PRINTER FRIENDLY VERSION

Environment, Resources and Development Court of South Australia

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Provisional Development Plan Consent sought to remove significant tree - refused by Council - appeal - provisions of Development Plan in relation to significant trees considered - evidence of health of tree - contribution to amenity of locality - possibility of damage or injury being caused by limbs dropping - risk can be reduced to acceptable level by appropriate pruning and maintenance - appeal dismissed.

Development Act 1993, referred to.

Russell v City of Burnside [2004] SAERDC 97; Gormley v City of Unley [2005] SAERDC 24; Cheung and Kindlen-Cheung v City of Onkaparinga [2004] SAERDC 21, considered.

 

 

1 This is an appeal against the decision of the City of Burnside ("the Council") to refuse Provisional Development Plan Consent to an application under the Development Act 1993 by Ashley Miller ("the Appellant"), which application sought Provisional Development Plan Consent for the removal of a significant tree on land at 5 Stonyfell Road, Wattle Park. Some relevant details are set out hereunder:

2 The tree proposed for removal is a River Red Gum (Eucalyptus camaldulensis subsp. camaldulensis). The tree is approximately 22m high by 12m wide with a single trunk up to a height of 4.0m above ground level from which point irregular heavy branching begins. The tree has an upright form, with the major scaffold branches growing at an angle of 45º or greater. It has a trunk circumference at 1.0m above ground level of 4.19m, meaning that it is a "significant" tree for the purposes of the Development Act 1993 and regulations under that Act.

3 Within the last three to six years, the tree has been extensively pruned, principally on the lower half and southern side. Branches up to 200mm in diameter have been removed back to larger branches or to the trunk up to a height of approximately 11m above ground level.

4 The tree is located in the rear yard of a residential property at 5 Stonyfell Road, Wattle Park. The base of the tree is located in a small, raised garden bed with a 400mm high brick and mortar retaining wall 1.0m from the base of the trunk on all sides. The base of the tree is approximately 3.5m from a single- storey dwelling on the subject land. Approximately 3.0m of the tree’s crown overhangs the dwelling. The crown of the tree largely overhangs the rear lawn area of the property.

5 The appellant gave evidence that, in February 1999, during construction of his dwelling, a substantial limb, estimated by him to be up to 200mm in diameter, had fallen from the tree in a location now occupied by the rear verandah of his dwelling. As a consequence of concerns raised by that event, a qualified arborist was engaged to undertake substantial pruning of the tree. Subsequent to that pruning, in December 1999, a smaller branch had fallen into an area now occupied by a swimming pool. Following the recent construction of that swimming pool and an adjoining tennis court, the space to the rear of the dwelling was the only remaining area in which his children could play, and the application to remove the tree arose from concerns regarding the potential risk of limb failure above that area.

6 The subject land is located within the Residential Zone, Policy Area 20, which is depicted on Map Bur/13 in the Development Plan for Burnside (City) dated 17 March 2005. The objectives for the zone place emphasis on residential uses, a range of dwelling types, and the protection and enhancement of residential amenity and the attractive qualities of streetscapes. More specific provisions apply within Policy Area 20, the most relevant of which are as follows:

Objective 2: Protection and enhancement of trees, and the natural features and open character of creeks, Ferguson Conservation Park, and local reserves.

Principle 1: Development should:

(a) conserve and enhance the character of the Policy Area, described in Objective 1, the natural features of Ferguson Park, and significant trees; and

(b) complement the scale, bulk, siting and positive elements of existing dwellings where a distinctive and attractive streetscape character exists.

7 Council-wide provisions of relevance are as follows:

Objective 19: The retention and protection of remnant indigenous vegetation.

Objective 20: The conservation of significant trees (including significant trees identified in Table Bur/4 and as shown on Figures Bur(ST)/1 to 8 inclusive) in Metropolitan Adelaide which provide important aesthetic and environmental benefits.

Objective 21: Development sited and undertaken to retain and protect a significant tree or group of significant trees.

Principle 41: Land should not be developed where the development would be likely to result in a substantial tree-damaging activity occurring to a significant tree.

Principle 42: Where a significant tree:

(a) makes an important contribution to the character or amenity of the local area; or

(b) is indigenous to the local area and its species is listed under the National Parks and Wildlife Act as a rare or endangered native species; or

(c) represents an important habitat for native fauna; or

(d) is part of a wildlife corridor of a remnant area of native vegetation; or

(e) is important to the maintenance of biodiversity in the local environment; or

(f) forms a notable visual element to the landscape of the local area;

development should preserve these attributes.

Principle 46: Development should be designed and undertaken to retain and protect significant trees.

Principle 47: Development should be undertaken with the minimum adverse affect on the health of a significant tree.

Principle 48: Significant trees should be preserved and tree-damaging activity should not be undertaken unless:

(a) in the case of tree removal;

(1)     (i) the tree is diseased and its life expectancy is short; or

(ii) the tree represents an unacceptable risk to public or private safety; or

(iii) the tree is within 20 metres of a residential, tourist accommodation or otherwise habitable building and is a bushfire hazard within the Bushfire Prone Area shown on Figure BurBPA/1; or

(iv) the tree is shown to be causing or threatening to cause, substantial damage to a substantial building or structure of value; and

all other reasonable remedial treatments and measures have been determined to be ineffective.

(2) it is demonstrated that all reasonable alternative development options and design solutions have been considered to prevent substantial tree-damaging activity occurring.

(b) in any other case;

(i) the work is required for the removal of dead wood, treatment of disease, or is in the general interests of the health of the tree; or

(ii) the work is required due to unacceptable risk to public or private safety; or

(iii) the tree is within 20 metres of a residential, tourist accommodation or habitable building and is a bushfire hazard within the Bushfire Prone Area shown on Figure Bur/BPA/1; or

(iv) the tree is shown to be causing, or threatening to cause damage to a substantial building or structure of value; or

(v) the aesthetic appearance and structural integrity of the tree is maintained; or

(vi) it is demonstrated that all reasonable alternative development options and design solutions have been considered to prevent substantial tree-damaging activities occurring.

8 Council Wide Objective 20 calls for the conservation of significant trees "which provide important aesthetic and environmental benefits". Council Wide Principles 38 and 42 respectively set out criteria for assessment of the worth of vegetation generally, and of significant trees in particular.

9 Expert evidence was given by Ms T Milne, a qualified and experienced ecologist, concerning the habitat and biodiversity value of the subject tree, and by Mr S Heseltine, a qualified and experienced landscape architect, concerning the value of the contribution made by the tree to the immediate landscape and the wider streetscape.

10 No expert evidence was adduced by the Appellant to contest these opinions, which are supported by my own observations on the view. Having regard to the evidence of Ms Milne and Mr Heseltine, I am satisfied that the subject tree does provide "important aesthetic and environmental benefits", and satisfies at least placita (b) and (c) of Council Wide Principle 38 and (a), (c), (e) and (f) of Council Wide Principle 42.

11 It having been established that the subject tree has characteristics which, prima facie, justifying its retention, it becomes necessary to consider whether its removal is justified on the basis that one or more of the placita under Council Wide Principle 48 is met.

12 Three arboricultural experts gave evidence in the matter: Mr D Nicolle, and Mr M Lodge, both consulting arborculturalists, and Mr J Draper, a qualified arborculturalist in the employ of the respondent Council.

13 Mr Nicolle, in evidence, estimated the subject tree to be between 40 and 80 years old. In his opinion, the tree was nearly fully-grown, but could increase further in height and spread, to an eventual size of approximately 25m tall by 18m wide. The tree was in good to excellent health, but could experience significant detrimental effects in the medium to long term as a consequence of excavations within the root zone for the Appellant’s dwelling and swimming pool, extensive paving, and the recent filling, compaction and sealing of a large area for a tennis court. While the tree could live for another 20 – 100+ years under current environmental and site conditions, the expected remaining life of the tree would depend largely on its ability to recover over the next 5 – 10 years from highly-modified site conditions.

14 Mr Nicolle considered the likelihood of whole tree failure to be low, but rated the risk to property and personal safety occasioned by limb failure to be moderate to high, on the basis that:

(a) the tree was one of a species susceptible to branch drop under warm, still non-storm conditions, the incidence of which was often exacerbated by environmental stress on the tree caused by modified site conditions;

(b) the likelihood of branch drop in this species increased with age, generally beginning at between 20 and 30 years of age;

(c) the tree showed evidence of ongoing minor to moderate branch failure in the crown;

(d) past pruning practices had resulted in "lion-tailing", this being the creation of relatively long, end-weighted branches; and

(e) the tree overhung portions of the Appellant’s dwelling and regularly-used outdoor areas.

15 Major crown-reduction pruning would, in Mr Nicolle’s view, reduce the likelihood and consequences of whole tree and branch failure over the short term. However, such pruning would reduce significantly the aesthetic appeal of the tree in the short term and would be required on a regular and ongoing basis to manage epicormic regrowth.

16 In Mr Nicolle’s assessment, removal of the tree was the only reasonable course of action. In response to a question from the Court, he advised that he would be likely to take the same view in respect of any tree of this species and age, which overhung a dwelling or regularly-used outdoor area.

17 The evidence of Mr Lodge was that the tree had good structure, with the major scaffold branches growing in an upright habit at approximately 45 degrees or greater, with minimal horizontal growth. While he acknowledged that the tree had lost several branches in the last seven years, its condition and growth pattern did not indicate that significant failures had occurred earlier in its life. This level of failure did not constitute an unusual or unreasonable failure history.

18 Mr Lodge disputed Mr Nicolle’s view that there was evidence of "lion-tailing" in the tree’s canopy, referring to the upright habit of the major scaffold branches as being inconsistent with this characterisation.

19 A tree hazard evaluation was undertaken by Mr Lodge, based on three criteria: failure potential, size of part most likely to fail, and the type of target area below the tree. This evaluation concluded that the tree’s failure potential was low, as it did not have a history of regular branch drop nor structural flaws which would significantly increase the rate of branch failure. The majority of branches over the target area had been pruned or removed. The size of limb most likely to fall was considered by Mr Lodge to be less than 100mm in diameter. The frequent use of the area beneath the tree gave a high target rating, but taking the criteria together, Mr Lodge concluded that the tree’s hazard rating was 5/12, suggesting monitoring and remedial treatment were the most reasonable courses of action. Given the high target rating, the most appropriate way to reduce the overall hazard rating was, in Mr Lodge’s opinion, modification of the tree’s canopy to reduce its potential to contact the existing target and any future targets.

20 Mr Lodge also carried out what he described as a Quantified Tree Risk Assessment. This assessment arrived at a measure of the risk of harm from limb or whole tree failure. This assessment arrived at a risk of harm of 1/32472; Mr Lodge’s evidence was that a risk of 1/10,000 was considered to be within generally acceptable limits. Pruning of the tree in accordance with his recommendations would, in his assessment, reduce the risk of harm to 1/540,000. Target hazard and formative pruning focussing on the removal of dead, damaged, diseased, weak or crossing branches would help encourage good quality growth and lead to evenly-balanced foliage throughout the canopy. While he did not suggest minor branch failure was unlikely to occur, Mr Lodge was of the view that adequate protection from such failure could be provided by utilisation of a suitably-designed shade sail structure over the area immediately beneath the tree.

21 Mr Draper, in evidence, acknowledged Eucalyptus camaldulensis was a species what had a reputation for sudden limb failure. In his experience, however, limb failure in this species was associated, in almost every instance, with some form of prior damage. The species was largely tolerant of root disturbance, and could withstand a greater loss of root mass than many other species of a similar size.

22 Like Mr Lodge, Mr Draper was of the view that the tree had not displayed a significant propensity to limb failure.

23 Mr Draper also undertook a risk assessment of the tree, and concluded, that, without any intervention or prescribed remedial action, the risk rating for the tree in relation to the dwelling to the south would be 7 or less, this representing an acceptable level of risk. Ongoing management and regular inspections of potential failure points would keep risks to an acceptable level. Mr Draper recommended that the tree be inspected in two years time with follow up inspections and pruning as required at 5, 7 and 10 years.

24 Mr Psaltis submitted that a conservative approach should be taken to assessment of the risks represented by a large tree in close proximity to a dwelling. In support of these submissions he referred to the evidence of Mr Nicolle, an acknowledged expert on eucalypt species, and to my decisions in Russell v City of Burnside [2004] SAERDC 97 and Gormley v City of Unley [2005] SAERDC 24. In my decision in Russell, I observed, at paragraph 20, that:

Where, as is the case here, a large tree is located in very close proximity to a dwelling, it seems to me appropriate to adopt an approach to risk assessment which is more conservative than that which might apply to a similar tree well removed from dwellings.

25 I expressed similar views in Gormley.

26 Ms Reina, for the Council, submitted that, on the evidence, the only limb failure of any consequence was that which occurred in February 1999, which predated the substantial pruning of the tree. Since that pruning, such failures as had occurred were minor, having regard to the evidence of Mr Lodge and Mr Draper as to the size of limb failure which would represent a significant risk to life or property.

27 Some degree of risk, Ms Reina submitted, was associated with any substantial tree, referring to the decision of this Court in Cheung & Kindlen-Cheung v City of Onkaparinga [2004] SAERDC 21, in which Judge Cole observed, at paragraph 13:

The Development Plan seeks to preserve trees of more than a specified size in the urban environment. A degree of risk is implicitly accepted. ….The reduction of the risk posed by a tree is generally within the power of its owner.

28 Finally, Ms Reina submitted that, having regard to the large number of River Red Gums within the suburbs of Metropolitan Adelaide, removal of the subject tree simply on the basis of a perceived risk associated with all trees of this species located close to dwellings, could create a basis upon which many other River Red Gums could be removed.

29 It is established law that each planning application must be determined on its own merits. In the cases referred to, Russell and Gormley, there were basic structural defects in the trees proposed for removal, which defects were likely to render ineffectual a regime of pruning and canopy management. I agree with the evidence of Mr Nicolle that River Red Gums are not a species of tree which should be planted in close proximity to dwellings, or beneath which new dwellings should be located. That said, this species is commonplace throughout the suburbs of Metropolitan Adelaide, and wholesale removal on the basis of a perceived but generalised risk would be to fail to distinguish between those trees which are susceptible to canopy management and other means of reducing risk to an acceptable level, and those which are not.

30 On the evidence, I am satisfied that the subject tree is in sound condition, and does not evidence fundamental structural defects. It does not have a history of significant limb failure, such failures as have occurred in the period since the tree was extensively pruned being relatively minor. With the adoption of the pruning and maintenance regime recommended by Mr Lodge and Mr Draper, perhaps supplemented by a suitably-designed shade sail structure over the area immediately beneath the tree, the risk represented by the tree can be reduced to a level generally considered acceptable.

31 Should regular inspection of the tree by an appropriately qualified arborist suggest that normal pruning and maintenance practices are insufficient to maintain risk at an acceptable level, it is open to the Appellant to make a further application to remove the tree. On the evidence, however, I am not persuaded that, in the present circumstances, removal is warranted.

32 That being the case, I have decided that this appeal should be dismissed. There will be an order to that effect.