Scully v Hornsby Shire Council

The Site

1. The site is a regular, rectangular shape, fronting, 54.87m to Cardinal Avenue, forming the western boundary, and 23.62m to Chapman Avenue, which forms the southern boundary. The total area of the site is 1419m². The proposed new lots will each have an area of 763 m² for lot 1, and 655.5 m² for lot 2.
2. As shown in the photographs tendered in evidence (Exhibit P), the road verges along Chapman and Cardinal Avenues are vegetated with mature trees, and there is a vegetated depression within each verge for the purpose of drainage.
3. An existing Council drainage pipe is located beneath the road reserve along Cardinal Avenue. Also, an existing stormwater pipe (circa ~1940) diagonally bisects the site draining towards the south-east corner. The condition of this pipe is understood to be poor, cracked and virtually unfunctional.
4. The site has a fall towards the southeast at a grade of between 7.5 to 14.7%.
5. Currently, the site has an existing, single storey dwelling located in the north of the site, with driveway access from Cardinal Avenue. This dwelling is proposed to remain, albeit with removal of a portion of the rear balcony and will be located on proposed lot 2. The remainder of the site is vegetated with native trees and introduced landscaping across proposed lot 1.

Relevant Planning Controls

1. The requirements of s 4.15(1) of the EPA Act are relevant for the Court's consideration, which must be satisfied for the grant of the DA under appeal.
2. The site is located within defined bushfire prone land, and therefore the requirements of s 4.14 of the EPA Act are relevant for the Courts consideration. The parties agree that the response from Rural Fire Service (RFS) and the bushfire assessment that supports the DA, satisfies the requirements of s 4.14 of the EPA Act. There is no contention and the parties agree the Court could be satisfied this requirements is addressed.
3. Some trees on the site, specifically T15 and T18, are identified as part of the Blue Gum High Forest ecological community, which are listed as a Critically Endangered Ecological Community (EEC) in Schedule 2 of the Biodiversity Conservation Act 2016 (BC Act). The provisions of s 7.3 and Schedule 4 of the BC Act are relevant for the Court's consideration to grant approval to the DA under appeal.
4. The site is located within the R2 Low Density Residential zone, as described in the Hornsby Local Environmental Plan 2013 (HLEP). Pursuant to cl 2.3 of the HLEP, the proposed development is permissible with consent. The parties agree that the amended design of the stormwater channel and proposed lot sizes after subdivision, satisfy the requirements of cll 6.3 and 4.1, respectively. The parties also agree that the provisions of cl 6.4 are not relevant for consideration, as the vegetation on the site is not mapped in the HLEP's Terrestrial Biodiversity map.
5. The parties agree that the proposed development complies with the relevant development standards of the HLEP.
6. The Hornsby Development Control Plan 2013 (HDCP) is particularly relevant for the Courts consideration of this appeal, and the parties draw the Court's attention specifically to the following sections: 1B.6.1 (tree preservation); 1B.7 (tress and vegetation preservation); 1C.1.1 (biodiversity); 1C.1.2 (stormwater); 1C.1.4 (earthworks); 1C.3.2 (flooding).
7. The parties agree that the 'watercourse' identified on the registered title for the site, shown as an existing easement across the site, is not actually mapped or defined as a watercourse for the purpose of enlivening the relevant provisions of the HDCP or HLEP. Any historic drainage line has been substantially altered by the construction of the pipe bisecting the site, undertaken in the 1940's.
8. The Australian Standard AS 4970 - 2009, Protection of trees on development sites, specifically cl 3.3.3, is relevant for the Courts consideration, as it addresses any incursion into a tree protection zone (TPZ) and structural root protection zone (SRZ).

Evidence

1. The Court was provided written and oral evidence from the respondents arboricultural and ecological experts, Mr Ian Hills and Mr Mark Hood, respectively.
2. The Court was provided written and oral evidence from the applicants arboricultural and ecological experts, Mr Peter Castor and Mr Danny O'Brien, respectively.

Are the significant trees, namely T15 and T18, sufficiently protected from the proposed construction of the stormwater channel in future lot 1 as a result of subdivision?

1. The Council contends that trees T15 and T18, will be detrimentally impacted from the proposed construction of the elevated, concrete lined stormwater channel, in addition to any new, future dwelling on proposed lot 1. Specifically, the Council is concerned that the proposed piers to support these works could affect the fibrous roots in the TPZ's of T15 and T18, and the structural roots in the SRZ of T18. It is also contended that the redirection of overland flow and the shadowing from the elevated (future) building could result in a decline in health of these trees, due to loss of water and nutrients.
2. The Council agrees that the amendments to the proposed stormwater works within the road verge along Cardinal Avenue will not have a detrimental impact to T1, and this contention is not pressed.
3. The parties agree that T15, a Sydney Blue Gum and T18, a Blackbutt, are part of the vegetation community of the Blue Gum High Forest (BGHF), listed as critically endangered under the Commonwealth's Environment Protection and Biodiversity Conservation Act 1999 and the BC Act. These trees are aged between 60 and 80 years, considered significant under the BC Act, and therefore should be retained and protected. The parties disagree as to the potential impact to these trees from the works proposed on lot 1 (both under this appeal and in the future), and whether the impact is contrary to biodiversity conservation, as described in the BC Act.
4. The applicant reasons that these trees, T15 and T18, have been adequately protected by the design of the proposed works on lot 1, sought under this appeal. Both the stormwater and future building structures are designed to be on piers. The piers will be sited based on the plans supporting the DA and the conditions of consent, which allow flexibility in pier placement by up to 300mm from designed. A construction management plan (CMP) will limit impact to the trees on the site. Also, the trees on the site will be maintained consistent with the Tree Management Plan (TMP) that supports the DA.
5. The experts agree that the calculations of the TPZ and SRZ for T15 and T18 are accurate, as shown in Exhibit Q, and that the proposed incursions into these zones from both the proposed future dwelling and the stormwater channel, as shown in Exhibit R, are to be relied on.
6. The primary dispute between the arboricultural experts is the potential severing of structural roots of T18 from the piers of the elevated stormwater channel within the SRZ of this tree. The experts agree that the proposed incursion into the SRZ of T18 is considered a major encroachment, as defined in AS4970-2009.
7. Mr Castor considers the design of the proposed works, together with the CMP, the TMP and the conditions of consent, provide adequate protection to T15 and T18, to ensure any adverse impact is minimised, as required in the HDCP.
8. Mr Hills however contends that the subdivision, as proposed, results in a design for a (future) dwelling and stormwater works that causes adverse impact to these significant trees, although agreed this is assessed as minimal. However, he considers that any impact to these trees should and could be avoided with the proper placement of buffer zones around T15 and T18. The potential adverse damage to the structural roots within the SRZ of T18 from unintended mechanical impacts or inadvertent damage to the roots during construction, he states would result in irreparable damage to this tree. The proposed design of the proposed works within the (20m) buffer zone will not protect trees of the BGHF, is a threatening process, and is therefore inconsistent with the requirements of s 7.3 of the BC Act and cl 1C.1 of the HDCP.
9. Further to this, Mr Hood is concerned that the proposed elevated structures could result in an impact to the fibrous roots of T15 and T18 due to pier construction in the TPZ, and also result in a loss of water/nutrients to these roots from the diversion of 'natural' flows across the site.
10. Mr Castor argues that the conditions of consent ensure protection of the roots for both significant trees from pier construction, without the need for buffer zones, and the proposed 'level spreader' located beneath the future dwelling on proposed lot 1, will ensure adequate water/nutrients is provided to the roots to replicate natural conditions.
11. With regards to the protection of the trees on the site that form part of the BGHF, identified as T15 and T18, cl 1C.1.1 is the relevant section of the HDCP for the Courts consideration, which seeks to achieve the following outcomes through prescriptive measures: "Desired Outcomes a. Development that provides for the conservation of biodiversity including threatened species and populations, endangered ecological communities, remnant indigenous trees, regionally and locally significant terrestrial and aquatic vegetation. b. Development that maintains habitat for native wildlife and wildlife corridors to provide for the movement of fauna species."
12. The Merriam-Webster Dictionary describes 'prescriptive' as being: acquired by, founded on, or determined by prescription or by long-standing custom. The relevant prescriptive measures in cl 1C.1.1 are as follows: "General a. Development should seek to: • avoid potential adverse impact on biodiversity, • if that impact cannot be avoided, minimise that impact, or • if the impact cannot be minimised, to mitigate the impact. … e. Development should incorporate and maintain a buffer zone to significant flora and fauna. Development should not include buildings, structures and earthworks within the required buffer zone prescribed in Table 1C.1.1(a)."
13. The buffer zone defined in the prescriptive measures of cl 1C.1.1 relevant for this site is 20 m from T15 and T18.
14. In addition to the proposed design of the stormwater channel and future building envelope, as shown in the plans that support the DA, the conditions of consent are to be relied on to protect T15 and T18. These are generally agreed in principle, except those that relate to the SRZ of T18 and the requirement of the level spreader to be registered on title.
15. After review of the expert evidence and submissions made by the parties, I find that the proposed subdivision with stormwater works as sought in this appeal, and consideration of the building envelope identified on the plans, subdivision of the site into two Torrens title lots is capable of protecting the trees that form part of the BGHF on the site, namely T15 and T18.
16. I accept that the piers of the proposed stormwater channel and future dwelling on proposed lot 1 will encroach (up to 10%) into the SRZ of T18, and also the TPZ's of T15 and T18. However, the potential impact to roots of these trees from the works associated with this DA is considered minimal, as agreed by the experts. I do not accept that the proposed subdivision contravenes the intent of the HDCP in cl 1C.1.1, or that it requires impact to these trees to be avoided at all costs, as posed by the respondent. The prescriptive measures in cl 1C.1.1 provide for the minimisation of impact, if impact cannot be avoided. I accept this is the case for this site.
17. I find that any potential impact to T15 and T18 cannot be avoided. The parties accept that an upgraded stormwater infrastructure is appropriate for this site, to protect downstream properties, as the existing stormwater system on the site is not functioning adequately. A do-nothing approach is not contended by the respondent as appropriate due to the volume of flows that flow through the site during a high rainfall event, and the current/potential impact to downstream properties. The existing stormwater pipe does not function and either needs to be replaced or decommissioned, as preferred by Council. It is the location of the piers that causes Council the most concern, not the fact that the works are required. By necessity, due to the size of the root zones of these large and significant trees, any works on the site that relate to stormwater management, even without subdivision, is likely to occur within a 20m buffer of the trees and result in some level of impact to the tree roots.
18. Council have insisted, by condition of consent, that the existing stormwater pipe on the site be decommissioned. Therefore, an alternative water management system is required and agreed in principle between the parties. The applicant has put significant effort into the design of a stormwater system that could function on the site, and which accommodates the site constraints, including protecting T15 and T18. It is agreed between the experts that due to the maturity and extensive root structure of T15 and T18, any engineering works within proposed lot 1 would potentially impact the roots of these trees.
19. I find that the proposed level spreader, as designed and described in the conditions of consent and plans supporting the DA, will have the effect to minimise the potential impact to the roots in the TPZ of T15 and T18, providing water and nutrients that mimic existing conditions.
20. I find that the proposed conditions of consent, as described below, together with the proposed design of stormwater works, can minimise any potential impacts to the roots of trees retained on site, specifically T15 and T18. Therefore, the requirements of the HDCP in cl 1C.1 are achieved. I do not consider it necessary to impose a 20m buffer zone to restrict construction around these trees, as described in prescriptive measure (e) of cl 1C.1.1 in the HDCP, because this is not achievable on this site due to the extensiveness of the TPZ's, but more importantly the buffer will not serve a purpose to achieve the desired outcome. The desired outcome in cl 1C.1.1, relevantly (a) is achieved by the proposed design of construction as outlined in the DA plans and conditions of consent. The roots of these trees are already encroached by the existing, non-functional stormwater pipe within the site. I consider the conditions of consent adequately protect the roots from adverse pier incursion.
21. I find that the proposed design of the works on the newly subdivided lot (1) are enforceable conditions of consent, will have the effect to minimise impact to protect the significant trees on the site. The design and construction requirements of the piers is founded on an understanding of the root system of the trees, as explained by the experts in evidence.
22. I find that the proposed works on proposed lot 1 do not contravene the prescriptive measures of cl 1C.1.4 of the HDCP. The respondent is concerned specifically with prescriptive measure (d). With respect, I find that any adverse impacts to the significant vegetation on the site is minimised and the proposed works satisfy cl 1C.1.4. The parties did not provide any engineering experts in evidence. Based on the proposed cut/fill plan shown in Exhibit R, the respondents arborculturalists and ecologists focused their concern on the excavation for piers within the SRZ of T18, and TPZ of T15 and T18, which the Court has already determined. Therefore, the insistence on the buffer zone would serve no additional purpose to protect the trees on the site.
23. I accept that the design of any future dwelling on the proposed lot 1 will be subject of a separate DA, by which the requirements of the relevant provisions of EPA Act, HLEP and HDCP will be considered. Therefore, the Court makes no determination on the details of any future dwelling except that the proposed location and construction of piers and level spreader is appropriate to minimise adverse impact to the TPZ of T15.
24. I find that the proposed subdivision, with construction of an elevated stormwater channel, as described in this DA is not inconsistent with the requirements of s 7.3 of the BC Act. I do not consider that the proposed works will significantly affect the BGHF identified on the site. As I find that the trees of the BGHF on the site are adequately protected by the proposed subdivision, the relevant requirements of the BC Act are achieved. Further to this, the DA, as described to the Court, does not describe a key threatening process that would result in the clearing of native vegetation, as described in Schedule 4.
25. Based on the evidence before me, I find that the proposed subdivision with construction of an elevated stormwater channel, and the DA under appeal is consistent with the requirements of subss 4.15(1)(a)(i) and (iii) of the EPA Act.

Is proposed subdivision in the public interest?

1. The Council contends that due to the potential adverse impact to the significant trees on the site, which belong to the BGHF, namely T15 and T18, the proposed subdivision is not in the public interest.
2. I find that, consistent with the determination made above, the proposed subdivision, including stormwater works as designed, is in the public interest. The submissions made in objection by residents following notification of the DA are resolved to my satisfaction, in my assessment of the evidence before me.
3. Therefore, s 4.15(1)(e) of the EPA Act is satisfied to grant consent to the DA under appeal.

Conditions of Consent

1. The parties filed a collated version of conditions of consent, which outline conditions as agreed, and those in dispute, on 27 July 2020. This is the version of conditions considered by the Court below.
2. The Court accepts the conditions that are agreed, and makes a determination regarding those conditions in dispute, below: 1. Condition 1, Approved Plans and Supporting Documentation - Reference to the CMP is accepted and referenced in the list of supporting documents. The CMP is consistent with the conditions of consent and provides relevant detail to ensure the significant trees are protected. 2. Condition 5 Amendment of Plans - (a) and (b) are deleted as proposed by the applicant. I accept that the piers will be constructed within (10% of) the SRZ of T18, although their actual location (within 300mm) will be determined after site investigation. I accept (c) to (e) as proposed by the respondent, as these conditions relevantly relate to the agreed plans. Renumbered accordingly. 3. Condition (unnumbered) Level Spreader - accepted as proposed by the respondent and renumbered. The position of the level spreader is an important consideration of the experts and by the Court to ensure the protection of the fibrous roots to the significant trees on the site. The spreader seeks to replicate existing water conditions and is an essential component of the water management plan for the site. 4. Condition 36 Restriction as to User - Protection of Land from Future Development - accepted as proposed by the respondent and renumbered. This condition ensures the protection of significant trees as assessed on the site, and reflects the expert advice and the requirements of the relevant legislation, including the BC Act.
3. The grant of the DA relies on the conditions of consent as approved and amended, which are provided in Annexure A of the Court orders.

Conclusion

1. The proposed development has been assessed by the Court, based on the evidence provided, including the DA's (amended) supporting plans, documents, expert reports and photographs.
2. I have considered the relevant sections of the EPA Act and BC Act in my assessment of this appeal. I am satisfied that the proposed subdivision with engineering works is consistent with the relevant provisions of the EPA Act to grant consent to the DA under appeal, and specifically subss 4.15(1)(a)(i), (1)(a)(iii), and (1)(e), which were in dispute between the parties. The relevant requirements of the BC Act are also satisfied.
3. The appeal that relates to DA 572/2017, being a Torrens title subdivision of land into two lots with associated engineering works, is approved with conditions, pursuant to ss 4.16(1)(a) and (2) of the EPA Act. The proposed subdivision, as intended to be carried out, does not result in a contravention of the EPA Act, BC Act, HLEP or HDCP.

Orders

1. Consequently, the orders of the Court are as follows: 1. The Court grants leave to rely on the amended subdivision plan, dated 23 July 2020 and amended conditions of consent, dated 27 July 2020. 2. The appeal is upheld. 3. Development Application 572/2017 which seeks Torrens title subdivision of one lot into two lots, partial demolition of an existing deck, relocation of an existing Council drainage pipe in the road reserve and construction of a new open, elevated channel for overland flow on Lot 3 DP 20358, also known as 112 Chapman Avenue, Beecroft, is approved subject to the conditions of consent shown in Annexure A. 4. The exhibits are returned, except A, L, Q, R, S, 1 and 8, which are retained.

Commissioner of the Court Annexure A (292255, pdf) Subdivision Plan (443078, pdf)

DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 06 August 2020