Land and Environment Court of New South Wales CITATION : Radray Constructions Pty Ltd v Hornsby Council [2010] NSWLEC 1174 APPLICANT Radray Constructions Pty Ltd PARTIES : RESPONDENT Hornsby Council FILE NUMBER(S) : 10339 of 2009 CORAM: Pearson C KEY ISSUES: DEVELOPMENT APPLICATION :- Seniors living Flood prone land Environmental Planning and Assessment Act 1979 Water Management Act 2000 LEGISLATION CITED: State Environmental Planning Policy (Housing for Seniors and People with a Disability) 2004 Hornsby Shire Local Environmental Plan 1994 Hornsby Shire Low Density Multi-Unit Housing Development Control Plan Hornsby Shire Council Sustainable Water Development Control Plan Radray Constructions Pty Ltd v Hornsby Shire Council [2007] NSWLEC 34 Segal & Anor v Waverley Council (2005) 64 NSWLR 177 CASES CITED: BGP Properties Pty Ltd v Lake Macquarie City Council (2004) 138 LGERA 237 Neate v Shellharbour City Council (No 2) [2007] NSWLEC 654 Chisholm v Pittwater Council and Anor [2000] NSWLEC 143 DATES OF HEARING: 23, 24, 25, 26 March, 30 April 2010; conditions 12 May 2010 DATE OF JUDGMENT: 2 August 2010 APPLICANT Mr I Hemmings, barrister Instructed by Mr J Hones LEGAL REPRESENTATIVES: Hones La Hood RESPONDENT Mr P Jackson, solicitor Pikes Lawyers JUDGMENT: THE LAND AND ENVIRONMENT COURT OF NEW SOUTH WALES Commissioner Pearson 2 August 2010 10339 of 2009 Radray Constructions Pty Ltd v Hornsby Council JUDGMENT 1 Commissioner: This is an appeal under s97(1) of the Environmental Planning and Assessment Act 1979 (the Act) against the refusal by Hornsby Council (the Council) of consent to a development application (No 942/2008) made by Radray Constructions Pty Ltd (the applicant) seeking approval for the demolition of two existing dwellings and construction of a Seniors Living development of 17 self care dwellings and associated basement car parking and landscaping at 15 Eyles Avenue Epping and 15 Anthony Street Carlingford (the site). The site and locality 2 The site is two adjoining properties, lot 12 in DP 28247 (No 15 Eyles Ave Epping) and lot 3 in DP 201713 (No 15 Anthony Street Carlingford). No 15 Eyles Avenue is a battleaxe lot with the handle on the western side of Eyles Avenue. The battleaxe lot adjoins the rear of No 15 Anthony Street which is an irregular shaped lot fronting the northern side of Anthony Street. Access to the site is from Anthony Street, and via a right of carriageway over the handle with adjoining properties at 17-19 Eyles Avenue and a partly elevated concrete driveway. 3 The site has a total area of 3,787 sq m. A watercourse which forms a tributary of Devlins Creek and the Lane Cove River flows south to north through the central part of the site. The watercourse enters the site from Anthony Street via a culvert, under 17 Anthony Street and a drainage reserve. The watercourse is permanent and forms part of the local stormwater drainage system. The watercourse is an open system through the site. At the northern boundary the watercourse flows via a piped system for 700m then as an open watercourse to Devlins Creek. On the southern side of Anthony Street there is a pollution control trap within the Council's drainage reserve. The site is subject to flooding. 4 The properties surrounding the site generally comprise low density residential development, and a townhouse development adjoins the northern boundary at 17-19 Eyles Avenue. 5 The site is vegetated and includes trees identified as remnant Blue Gum High Forest, a critically endangered ecological community. The proposal 6 The proposed development has been amended during the course of these proceedings and now comprises 16 self care dwellings comprising 1 x 1 bedroom and 12 x 2 bedroom dwellings in a two storey building at the Anthony Street frontage and 3 x 2 bedroom dwellings in a single storey building at the rear. The basement car park is proposed to be accessed from Anthony Street. 7 The proposed dwellings are elevated on piers above the floodway and basement car park and interconnected by elevated timber walkways. During flooding, floodwaters cover Anthony Street and the road is impassable. The plans before the Court include floodgates at the entrance to the carpark; an alternative design of raising the crest at the entrance to the car park was the subject of evidence during the hearing. A flood free pedestrian access is proposed to Eyles Avenue. The proposed development has been designed to allow flood waters to pass beneath units 1 and 2 on the Anthony Street frontage, and for access to and evacuation from the site during flooding to be along the pedestrian walkway to Eyles Avenue. 8 The proposal includes the realignment of the watercourse, and excavation for the proposed basement carpark, and the removal of certain trees. 9 The site was the subject of a previous development application for a development under the State Environmental Planning Policy (Housing for Seniors or People with a Disability) 2004 for 18 dwellings. An appeal against the Council's refusal of that application was dismissed by Roseth SC: Radray Constructions Pty Ltd v Hornsby Shire Council [2007] NSWLEC 34. Issues 10 The Council's Amended Statement of Facts and Contentions filed on 8 March 2010 raised 11 contentions. During the course of the hearing, five of those contentions were resolved. The issues that remain in dispute are whether the site is unsuitable for a seniors living development because it is subject to flooding; whether the physical constraints of the site are acceptable; whether there are adverse impacts on the watercourse; whether there are adverse impacts on the social environment; the public interest; and tree protection. Planning Controls 11 The site is zoned Residential A (Low Density) under the Hornsby Shire Local Environmental Plan 1994, and housing for aged or disabled persons is permissible with consent. 12 The proposed development is permissible under State Environmental Planning Policy (Housing for Seniors or People with a Disability) 2004 (SEPP (SL)). The aims of the SEPP(SL) are: 2 Aims of Policy (1) This Policy aims to encourage the provision of housing (including residential care facilities) that will: (a) increase the supply and diversity of residences that meet the needs of seniors or people with a disability, and (b) make efficient use of existing infrastructure and services, and (c) be of good design. (2) These aims will be achieved by: (a) setting aside local planning controls that would prevent the development of housing for seniors or people with a disability that meets the development criteria and standards specified in this Policy, and (b) setting out design principles that should be followed to achieve built form that responds to the characteristics of its site and form, and (c) ensuring that applicants provide support services for seniors or people with a disability for developments on land adjoining land zoned primarily for urban purposes. 13 The SEPP (SL) defines "seniors" and "people with a disability": 8 Seniors In this Policy, seniors are any of the following: (a) people aged 55 or more years, (b) people who are resident at a facility at which residential care (within the meaning of the Aged Care Act 1997 of the Commonwealth) is provided, (c) people who have been assessed as being eligible to occupy housing for aged persons provided by a social housing provider 9 People with a disability In this Policy, people with a disability are people of any age who have, either permanently or for an extended period, one or more impairments, limitations or activity restrictions that substantially affect their capacity to participate in everyday life. 14 Part 2 of Chapter 3 of the SEPP(SL) includes site-related requirements, which include location and access to facilities (cl26). Part 3 sets out Design requirements, which include in Div 2 Design principles. 15 The Hornsby Council Sustainable Water Development Control Plan (the Sustainable Water DCP) defines a watercourse in the following terms: Watercourses are defined by any blue line on the 1.25000 topographic map produced by the Central Mapping Authority an/or any drainage line displaying aquatic or semi-aquatic habitat. 16 The Sustainable Water DCP includes the following Performance Criteria for Watercourses: The design and open space planning of any development should include the retention of natural drainage systems including any watercourse or water body located on a site. Building works should be sited outside flood ways. Any development and/or drainage structures provided on a site should be designed to ensure that the environmental flow requirements of down stream watercourses are maintained. Drainage works should include measures to improve water quality and minimise the impact of stormwater discharge on natural vegetation and watercourses. Drainage works should provide for the restoration of estuarine and riparian vegetation along or adjacent to watercourses. 17 The Hornsby Shire Low Density Multi-Unit Housing Development Control Plan includes as a prescriptive measure for Drainage Control that the habitable floor areas of dwellings constructed adjacent to trunk drainage systems, watercourses and creeks should be a minimum of 0.5m above the 100 year average recurrence interval (ARI) flow level. 18 The works proposed for the watercourse require approval of a "controlled activity" under the Water Management Act 2000 and the proposed development is therefore integrated development under s91A of the Act. The NSW Office of Water provided its General Terms of Approval on 19 March 2010, which include 23 conditions (exhibit 1). Evidence 19 The Council notified the application, and re-notified the application following the amendment made to the plans in 18 November 2009, and received a number of written submissions which are in evidence before the Court. Those submissions raised concerns about adverse impacts from flooding, adverse visual impact, loss of trees, change in the residential character of the area, impacts on privacy, adverse impact on the watercourse and stormwater runoff, increased traffic and congestion, loss of privacy, change in soil conditions, and suitability of the site for seniors living. 20 The hearing commenced on site with a view. Evidence was heard on site from the residents of 5 and 11 Anthony Street, 12, 25, and 27 Eyles Avenue, and 3 and 4 Paterson Street Carlingford. The concerns of the neighbouring residents related to increased traffic and issues with parking, flooding, loss of trees, and loss of privacy. The opportunity was taken to visit 27 Eyles Avenue to view flooding impacts from previous floods, 4 Paterson Street Carlingford in relation to visual amenity and privacy impacts, and 11 Anthony Street. The owner of 11 Anthony Street stated his concerns relating to impact of the basement on the water table and trees; the location of the building forward of the front alignment of the existing dwelling; vehicle noise from the driveway; inadequate landscaping and tree removal; and flooding. 21 Expert evidence was given on behalf of the applicant by: Mr L Fletcher – planning Dr D Martens – flooding and stormwater Mr W Davies – geotechnical Mr M Relf – accessibility Mr A Morse – engineering Dr S Ambrose – ecological Mr P Castor - arborist 22 Expert evidence was given on behalf of the Council by: Mr N Kennan – planning Mr D Bewsher – flooding and hydrology Mr A Fraser – ecological Mr D Foster - arborist Mr P Clare – engineering 23 The access requirements of cl26 and cl38 of the SEPP(SL) were addressed in Mr Relf's Statement of Evidence. Mr Relf expressed the opinion that subject to the installation of a footpath on Eyles Avenue and a section of the northern side of Dunrossil Avenue, the development is appropriately located in terms of access to public bus services that travel at appropriate times to shopping centres that have an appropriate range of services to satisfy all aspects of cll26 and 38(a) of the SEPP(SL). Mr Relf was not required for cross examination. 24 The Council's contention relating to non compliance with the SEPP (SL) includes particular 3.5, that the proposal does not adequately address the requirements of cl37 Crime Prevention in the SEPP(SL) in terms of windows facing the walkways, and a number of other particulars raising design issues relating to solar access, internal site amenity, window design for units 2,4, 11, internal storage, and acoustic impacts. Mr Fletcher and Mr Kennan in their joint report addressed contention 3.1, that the proposal does not comply with the aims of the SEPP(SL) in cl2(1)(a) and (c). Mr Kennan noted that he had in his Position Paper dated 12 February 2010 identified a number of significant design issues with the then proposed development. On the basis of the amended plans which addressed many of those design concerns, and the agreement with Mr Fletcher as part of the joint conference on a number of additional changes that could be made to the design, Mr Kennan was of the opinion that the design of the proposed development would be such that any remaining deficiencies would be minor and acceptable. The experts agreed that on the basis of design amendments made as detailed in their joint report, the proposed development would satisfy the aims of the SEPP(SL). 25 The agreed amendments relate to improvement of security by provision of security gates on the walkways; mitigation of privacy issues by including frosted glazing on windows facing the walkway; provision of a small balcony and reorganising internal layout for one unit to achieve direct solar access to private open space areas that meets the requirements of cl50(e) of the SEPP(SL); inclusion of conditions of consent to manage access to the ground level communal open space during time of flood, and facilitate access for those with a disability; removal of one car space to provide additional storage areas. The expert planners also addressed contention 5 relating to the garbage bin area and agreed that with the latter amendment there would be room to establish a small garbage room to accommodate the required bins. Mr Fletcher and Mr Kennan were not required for cross examination. 26 The Council's contention relating to the path of travel to access the proposed stairs and lift in the basement carpark was resolved following agreement to amend the plans to delete one carparking space. The Council's contention relating to access to the on site detention was also resolved during the course of the hearing by an amendment to the plans. 27 The parties agreed on conditions other than those relating to a construction management plan, a flood management plan, and a revised flood study. The Council proposed a deferred commencement condition under s80(3) of the Act requiring the submission of a construction management plan detailing the construction of the basement car park and environmental protection measures, a suitable flood management plan, and a revised flood study, and condition 10(4) requiring the crest of the driveway to be a minimum of 99.0 AHD or to a level set by the revised flood study. The Council's submission was that the uncertainty remaining as to the final flood levels and potential increase in high hazard area is such that consent ought to be refused, and if not, that deferred commencement conditions should be imposed. Mr Jackson for the Council submitted that this would not be appropriate as it would not be final and conclusive. 28 The applicant opposed the imposition of deferred commencement conditions, and proposed in the alternative conditions in similar terms to be complied with before the issue of a Construction Certificate. Mr Hemmings for the applicant submitted that after the second joint report of Mr Bewsher and Dr Martens there is agreement as to the level of the driveway crest and that final flood levels should be set before the issue of a construction certificate; Mr Bewsher in the first joint report accepted that even thought there was potential for the levels to increase by up to 0.5m, it could be dealt with at construction certificate stage; and that there is sufficient certainty for consent to be granted. Consideration The assessment framework 29 The proposed development is permissible under the LEP and the SEPP(SL). As submitted by the applicant, the starting point is that in general terms planning decisions must generally reflect an assumption that, in some form, development which is consistent with the zoning will be permitted: McClellan CJ in BGP Properties Pty Ltd v Lake Macquarie City Council (2004) 138 LGERA 237 at [117]. However, this proposition is qualified at [118] by the requirement that the design of the project results in acceptable environmental impacts. Considering first, as required by s79C(1)(a) of the Act, the provisions of the SEPP(SL) I am satisfied, based on evidence of Mr Relf which was not contradicted, that the relevant site related requirement in cl26 regarding location and access to facilities is met. Based on the evidence of the expert planners, I accept that the design requirements in Chapter 3 Part 3 are met. The SEPP(SL) does not include any provision dealing specifically with development of housing for seniors living on flood prone land, which is in contrast with cl27 which makes specific provision for development on land identified as bush fire prone. 30 In considering the provisions of the Sustainable Water DCP, it was common ground that the watercourse on the site is not identified as a "blue line" watercourse on the 1:25000 topographic map. The Council submits, based on the Flora and Fauna Assessment Report of Dr Ambrose, that the site displays either aquatic or semi aquatic habitat and that accordingly the Performance Criteria for Watercourses in the Sustainable Water DCP apply. It was common ground that the watercourse is currently in a very degraded condition, and that the site was likely never to have had a fully structured riparian zone. I accept the applicant's submission, which is supported by the ecological evidence, that while there are some uncertainties as to the precise construction of the watercourse, the proposed works and provision of a riparian zone are likely to improve the ecological functioning of the creek and riparian zone, which is consistent with the requirements of the Sustainable Water DCP. 31 Section 79C(1)(c) requires consideration of the suitability of the site for the development. Suitability of the site - flooding The contentions 32 The Council's first contention is that the site is unsuitable for the proposed development because it is subject to flooding. It was not in dispute that approximately 60 per cent of the site is flood prone land and that part is high hazard. It was common ground between the experts that Anthony Street is overtopped somewhere between the 1 in 5 year event and 1 in 20 year events; that vehicle access to the site from Anthony Street would be prevented during a 1 in 100 year event for a period in the order of half to 1 hours; and that vehicle and pedestrian access from Anthony Street to the proposal is not possible in the 1 in 100 year event. 33 The Council submitted that there had been insufficient information provided by the applicant to know the full extent of the flooding impact on the site; that there is no final flood study containing all relevant information; and that the information that has been provided establishes that the proposed development is unacceptable for seniors living development. The Council submits that there is insufficient detail in the flood studies to fully assess the application, and that the evidence establishes the following: No allowance has been made for the maintenance of flood storage values on site; While the engineers agree that flood storage maintenance can be dealt with by way of condition, such storage is likely to be achieved by additional excavation which may have consequences beyond hydrological matters The extent of flooding and high hazard areas will increase and are not yet quantified; There is a need for a further two dimensional flood model; The extent of the proposal in respect of the entry to the basement car park is unknown; There is potential for the basement layout to change if the levels at the entrance are altered, and if floodgates are to be used there is insufficient evidence as to their design and manner of operation; Finished floor levels of some units, and the boardwalk levels to Eyles Avenue, need to be raised; There is a potential for debris to flow under the proposed units and cause blockage with potential adverse impacts on flood waters across the site and upon the dwellings. 34 The applicant submits that in dealing with the physical impacts of flooding, the development is proposed to be both above and beside the floodwaters, that it will not impede the passage of those floodwaters, and that it has been designed to accommodate those floodwaters and any impacts from floodwaters. The applicant's position is that the proposal has been designed so that all pathways and floor levels would be above a probable maximum flood (PMF). The applicant submits that when considering together the original flood study prepared by Dr Martens, the oral evidence of both experts and their two joint reports, there is sufficient information before the Court to ensure that potential impacts from flooding have been considered. 35 The third component of the Council's contention on suitability of the site raised issues which are also raised in its further contention that there is an adverse impact on the social environment. The Council relies on the evidence of Mr Bewsher that the amenity and anxiety levels of the occupants of the units is an unacceptable element of the proposed development. The Council submits that there is no meaningful emergency evacuation plan or plan of management dealing with the flood issue and that that this critical matter cannot be left to a condition of consent. 36 The applicant submits, on the non-physical issues, that there is no empirical, peer reviewed, data to support Mr Bewsher's opinion that it is inappropriate to develop aged housing over high hazard floodways; that market forces are relevant; and that the application prevents the sterilisation of flood prone land, provides for seniors living housing consistent with the aims and objectives of the SEPP(SL), and results in the orderly and economic development of land as required by the Act. The applicant submits that the assessment of Mr Bewsher's concerns should be considered in the context of the planning framework including the permissibility of the development, and the encouragement of provision of housing for seniors living, the agreement that the aims of the SEPP(SL) are complied with, and that while it is relevant to take into account the potential for risk, that has been measured and assessed and there is no unacceptable risk other than Mr Bewsher's suggested terror and anxiety. The evidence: flood model 37 The first matter addressed in the joint conferencing between Dr Martens and Mr Bewsher was to determine the appropriate flood model to use, and the second, having agreed on the appropriate model, what the flood levels would be in a 1 in 100 year event and in a PMF. 38 Dr Martens prepared the flood study (November 2009) provided as part of the development application using the DRAINS hydrologic/hydraulic modelling package, being an extension of the Council's current DRAINS model for the local drainage system with a number of amendments. In his Position Paper Mr Bewsher stated that the DRAINS model cannot adequately account for the complex flow behaviour that occurs on the site. The first joint report of Mr Bewsher and Dr Martens dated 17 March 2010 (Exhibit 8) records their agreement that the HEC-RAS model is the more suitable to use for flood modelling. The experts agreed that the HEC-RAS model would need to be amended and updated as part of the detailed design/construction certificate process, and that changes to the HEC-RAS model as suggested by Mr Bewsher could raise levels by about 0.5m and that this would have implications for floor levels and walkway levels. 39 At the commencement of the hearing the parties disagreed as to whether sufficient access to the HEC-RAS model had been provided to Mr Bewsher. Dr Martens and Mr Bewsher held another joint conference on the first and second days of the hearing. In a second joint report (Exhibit 22), provided on the second day of hearing, Mr Bewsher stated that he accepted the revised 100 year flood levels provided by Dr Martens following the first joint conference. The experts were in agreement that the implications of the revised 100 year flood levels are that if floodgates are not used the driveway crest at the entrance to the basement car park would need to be raised from 98.5m AHD to about 99.0mAHD; that the final levels would need to be set before construction certificate using a two-dimensional flood model; and that the extent of flooding and extent of high hazard areas would increase and are yet to be quantified. The evidence: flood level 40 The second joint report raised an issue as to the modelling of the PMF discharge. The Council's Statement of Facts and Contentions included in Part A Statement of Facts (at 2.8) the statement that: A flow rate of 47 cubic metres of water per second is estimated at the Anthony Street culvert during a maximum flood. 41 The second joint report stated: Since receipt of Dr Martens' models, Mr Bewsher has derived the PMF discharge at 78 m³ per second based on the usual hydrological procedures. Dr Martens generally accepts the methodology used by Mr Bewsher noting that neither expert has had sufficient time to rigorously review the calculations. 42 The second joint report included a table showing the adjustments necessary to proposed floor levels on the basis of PMF levels of 47 and 78 m3/s. 43 On the third day of the hearing, the applicant's position was that Dr Martens had been able to run a version of the model that suggested that 47 m3/s was too low and 78 m3/s was too high, however he was not in a position to confirm that, or what the consequence of an increased volume for the PMF was other than at 78 m3/s. The parties agreed that the matter should be determined on the basis of the hydrological evidence as to the 1 in 100 year calculations and the PMF at 47 m3/s. 44 The evidence included a video of a flood event recorded from the dwelling at 15 Anthony Street in 1990. Mr Bewsher's evidence included his observations of a flood event at the site in February 2010. Mr Bewsher and Dr Martens agreed that both events were somewhere between a 1 in 5 and 1 in 20 year event. Both agreed that a flow similar to that in 1990 would move under the dwellings at the Anthony Street frontage. They agreed that there would be some debris, however Dr Martens was of the opinion that the gross pollutant trap on the other side of Anthony Street would mean that there would be a lesser volume than in a more free channel system. Mr Bewsher was of the opinion that the debris would require clean up, and would result in erosion, and that there is a possibility that the debris could cause obstructions to the flow path. Both experts agreed in a 1 in 100 year event the depths over Anthony Street would be hazardous to vehicles, and that it is possible that a vehicle could be washed off. 45 The experts agreed that because of the depth and velocity of the flow it would not be possible to drive out of the driveway or walk out onto Anthony Street in flooding; that the duration of flooding would be 1 to 2 hours; and that access would be cut for a half to one hour in a 1 in 100 year event. Both agreed that there would not be much difference between the 1 in 20 and 1 in 100 level. It was common ground that in small floods there would be no pedestrian or vehicle access to Anthony Street and that if residents are leaving it would be via the walkway to Eyles Ave, which is up to 100m from the Anthony Street frontage. The experts agreed that the extent of high hazard areas on the site could increase with the revised 1 in 100 year flood levels following their joint conferencing, and that the walkway to Eyles Ave would need to be raised. 46 In relation to the driveway to the basement car park, the experts agreed that if floodgates are not used, and the crest is raised, it would need to be at 99m AHD. Dr Martens' evidence was that floodgates are unusual for a basement car park for residential living, and that his preference is to engineer them out. The experts agreed that if the crest is raised, for the gradient not to change the length of the driveway down into the car park would have to increase. Dr Martens' evidence was that the details of the design for the car park configuration would not need modification, however the driveway would, and there is an option of elevating the driveway for some distance; if so, it would need to be constructed as a bridge so water could pass underneath. If the driveway was not elevated and at grade, water would pass over it. Dr Martens' opinion was that the outcome could be a floodgate, a modification to the basement car park arrangements, or a modification to the driveway entry point, and that this is an issue that can be resolved at the detailed design stage. 47 Dr Martens and Mr Bewsher agreed that there needs to be an emergency management plan prepared for the site which demonstrates how the occupants can be safely evacuated if required in the event of a major flood. They agreed that there needs to be a visual and aural warning within the basement car park in the event of flood waters entering the car park; that access to flood liable land should be suitably gated to restrict access; and that the basement carpark lift should be fitted with appropriate controls to ensure safe operation during a flood. Findings - flooding 48 I accept the evidence of the hydrologists that in a 1 in 5 to 1 in 20 year flood event, water would flow beneath proposed units 1 and 2 of the development; that in a 1 in 100 year event the depth and velocity of water would make it unsafe for pedestrians to access Anthony Street, and that vehicle access would not be possible from Anthony Street. The proposed development is designed on the basis that flood waters will flow underneath the building under units 1 and 2. In their second joint report the hydrologists agreed that that the final levels would need to be set before construction certificate using a two-dimensional flood model; and that the extent of flooding and extent of high hazard areas would increase and are yet to be quantified. Even if the approach in Chisholm v Pittwater Council [2000] NSWLEC 143 is adopted, and the material contained in the original flood study, the two separate position papers, and the two joint reports, together constitutes a flood study, the evidence is that the final flood levels will be higher than currently agreed. The hydrologists agreed on a possible increase in flood level of about 0.5m. On the basis of their evidence, I accept that the structural stability of the proposed dwellings and the services located under the slab have been either addressed in the plans or could be addressed at the detailed design stage. The proposed development depends on access to the site or evacuation during a flood event using the walkway elevated above the floodwaters to Eyles Avenue. I accept the hydrologists' evidence that while the precise levels are not known at this stage, the walkway could be designed at an appropriate height above the relevant flood level, structurally stable, and with a gradient so as to be accessible. Mr Bewsher was of the opinion that the walkway should be covered. 49 Mr Bewsher and Dr Martens agreed that more stringent controls to mitigate flood damage and personal safety risks are required for a seniors living development than for normal residential development. The central difference of opinion between the experts related to social impacts. 50 Mr Bewsher's evidence was that he would expect some occupants of units 1 and 2 and their second storey counterparts "to become terrified during moderate flooding (eg 20 year flood event)", and that there remains an issue "related to amenity and particularly anxiety of the occupants of these units". 51 Dr Martens disagreed. In the first joint report Dr Martens stated that any reduced amenity below the buildings in relation to units 1 and 2 would not be unacceptable. In terms of resident anxiety, major flooding is highly infrequent and occurs generally only for a short duration. There is a possibility that some new resident may initially experience elevated anxiety should they observe flood waters passing under their dwelling; however flood awareness initiatives could be put in place including signage, flood information contained within the contract sale package, and which would be detailed in an emergency management plan; and once a resident had experienced and observed a flood event anxiety levels would be lower on the next event. 52 Mr Bewsher's position paper included the following statement: 21 In normal circumstances, medium density development of a significantly floodprone site, such as the one before the Court, would be considered unsuitable, or at best, heavily constrained by flooding. What makes the proposed development even more heavily constrained is that the subject site is proposed for seniors or those with a disability. 53 Mr Bewsher conceded in oral evidence that this passage was the same as that quoted by Roseth SC from his report as a single expert in Radray Constructions Pty Ltd v Hornsby Shire Council [2007] NSWLEC 34. Mr Bewsher stated that in contrast to the position in the previous proceedings, there is more information available in these proceedings including the high hazard map, and the extent of the high hazard area beyond the creek is now quantified. 54 Mr Bewsher's experience includes the preparation of floodplain risk management studies and plans for approximately 30 councils, and flood risk assessment and modelling of flood behaviour, for over 20 years. The floodplain risk management process under the NSW Floodplain Development Manual (2005) includes measurement and estimation of flood damages, to be considered in long term strategic planning of future land use decisions. Appendix M of the Floodplain Development Manual addresses the various types of flood damage, and includes both tangible and intangible damages, the latter including "the increased levels of emotional stress and mental and physical illness caused by the flood episode". While Mr Bewsher was not able, in cross examination, to identify specific peer reviewed or empirical data to support his evidence as to social impact, I am satisfied that his qualifications and experience qualify him to provide expert evidence on the impacts of flooding, including human impacts, and I see no reason not to accept his evidence on the implications for an aged or disabled population. 55 The applicant relies on the decisions in Radray Constructions Pty Ltd v Hornsby Shire Council [2007] NSWLEC 34 and Neate v Shellharbour City Council (No 2) [2007] NSWLEC 654 to support its position that a seniors living development can be approved on flood prone land. While acknowledging that Segal & Anor v Waverley Council (2005) 64 NSWLR 177 requires that the decision be based on the evidence in these proceedings, Mr Hemmings submitted that the earlier proceedings in Radray Constructions Pty Ltd v Hornsby Shire Council [2007] NSWLEC 34 concerned the same site, the same creek, and the same expert using the same words. While I accept that general description, there are minimal details of the proposal considered by Roseth SC. It is evident from the Senior Commissioner's reasons that the proposal then was for 18 dwellings over basement parking, and a series of boardwalks; however those reasons do not detail the arrangement of the dwellings and boardwalks on the site, or the proposal then under consideration for works on the watercourse, and evidence of those matters is not otherwise before me. The Senior Commissioner refused approval on the basis that the proposed buildings were located within the 5m riparian zone required by the NSW Office of Water. In relation to the flooding issue, the Senior Commissioner commented: 10 Despite Mr Bewsher's lack of enthusiasm, there is nothing in his report that would support a refusal, apart from the unsafe velocities on the pedestrian access from Anthony Street. No doubt, these could be overcome by changes to the levels of the access. If the application were otherwise worthy of approval, I would provide an opportunity to the applicant to make the necessary changes to the levels. I note, however, that the appeal was lodged in December 2004 and Mr Bewsher's preliminary report became available in July 2006, so there should have been ample time to design a safe pedestrian access before the hearing. 56 In contrast, the application before me does not include obtaining pedestrian access to Anthony Street in flood events, there being agreement that the depth and velocity of the water flow would make it unsafe, and agreement that the only access to the site during a flood event would be along the walkway from Eyles Avenue. 57 Neate v Shellharbour City Council (No 2) [2007] NSWLEC 654 is an example of a development consent granted to a seniors living development on flood prone land. There are some similarities, including that habitable floors were designed above the PMF level, and residents could stay in their dwellings during floods; however, in those proceedings vehicle access would still be available by means of a permanently assigned 10 seater bus that would enable access in the 1 in 100 year event, although not a PMF, and there would be 24 hour nursing care and resuscitation equipment on the site. That is a different situation to one where, as in these proceedings, the only means of access to or evacuation from the site in a flood event of greater frequency would be along a walkway above the flood waters. 58 The NSW Floodplain Development Manual (2005) sets out the NSW Flood Prone Land Policy, and recognises that flood prone land is a valuable resource that should not be sterilised by unnecessarily precluding development. Clause 14 of the SEPP(SL) provides that it is an objective of the provisions allowing development for seniors living that opportunities are created for development of housing that is located and designed in a manner "particularly suited to both those seniors who are independent, mobile and active as well as those who are frail, and other people with a disability regardless of their age". While accepting that not all residents of the proposed development would necessarily be frail or less mobile, I accept the evidence of Mr Bewsher that residents in a seniors living development may be older, or may have a disability, and so perhaps may have increased anxiety. While there is no necessary barrier to the approval of a seniors living development on flood prone land, the particular proposed development must be considered in the context of the site on which it is proposed. The context of this proposed development includes there being no direct vehicle access, pedestrian access and evacuation along an elevated walkway for a distance of up to 100m, and the agreed risk to personal safety for any resident who attempted to leave the site by Anthony Street, during a flood event. Even with an emergency management plan as foreshadowed by the hydrologists, having regard to the restricted access to residents who may require assistance and means of evacuation, together with potential increased anxiety in residents aware of flood waters passing underneath the building and through the site, I am not satisfied that the site is suitable for the development as proposed, and consent should be refused. 59 For completeness, I will briefly deal with the other contentions. Watercourse 60 The Council contended that there would be an adverse impact on the watercourse, and that there were insufficient details concerning the proposed earthworks and creek design, noting that the General Terms of Approval provided by the NSW Office of Water require an amendment to the plans to incorporate pool and riffle sequences, rather than the rock lined channel in the plans. Mr Jackson submitted that there is insufficient detail concerning the channel widths and the ultimate location of the realigned watercourse, and that there is at the least uncertainty as to whether there is a riparian zone at least 5m wide from the realigned watercourse. I agree with the applicant's submissions that the NSW Office of Water General Terms of Approval were based on the plans for which consent is sought, that those plans show the riparian zone proposed for the site, and that more detailed plans will be required before a Controlled Activity Approval is obtained under the Water Management Act. In those circumstances, the absence of final detail for the works to be undertaken on the watercourse would not of itself be a basis for refusal of the application. Trees 61 The site contains a number of canopy trees which are part of the Blue Gum High Forest, which is a critically endangered ecological community. The applicant proposes to remove two Eucalyptus saligna (Sydney Blue Gum) and plant 10 trees, which exceeds the Council's offset ratio. There are two trees, identified on the plans as tree 21 and tree 29, which are in close proximity to the proposed building and realigned watercourse, and the Council contends that the proposal is uncertain as to the effects of the works. 62 Arboricultural assessments of the site have been undertaken until early 2010 using the British Standard BS 5837: 1991 Guide for Trees in relation to construction ("British Standard") by agreement between the parties. In August 2009 Australian Standard AS 4970-2009 Protection of trees on development Sites ("Australian Standard") was adopted. Mr Foster and Mr Castor agreed that current industry standards in relation to trees on development sites adopt the Australian standard, and both assessed the potential impacts on trees 21 and 29 against both standards. Both agreed that the impact arising from construction of the basement carpark and realigned riparian zone would comply with the British standard. The Australian standard states at 3.3.3 that if a proposed encroachment is greater than 10% of the tree protection zone (TPZ) or inside the structural root zone (SRZ) the project arborist must demonstrate that the tree would remain viable, and that the area lost to the encroachment should be compensated for elsewhere and contiguous with the TPZ. The experts were in agreement that there would be no impact inside the SRZ; they agreed that the proposed works would have a major impact as defined in part 3.3.3 of the Australian Standard, however they disagreed as to whether this would lead to the death or decline of the trees. 63 Mr Castor was of the opinion that the proposal to replace soil disturbed during construction of the carpark with soil over the carpark roof would provide ample rootable soil volume post-construction; that the recent removal of two trees and the proposed removal of another would provide more water and nutrient to tree 21 and 29; and that both trees are in good health and vigour. Mr Foster disagreed, on the basis that the area of soil replaced would be less fertile over time as the area would be enclosed. The experts disagreed as to whether it had been demonstrated that the proposed realigned watercourse can be constructed without impacting on the existing trees. 64 I accept that it is appropriate to assess the impact on trees 21 and 29 by reference to the Australian Standard. This standard was agreed between the arborists to be part of current industry standards, and is stated to provide guidance for all those, including determining authorities, involved in consideration of protecting trees on land subject to development. 65 Mr Castor accepted that 40% of the TPZ for tree 21 was impacted by the basement works, and was of the opinion that there would be adequate capacity for the tree to grow new roots into the soil placed over the constructed basement. Mr Foster accepted that while the feeder roots of tree 21 would be cut on the western side during construction, there was no physical or arboricultural reason why they would not grow back on that side. The experts agreed that using the Australian standard, there would be impact on 49% of the TPZ for tree 29. Mr Foster was of the opinion that it would not survive; Mr Castor that it was getting close to not being acceptable. This opinion was qualified, on the basis that the calculations had been based on drawings that were not construction drawings, and that the area of calculation for both trees would not actually be constructed. Mr Castor confirmed his opinion that with the placed soil where the water source is, the trees should survive. Mr Castor was of the opinion that there were appropriate materials that could be used to hold the soil over the basement in place to prevent scouring but still allow aeration and water to get through so the soil would be viable for tree root development. 66 Based on this evidence, I accept the applicant's submissions that there will be no impact on the SRZ of either tree 21 or tree 29 during construction. It was common ground that there would be construction impacts on the TPZ of both trees; the issue is whether those impacts are likely to have long term consequences for either tree. I accept the evidence of Mr Castor, with which Mr Foster agreed, that the replacement of soil after the construction of the basement car park will provide a medium in which feeder roots of tree 21 can re-grow, in contrast to a situation where there is a permanent barrier to re-growth. However, the details of the construction of the basement car park are not finally established. I agree with the Council that depending on the final design of the entrance to the driveway there is the potential for the basement layout to be altered. Mr Castor expressed the opinion that the prospects for tree 29 would be improved by location of the creek works a little further to the east; as noted above, the final location and configuration of the creek works are to be the subject of an approval under the Water Management Act. I am not satisfied that there is sufficient certainty to ensure that the long term retention of these trees has been addressed. However, given the conclusion reached above on the suitability of the site, it is not necessary for me to determine this issue, including whether it could be appropriately addressed by means of a deferred commencement condition. Orders 67 The Orders of the Court are: 1. The appeal is dismissed. 2. Development application No 942/2008 for approval for the demolition of two existing dwellings and construction of a Seniors Living development at 15 Eyles Avenue Epping and 15 Anthony Street Carlingford is refused. 3.The exhibits are returned except for exhibit 2. Linda Pearson Commissioner of the Court 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.