Rothshire Pty Ltd v Blacktown City Council

Site and setting

1. The site sits on the corner of Willis Street and Learmonth Street in Rooty Hill and has a near rectangular shape. The site area is some 1486m2. The north-eastern boundary fronting Learmonth Street is 46.8m. The south-eastern boundary to Willis Street is 31.09m. The site is vacant.
2. Proposed Lot 1 would front Learmonth Street and have an area of 522m2. Proposed Lots 2 and 3 would front Willis Street and have areas of 462m2 and 503m2 respectively. The proposal also indicates building platforms for each of the new individual lots.
3. To the immediate south-west of the site is 28 Willis Street (Lot 3 DP 515160) which has previously been approved for use as a service station and motor mechanics. It now appears to be used only for the latter purpose, according to Council's Statement of Facts and Contentions (Ex 1 par 11). To the immediate north-west is 9 Learmonth Street (Lot 1 DP 515160). There was no information in Ex 1 regarding development on this site, but the site inspection suggested it is underdeveloped having regard to the fact that it (along with 28 Willis Street) enjoy the same zoning as the site. There is low density residential development across both Learmonth Street and Willis Street.

Pertinent planning policy considerations

1. The site is located within Zone R2 Low Density Residential under Blacktown Local Environmental Plan 2015 (BLEP). Clause 2.3(2) of BLEP requires that the consent authority must have regard to zone objectives. The objectives of the R2 zone are: • To provide for the housing needs of the community within a low density residential environment. • To enable other land uses that provide facilities or services to meet the day to day needs of residents. • To enable certain activities to be carried out within the zone that do not adversely affect the amenity of the neighbourhood.
2. Subdivision is permitted with development consent under cl 2.6 of BLEP. The proposal complies with the minimum subdivision lot size control of 450m2 under cl 4.4 of BLEP.

Map indicating "future road pattern"

1. Council has prepared a future road pattern plan (Ex 1 par 12) which would extend existing Pimelea Place (currently terminating south-west of 9 Learmonth Street). What henceforth we will call the Pimelea Place Extension is shown in the figure below (dashed lines extending from the south-west through to intersect with Learmonth Street - with north pointing up the page). Mr Vance indicates, and it was not disputed, that this future road pattern plan "(was) extracted from BDCP" (Ex 5 p 8). Although it appears to only exist in on-line format, its status as part of the Blacktown Development Control Plan 2015 (BDCP) was not a point of dispute. Figure 1 - Future road pattern plan Pimelea Place extension (source: Ex 1 Figure 3)
2. Council saw this depiction of an intended future road alignment as providing for an orderly pattern of development for the local undeveloped parcels. However, with the subdivision as currently proposed, the Pimelea Place Extension would leave a "a small unusable parcel of land approximately 10m wide and 310m2 in total area" on 9 Learmonth Street (Ex 1 p 11 - this is the area between the north-west corner of the site highlighted red in Figure 1 and the line of the Pimelea Place Extension). Mr Vance saw this as a disorderly configuration which should not be supported, mindful of the weight attributable to development control plans under s 4.15(1)(a)(iii) of the EPA Act.
3. Council sought an amendment to the proposed subdivision layout to include a residue lot of about 8m width south-east of the above-referenced 310m2 parcel on 9 Learmonth Street. The intent was that these two areas would be consolidated when the Pimelea Place Extension goes ahead.
4. Ms Roberts-Thomson did not see future development potential of 9 Learmonth Street as a relevant consideration in the current application, given no works are proposed on 9 Learmonth Street and the proposed development would result in no impact on 9 Learmonth Street as it exists (Ex 5 p 6). Ms Roberts-Thomson also indicated that there was a capacity to re-align the Pimelea Place Extension such that a larger and more useable area might be available for the south-eastern portion of 9 Learmonth Street. Finally, it was argued that there were many examples of small and narrow parcels of land in the site vicinity which had been successfully developed and are now occupied. Some such sites were pointed out during a site inspection, although in many instances these developments occurred under previous planning controls.

Consideration

1. It can be a very desirable thing, in planning terms, for local Councils to indicate future road patterns in areas having fragmented ownership but with significant development potential. The point is the very ambition of doing as much as one practically can in regard to ensuring orderly development of land. Here "orderly" can include ensuring expected development yields can be achieved, with reasonable cost-effective servicing. In that sense, there is both a public and private interest at play.
2. In turn, it can at times be entirely relevant to consider the implications for other nearby parcels when assessing a subdivision application, and here we disagree with Ms Roberts-Thomson.
3. However, there are a number of factors which, on balance, draw us to the conclusion that the application's (essential) disregard of the Pimelea Place Extension is not fatal to the application. These factors include:

• The significant existing development which is evident at 28 Willis Street (noting that this parcel would likely also have a role to play should the Pimelea Place Extension become an ongoing concern in accordance with Mr Vance's outline).
• The fact of the considerable road frontage enjoyed by 9 Learmonth Street which opens up the potential for an independent development on that site, the relative size of each of these parcels (ie scale can be considered as a factor in regard to potential development independent of others).
• Our agreement with Ms Roberts-Thomson that there is the opportunity to introduce a bend in Pimelea Place Extension (with or without participation of 28 Willis Street) which would minimise any adverse implications of the current subdivision.

Note on BLEP provisions

1. State Environmental Planning Policy Amendment (Flood Planning) 2021 (Flood Planning SEPP) commenced on 14 July 2021 and had the effect of repealing cl 7.1 of BLEP which had been concerned with flooding matters. On the same day, the Standard Instrument (Local Environmental Plans) Amendment (Flood Planning) Order 2021 (Standard Instrument Order 2021) amended BLEP by inserting a new clause (cl 5.21 Flood Planning), as a compulsory item.
2. It was agreed by the parties that the applicable savings and transitions provisions (Standard Instrument (Local Environmental Plans) Order 2006 cl 8) meant that cl 5.21 of BLEP does not apply to this application as the application was made (but not finally determined) before the commencement of cl 5.21 of BLEP as an amending provision.
3. In short, BLEP as it would be applied here, does not include a directly flood-related provision.

Framing the dispute

1. A number of factors are involved in the framing up of the dispute between the parties in regard to flooding. These factors involved:

• The specific pleadings on the part of Council.
• The fitness for purpose of existing baseline flood modelling work adopted by Council and more recent flood modelling work undertaken by the Applicant.
• Weighing up evaluation parameters.

Pleaded contentions

1. It was pointed out by the Applicant that Council's pleaded contentions in regard to flooding include references to cl 7.1 of BLEP (Ex 1 p 7-8). In closing submissions, Council indicated that the particulars of the flood contention could be considered as standing without including particulars (b) and (e) (ie the particulars which make direct reference to former cl 7.1 of BLEP). Noting the agreed position that flood hazard compatibility was no longer at issue, Council's flooding contentions might be summarised as follows: 1. Council adopts a maximum rise of 0.02m on an adjoining property when considering flood impacts (Contention 1 particular (c)). 2. A flood study, relating to the site and factoring in building footprints for dwellings on three lots, showed increases beyond 0.02m on adjoining property and in Learmonth Street for the 1% AEP storm event. This study was commissioned by the Applicant and prepared in 2019 by Council (provided behind Tab 22 to Council's bundle of documents (Ex 2) and henceforth referred to as the 2019 flood study). The 2019 flood study's modelling indicated originally "proposed" future building footprints on each of the three future lots would result in flood depths increasing by up to 200mm at 28 Willis Street and 100mm at 9 Learmonth Street. This modelling did not factor in "garage or driveway locations" (Contention 1 particulars (c), (d)(iii)-(v) and (h) - and shown in detail at Appendix B to the 2019 flood study). 3. The 2019 flood study included modelling of smaller building footprints which reduced external flooding effects but, even assuming only two dwelling footprints, the modelling "still demonstrated a greater than 20mm increase in flood levels on adjoining properties or on Learmonth Street" (Contention 1 particulars (f) - and shown in detail at Appendix E to the 2019 flood study). 4. The Applicant has not demonstrated that the lots proposed to be created are capable of accommodating future residential development without adversely affecting adjoining properties, or public roadways, through raising flood levels. As such, the proposal is not in the public interest (Contention 1 particulars (g), Contention 5), and there are consequential, unsustainable social and economic costs to the community (Contention 1 particular (d)(vii)).

Concerns in regard to flood modelling material before the Court

1. Council, through Mr Merrilees, acknowledged that the 2019 flood study overestimated flooding effects of the proposed development, but it was not clear to what extent it did so.
2. The Applicant had completed new flood modelling work which, according to Mr Dhiacou, demonstrated significantly reduced flooding effects, when compared to the 2019 flood study. This modelling, prepared by Martens and Associates consulting engineers, formed Attachment B to Ex 4 (Martens flood study). Mr Dhiacou indicated he was the staff member within Martens and Associates who had prepared this study.
3. Council contested the admissibility of the Martens flood study. There was a software compatibility problem to the extent that Council was unable to validate the modelling undertaken in the Martens flood study. The admission of this study was seen to be procedurally unfair by Council. In addition, Mr Merrilees did not agree with certain parameters assumed in the Martens flood study.

Approach adopted on flood modelling material before the Court

1. In the interests of just, quick and cheap conduct of the proceedings (and s 56 of the Civil Procedures Act 2005), we adopted an inquisitorial approach, in part at least, as a means of coming to terms with the uncertainties relating to the flood modelling. By this we mean we questioned the flooding experts directly as a principal approach to gaining an understanding of the issues at hand, while also allowing questions from the parties at certain points.
2. We first sought to understand Mr Merrilees' concerns in regard to the parameters adopted in the Martens flood study, and then heard Mr Dhiacou's responses in regard to them. Two points seemed to be of most note. First, is the Marten flood study's adoption of a "rain on grid" approach. Mr Merrilees indicated that Council saw this approach as useful for larger catchments but did not rely on it for smaller site-based studies, such as in play here. Mr Dhiacou saw this approach as appropriate, and referred to other flood modelling work undertaken under Council auspices which had adopted the same approach. Second was in regard to the "boundary conditions" adopted in the Martens flood study's modelling (ie how the model introduces upstream flows into its calculations). Mr Merrilees believed the boundary line (adopted as Frances Road in the Martens flood study) was located on sloping topography which could push the water flows disproportionally to the east (along Frances Road rather than down Acacia Street and towards the site). Under questioning from the Applicant, Mr Merrilees provided evidence of a 1%+ gradient or slope along that line, in support of his position.
3. We heard evidence from both experts in regard to upstream flows towards the site environs, and in particular flows down Acacia Street immediately upstream of 28 Willis Street. According to Mr Dhiacou the Martens flood study modelling indicated that the relevant flood flows down Acacia Street were in the order of 0.8m3/sec and compared this to Council's current model which suggested 4m3/sec. Mr Dhiacou estimated an upper level figure for the Acacia Street flood flow of 1.55m3/sec, as a means of accounting at least in part for Mr Merrilee's concerns. Mr Merrilees indicated he saw the 1.55m3/sec figure as a lower limit rather than upper. Nonetheless, even as a lower limit figure in flood modelling terms, we note that 1.55m3/sec suggests something of the scale of the overestimate within the Council 2019 flood study, which was suggested to predict flows of 4m3/sec down Acacia Street and towards the site environs.

Martens flood study findings

1. We decided to hear from Mr Dhiacou in regard to predicted flood levels in the site environs based on the Martens flood study. We did so mindful of the concerns raised by Council in regard to the adopted parameters and not having been able to test the model more generally. Mr Dhiacou used the Martens flood study's model to physically demonstrate during the proceedings (ie using the share-screen function on the MS Teams platform) that, under this modelling, the area of 28 Willis Street which would be affected by flooding would be as follows:

• An area of 158m2 within 28 Willis Street would be subject to flood level increases of 0.02m-0.05m.
• A further area of 12m2 of 28 Willis Street would be subject to flood level increases a little higher than 0.05m.

1. Without quantifying it, Mr Dhiacou indicated that much of the 158m2, which was subject to flood level increases of 0.02m-0.05m, was in fact subject to less than .03m of increased flooding.
2. The marked difference between the nominated flooding increases on 28 Willis Street, under the Martens flood study, and those from the Council 2019 flood study were noted by the Court (see [21(2)]).

Evaluation parameters

1. Section 4.15(1) of the EPA Act sets out the matters to be taken into consideration, as relevant, in determining a development application. In the absence of any flooding-related provisions in BLEP or any other environmental planning instrument, the Applicant drew attention to the provisions of s 4.15(1)(a)(iii) of the EPA Act. The Applicant suggested BDCP needed to be taken into account as a "focal point" in our evaluative task (mindful of Zhang v Canterbury City Council (2001) 51 NSWLR 589; [2001] NSWCA 167 ('Zhang') at [75], discussed further below).
2. Section 9 of Part A BDCP is concerned with development on flood liable land. The nominated aims and objectives are as follows: "Council's primary aim in relation to the development of flood prone land is to reduce the impact of flooding and flood liability on individual owners and occupiers and to reduce private and public losses resulting from flooding by: (a) Carrying out flood mitigation works subject to the availability of necessary flood data and funding (b) Adopting a merit-based approach to all Development Applications (c) Encouraging development and construction which is compatible with the identified flood hazard to ensure the safety of the development itself. To achieve this, the objectives of this section are to: (a) Define the flood standard (b) Inform the community of Council's policy on the development and use of flood liable land (c) Alert the community to the extent and hazard of flood liable land."
3. Section 9.3 of Part A of BDCP includes a number of definitions, including: "Designated flood level means the designated flood level is the level of a flood having an Average Recurrence Interval of 100 years. That is, the flood level that will have one chance in a hundred on average of being equalled or exceeded in any one year period. Design floor level means a level which is 500mm above the designated flood level for residential buildings and 300mm above that level for commercial and industrial buildings."
4. Section 9.4 of Part A of BDCP is headed "(control) of development on flood prone land", with provisions including: "In determining any application for development on land designated as being within the floodway or flood fringe, Council will take into consideration those matters listed under Section 79C of the Environmental Planning and Assessment Act 1979 as appropriate. Council shall also take into consideration the following: … (b) Whether the buildings are to be sited in the optimum position to avoid flood waters and allow evacuation (c) Whether proposed structures or the filling of land are likely to affect flood flows … (e) The NSW Government Floodplain Development Manual 2005."
5. We note that the reference to "Section 79C", in the quote above, refers to an earlier version of the EPA Act, the provisions of which are now represented generally at s 4.15 of the EPA Act (see [31]).
6. Part J of BDCP is entitled "Water Sensitive Urban Design and Integrated Water Cycle Management". The objectives of Part J are nominated as to: "(a) Provide direction and advice to applicants in order to facilitate water sensitive urban design and integrated water cycle management within the Development Application (DA) process (b) Provide design principles that will assist development to meet the aims of this Part of the DCP (c) Provide objectives, targets and controls for water conservation, water quality, waterway stability, on-site stormwater detention, erosion, sediment and pollution control and groundwater."
7. The final reference of relevance to evaluation of the application is called: "Water sensitive urban design (WSUD) developer handbook - MUSIC modelling and design guide 2020" (an excerpt was provided at Ex C behind Tab 2 and henceforth referenced as the WSUD handbook). This Council work is not a development control plan but references itself as a "technical handbook … for the use of civil engineers …" (Ex C p 17). It is the WSUD handbook that refers to 0.02m flooding control. A relevant provision is at Section 15, as follows: "A Flood report must be prepared for sites identified as affected by mainstream flooding, local runoff, local overland flooding, or sites situated in a defined low point with the potential for overland flows. The Flood report must: • ... Demonstrate that neighbouring properties are not adversely impacted by the new development for flood events up to and including the 1% AEP flood event. Maximum isolated rise in 0.02 m." …
8. Section 15.6.2 of the WSUD handbook similarly says "(a) maximum isolated rise of 0.02m is permitted in a flood section or cell external to the site. Multiple rises to this level will not be permitted". Section 15.6.4 of the WSUD handbook is concerned with flood modelling techniques, indicating strengths and weaknesses of some of the flood models, at the same time indicating some limitations on Council's capacities to access model versions for evaluative purposes.

Evidence

1. There are three major areas of dispute between the experts in regard to the flooding question, which are considered in turn below.

Quantum of increased flooding

1. There is no dispute that there would be an increase in flooding. The dispute was in regard to how much and where. As indicated above, Mr Dhiacou saw increases of 20-50mm over an area of 158m2 within 28 Willis Street, and exceeding 50mm somewhat for an area of some 12m2 based on the Martens flood study. Further in regard to the Martens flood study it was argued (Ex 4 p 6): … "c. There are small areas of flood level increase in the Learmonth Street and Willis Street road reserves which is a direct consequence of the new driveways, and does not affect road or pedestrian trafficability. d. The proposed development does not cause any lots to become newly flood affected. … f. There are no impacts on existing land uses or future development potential in terms of flood planning levels (FPLs). FPLs on the adjoining land are not increased by the proposal. g. Areas of flood level increase are isolated and directly adjacent to the site boundaries and driveways, and hence there is no potential for cumulative flood impacts which cover large areas of the floodplain. h. The flood impacts associated with the proposed development are therefore acceptable, and the development will not significantly adversely affect flood behaviour resulting in detrimental increases in the potential flood affectation of other development or properties."
2. Mr Dhiacou also argued that the Martens study adopted "worst case building footprints" (ie conservatively large), and that actual buildings could be designed to further minimise flood impacts.
3. Mr Merrilees was not confident in these estimates of the Martens flood study and believed the Applicant still had to prove up its case on the extent to which the 2019 flood study overestimated things. According to Mr Merrilees, there was a need to prove this using modelling parameters as indicated in the WSUD handbook.

Policy objectives and flexible application of policy

1. Mr Dhiacou highlighted various provisions in Council's policies and in s 4.15(3A) in regard to the flexible application of development control plan provisions, and argued as follows (Ex p 5): "a. The BDCP is to be considered, however it is not compulsory to comply with the BDCP controls and they are not to be strictly enforced; rather, the approving authority is to be flexible in applying the BDCP provisions. b. The BDCP promotes a merit-based approach rather than a strict enforcement of an arbitrary impact threshold, and does not qualify that this approach would not apply to new development. c. The BDCP requires flood impacts to be reduced, not eliminated. d. The BDCP does not require strict compliance with the WSUD guide. e. The maximum water level increase of 0.02 m noted in the WSUD guide is not to be rigidly applied as a performance criterion for the proposed development, and cannot be used as a basis for refusal."
2. Mr Merrilees did not seem to favour the flexible application of its flood control policy (Ex 4 p 8): "I am not a planner, but in my observance over many years the planners exercise various discretions as to aspects of the building such as window location and sizes, or permitting parts of a building such a front porch to encroach into the setback. However, I have not seen the application of such a clause being used to justify significant flooding impacts on neighbouring properties."
3. He indicated that in his role as the leader of the team responsible for flooding assessment: "Council agrees to a merits-based approach where appropriate such as house extensions in flood affected areas. It has never been applied to new developments."
4. He argued that Council's objective is to have "zero impact to neighbours" in regard to additional flooding from new development, with the 0.02m leeway allowing for "odd nuances with different digital models that produce minor changes in odd locations" (Ex 4 p 7): "The isolated 0.02 m maximum increase will ensure minimal adverse impact to individual properties at the time of development and is set in part to minimise the cumulative effects of future adjacent developments causing other flood increases. Accepting a 90mm increase with one development then may become 180 mm on two, more on three, etc . resulting in flood creep and significant impacts to neighbours or the public areas."

Whether conditions of consent can satisfy flooding concerns

1. As is usual in the circumstances, the parties filed draft conditions of consent, without prejudice on the Council's part. An argument of the Applicant was that even if we were against it in regard to flooding impact, the option was open for us to approve the application, adopting Council's conditions of consent. These conditions indicate a requirement for compliance with the WSUD handbook, with further flood modelling to demonstrate how this might occur.
2. The context was explained to an extent in Mr Dhiacou's expert evidence (Ex 4 p 6): "Further, the modelled conceptual worst case building footprints are conservative (i.e. very large}, are nominally located and have not been specifically designed to further minimise flood impacts. Hence actual flood impacts arising from any future development applications for individual buildings will require supplementary flood modelling whereby the worst-case conceptual impacts modelled as a part of this application will be further reduced by design."
3. Mr Merrilees indicated he was yet to be convinced that the missing flood modelling would indeed demonstrate that there was a capacity for three dwellings on the site (eg rather than perhaps two only) (Ex 4 p 8): "Reducing the building footprints will likely reduce the flood impacts on the adjoining properties and to the public domain, However, it is not clear how much reduction will occur and how many buildings and of what size it can support (if any) to ensure no adverse impacts and whether three lots are achievable."

Quantum of increased flooding

1. There are uncertainties in regard to both the 2019 flood study and the Martens flood study. The fact of the uncertainty relating to the 2019 flood study is acknowledged by Council, but the extent of its overestimates is unconfirmed. When we turn to the Martens flood study, we found Mr Merrilee's evidence convincing in regard to a question relating to boundary conditions adopted in the Martens flood study modelling. This suggested to us that there were underestimates in the Martens flood study, as far as the site environs is concerned. We note here that Council had not had a chance to fully examine the Martens flood study. But we know at least that under the Martens flood study there would be flooding increases in both private property and on the public road. The extent of external flooding (ie flooding off the site) will not be as high as indicated in the 2019 flood study, but it has not been proven that flooding will not be higher than indicated in the Martens study.

Consideration of evaluative framework

1. The basis of development application evaluation is of course s 4.15(1) of the EPA Act. Mandatory considerations include applicable environmental planning instruments (in this case we have already accepted that there are no applicable flooding-related provisions under BLEP) and development control plans. As indicated above, the Applicant drew our attention to Zhang in its argument that little weight should apply to the WSUD handbook. In Zhang, Spigelman CJ at [75] explains the discretion to be exercised and the weight to be applied to relevant provisions of a development control plan in the decision making process (coincidentally in a setting where "the public interest" was also an evaluative factor): "75. The consent authority has a wide ranging discretion - one of the matters required to be taken into account is 'the public interest' - but the discretion is not at large and is not unfettered. DCP 23 had to be considered as a "fundamental element" in or a "focal point" of the decision making process. A provision so directly pertinent to the application for consent before the Council as was cl 4.0 of DCP 23 was entitled to significant weight in the decision making process but was not, of course, determinative."
2. Council drew attention to the wider ambit of s 4.15(1) of the EPA Act, including the considerations at ss 4.15(1)(b) and 4.15(1)(e), concerned with the likely impacts of development and the public interest, respectively. Council referenced a number of citations which were concerned with the argument that in development application evaluation, the available "discretion" should include the application of policy documents like the WSUD handbook. Council referred to Carstens v Pittwater Council (1999) 111 LGERA 1; [1999] NSWLEC 249 at [25] (in each of the citations immediately following, reference is made to "s 79C(1)" of the then EPA Act - for our purposes this can be seen to correspond with s 4.15(1) of the current EPA Act): "25. I thus conclude that the matters for consideration listed in s 79C(1) are not the only matters to which a consent authority may have regard. The listed matters are those which a consent authority must consider. The consent authority may also take into consideration other matters not included in those which are listed. Those other matters include, in the public interest, any matter which relates to the objects of the Act set out in s 5. This does not mean that the decision-maker may take anything into consideration. The relevant considerations are confined so far as the subject-matter, scope and purpose of the Act and any environmental planning instruments allow. The draft DCPs and the Values Statement in the present case are relevant as documents which relate to the matters described in sub-paras (i), (ii), (vi) and possibly (vii) of para (a) of those objects. In taking those matters into consideration the Commissioner made no error of law."
3. Council also refers to Terrace Tower Holdings Pty Ltd v Sutherland Shire Council (2003) 129 LGERA 195; [2003] NSWCA 289, where it was found at [56]: "Section 79C(1) does not stipulate or imply a hierarchy among its various paragraphs or among the subparagraphs of (a). This was common ground in the appeal."
4. Our main conclusion here is that we believe we would be in error to rule out the application of the WSUD handbook in the evaluation of the matter before us. We accept the commentary in the opening to the WSUD handbook, as indicated by Mr Seton, that it has been prepared "after careful review and consultation", and the evidence from Mr Merrilees that it has been consistently applied, in regard to central query before us here. As to weight, the WSUD handbook is clearly an issue specific policy document concerned with water sensitivity in the design process. But BDCP also includes flooding related provisions. Further comments on weight follow in the evaluation section below.

Evaluation

1. Our first point is that we don't see BDCP as providing much in the way of support for the application. Section 9 of Part A of BDCP says "Council's primary aim in relation to the development of flood prone land is to reduce the impact of flooding and flood liability on individual owners…" (see [32]). We think Mr Dhiacou may be misinterpreting this primary aim when he suggests "BDCP requires flood impacts to be reduced, not eliminated" (see [43]). The "primary aim" is not to reduce additional flooding on already flood prone land, as a consequence of new development, from a higher increase to a lower increase. It is, in relation to the development of flood prone land, to reduce flooding impacts, per se. According to BDCP (see [32]), this will occur through flood mitigation works but also through a merits-based approach to development application assessment. The ambit of the merits-based assessment is not indicated. Mr Merrilee's indicates flexibility is applied in regard to certain house extensions but a wider example might include allowing increased yields where there was some associated flood mitigation in accordance with the primary aim. We question whether the ambit of merits-based assessment includes allowing development which worked against the "primary aim".
2. Nonetheless, Mr D is correct in his view that BDCP, like other development control plans, is to be applied flexibly.
3. The essential question this leads us to is whether it is unreasonable to apply the control of a maximum of 0.02m flood increase as found in the WSUD handbook. It is Council's position that there is in-built flexibility in this control. That is to say, the real ambition is for development to have no increase in external flooding whatsoever, but that the 0.02m control allows for modelling errors and the like.
4. It is our finding that it is reasonable for new development in flood prone areas to manage its flooding effects entirely, with some tolerances such as the 0.02m allowance under the WSUD handbook. The consequences of not doing so would need to be borne by the newly affected land. In this case, were there to be an ambition for the adjoining lands to be developed for residential purposes in accordance with the zone objectives, then the increased flooding risk is an unfair burden and adversely affects this development potential.
5. As things stand, the Applicant acknowledges certain flooding increases on external lands (see [28]). While as indicated above, there is some uncertainty about the modelling behind these findings, even at the flood level increases proposed by the Applicant, this application cannot be supported.
6. With reference to the Applicant's submissions, it would be inappropriate to assume that the proposed conditions of consent (without prejudice on Council's part) address this concern, as it is unknown at present whether two or three building platforms will be appropriate until the modelling uncertainties are resolved.
7. The Court orders that: 1. The appeal is dismissed. 2. Development application DA-18-01229 for land subdivision is refused. 3. The following exhibits are returned: 2-6 and C. ………………………. ………………………. P Walsh L Sheridan Commissioner of the Court Acting 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. Decision last updated: 15 March 2022