a broad exemption for tree removal under the Vegetation SEPP, as that would result in almost all trees being exempt. It is more likely that such an exemption only applies where the risk of a tree causing injury or damage is high or very high, and even then perhaps only when the risk is imminent, or likely to be realised in the short term, so that there is no time for detailed analysis of suitable mitigation measures that might avoid tree removal.

21. The on-site evidence exhibited by the tree, in terms of the likelihood of damage or injury, does not satisfy me that such a high level of risk, with imminent consequences, exists. I find that the exemption at cl 8(3) of the Vegetation SEPP does not apply to the tree.

22. The tree is located in an environment characterised by native vegetation. Therefore, regardless of its dimensions, a permit is required for its removal pursuant to Part 1 of the HDCP. It is not on the list of Exempt species at Table 1B.6(b), and nor do the conditions for Exempt Tree Work, at Section 1B.6.1(d) apply. Though point 6 of these exemptions is “Trees deemed by Council in writing and shown by recorded photographic evidence or written evidence provided by a qualified Arborist (AQF level 5) as an imminent risk to human life or is causing or likely to cause substantial damage to property”, Council have deemed that the tree does not satisfy these conditions.

Council may issue a permit to remove the tree

23. Having navigated this path through the statutory framework, I find that the tree is a tree requiring consent for its removal. I find also that Council can grant a permit for its removal, subject to any conditions specified in the permit.

Should consent be granted for removing the tree?

Overview of the assessment criteria

24. Mr Natoli applied to remove the tree because of “grave concerns for myself , my family and my property”, and “a risk of serious harm”, relating to the tree.

25. The decision guidelines for determining an application for tree removal are at Section 1B.6.1 of HDCP;

“Consideration of an Application for Tree Work

…

i. The removal of, or work to, trees should be consistent with the applicable provisions of the HLEP and HDCP.

j. The impact of development upon trees will be assessed using arboricultural, ecological and/or occupational health and safety based evaluation to determine the significance of the trees. Accordingly, any application for removal should demonstrate that the removal of the tree is appropriate based on an assessment of the:

● significance/health/longevity of the tree; and

● risk to human life or property.

k. Where trees are to be retained, the provisions of Australian Standard AS4970 Protection of Trees on Development Sites must be applied.

l. All tree pruning work must be carried out in accordance with Australian Standard AS 4373 Pruning of Amenity Trees.

m. Any tree approved to be removed from a site should be replaced with a tree of like habit which is not listed in the list of exempt species in Hornsby Shire, planted as near as practicable to the location of the removed tree, grown to maturity and replaced if the planting fails to survive and thrive in accordance with Council’s Green Offsets Code.

…”

Council’s reasons for refusing consent

26. Council’s determination of Mr Natoli’s application gave three reasons for refusing consent for tree removal;

“Removal is not granted as insufficient evidence has been presented to enable permission to be granted under Council’s Tree Preservation measures such as:

a) There were no obvious structural dysfunctions observed to warrant pruning or removal.

b) There has been no diagnostic evidence to support the claim to warrant pruning or removal.

c) Council has applied a Quantified Tree Risk Assessment (QTRA), an industry recognised methodology and determined the level of risk to broadly acceptable.

Under “Important points to note”, at point 3 is:

“3. The onus falls on the property owner to provide sufficient information to support the request for pruning or removal of a tree.”

The arboricultural evidence

27. The primary issue being considered by the arborists, is the risk of failure of the tree near or below ground level, and/or failure of elements of the rock shelf amongst which the tree roots are likely to be anchored. Fundamentally, it is the stability of the tree, and its probability, or likelihood, of failure.

28. Mr Natoli initially applied for removal of three Angophora costata in 2018. Mr Wilkie conducted the inspection and assessment, and granted permission for one tree (tree 1), located close to the dwelling, to be removed, and for the two others (trees 2 & 3), to be pruned, subject to conditions. Tree 2 is the focus of this appeal.

29. The rationale for refusal of trees 2 and 3 included that “insufficient evidence had been submitted to enable granting of permission”. Mr Wilkie also provided advice that “additional information for tree (2) such as a resistograph test of the trunk would determine if there has been any previous issues relating to termites with this tree and can be used as supporting evidence if the tree failed this testing”.

30. Mr Natoli subsequently commissioned an arborist report, from Stuart Pittendrigh, to assess the “condition and safety” of the tree. It is dated October, 2019, and was included with the appeal application (Exhibit C).

31. Mr Pittendrigh’s key findings were challenged by Council, and, to a great extent, also by Mr Natoli’s current arborist, Mr Kingdom. Mr Pittendrigh noted that although the tree displays a full crown of healthy foliage, a large arboreal termite nest is present, high on the tree’s main stem. Quoting Hadlington and Johnston, from Australian trees: their care and repair, he notes that “the nest indicates that the tree is degenerating, and is usually not worth retaining”.

27. He also cites Jacobs, from Growth Habits of the Eucalypts, which ostensibly notes that the genus Angophora “have an efficient method for shedding limbs.” From this, Mr Pittendrigh generalised that “larger species such as Angophora costata should not be planted so that they will overhang dwellings or in this situation be retained on site too close to buildings”.

28. Both Mr Hambridge and Mr Kingdom acknowledged that, contrary to the Hadlington and Johnson opinion, the presence of arboreal termites does not necessarily mean that the tree is “degenerating, and is usually not worth retaining”, and Mr Hambridge noted that this statement is “generally not accepted as accurate”. Mr Hambridge also suggested that Mr Pittendrigh had mis-referenced Jacobs.

29. Strangely, Mr Pittendrigh assessed the tree using procedures informed by AS4970-2009-Protection of trees on development sites, and calculated Tree Protection Zone (TPZ) and Critical Root Zone (CRZ) accordingly. While such measurements may be relevant to risk assessment in terms of availability of sufficient root range, they were not considered in this way, and it is therefore unclear why they were determined at all.

30. There are two main arboricultural risk assessment methods used and accepted internationally, Quantified Tree Risk Assessment (QTRA), which Council applied in its assessment, and Tree Risk Assessment Qualification (TRAQ). Both require initial and ongoing training, and assessment.

31. Significantly, no risk assessment was used by Mr Pittendrigh, or provided in the report. Of some relevance is his Safe Useful Life Expectancy (SULE) analysis, which he determined to be greater than 15 years, but overall, this report was of little use to the Court.

32. In his initial report, dated 13 November, 2020 (Exhibit B), Mr Kingdom claimed the tree was 26 metres tall with a canopy spread, north to south of 22 metres, and 24 metres from east to west, that “the trunk of the tree has a 15 degree lean to the east, with no compression roots to the east due to the vertical cliff”, that “it is quite obvious that the crown is unbalanced” and that the “tree is excessively large and would probably weigh in excess of 30 tons”. He adds, “At the base of this tree are several large sandstone rocks which clearly support the main load of this tree on the eastern side of the trunk”, and provides the “Arboricultural opinion, if these rocks were to fail and fall, the tree would probably fail and fall to the east, placing the whole of the tree onto the house below. It is not uncommon for A. costata (Sydney Red Gum) to have branch failures”.

33. He also contends that “the tree has reached the end of its useful life expectancy”. Though he claimed that “the level of risk is considered to be completely unacceptable”, Mr Kingdom also provided no risk assessment methodology, results, or evidence to substantiate that an arboricultural risk assessment had been undertaken.

34. In their joint report of 1 March 2021 (Exhibit 3), in response to the respondent’s Statement of Facts and Contentions (14 October 2020 - Exhibit 1), both Mr Kingdom and Mr Hambridge agreed that the tree is mature, exhibits good health, vigour, and form, and appears to be in good structural condition. Mr Kingdom was of the opinion that the sandstone cliff on which the tree is growing, should be assessed by a geotechnical engineer.

35. Findings from the Crozier report, dated 16 February 2021, were considered in the arborist’s joint report. With respect to whether the tree is structurally stable, Mr Kingdom disagreed, noting Mr Crozier’s statement that “The existing tree is exacerbating the deterioration of the cliff and will be expected to result in eventual dislodgment and cliff line failure. As the tree is dependent on the stability of the cliff, any failure in the cliff is expected to be in conjunction with the collapse of the tree”. Informed by these Crozier conclusions, Mr Kingdom conducted a QTRA, with a result of 1:400, which is an unacceptable risk level.

36. Mr Hambridge did not agree with the findings of the Crozier report, noting inadequate detail in the report, especially because the “tree is growing in a manner typical of the species. There is no evidence to suggest the visible sandstone is the only thing holding the tree up. It is widely understood that tree roots on slopes have a much greater mass up slope and across slope”.

37. Both arborists agreed that the information provided to Council, with the April 2020 removal application, was limited, and included “no diagnostic evidence” supporting removal.

38. Addressing the applicant’s Statement of Facts and Contentions in reply (28 October 2020 - Exhibit D), Mr Kingdom claimed the tree is a danger to human life and property, because “the residence is the target zone of this tree”, if the tree fails. Mr Hambridge disagreed, on the basis that “the size and location of this tree is not sufficient grounds on its own to support this statement as the evidence of a strong possibility (of failure) hasn’t been elucidated”.

39. Both arborists accepted that the “bulk of the crown overhangs the dwelling”, and that kino exuding from the tree was not excessive, and was reflective of good tree health.

40. Within his bundle of documents (Exhibit B), Mr Natoli included a list of measurements, recorded with a laser tool across six periods of time between January and November, 2020, which he claims show the increasing distance between a point on the trunk, approximately four metres above ground level, and a point on the rock face west of the the tree, and thus increasing tilt movement towards the house. These figures suggested that the extent of movement has been inconsistent over this period, and totals 92mm.

41. Addressing whether the tree has moved closer to the dwelling over time, Mr Kingdom notes “this is possible, but not clearly documented”, while Mr Hambridge adds that “no reasonable report outlining method and conclusion have been supplied to suggest it is moving”.

42. With respect to visible evidence of structural faults, Mr Kingdom claims that “there are some wounds in crotches of scaffold branches in the crown”, which are “frequently associated with failed branches”, while Mr Hambridge claims that there are “no structural faults that would increase the risk of failure by a significant amount”.

43. As to whether this type of tree is prone to shedding limbs so should not be allowed to overhang dwellings, Mr Kingdom noted that this species was not generally prone to sudden branch drop, but may “drop branches in storm events”, or if there is damage to branch structure. Mr Hambridge suggested that Mr Pittendrigh had misrepresented a reference, in that Jacobs comment related to ‘Eucalypts’, rather than specifically the genus Angophora.

44. Addressing whether the arboreal termite nest indicates that the tree is degenerating, both arborists agree that “arboreal termites only process heartwood and do not affect a tree’s structure”.

45. The question of whether a structural root zone analysis by Mr Pittendrigh showed that the tree had surpassed its SULE, was set aside as Mr Hambridge noted that no structural root zone analysis was included in his report, while Mr Kingdom had not seen the report.

46. The applicant claimed that Council had provided insufficient information in support of its contentions, particularly with respect to Council’s QTRA. Mr Hambridge noted that his QTRA report was based “on the condition of the tree at the time of the inspection and the information supplied by the applicant”, including Mr Pittendrigh’s report. Mr Kingdom had not seen the QTRA details referred to, and re-emphasised the results of his QTRA informed by the Crozier report.

The engineer’s joint report

52. The Geotechnical engineer’s joint report of 23 March, 2021, references both parties’ Statement of Facts and Contentions, the arborist’s joint report, and the Crozier report. For the majority of questions considered, further arborist input was sought, and this was provided in an addendum joint report dated 15 April, 2021 (Exhibit B).

53. Both engineers agreed that the tree does impose loads on the blocks of rock in the rock mass, and that growth of roots does “appear to have caused some movement of some of the blocks previously. They could not say how much extra capacity the rock mass has to support the tree.

54. As to whether growth of the tree will cause additional loads on the rock mass, they asked the arborists to determine how much growth will occur, and where. Both arborists agreed that growth will cause additional loads, without quantifying how much, or where.

55. To determine whether the tree would tilt further downhill and topple, if the rocks below the tree are stabilised, both engineers agreed that this was “a function of the stability of the rock mass, and the action of the root ball”. They deferred to the arborists to provide advice on rotational toppling, with respect to the shape and extent of the root ball.

56. Mr Kingdom opined that it is probable that the tree will tilt further downhill and topple, that “the extent of the root ball is determined by the amount of topsoil and the makeup of the rocks in, and behind, the cliff face”, and that “all roots of this tree are contained in topsoil to the west of this tree and in voids within the cliff face”. He noted that “the location and size of the roots is unable to be quantified”.

57. Mr Hambridge disagreed, noting that “The tree’s stability is dependent on its roots maintaining strength and the substrate maintaining integrity. No evidence has been produced that shows the tree is moving. The size and excellent health of the tree suggest an equally impressive root system. If the rocks that have been suggested to be suspect are stabilised then there is no reason to suggest the tree will topple.”

58. In response to whether further trunk growth would cause the upper level blocks of sandstone to move, the engineers again sought arborist opinion. Mr Kingdom said small rocks would be moved, while the tree would grow over large rocks. Mr Hambridge disagreed, noting that “The majority of the upper level sandstone blocks are already being grown over. The tree will effectively grow over and hold them. There is one smaller block that looks to have been lifted. It may lift further but can easily be removed."

59. Both engineers agreed that the rock mass below the tree can be stabilised without removing the tree first. Mr Crozier expressed concern about the scale of the retention system, and potential impact on tree health. He noted that a substantially over-engineered retention system would be required to allow for existing roots, future root growth, trunk movement and uncertainties. Mr Wright believed that system design could provide allowance for movement of up to about 20mm, and estimated that that such a system may include a small amount of underpinning and about 15 rock bolts. He also noted concern “that the action taken during the removal of the tree could destabilise some of the blocks of sandstone”.

60. Mr Hambridge agreed, while Mr Kingdom opined that the tree needs to be removed first, because the retention system suggested would be a large amount of difficult, expensive work, and that the stabilisation doesn’t change the house being the target zone. He notes that “a rock wall requiring 15 bolts to stabilise is obviously in poor condition and could fail”, that the work “does not appear to be guaranteed by the geotechnical engineers and the tree will still fail”.

61. The final issue addressed was whether the installation of the stabilisation measures would damage the tree, resulting in its deterioration. The engineers’ unified response noted the possibility that roots could be mechanically and chemically damaged if rock bolts were drilled through them. The arborists were asked to comment on the likelihood of drill impact on roots based on the likely extent of roots in the rock mass, and given the assumed stabilisation requirement of about 15 holes, of 100mm diameter and about four metres depth, drilled sub-horizontally into the rock mass.

62. Both arborists agreed, but interpreted the impact quite differently. Mr Kingdom said there will be live roots in the defects within the rock mass, and that mechanical damage was probable, and chemical damage, possible. He noted that damage to the roots in the defects can lead to decay, and reduction of strength of the root plate, and deemed any damage to be unacceptable.

63. Mr Hambridge also noted that root damage was probable, with the likelihood of the damage being significant depending on the location of the bolts. He assumed it desirable for the majority of each bolt to be within the sandstone, and not located next to an existing fracture, and if so, predicted that striking roots would be a less likely outcome.

Cross examination of expert evidence

64. Mr Johnson suggested that Mr Hambridge, in making his determination, was unduly influenced by Mr Wilkie’s prior removal application rejection, and was therefore biased. Mr Hambridge rejected this, and noted his prior acknowledgment of his duty to the Court.

65. Mr Pickup similarly suggested Mr Kingdom was displaying bias, particularly noting Mr Kingdom’s impassioned concluding speech where he raised the spectre of an ostensibly similar situation in the Shoalhaven region, where a man was killed by a tree falling on his house.

66. There is no doubt that a major element of the applicant’s case was to cast aspersions on the safety of the tree, but this is not unexpected, particularly given Mr Natoli’s extreme fear. Though it sometimes appears difficult to navigate a line between a client’s interests, and the duty expert witnesses are required to exercise to the Court, all experts here acted professionally, provided useful evidence, and I don’t accept that any were inappropriately biased.

67. With respect to chemical damage, specifically pH alteration, Mr Kingdom expected the geotechnical work to cause pH “issues”, while Mr Hambridge disagreed, on the basis that most of the roots would be found in upper layers of the soil.

68. On two occasions, Mr Wright re-iterated his opinion that the cliff face below the tree can be stabilised, notwithstanding that, should the tree be retained, a “beefed up” system would be required to allow for uncertainty. In relation to the allowance for movement, in Mr Wright’s proposed retention system, Mr Kingdom opined that 20mm of rock shelf movement around the rock bolts could be expected, in response to wind, gravity and opportunistic root growth, but again this is based on unknown assumptions, and geotechnical knowledge, which is outside his area of expertise. Mr Crozier offered no additional opinion in this regard.

69. While much of the questioning of both arborists focussed on the accuracy and basis of the various components which underpin QTRA calculations, strong confidence in either arborist’s conclusions was compromised by the inadequacy of information informing their assumptions, particularly with respect to probability of tree failure.

70. From this limited evidence, the tree’s observed condition and characteristics, and the tree species, I was more persuaded by Mr Hambridge’s conclusions, as they more closely reflected the available site evidence and known root characteristics of this species, while Mr Kingdom’s results were based on largely unsubstantiated assumptions.

Conclusions

71. Reviewing the adduced evidence and expert’s opinions, and bringing my own arboricultural expertise to these issues, I conclude the following:

72. I concur with Mr Hambridge and Mr Pittendrigh that the tree’s height and canopy spread are within the ranges of 18-20 metres and 15-17.5 metres respectively, rather than the 26 metre height and average 23 metre canopy spread estimated by Mr Kingdom.

73. I also agree with Mr Hambridge, that “it is widely understood that tree roots on slopes have a much greater mass up slope and across slope”, that the “tree is growing in a manner typical of the species”, that “there is no evidence to suggest the visible sandstone is the only thing holding the tree up”, and that “the size and excellent health of the tree suggest an equally impressive root system”, notwithstanding that this remains an assumption.

74. For a mature Angophora costata, growing on a slope in a geological landscape such as this, it is reasonable to expect an extensive web of roots, particularly upslope, spreading well beyond the tree’s canopy wherever the opportunity for growth presents, intertwined in cracks and crevices amongst the sandstone, without necessarily unduly prising them apart, and cumulatively providing anchorage to the tree, primarily under tension. It would not be surprising to also find roots grafted to those of other Angophora costata nearby. Structural roots to the east of the tree would be expected to be much more proximal to the trunk base, less numerous, often more vertical, and generally loaded in compression.

75. Additionally, just as with trunks and branch development, root growth is not passive, but occurs in response to the various environmental loads on the tree, particularly wind and gravity. Given the forces exerted on the tree over its long life to date, and its impressive health and vigour, one can expect that the resultant root system, particularly on the upper tension side, has been naturally “beefed-up”, to compensate for the loads resulting from its coastal exposure, and lean.

76. In this respect, it may be prudent to consider the paradoxical situation that may exist here, that this expected extensive web of roots may be binding the stone landscape, contributing to the stability of the various rock components, rather than compromising them.

77. Mr Kingdom said “the location and size of the roots is unable to be quantified”. To the contrary, careful root mapping can be undertaken under arborist supervision, with little risk, given the low shear resistance of the sandy topsoil, alluded to on site by Mr Kingdom. In his Curriculum Vitae, Mr Kingdom notes attendance at an industry root mapping seminar in 2016, so he will likely be familiar with appropriate procedures. This excavation should provide evidence allowing determination of whether the root system conforms to that expected for trees on slopes generally, and to the normal extensive spread of Angophoras costata, with penetration and binding amongst the rocks. There are accepted industry practices to garner information; assessment of presence and strength of root tissue using a nylon mallet initially, and resistograph assessment, especially in the root crown zone, in accordance with the advanced diagnostic procedures established by Dr Claus Mattheck. Mr Kingdom notes attendance at a Mattheck seminar in 2004.

78. Mr Wilkie had suggested resistograph assessment of the trunk to clarify termite impact, in response to Mr Natoli’s original removal application, but there is no indication that such testing was implemented.

79. Quantification of trunk movement towards the house, should it be occurring, is clearly an important assessment, but it is reasonable for Council to require that this should be completed by an independent specialist, and based on sound, reliable methodology. While I have no reason to doubt Mr Natoli’s findings, he has a vested interest in the tree’s removal, and thus may lack objectivity.

80. If stability is confirmed, even though both arborists noted that arboreal termites only process heartwood, it would be prudent for an aerial assessment to be undertaken, as it is likely to allow assessment of residual sound trunk tissue, and also clarify Mr Kingdom’s concerns with respect to possible wounds in major branch junctions.

81. This is a significant tree. It provides an extensive range of environmental services, which may be quantified as a monetary value, using industry accepted methodology. It is a long lived species, providing extensive habitat, in a high biodiversity bushland environment. It is also a front line waterfront tree adapted to harsh conditions due to exposure to the elements, and offers a protective role to trees further inland which are currently less exposed. Its contribution in terms of canopy cover, habitat and biodiversity would be difficult to replace on the same site within a reasonable timeframe.

71. This does not take away from the obligation to primarily consider risk, but it does make it reasonable to expect allocation of funds towards measures to mitigate risk, provided it is proportional to the tree’s value. Given that both engineers appeared to agree that the cliff-face would require stabilisation, regardless of the presence of the tree, then the difference in cost between the engineering system required with the tree absent, and the more robust system required should the tree be retained, is the financial impost to be considered. Mr Natoli noted estimates of $30,000 to $80,000 for such works with the tree retained, but again, no reliable evidence for such estimates was provided.

72. Mr Johnson concluded that the tree will inevitably fall, and that “if the tree can’t survive without geotechnical stabilisation, then it should be allowed to be removed”. Just as we will inevitably die, the tree will inevitably fall (without intervention), but the evidence provided is insufficient to substantiate a claim that this is currently imminent or probable, or that the tree can’t survive (and maintain its structural stability) without geotechnical stabilisation. On this basis, I do not accept Mr Johnson’s position that removal should be allowed for these reasons.

73. Risk assessments are meaningless unless they are defined temporally, and the usual period is one year. Mr Kingdom, in his revised QTRA of 1:400, appears to have applied Mr Crozier’s conclusions as if they related to such a period. Mr Crozier’s text “will be expected to result in eventual dislodgment and cliff line failure” is not defined by a time period, and “eventual dislodgment and cliff line failure” does not necessarily reflect an imminent or even probable occurrence in the short or medium term.

74. Mr Kingdom’s QTRA is also not based on the facts currently available, but unproven assumptions. Significantly, he has agreed with Mr Hambridge (in the joint report) that inadequate evidence has been provided to show that the tree is tilting, yet appears to continue to factor that assumption into his probability of failure, as if tilting is occurring.

75. The decision guidelines for determining an application for tree removal at 1B.6.1 (j) of HDCP include;

“Accordingly, any application for removal must demonstrate that the removal of the tree is appropriate based on an assessment of the safe useful life and risk to human life or property using industry relevant risk assessment such as Tree Risk Assessment Qualification (TRAQ) or Qualified Tree Risk Assessment (QTRA).”

87. Council’s determination of Mr Natoli’s application gave three reasons for refusing consent for tree removal;

“Removal is not granted as insufficient evidence has been presented to enable permission to be granted under Council’s Tree Preservation measures such as:

…

d) There were no obvious structural dysfunctions observed to warrant pruning or removal.

e) There has been no diagnostic evidence to support the claim to warrant pruning or removal.

f) Council has applied a Quantified Tree Risk Assessment (QTRA), an industry recognised methodology and determined the level of risk to broadly acceptable.”

88. Based on observation of the tree, the site, and the evidence adduced, there are no obvious structural dysfunctions observed to warrant pruning or removal, and there has been no reliable diagnostic evidence provided to support the claim to warrant pruning or removal. On this basis, it is reasonable for Mr Hambridge to have reached his determination.

89. This does not confirm that the tree does not present an unacceptable risk, but given that “the onus falls on the property owner to provide sufficient information to support the request for pruning or removal of a tree” (as per point 3 of Council’s refusal letter), I also find that there has been insufficient reliable diagnostic evidence provided to justify granting permission for removal.

Orders

90. For the reasons given above, the Court orders that:

1. The appeal is dismissed.

……………………………….

John Douglas

Acting Commissioner of the Court

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Decision last updated: 30 July 2021