Svensson v Conservator of Flora & Fauna (Administrative Review)
[2010] ACAT 10
•9 March 2010
ACT CIVIL & ADMINISTRATIVE TRIBUNAL
SVENSSON v CONSERVATOR OF FLORA & FAUNA (Administrative Review) [2010] ACAT 10
AT 94 of 2009
Catchwords: ADMINISTRATIVE REVIEW – Tree protection – review of reconsidered decision by Conservator of Flora and Fauna to refuse approval to remove a regulated tree – Fraxinus excelsior ’aurea’ (Golden Ash) – whether application for approval to a tree-damaging activity meets criteria in Tree Protection (Approval Criteria) Determination No 2 – whether the tree represents and unacceptable risk to public or private safety – whether the tree is shown to be causing or threatening to cause substantial damage to a substantial building, structure or service – whether damage to a stormwater drain constitutes substantial damage to a substantial structure or service – whether all other reasonable remedial treatments and risk mitigation measures have been determined to be ineffective.
Legislation:Tree Protection Act 2005 (ACT) ss 15, 19, 21, 25, 106, 107, 107B
Tree Protection (Approval Criteria) Determination 2006 (No 2) 2006 (ACT) (Disallowable Instrument DI 2006-60)
Case Law:Maleganeas and Conservator of Flora and Fauna [2007] ACTAAT 24 (15 November 2007)
Tribunal: Mr JF Ashe, Senior Member
Mr GJ Lunney SC, Member
Date of Orders: 9 March 2010
Date of Reasons for Decision: 9 March 2010
AUSTRALIAN CAPITAL TERRITORY )
CIVIL & ADMINISTRATIVE TRIBUNAL ) AT 94 of 2009
BETWEEN:
GARRY ROBERT SVENSSON &
ROBYN LOUISE SVENSSON
Applicant
AND:
CONSERVATOR OF FLORA & FAUNARespondent
Tribunal:Mr JF Ashe Senior Member
Mr GJ Lunney, SC Member
Date: 9 March 2010
ORDER
The decision under review is set aside and in its place is substituted a decision that the application to remove the subject tree is approved.
……………………………….
Mr JF Ashe
Senior Member
REASONS FOR DECISION
The application
This is an application to the Tribunal for review of a reconsidered decision by the Conservator of Flora and Fauna (‘the Conservator’ or ‘the respondent’) made on 14 October 2009 to refuse approval for the removal of a regulated tree under section 107 of the Tree Protection Act 2005 (ACT) (‘the Tree Protection Act’).
The tree has been identified by ACT Government officers as a Fraxinus excelsior ‘aurea’, commonly known as Golden Ash (‘the Golden Ash’, ‘the tree’ or ‘the subject tree’). It is located on a residential block at Block 3, Section 115, 85 Wheeler Crescent, Wanniassa (‘the property’). Mr GR and Mrs RL Svensson (‘the applicants’) are the lessees of the block and have applied, under section 107B of the Tree Protection Act, for review of the reconsidered decision made by the respondent.
The applicants first applied to remove the tree on 7 August 2009, as they wished to extend their home and the proposed addition to the rear of the existing dwelling would be close to the tree. A Tree Inspection Officer inspected the tree on 25 August 2009 and recommended that the application be refused. A delegate of the Conservator refused the initial application on 3 September 2009, under section 25 of the Tree Protection Act, on the grounds that it had not been established that any of the criteria for removal set out in Schedule 1 of the Tree Protection (Approval Criteria) Determination 2006 (No 2) (Disallowable Instrument DI 2006-60) (‘the Criteria Determination’), made under section 21 of the Tree Protection Act, had been satisfied.
Section 106 of the Tree Protection Act provides that a person may seek reconsideration of a decision by the Conservator to refuse to approve an activity under section 25. The applicant sought such reconsideration on 21 September 2009. The stated reasons were:
· the applicants wished to extend their home;
· there were concerns that the root system of the tree had invaded the stormwater pipes and may invade the sewer line;
· the tree roots may be causing cracking to the garage floor; and
· the tree roots may cause foundation problems to the main house in the future.
In accordance with section 107(1) the application was referred to a Tree Advisory Panel. The Chair of the Panel, Dr Peter Coyne, inspected the tree on 22 September 2009 and advised that the tree did not meet the criteria for removal. At its meeting on 28 September 2009 the Tree Advisory Panel endorsed that advice and recommended refusal of the application on the basis that none of the criteria for approval had been satisfied. On 14 October 2009 the Conservator confirmed the original decision.
Tribunal’s jurisdiction
Section 107B of the Tree Protection Act provides for review by the Tribunal of a decision of the Conservator under section 107 of the Tree Act following reconsideration of a decision originally made under section 25 of the Tree Protection Act.
Applicable law
It is an offence under the Tree Protection Act to damage a protected tree (section 15) unless, pursuant to section 19, approval has been granted by the Conservator under section 25. Removal of a regulated tree therefore requires approval.
Section 25(3) of the Tree Protection Act sets out the matters to which the Conservator, and therefore this Tribunal, must have regard when making a decision on an application. They are:
(a) the approval criteria; and
(b) the advice (if any) of the advisory panel; and
(c) anything else the conservator considers relevant.
Section 21 of the Tree Protection Act provides for the Minister to determine the criteria to be applied when considering an application for approval to a tree-damaging activity. On 4 April 2006 the Minister for the Environment made Tree Protection (Approval Criteria) Determination (No.2) (Disallowable Instrument DI2006–60), for the purposes of section 21. The relevant criteria for consideration in this case are in paragraph 1(1):
(1) The Conservator of Flora and Fauna (the Conservator) may give an approval to damage a regulated tree under section 25 when:
…
(b)the tree represents an unacceptable risk to public or private safety; or
(c)the tree is shown to be causing or threatening to cause substantial damage to a substantial building, structure or service;
…
and all other reasonable remedial treatments and risk mitigation measures have been determined to be ineffective.
Agreed facts
It is agreed that the tree is a regulated tree and that its removal requires approval. It is not disputed that the tree is in good health, although there are some dead branches. The tree is on the southern side of the house, in the centre of the backyard, some 9 metres from the house and some 12 metres from the garage to the south west of the house. The tree is estimated to have a height of 10+ metres with a canopy spread of approximately 11 metres and a trunk greater than 1.5 metres in circumference.
Site inspection
On the morning of the hearing the Tribunal conducted a site inspection of the tree and the property. Our attention was drawn to cracks in the walls and floor of the garage, and in the walls of the house; to work on the downpipes to provide access to the stormwater drains to enable the removal of tree roots which had caused blocking; to the presence of a wisteria attached to the rear of the house on the southern side; and to two areas where soil had been excavated to investigate the presence of tree roots. We were also shown the area where two large eucalypts on the south western side of the house had been removed in August 2009; and our attention was drawn to three eucalypts in the front garden close to the northern wall of the house. The Tribunal noted the presence of a large eucalypt towards the rear of the property. We also observed that there were some small dead branches in the tree, and our attention was drawn to a dead branch, some 2–3 metres in length and some 30 mm in diameter at its thickest section, which had recently fallen from the tree. The garden showed signs of drying out due to the effects of the lack of rain that Canberra has been experiencing in recent years.
The applicants’ evidence and contentions
Mr Svensson provided evidence at the hearing, and Mr Simon Munslow, of counsel, appeared before the Tribunal on behalf of the applicants. Mr Don McInnes, a consultant engineer, also provided evidence on behalf of the applicant.
In their application to the Tribunal for review of the Conservator’s reconsidered decision, the applicants stated:
Reconsidered decision failed to apply due weight to evidence of root damage to stormwater pipes, cracking in the garage floor and damage to foundations, & cracks in house walls caused by the tree.
Mr Svensson said that there were cracks in the wall of the garage when he and his wife bought the house in 2000, but that cracks in the walls of the house have only become evident more recently. In December 2009 he was woken up, in the early morning, by a large bang and subsequently discovered new, extensive cracking in the north and west walls of the house and cracking in the vicinity of the west wall at the en-suite bathroom window. He said that this cracking has reached the point where it is displacing tiles in the en-suite bathroom.
Mr Svensson also told the Tribunal that in the last 18 months he has called a plumbing company to his home a number of times to clear blocked drains on the property. Mr Svensson’s affidavit said that it annexed a copy of a letter from Mr Peter Laurent of Eveready Plumbing, dated 1 December 2009. That letter does not appear to have been actually annexed to the affidavit; however, it is presumably the same as that filed by Mr Munslow on 21 December 2009 as material which he relied on. The letter states that Mr Laurent’s company had been called a number of times in the previous 18 months to clear blocked drains within the backyard of the property. Mr Laurent thought that the roots cleared from the pipes were from the Golden Ash and recommended that the tree be removed to prevent further problems to the drainage system. Little weight can be given to that opinion, since Mr Laurent does not explain by what process he identified the roots as being of a particular tree, nor was his opinion tested in cross examination. The Tribunal is satisfied, however, that tree roots had to be removed from the stormwater drains on several occasions.
Mr Svensson’s affidavit also stated that during recent windy weather the tree has shed branches and he was concerned about possible injury to his children and their friends. One such branch was approximately 3 metres long with a thickness of 3 centimetres.
Mr McInnes is a Director of Sellick Consultants Pty Ltd, a practice of consultant structural, civil and hydraulic engineers. He has a Bachelor of Engineering (Hons) and an ME (Hons) and is a member of a number of professional engineering institutions. His degrees are in civil engineering, majoring in soil mechanics and structures. At Mr Svensson’s request, Mr McInnes conducted an inspection of the property on 17 November 2009 and provided an initial written report to Mr Svensson on 26 November 2009. The stated objective of the inspection was ‘to assess the structural condition of the residence and the garage with a view to possible effects the subject tree may be having on the performance of the structures’. Mr McInnes provided an addendum to his report on 21 December 2009.
In his initial report McInnes stated that a fine hairline crack existed below the rear window closest to the subject tree and that a hairline crack existed to the north-western boundary wall. The report also stated that a severe crack has developed close to the rear window of the garage corresponding to progressive development below the window sill, and that a severe crack has developed above the window to the northern face of the garage.
Mr McInnes’s report also indicated that there was evidence of stormwater drainage maintenance, which Mr Svensson had told him had been carried out due to root infiltration. The report commented that the service ties appear to be located to the rear of the property where, the report said, one expects the drainage to pass through the drip zone of the tree.
The report noted that minor excavation of the soil had been carried out along the surface of the residence and the garage, which showed signs of root infiltration to the surface soils. The report said that the source of the roots could not be determined other than to observe that there was minimal vegetation to the rear of the residence between the subject tree and the residence.
Mr McInnes’s report stated that he was of the opinion that the subject tree has not directly caused structural damage to the residence or garage. The immediate issue influencing the structural performance, the report said, is the effect of the drainage where blockages appear as regular occurrences, which will play on the moisture condition within the founding soils and will in turn affect founding movements. The report commented that the stormwater drainage is of segmented concrete units, which are prone to root infestation and have a limited life when undergoing regular cleaning. Mr McInnes’s view was that eventually such pipes will require replacement by p.v.c., which will ultimately affect the health of the tree when works are undertaken.
Mr McInnes’ report recommended that the subject tree be removed for the following reasons:
·The tree will affect the performance of the existing structure in the future;
·The tree is affecting the existing stormwater drainage which is currently being maintained. However such maintenance has a finite life and replacement of drainage would be required before structural ramifications develop. This replacement would involve trenching through the drip zone of the tree;
·The tree was closer to the house than recommended by the CSIRO formula for estimating the minimum distance between trees and houses on different classes of soil.
Mr McInnes provided an addendum to his report on 21 December 2009. In the addendum Mr McInnes stated that, since his inspection of the subject property on 17 November 2009, he had been advised that further movement has since occurred, in that the hairline crack which was observed to the north-western boundary wall has since developed into a crack of approximately 1.0+ mm. Such movement, Mr McInnes said, is consistent with his initial report in that the subject tree will progressively cause structural damage to the residence as per the recommendation in the initial report.
At the hearing Mr McInnes responded to questions concerning matters discussed in CSIRO publication, Guide to home owners on foundation maintenance and footing performance (updated for AS 2870–1996) (Revised August 1996) (‘the CSIRO document’). Among other things this publication includes a classification of soils according to the degree to which they swell and shrink with changes of moisture content, including:
Class M: Moderately reactive clays that may cause minor damage to brick houses on old-style light strip footings. Moderately reactive clay soils are common.
Class H: Highly reactive clays that often damage houses, paths and fences.
Mr McInnes said that the clay soils of Wanniassa were regarded as being moderately reactive. However, having visited the site, he regarded the soils of the subject block as being borderline highly reactive.
The CSIRO publication recommends that, to minimise the risk of damage, trees should not be planted near houses on reactive clay soils and recommends limits according to the reactivity of the soil. In the case of Class M sites, it recommends that a tree should not be planted any closer than 0.75 times the height of the tree; and for Class H sights a tree should not be planted any closer than 1.0 times the height of the tree.
Mr McInnes said he was confident that due to the size of the tree it would be having an effect of the structural performance of the house, but he did not think the tree is causing damage to the garage. He was of the view that the house is under stress and thought that the tree could be having an effect on the northern face of the house.
In response to questions from Mr McCarthy, Mr McInnes agreed that the cause of cracking in walls is due to the wetting and drying of soils, which cause expansion and shrinking of the soils, and in turn movement of the founding soils on which the house is built. He agreed that changes in the quantity of water in the soils is the cause of movement in the soils, and that whatever causes changes in the amount of water in the soils will cause changes in the movement of the soils.
Mr McInnes agreed that such problems are common in Canberra and that a common cause is the lack of rainfall, which causes shrinkage of the soils. He agreed generally with the proposition put by Mr McCarthy that the shrinkage of soils in Canberra would have been noticeable and prolonged over the previous three months, although in his view that effect was not as bad as some years ago, and because there had been some recent wet weather.
Mr McInnes agreed that the effect of trees is that the roots draw water from the soil, which causes shrinkage. He also agreed that the swelling and drying of soils could have other causes apart from the removal of moisture by tree roots. He agreed that rainfall can lead to swelling of soils and drought can lead to shrinkage. He also agreed that if roots can get into the drains, this is another way in which water could enter the soil and cause soil movement. Mr McInnes agreed that the underlying issue is the source of water and that there could be a combination of causes. It was also his experience that in prolonged dry spells, the roots of trees will search for water and extend their zone of influence. The Tribunal notes in this regard that the CSIRO document states that trees and large shrubs require substantial amounts of water and, if the soil near a tree dries out, the roots will extend in search of soil moisture.
Mr McInnes confirmed that he had seen tree roots on site, but he could not say categorically that they came from the subject tree. He acknowledged that he had not done any excavation, so did not know the extent of the root spread.
Mr McInnes agreed that the two eucalyptus trees to the south west of the house, which were removed in the latter half of 2009, would affect the local area. He also agreed that the wisteria attached to the deck on the southern side of the house would also draw water from the soil.
Mr McInnes agreed with the proposition put by Mr McCarthy that, if the subject tree were removed, there would still remain any number of other causes, for the wetting and drying of the soil, including the effects of other plants. He also agreed that, if there were a prolonged period of rain, it would tend to counteract the effects of shrinkage of the soils due to prolonged drought.
Mr McInnes thought that the effects of the tree on the drainage system are compounding the problem. His recommendation is that, as well as removal of the Golden Ash, the stormwater drains should be replaced. He acknowledged that if this were done, there would still remain effects on the soil from prolonged drought or rain, but he thought that the measures he proposed would have a beneficial effect.
In response to questions from members of the Tribunal, Mr McInnes clarified that the effect of tree roots on the drains is twofold––the roots draw water from the drains, and also damage the drains thus allowing water to escape. He confirmed that he had not done an investigation of the drains.
The respondent’s evidence and contentions
The respondent contends that it has not been shown that damage to the applicant’s home is caused by the roots of the subject tree or that the damage is ‘substantial damage’. The respondent further contends that it has not been shown that the subject tree is threatening to cause substantial damage to the applicant’s home and that all other reasonable remedial and risk mitigation measures have been determined to be ineffective. The respondent accepts that, for the purposes of paragraph 1(c) of the Criteria Determination, the applicant’s home is a substantial building.
Mr Geoff McCarthy, of counsel, appeared before the Tribunal for the respondent. Dr Peter Coyne provided evidence for the respondent and provided two witness statements. Dr Coyne Has a BSc (Forestry) (Hons) and PhD in plant ecology. He is the Chair of the Tree Advisory Panel and inspected the tree and the property on 22 September 2009. At that time his assessment was that the tree was an ‘excellent tree’, and that it was healthy, with only minor deadwood, minor epicormic growth and negligible tip dieback. The crown was healthy, in his view, and the tree was not in decline.
In relation to the location of the stormwater drains, Dr Coyne’s assessment report of 22 September 2009 said:
The applicant showed me the drainage plan which shows the drains are well beyond the dripline of the tree but run under three eucalypts which include trees 2 and 3 of application 19323.
The garage and the house are well beyond the dripline of the tree and the tree does not threaten the damage mentioned in the application.
Dr Coyne enlarged on those views in his oral evidence. His view was that blockages of the stormwater drains could be due to any or all of the three eucalypts. In his view the Golden Ash is certainly not invading the drains as its roots would not be expected to extend far beyond the dripline of its canopy. Dr Coyne said that the garage is well away from the Golden Ash and cracking to the garage floor could not have been caused the Golden Ash.
There is a plan of sanitary drainage which was attached to a supporting request for reconsideration of the original decision filed by a neighbour, Mr Wills. It is at page 39 of the Tribunal Documents. It is not clear whether this is the plan referred to by Dr Coyne; however, it shows that the drainage trench stands well out from the rear alignment of the house where the crack has appeared. The evidence indicated that the stormwater drains would generally run in the same trench as the sewerage line. The Tribunal therefore questions whether it could be accurately said that the drains that run parallel to the rear wall of the house are well beyond the dripline of the tree It appears likely that the stormwater drains pass through the ‘drying zone’ of the Golden Ash as referred to in the CSIRO document.
Dr Coyne commented that keeping drains clear is a management issue and their blockage does not normally constitute grounds under the Tree Protection Act for approval to remove a tree. He was of the view that, once drains have been cleared by an electric eel or other effective means, they can be maintained clear of roots by monthly applications of small quantities of copper sulphate at minimal cost.
Dr Coyne referred to two ACT Government publications which recommend appropriate distances between trees and houses which should be observed when planting new trees. In Design Standard 23: Plant Species for Urban Landscape Projects, the Golden Ash is included in the category of ‘Introduced trees less than 10 metres high’ with a recommended minimum setback of 7 metres. A publication by the Yarralumla Nursery recommends that large trees such as a Golden Ash should be planted at least 5 metres away from a house, drains, paths or other fixed surfaces. In response to Mr McCarthy in reference to the CSIRO publication, Dr Coyne observed that the tree is more than 0.75 times the height of the tree from the house. In Dr Coyne’s view, these publications support his estimate of the spread of the roots from the Golden Ash and his opinion that the Golden Ash is not the cause of the cracking to the house because its roots are unlikely to have reached the house, or to do so.
Dr Coyne thought it ‘incredibly unlikely’ that the roots from the subject tree could spread to the front of the house. He had never encountered a root spread like that, which would be more than double the diameter of the crown of the tree. His expectation was that the roots would spread to the edge of the tree canopy, that is, about to the edge of the deck at the rear of the house, and would not extend closer than 2 metres from the house.
Dr Coyne said he would not feel confident about identifying the source of a root only from its colour and smell.
Dr Coyne observed that cracking of the kind described by Mr Svensson is very common in Canberra houses and the prolonged drought in Canberra in recent times has caused noticeable shrinking in the clay soils of Canberra, which in turn has caused noticeable cracking in a great number of Canberra homes. In his opinion, soil movement was the most likely cause of the cracking described by Mr Svensson. He also thought that if roots were playing any part in any cracking of the house, particularly on the western wall, it was more likely to be roots from Eucalyptus Tree No 1, which (before its removal) was much closer to the house than the Golden Ash.
Dr Coyne agreed with the description of the causes of soil movement in reactive clay soils given by Mr McInnes, including the effects of rain and tree roots. In addition, Dr Coyne identified evaporation as a further cause of drying in soils.
Dr Coyne thought that the two eucalyptus trees, previously near the south west corner of the house and removed in about August 2009, were slightly taller than the Golden Ash and that each tree would have had a greater effect on the house than the Golden Ash. In his view, collectively the two trees would have had a much greater effect on the house than the Golden Ash. Now that the two trees have been removed, but depending on rainfall, he would expect the situation to stabilise considerably. It was possible, he thought, that with rainfall to replace lost moisture, the contraction of the soils might retract a bit.
In response to Mr McCarthy, who asked what would be the effects of the Golden Ash, given its position in relation to the house, Dr Coyne thought it would be close to negligible, based on the rules he had been using in his work and the recommendations in publications such as the CSIRO document discussed earlier in the hearing and the two publications to which he referred in his second witness statement. Dr Coyne commented that in every case the advice in the recommendations places the Golden Ash outside the zone of concern.
Dr Coyne’s estimate is that the tree is not more than 10 metres in height. Applying the CSIRO clearance of 0.75 times the height for moderately reactive soils, this gives a recommended clearance of 7.5 metres from the house. He thought that this confirms his assessment that the Golden Ash would be having only a negligible effect on the house. The Tribunal notes that, for soils that are borderline highly reactive, an appropriate clearance would be greater than 7.5 metres and approaching 10 metres. If the tree is taller than 10 metres, this would require an even greater clearance.
In response to Mr McCarthy as to the cause of cracking to the front of the house, Dr Coyne thought that it likely that it was due to soil movement, although movement of the timber frame was also a possibility. He could not say with confidence that it was caused by the two large eucalypts in the front garden, although he thought this was possible because both have crowns which overhang the house. He thought it likely that the roots from those trees do come close to the house. He also thought that it is extremely unlikely that the Golden Ash is drawing water from the front of the house.
An issue raised with Dr Coyne by Mr Munslow was whether the subject tree may be Fraxinus excelsior ‘Jaspidea’ rather than a Fraxinus excelsior ‘Aurea’, which are two cultivars of Golden Ash, and which, Mr Munslow proposed, may have different growth habits. The issue was not resolved, although Dr Coyne, in response to Mr McCarthy, said that to his belief it had no bearing on the evidence he had given to the Tribunal.
In his second witness statement Dr Coyne responded to concerns about the risks of personal injury raised in Mr Svensson’s affidavit. His view was that falling branches are very rarely a safety hazard, and that the injuries that might be caused by a falling branch of the size reported by Mr Svensson would be unlikely to be serious even if the branch did hit a child. He noted that Mr Svensson had made no mention of falling branches when Dr Coyne visited the property on 22 September 2009. Nonetheless he had considered the issue when he prepared his assessment. In his opinion the most likely outcome of a falling branch would be ‘Fright’ and the chances of that happening are ‘Very Unlikely’.
Consideration of evidence
Only two of the criteria for approval to remove a tree set down in the Criteria Determination are relevant in the present case. The Tribunal’s consideration of the evidence in relation to each of these criteria and our conclusions are as follows.
Criterion 1(b): The tree represents an unacceptable risk to public or private safety.
Although the issue of personal safety was raised in Mr Svensson’s affidavit, it was not pressed, and Mr Munslow conceded that risk to public or private safety was not significant. We find that this criterion has not been met.
Criterion 1(c): the tree is shown to be causing or threatening to cause substantial damage to a substantial building, structure or service.
The applicant accepts Mr McInnes’s evidence that the tree is not causing damage to the garage, so we have considered this criterion in relation to the house and the stormwater drains.
On the issue of the effects of the Golden Ash on the stormwater drains and the house we find the evidence of Mr McInnes persuasive and generally to be preferred to that of Dr Coyne. We accept Mr McInnes’s evidence that the soils on the property are borderline highly reactive. We also accept his evidence that the section of the stormwater drains running east-west at the rear of the house passes through the root zone of the Golden Ash. This is consistent with the drainage plan at T39, which indicates that stormwater drain is located at some distance from the wall of the house.
The Tribunal has noted Mr McInnes’s evidence that the Golden Ash has been having an influence on the soils at the rear of the house on two bases. Firstly its roots are drying the soils, particularly in dry weather when trees extend their zone of influence. This is confirmed by the CSIRO document. This drying causes shrinkage of the soil. Second the roots have damaged the stormwater drain, allowing water to escape when there is rain, and causing wetting and swelling of the founding soils. The drying effects of the tree roots and the wetting effects of the leaking drain exacerbate the natural processes of rain and drought. Mr McInnes’s evidence is consistent with the guidance in the CSIRO document, which warns against the dangers of damage to homes from tree roots, especially on highly reactive soils.
The Tribunal takes the view that the evidence establishes that there was deterioration in the condition of the structure of the house in the November to December period of 2009 in that the crack in the brickwork at the rear of the premises widened. The widening of the crack was due to subsurface soil movement. That movement was exacerbated by the drying effect of tree roots at the rear of the property, one of those trees being the Golden Ash. The movement was also exacerbated by the introduction of water into the subsoil due to damage to the stormwater drains caused by tree roots, one contributing tree being the Golden Ash. We note Mr McInnes’s evidence in the addendum to his report that such movement is consistent with the advice in his initial report that the tree will progressively cause damage to the residence as per the recommendation in his initial report. The Tribunal is of the view that the widening of the crack in such a short period indicates that further and substantial damage is threatened to the house unless preventative action is taken.
Although the Tribunal is satisfied that the Golden Ash is causing damage to the wall of the house closest to the tree, we are not satisfied that there is sufficient evidence that the tree is causing or threatening to cause damage to the western and northern walls of the house.
Mr McInnes has provided evidence that, as a consequence of the entry of the roots of the Golden Ash and the need for unblocking by means of an electric eel on several occasions, the drainage system has been damaged and further damage is likely if the Golden Ash is not removed. The roots from the two eucalyptus trees that have been removed may also have caused damage to the drains. However, The Tribunal is satisfied that the Golden Ash has been a significant contributing cause of damage to the drainage system at the rear of the house and threatens to cause further damage.
It is necessary to consider whether the drainage system is a substantial structure or service and whether the damage is substantial. As noted in a number of cases in the former Administrative Appeals Tribunal, for example Maleganeas and Conservator of Flora & Fauna [2007] ACTAAT 24 (15 November 2007), the Full Federal Court has considered the meaning of the word ‘substantial’. The Court concluded that the word meant, large, weighty, considerable or big, and not trivial, minimal or nominal. This interpretation is helpful in the present case, and we find that the drainage system is a substantial service and that the damage being caused by the Golden Ash is also substantial. The respondent accepts that the house is a substantial building.
The Tribunal must also be satisfied that ‘all other reasonable remedial treatments and risk mitigation measures have been determined to be ineffective’. There was no evidence of a remedial treatment for the drying effects of the tree roots on the founding soils in the vicinity of the southern wall of the house. Once the structural integrity of the drains had been breached, removing the roots by electric eel and the regular introduction of chemicals might keep the drains clear of roots but would not rectify the damage to the drains and the continuing discharge of water from the damaged drains.
Replacing the drains with p.v.c. pipes would be effective in stopping discharge of water from the pipe. However, this would no doubt involve considerable expense, and in the Tribunal’s view could not be regarded as being either remedial or reasonable. Nor would this overcome the problem of the drying effects of the tree roots on the soil and consequential effects on the founding soils.
The Tribunal has determined therefore that in the particular circumstances of this case there are no other reasonable and effective remedial treatments to protect the house and the drains.
We find that this criterion has therefore been met.
Conclusion
The Tribunal has concluded that one of the criteria for approval to remove a regulated tree has been met and that it is therefore appropriate to set aside the Conservator’s decision and approve removal of the tree.
…………………………………..
Mr J F Ashe
Senior Member
PUBLICATION DETAILS
TO BE PUBLISHED
To be completed by Tribunal Staff
PART A FILE NO: AT 09/94
APPLICANT: GARRY ROBERT SVENSSON & ROBYN LOUISE SVENSSON
RESPONDENT: CONSERVATOR OF FLORA & FAUNA
COUNSEL APPEARING: APPLICANT: MUSLOW
RESPONDENT: McCARTHY
SOLICITORS: APPLICANT:
RESPONDENT: TOMLINS
OTHER: APPLICANT:
RESPONDENT:
TRIBUNAL MEMBER/S: MR JF ASHE, SENIOR MEMBER
MR GJ LUNNEY SC, MEMBER
DATE/S OF HEARING: 10 February 2010 PLACE: CANBERRA
DATE/S OF DECISION: 9 March 2010 PLACE: CANBERRA
PART B
RECOMMENDATION:
FULL REPORT ( ) CASE NOTE ( ) UNREPORTED DECISION ( )
COMMENTS:
2
1
0