[section 27(1) of the Planning and Environment Act 1987 (the PE Act)]

For the Amendment to proceed, it must be adopted by the planning authority and then sent to the Minister for Planning for approval.

The planning authority is not obliged to follow the recommendations of the Panel, but it must give its reasons if it does not follow the recommendations. [section 31 (1) of the PE Act, and section 9 of the Planning and Environment Regulations 2015]

If approved by the Minister for Planning a formal change will be made to the planning scheme. Notice of approval of the Amendment will be published in the Government Gazette. [section 37 of the PE Act]

Planning Panels Victoria acknowledges the Wurundjeri Woi Wurrung People as the traditional custodians of the land on which our office is located. We pay our respects to their Elders past and present.

Planning and Environment Act 1987

Australian Rainfall and Runoff Guidelines, Australian Government, 2019

tabled document [number] (refer to Appendix A)

Planning and Environment Act 1987

Submission [number] (submissions to the exhibited Amendment referred to the Panel by Council)

Merri-bek City Council - Creating the Local Drainage Stormwater Map, Engeny, 2 November 2023

Insert a new Schedule 2 to the Special Building Overlay into the Planning Scheme

Land affected by overland flow of stormwater from the local drainage network in a 1 percent annual exceedance probability (AEP) storm event

The initial exhibition period was between 16 May and 17 June 2024. On 14 August 2024 Council resolved to extend exhibition to 13 December 2024

Sarah Vojinovic, Project Support Officer, Planning Panels Victoria

Planning Panels Victoria and by video, 12 and 13 June 2025

Merri-bek City Council represented by Briana Eastaugh of Maddocks, who called expert evidence on drainage engineering from Glenn Ottrey of Egis (formally Engeny)

Builtmore Investments Pty Ltd represented by Peter Farah who called expert evidence on hydraulics engineering from David Moret of DPM Consulting Group

Merri-bek Planning Scheme Amendment C196more (the Amendment) proposes to apply a new Special Building Overlay Schedule 2 (Council drains) (SBO2) to land in Merri-bek that is predicted (by modelling) to be inundated by overland stormwater flows from the local drainage network in a 1 percent annual exceedance probability (AEP) storm event.

Council engaged Engeny to undertake modelling of overland flows from the local drainage network, to inform the mapping of the SBO2 extent across the municipality. The modelling was robust and thorough, and followed applicable standards, guidelines and industry practices.

Engeny undertook site specific reviews of every property in relation to which a submission was made seeking removal of the SBO2. Engeny compared on ground conditions to the modelling inputs, and made adjustments where required. This resulted in several properties being removed from the proposed SBO2 extent. In many other cases, on ground observations and investigations revealed a high degree of correlation between on ground conditions and the modelling inputs, and no changes to the SBO2 mapping were made.

It is inevitable that with a catchment wide modelling exercise, there will be localised discrepancies and inaccuracies in the modelling. It is also likely that some of those localised discrepancies have not been brought to the attention of Council and Engeny through the submissions process. This does not undermine the fundamental suitability of the catchment wide modelling for informing the SBO2 extent. Any remaining localised inaccuracies that have not been identified through the submission review process can be dealt with at the permit application stage.

The proposed SBO2 has an important role to play in identifying the potential flood risk for current property owners and future purchasers of affected properties, so they can make informed decisions about the property and about planning for their own safety during storm events. The SBO2 will ensure that future development of the affected land is designed to be resilient to the impacts of potential flooding, and does not exacerbate existing flood conditions in the area.

The Amendment has strong policy support, will deliver a net community benefit, and should be progressed.

Based on the reasons set out in this Report, the Panel recommends that Council:

Merri-bek Planning Scheme Amendment C196more (the Amendment) proposes to apply a new Schedule 2 (Council drains) to the Special Building Overlay (SBO2) to land that is predicted (by modelling) to be inundated by overland flows from the local drainage network in a 1 percent annual exceedance probability (AEP) storm event.

A 1 percent AEP event is a major storm event where there is a 1 percent probability the event will happen in any given year (which generally equates to a once every 100 year event). This is sometimes referred to as the '1 in 100 year storm'.

The local drainage network consists of stormwater drains for which Merri-bek City Council (Council) is the responsible drainage authority. An existing SBO (to be renamed SBO1) already applies to land in the municipality predicted to be inundated in a 1 percent AEP event from overland flows from the regional stormwater drainage network (for which Melbourne Water is the responsible drainage authority).

Council's Part A submission (D9) provides a comprehensive account of the purpose and effect of the SBO2, the properties affected, and the background to the preparation of the Amendment. This assisted the Panel in its consideration of the submissions, but is not repeated in this Report.

The land to which the SBO2 is proposed to be applied is shown in Figure 1 below. Figure 1 is the exhibited version - Council produced a revised 'Day 1' version following Engeny's review of the mapping in response to submissions (discussed in more detail in Chapter [[1]](2025_36.html#_R<a name=)).1

Figure 1 Map showing the proposed extent of the Special Building Overlay Schedule 2

Builtmore Investments Pty Ltd (Builtmore) advised the Panel at the Directions Hearing that it had been seeking information to enable its hydraulic engineer Mr Moret to test the modelling. Council indicated that some of the data that Mr Moret had requested was not owned by Council (rather, it was Melbourne Water data).

The Panel requested Builtmore to detail its request with a specific list of information requested (D3), and encouraged Council to see if it could obtain Melbourne Water's consent to the release of the data on the basis that Mr Moret entered into an agreement with Council and Melbourne Water about the use and distribution of the data (which he agreed to do).

Council was not able to secure Melbourne Water's consent to the release of the data. The parties requested the Panel to make a direction that the data be provided, which the Panel did (D4). The Panel's direction was to provide the information listed in Builtmore's request (D3). Council provided the information to Mr Moret on 7 and 9 May 2025 (D5).

On 23 May 2025, Builtmore wrote to the Panel with a request for a 7 day extension to the filing date for Mr Moret's evidence (which was due on the day the request was made). The request attached an email from Mr Moret to Builtmore dated 21 May requesting additional information in relation to the modelling. Builtmore did not pass that request on to Council or to the Panel until circulating it with the extension request.

Council responded on 23 May 2025 (D17) opposing the extension request. Council:

• confirmed it has provided all information included in the Panel's Direction
• advised it had not received any further request for information from Builtmore or Mr Moret
• submitted that:
  • - the additional information should have been included in the initial request
  • - it is entirely unreasonable to request further information on the day the evidence is due
  • - the extension, if granted, would be entirely prejudicial to Council's case as it would mean Mr Moret's evidence would be due on the same day as Council's Part B submission, and only one business day before the Hearing was due to commence (on 2 June 2025). This would mean Council would have very limited opportunity to properly consider and respond to the evidence.

On 26 May 2025, Builtmore wrote again to the Panel (D18) raising concerns about procedural fairness (among other things) associated with Council allegedly withholding information, and advising that neither its representative who it had engaged to appear at the Hearing (Ms Wilson) nor Mr Moret were available to appear at the Hearing on 2 June, as Ms Wilson was interstate and Mr Moret was overseas.

The Panel wrote to the parties on 26 May 2025 (D19) indicating the Hearing day on 2 June would be converted into another Directions Hearing to reschedule the Hearing so Mr Moret could attend. The Panel and parties eventually received Mr Moret's evidence on 4 June 2025, and the Hearing was rescheduled to commence on 12 June 2025.

It is unclear why Builtmore retained a representative and expert who were not available on the originally scheduled Hearing dates. Builtmore's second request for information from Council was unreasonably late, and the resultant delays caused considerable inconvenience to the Panel, Council and the other parties. Builtmore should have been better organised.

At the Hearing, the Panel asked Mr Moret whether he received all the information he had requested and needed to understand the modelling. He confirmed that he had.

Mr Allenby also raised concerns in relation to the provision of information from Council (D23). He wrote to the Panel on 28 May 2025 indicating that some of his information requests going back as far as 2021 had not been responded to. Mr Allenby did not describe the information he had requested which had not been provided. Nor did he seek a direction from the Panel that the information be provided. Accordingly, it is not clear to the Panel whether (or how) the information requested by Mr Allenby may have assisted the Panel.

Historical information requests and the consultation engaged in by Council and Engeny in preparing the Amendment are not matters that are before the Panel. That said, the consultation process (which was outlined in detail in Council's Part A submission) appeared to be comprehensive and went significantly beyond the statutory requirements for notice and consultation. There is no evidence before the Panel that Council withheld information, or was anything other than diligent and comprehensive in its response to submitter concerns about the Amendment.

• technical issues in the modelling and mapping, including:
  • - methodology and suitability of the modelling to predict land likely to be inundated in the 1 percent AEP event
  • - whether climate change was appropriately factored in to the modelling
  • - the accuracy of the topographic data inputted into the model
• the modelling had not taken account of site specific issues which may impact overland flows on individual properties, such as ground levels and the impacts of fences and buildings.

Submissions raised several issues that are not relevant to the question of whether the Amendment should be supported. These included:

• developers of upstream land should be responsible for reducing or eliminating any stormwater runoff
• flooding issues have been exacerbated by urban development in the municipality
• Council should be undertaking other action to mitigate flooding, such as maintaining or upgrading its drainage network, rather than applying the SBO2 and shifting the burden onto private landowners
• the SBO2 impacts development opportunities on the affected properties
• the SBO2 has financial implications including reducing the value of affected properties and increasing insurance premiums
• consultation and transparency in preparing the Amendment.

Council's Part B submission provided a comprehensive response to these issues, including demonstrating why these issues are not relevant to the Amendment. The Panel accepts those submissions and notes that there is a long standing and well accepted line of Panel reports establishing why these issues are not relevant at the Amendment stage.

The Panel has not attempted to summarise these previous reports or Council's submission in any detail, but highlights the following key well established principles:

• It is well accepted that many inner urban drainage networks were designed decades ago, for much lower capacity than that required for the 1 percent AEP event. There is no legal obligation on councils (as local drainage authorities) to ensure no overland flows in a 1 percent AEP event. Designing a system that results in no overland flows in such an event (or upgrading existing systems to meet this standard) would be practically impossible without huge disruption to urban streets and private property. It would also be hugely costly, and well beyond the budgets of local councils.
• It is well accepted that modelling and mapping of overland stormwater flows should be based on current development and infrastructure, not hypothetical or potential future upgrades of infrastructure.
• Several previous panels have accepted, based on evidence, that while increased urban development inevitably results in increased runoff, this is unlikely to cause or significantly impact on overland stormwater flows in a 1 percent AEP event.
• The SBO does not prevent future development of the affected land. Rather, it applies a permit trigger to ensure that future development is designed to be resilient to the impacts of future flood events, and does not exacerbate existing flood conditions in the area.
• There is no evidence that an SBO impacts the value of a particular property. Property values are impacted by a complex range of matters related to the broader economy and property markets. In any event, private financial impacts such as impacts on property values and increased insurance premiums are not relevant considerations for strategic planning projects.

The Panel considered all written submissions made in response to the exhibition of the Amendment, submissions, evidence and other material presented to it during the Hearing. All submissions and materials have been considered by the Panel in reaching its conclusions, regardless of whether they are specifically mentioned in the Report.

This Report deals with the issues under the following headings:

• Strategic issues
• Technical issues
• Site specific issues.

This chapter identifies the key parts of the strategic planning context relevant to the Amendment.

Clause 13.01-1S (Natural hazards and climate change)

• - housing for all Victorians
• - accessible jobs and services
• - great places, suburbs and towns
• - sustainable environments

Ministerial Direction on the Form and Content of Planning Schemes

Ministerial Direction 9 (Metropolitan Planning Strategy)

Ministerial Direction 11 (Strategic Assessment of Amendments)

Planning Practice Note 12: Applying the Flood Provisions in Planning Schemes

Planning Practice Note 46: Strategic Assessment Guidelines

There was no dispute among the parties that the Amendment is strategically justified.

The Panel has assessed the Amendment against the key parts of the strategic planning context and the principles of net community benefit and sustainable development, as set out in Clause 71.02-3 (Integrated decision making) of the Merri-bek Planning Scheme (the Planning Scheme). The Panel was assisted in this task by Council's submissions, particularly its Part A submission.

• the Victorian planning objective in section 4(1)(c) to "secure a pleasant, efficient and safe working, living, and recreational environment for all Victorians and visitors to Victoria"
• the ability in section 6(2)(e) for a planning scheme to "regulate or prohibit any use or development in hazardous areas or in areas which are likely to become hazardous areas".

The Amendment is consistent with key principles of State policy, in particular to:

• ensure planning for growth considers land capability and natural hazards
• identify land affected by flooding, including land inundated by the 1 percent AEP flood event
• minimise the impacts of natural hazards and adapt to the impacts of climate change through risk-based planning
• assist in protecting life, property and community infrastructure from flood hazard
• create safe urban environments by requiring development to respond to its context and climate.

The Amendment is consistent with key Ministerial Directions, including the need to:

• promote urban design excellence in every aspect of the built environment
• reduce the likelihood and consequences of natural hazard events and adapt to climate change
• mitigate exposure to natural hazards and adapt to climate change impacts
• protect water, drainage, and sewerage assets
• protect stormwater quality and ensure flash-flood impacts are minimised to protect life, property, assets, and the environment.

The Amendment is consistent with key pillars and principles in Plan for Victoria including:

• ensuring Victoria's suburbs, towns and neighbourhoods are vibrant, resilient and inclusive to support strong communities
• recognising that the quality of the places we live affects all aspects of our lives, from our health and wellbeing to our impact on nature
• ensuring our cities and towns are resilient to climate change impacts because buildings and developments are designed and built in environmentally sustainable ways.

The Amendment will have positive social and economic effects by ensuring the community is aware of areas liable to inundation in a 1 percent AEP event, and ensuring future development in those areas is resilient to the impacts of potential flooding, and is designed to avoid exacerbating flooding.

Amendments VC267, VC276 and VC280 seek to increase housing supply and are likely to result in increased intensification of residential development in Melbourne's suburbs. The Panel accepts Council's submission that this reinforces the importance of ensuring that suitable frameworks are put in place to require development in flood risk areas to respond to flooding risks.

Planning Practice Note 12: Applying the Flood Provisions in Planning Schemes (PPN12) provides guidance about applying the flood provisions in planning schemes including identifying land affected by flooding and the application and operation of the flood provisions. The Amendment is consistent with PPN12 in mapping land liable to inundation in a 1 percent AEP event, and selecting the SBO to apply to that land. The SBO is the appropriate planning tool as it specifically relates to urban stormwater overland flow paths and managing development in urbanised locations that may be affected by overland stormwater flows.

Council's approach in engaging Engeny to prepare the flood modelling and mapping and applying the SBO2 to land affected by the 1 percent AEP storm event is consistent with a range of other important government policies and reports, including the:

• Victorian Floodplain Management Strategy 2016, which emphasises the need to adapt to climate change and ensure strategic planning considers flooding and its impacts
• role of local government outlined in Flood Management Strategy Port Phillip and Westernport 2021, which includes:
  • - managing local drainage systems
  • - doing flood modelling and mapping for catchments less than 60 hectares
  • - applying planning scheme controls to land affected by a 1 percent AEP storm event
• Guidelines for Development in Flood Affected Areas 2019, which states the 1 percent AEP event is the appropriate event to be used in flood mapping, and acknowledges the SBO as the preferred tool for mapping 1 percent AEP urban stormwater overland flows
• Victorian Auditor General's 2005 Report Managing Stormwater Flooding Risks in Melbourne, which refers to the need for agencies to apply strategies that provide a higher level of flood protection and educate the community to prevent inappropriate development that exacerbates flooding risks
• report of the Parliamentary Inquiry into the 2022 Victorian Floods, which states that:
  • - land use planning can mitigate flood risk through appropriate planning and building controls
  • - Victoria's strategic land use planning needs to limit inappropriate new housing and business developments inside 1 percent AEP floodplains.

The proposed SBO2 has an important role to play in identifying the potential flood risk for current property owners and future purchasers of affected properties, so they may make informed decisions about the property and about planning for their own safety during storm events. It will ensure that future development of the affected land is designed to be resilient to the impacts of potential flooding, and does not exacerbate existing flood conditions in the area.

The Panel considers the Amendment strikes the appropriate balance between competing objectives in favour of net community benefit and sustainable development, while providing improved transparency of overland flow considerations during severe storm events.

The Panel acknowledges that the Amendment is part of an integrated approach being taken by Council to manage flood risk in its municipality, including:

• pursuing structural improvements to its local drainage network
• accurately mapping the 1 percent AEP event in the planning scheme
• raising landowner awareness to urban stormwater flooding.

• The Amendment:
  • - implements the Planning Policy Framework and is consistent with the relevant Ministerial Directions and Planning Practice Notes
  • - is well founded and strategically justified
  • - should proceed, with the adjustments to the SBO2 mapping resulting from Council and Engeny's review of the modelling and mapping in response to submissions (discussed in more detail in Chapter 3.1).

Adopt Merri-bek Planning Scheme Amendment C196more with the change recommended in this Report.

The issue is whether the modelling used is suitable for the purpose of determining the flood mapping used to inform the application of the SBO2.

The Amendment is supported by a Technical Report entitled Merri-bek City Council - Creating the Local Drainage Stormwater Map, Engeny, 2 November 2023 (the Technical Report).

Some 71 submissions raised concerns with the methodology behind the preparation of the SBO2 map, including the modelling that underpins the mapping. This included submissions that the modelling was not sufficiently fine grained and did not take account of site specific features such as the effect of existing on-site structures and drainage infrastructure on the movement of overland flows across a site. Site specific issues are discussed in more detail in Chapter 4.

Council submitted the approach taken to the catchment wide modelling and mapping was particularly thorough, robust and verified which gives a high degree of confidence in the proposed SBO2 extent. It noted Melbourne Water had given strong written support for the Amendment, and submitted the modelling used to inform the SBO2 mapping provides a sound and strategically justified basis for the Amendment.

Council submitted the modelling was completed in accordance with accepted criteria, published guidelines and in consultation with the Floodplain Management Authority (Melbourne Water). It submitted the modelling was based on best practice flood mapping principles and used appropriate key data inputs.

Council explained that the modelling was part of a five step process described in detail in the Technical Report and the evidence of Mr Ottrey. It observed that the only other hydraulic expert who gave evidence (Mr Moret, for Builtmore) agreed the modelling had generally been approached correctly. Where Mr Moret's opinion differed on the approach used, Council submitted these were site specific issues and do not undermine the modelling more broadly or the general methodology applied to the modelling and mapping.

Council explained that the modelling and mapping was reviewed in response to submissions, resulting in refinements to the mapping as reflected in the Day 1 SBO2 map. It submitted the review process added a degree of thoroughness and robustness, ensuring the mapping was more responsive to local conditions.

The review process included on-site observations which resulted in:

• refining the mapping to remove the SBO2 from properties only marginally affected
• validating the mapping to account for recently completed civil drainage works and the effects of recently constructed major projects (such as level crossing removals) on stormwater flows.

Reviews were undertaken of the specific properties in relation to which submissions were received, as well as surrounding properties (whether or not submissions were received). Council tabled a memo prepared by Engeny which included information about the number of reviews done and changes made to the SBO2 map in response to submissions. The key information is extracted in Table 2. The review resulted in 72 properties being removed from the SBO2 extent.

In the table below, the unfiltered property layer represents all properties which were liable to inundation in the future 1 percent AEP event including climate change, no matter how minor. Criteria were then applied (such as flood depth and extent of the property affected) to derive the 'filtered property layer'. The exhibited SBO2 extent was based on the filtered property layer, and included 6,503 properties.

Table 2 Outcomes of mapping reviews in response to submissions

Total number of properties with SBO2 applied (in whole or in part):

Number of submissions requesting a review of the application of the SBO2 to their property

Number of properties proposed to be removed following further review in response to submissions:

* 75 submitters requested property reviews, however two withdrew their submissions

Source: Document 010 - Appendix 1 to Council Part A submission

Council submitted that while the review process revealed some localised inaccuracies in the initial modelling and mapping, the refined 'Day 1' SBO2 map is fit for purpose, and any further refinements are best done at the planning permit application stage when an applicant will need to prepare a survey plan for their land. Council noted the findings of the Panel for Yarra Planning Scheme Amendment C210 which observed that:

The Panel accepts that there may be some localised inaccuracies in the mapping but site-specific characteristics can be considered in more detail at the planning permit application stage. The SBO is essentially only a permit trigger for the area identified at risk that alerts landowners and the responsible authority that there may be local flooding issues that need be considered when planning for subdivision, buildings or works. In that sense, small localised inaccuracies are not significant.

In his evidence for Council, Mr Ottrey stated the modelling:

• was undertaken using Runoff Routing (RORB) and Two-dimensional Unsteady FLOW (TUFLOW) programs which are widely used in flood modelling in Victoria
• was completed generally in accordance with the Australian Government's Australian Rainfall and Runoff Guidelines 2019 (ARR Guidelines)
• reflects technical specifications issued by Melbourne Water.

The ARR Guidelines were updated in 2024, after the modelling project commenced. Relevant Melbourne Water guidelines were also updated after the modelling commenced. The modelling was not updated to take account of the changes to the guidelines. Mr Ottrey's evidence was that it is "necessary and standard industry practice" to adopt a particular version of a guideline or standard at the beginning of a project and carry that guideline or standard through to completion of the work, even if a newer version is released part way through the project. He stated:

The reason it is necessary not to change mid-project is that updated standards can change guidance for components of the project that have already been completed. For example, the update to Australian Rainfall and Runoff changed the hydrology assumptions associated with climate change.

Completing the hydrology model runs is one of the first steps in developing a flood extent, so having to update the hydrology runs means that all other steps after that point in the project must also be completed again. The runs of the hydraulic model represent a key stage in the process, with thousands of hours of computer processing time required to complete these runs. This makes updates to the hydraulic modelling or any step in the process before the hydraulic modelling very time-consuming. It is also not possible to do a "small update" for the hydraulic models without rerunning them in full, as the models are setup to simulate a complete storm and so must run from the start to the completion of each storm event.

Mr Ottrey's evidence was the modelling was undertaken in accordance with relevant standards and guidelines at the time it was commenced and provides a suitable basis for the development of the SBO2 mapping. He was satisfied the changes in the guidelines do not mean that the modelling needs to be updated before the Amendment can be implemented.

Mr Moret gave hydraulic engineering evidence for Builtmore, the owner of 142 Dawson Street Brunswick West. He undertook a desktop review of the hydrological and hydraulic modelling used to support the Amendment. He concluded the TUFLOW and RORB models broadly adhered to current industry practices and standards relevant to floodplain mapping in urban catchments. He added that the TUFLOW model demonstrated a clear structure with modular references to geometry, materials and event files. In his view, the use of event configurations that comply with the ARR Guidelines, pre-wetting conditions and pit inlet hydraulics suggests that the modelling framework has been developed with reference to contemporary guidance including Melbourne Water's flood mapping specifications. He concluded the RORB model appeared to have applied industry standard loss parameters, routing coefficients and temporal inputs consistent with the ARR Guidelines.

Mr Moret stated that no global errors or critical faults were identified in the overall model structure. He noted, however, that observations he made during his review highlight "aspects of the model that may influence interpretation of predicted flood behaviour at 142 Dawson Street". He noted the modelling did not include or account for:

• the existing building across the northern boundary of the site, which would act as a physical barrier to stormwater flows
• potential localised smoothing of topographical detail
• the grated drainage pits within the car park area on the site
• the associated uncertainty regarding the routing and continuity of overland flow paths across the site.

The site specific issues are discussed in more detail in Chapter 4.5 below.

While the Panel acknowledges that some submitters raised concerns over the flood modelling, no evidence was presented to the Panel that called into question the fundamental soundness of the modelling methodology. Both experts agreed that the modelling adhered to industry best practice and was based on the appropriate AAR Guidelines and Melbourne Water guidelines current at the time the modelling was commenced.

Guidelines have been updated since the modelling was undertaken. This does not, in the Panel's view, negate the soundness and efficacy of the modelling. In practical terms, the flood modelling and hence the mapping needs to be based on the best information and guidance available at the time. As Mr Ottrey pointed out, it is standard industry practice to adopt a particular version of a guideline or standard at the beginning of a project and carry that through to completion of the work, even if a newer version is released part way through the project. To adopt an updated guideline or standard during the course of a modelling project would be impractical and costly and could mean a modelling project would be in a constant state of updating with no settled output.

The site specific reviews of the SBO2 mapping in response to submissions resulted in the removal of several properties from the SBO2, and modifications to the extent of the mapping affecting other properties. On their face these reviews appear to have been thorough and done on a rational and consistent basis.

Catchment wide modelling will inevitably result in some localised inaccuracies in mapping, but this should not call into question the fundamental soundness of the modelling. An SBO creates a permit trigger to alert landowners and the responsibility authority to the potential for local flooding issues that should be addressed at the planning application stage. The Panel agrees with the findings made by the Yarra C210 Panel that small, localised inaccuracies are not significant and can be considered in more detail at the planning permit application stage.

The Panel concludes the modelling underpinning the SOB2 map is:

• based on accepted industry standards and practices, relevant guidelines and flood mapping principles
• fundamentally sound
• fit for purpose to determine the SBO2 mapping.

Adjust the mapping of the Special Building Overlay Schedule 2 to reflect the 'Day 1' version revised following the review of the mapping in response to submissions (part of Document 10).

• the impacts of climate change have been appropriately addressed in the modelling
• a history of lack of flooding at a particular location is a relevant factor in predicting future flooding risk, given the impacts of climate change.

Several submitters raised concerns with how climate change has been considered in the preparation of the SBO2 mapping.

Council submitted the modelling has appropriately factored in climate change considerations consistent with guidance in the Climate Change Act 2017 and in accordance with industry standards contained in the ARR Guidelines. It cited the Technical Report which states that:

The consideration of climate change has remained consistent between the work done in 2017 and 2023. The modelling is assuming Representative Concentration Pathway (RCP) 8.5, which assumes 3.5 degrees of warming by 2100. The modelling is simulating the assumed climate conditions in 2100. The hydrologic modelling has assumed an 18.5% increase in rainfall intensity because of the 3.5 degree warming in 2100. An 18.5% increase in rainfall intensity can translate to a greater increase in peak flow rates as rainfall intensity and the resulting overland flow peak flow rates are not linearly linked.

Council stated that Melbourne Water in its submission to the Amendment recognised that the SBO2 mapping effectively considered climate change impacts. Council submitted this is particularly notable with the recent release of Melbourne Water's publication How the Victorian Flood and Planning Frameworks consider flood and climate impacts for land use planning, Melbourne Water, 2024. Council added that the key settings outlined in Melbourne Water's publication (namely the 1 percent AEP event, rainfall intensity and planning horizon) were used for the preparation of the SBO2 map.

Finally, while Council emphatically submits that the need to consider and factor in climate change should be undeniable, it recognises that some submitters may feel that the risk to their individual properties is remote. The conclusion reached by the Banyule C101 Panel when considering the issue of 'Historical flood data and information', encapsulates the position that Council adopts in response to these submissions:

The Panel accepts as reasonable that some properties may have not been inundated during the most recent severe rain events, and this could be as a result of several variables (referred to in the preceding section of this report). However, because inundation has not been experienced previously does not necessarily mean that flooding cannot occur in the future, particularly in light of climate change predictions relating to more intense rain events. Where the modelling has validated that there is a probable risk of inundation the Panel considers it appropriate for ground truthing of the in situ built structures and mitigation features via review and consideration of circumstance when a development permit is being considered.

It is not an issue of whether a specific site has flooded previously, but the likelihood of it meeting the threshold flooding criteria in a 100 year AEP event.

In conclusion, Council submitted the consideration of climate change in the Technical Report, and by extension the Amendment, has been appropriate and suitably informs the proposed application of the SBO2.

Mr Ottrey's evidence was that the modelling applied an 18.5 percent increase in rainfall intensity to the 'intensity duration frequency' rainfall data obtained from the Bureau of Meteorology. He stated the modelling was completed generally in accordance with the ARR Guidelines version 4.1 which was current at the time the modelling commenced.

Mr Ottrey explained that the ARR Guidelines version 4.2 was released in mid 2024, with the main change being how the influence of climate change on rainfall is estimated. Methodologies in version 4.2 increase the amount of rainfall expected in 2100 under different climate change scenarios, based on four shared socioeconomic pathways (SSPs) (low, medium, high and very high expected increases in temperature by 2040, 2060 and 2100). Each SSP has rainfall intensity increase factors.

Mr Ottrey noted the Victorian Government has not made a clear directive on which SSP to assume for future flood protection, and nor has Melbourne Water given advice on which SSP should be adopted.

Mr Ottrey advised that the worst impact on most of the local drainage network was from overland flows in storms of durations of one hour or less. Regardless of which SSP is chosen, the expected increase in rainfall intensity by 2030 is 18 to 20 percent for storms of one hour or less. Mr Ottrey considered this increase to be generally equivalent to the climate change increase of 18.5 percent which was modelled. In effect, this means that under the updated ARR guidance, the modelling only captured the expected climate change impacts up to 2030, not to 2100.

Mr Ottrey explained that under the updated ARR guidance, for storms of 1 hour of less the increase in rainfall intensity by 2100 ranged from 22 percent under the low SSP scenario to 86 percent for the high scenario. The upper end of these rainfall intensity increases is therefore significantly higher than what has been modelled. He explained that if the updated climate change guidance was applied to the modelling, the impact would depend on which SSP was chosen:

• the lowest SSP would give results very similar to what the modelling shows
• the higher SSPs would give an increase in depths of flooding throughout the model and a corresponding increase in the extent and number of properties impacted.

Mr Ottrey concluded that while the modelling may not represent the full impact of climate change by 2100, the current modelling covers the properties that would be most significantly impacted under the higher SSP scenario, which means the properties at highest risk of flooding are being captured by the proposed SBO2. Mr Ottrey considered this to be appropriate from a risk management perspective.

The Panel is satisfied that the modelling has factored in the impacts of climate change based on the ARR Guidelines current at the time the modelling was commenced. The climate change scenarios in the ARR Guidelines version 4.2 mean the predicted impacts of climate change on the extent and severity of flooding by 2100 (and even the intervening years) is likely to be more widespread than what has been modelled. This is likely to mean that if the modelling were to be re-run based on the updated ARR Guidelines, more properties would be affected.

Mr Ottrey stated that the modelling is representative of 2030 conditions under the higher climate change scenarios outlined in the updated ARR Guidelines. He considered that if the model was re-run using the higher climate change scenarios in the updated ARR Guidelines to 2100, the most significant change would likely be that the flooding of the higher risk properties would be more severe, rather than a significant expansion to the SBO extent. He considered the SBO2 mapping therefore captures the properties most at risk of flooding in a 1 percent AEP storm event now and in the future, and is appropriate.

The Panel considers that the modelling and mapping will likely remain valid for some time beyond 2030, because it captures the most at risk properties even under the higher SSPs where climate change effects are predicted to be more severe. At some point in the future, revised modelling will need to be undertaken based on the advice of government on which SSP in version 4.2 of the ARR Guidelines should be adopted. While the SBO2 mapping may need to be updated in future, this does not invalidate the modelling or the SBO2 mapping done to date.

The Panel concludes climate change has been appropriately factored in to the modelling, noting:

• the modelling was based on the best guidance available at the time to account for the impacts of climate change
• the SBO2 covers the properties that would be most severely impacted by flooding in 2030 under a higher climate change scenario, which is appropriate from a risk management perspective.

The issue is whether the data used in the modelling reflects the topography across the municipality and specific properties with sufficient accuracy.

Mr Ottrey stated the topographic data used in the model was based on Light Detection and Ranging (LiDAR) captured in 2017 to 2018. His evidence was that the 2017 to 2018 LiDAR data is accurate to 100 millimetres vertically and ± 200 millimetres horizontally, with a root mean square error confidence of 68 percent. This level of accuracy means the data is suitable for use in flood modelling.

Mr Ottrey stated that the use of LiDAR is commonly accepted industry practice for two-dimensional flood modelling and it is not practical or necessary to use (generally more accurate) survey data to determine the topography information input into the model across the entire municipality. He added that some updates to the topographic data were made using design and as-constructed digital elevation models for major infrastructure projects (such as level crossing removals), and other minor adjustments were made to address localised inaccuracies in the LiDAR data.

Mr Ottrey explained that some submitters provided survey data of their properties, which were compared to the LiDAR levels. In most cases the surveyed levels were very close to the levels shown in the LiDAR. Where there was a larger difference, it was usually due to the presence of a vertical wall, such as a retaining wall, which LiDAR is not able to accurately represent.

Relying on Mr Ottrey's evidence, Council submitted the topographic data used in the modelling reflects accepted industry standards and provides a reliable basis for preparing the SBO2 map. It noted Engeny and Council officers did several site visits in response to submitter concerns, and in most cases on-site observations confirmed that the LiDAR data was generally an accurate reflection of on ground conditions.

Council noted the use of LiDAR data was considered by the Banyule C101 Panel which concluded reliance on LiDAR is a practical and cost effective method and "the accuracy of the (then) most current 2008 LiDAR data is regarded by the Victorian Government as sufficient to be applied to SBO mapping". The Banyule C101 Panel found that:

Whilst there may be variations between LiDAR and in situ levels, the relative extent of the predicted flood shapes and their location in relation to the building envelope are salient considerations. Minor landform structures such as garden landscape walls and fence plinths are not necessarily permanent.

The use of LiDAR is common practice and is the only practical and cost effective way to account for topography in catchment wide flood modelling. There are some limitations to the LiDAR data (such as the presence of vertical walls) but overall, the Panel is satisfied that the level of accuracy of the 2017 to 2018 LiDAR makes it suitable for modelling purposes.

The topographic data was corrected to match available as-constructed height data for major projects. Council and Engeny also responded to specific requests from submitters to review LiDAR levels against actual ground conditions and/or survey information, and adjustments were made where there were significant differences. There may be other locations where the LiDAR levels are inaccurate that were not drawn to the attention of Council or Engeny through submissions. The Panel accepts that undertaking extensive land surveys across the municipality for the purpose of validating the LiDAR data would not be justified.

As noted earlier, an SBO provides a permit trigger to alert landowners and the responsibility authority to the potential for local flooding issues that should be addressed at the planning application stage. The impact of localised inaccuracies on the potential for development of land within the SBO2 can be addressed at the permit application stage. Any small localised discrepancies in the LiDAR levels are not significant in terms of the accuracy of the municipal wide mapping.

• the LiDAR data used in the modelling is fit for purpose to reflect with a sufficient degree of accuracy the topography of the municipality and specific properties
• while there may be some variations between LiDAR and actual levels at some properties, these are likely to be marginal and can be accounted for at the permit application stage.

The issue is whether obstructions to overland water flows caused by fences and buildings (which were modelled using the 'roughness' approach) have been modelled appropriately.

Mr Ottrey explained that buildings have been represented in the model using a higher 'Mannings' roughness value based on estimated building footprints. This approach is common industry practice and is supported by Melbourne Water's Technical Specification and the ARR Guidelines. Mr Ottrey explained this allows for the flow of water through buildings being slower than over open ground such as a road or garden, but does not assume a building will completely obstruct overland flows.

Mr Ottrey explained there are multiple reasons why fences and buildings have not been modelled as obstructions to flows (using a 'block out' approach), including:

• fences are made from different materials, some of which will deflect or block flows while others (such as open mesh fences) will have little to no effect on flows
• fences and buildings often have openings
• fences cannot be relied on to provide flood protection to a dwelling
• there is little control over the removal or changes to fences and buildings
• building construction standards vary significantly including the type of foundations, the location of doors and windows and the potential for basements and underground car parks, all of which impact on the degree to which the building will block overland flows.

Mr Ottrey stated that the only instance where a wall was modelled using a 'block out' approach rather than a roughness approach was at the former Pentridge Prison, where a shallow flow path intersects with the external wall of the former prison. This is discussed in more detail in Chapter 4.4.

Mr Moret's evidence was that the building at 142 Dawson Street is likely to act as a physical obstruction to overland flow. He considered the approach of only applying a roughness value does not appropriately account for this obstruction. He stated that from a modelling input perspective, the land use and building two-dimensional roughness file may not accurately reflect the actual building footprint. He considered this, combined with the adopted grid resolution and sampling approach in the model, "may contribute to localised uncertainty in the modelled flow patterns and depths" across the site.

In presenting his evidence, Mr Moret accepted that the roughness approach was common practice for catchment wide flood modelling but considered there may be instances where it is appropriate to apply the block out approach.

In responding to the issues raised by Mr Moret, Mr Ottrey noted the roughness approach followed the guidance set out by Melbourne Water in its Technical Specification Flood Mapping Project Specifications (July 2020). He noted the Technical Specification allows for both roughness (a Mannings coefficient) and building obstruction (block out) modelling of buildings. He quoted the Melbourne Water modelling guidelines which state that issues around the modelling of buildings are primarily related to scale, and Melbourne Water normally adopts the roughness approach.

Mr Ottrey also referred to a paper by Smith and Wasko (2012)[2] which used a physical scale model of an overland flow path through a housing development and drew the conclusion that representing buildings as block outs provided more accurate flood levels compared to roughness when using two-dimensional modelling such as TUFLOW.

However, Mr Ottrey noted that a key qualifier to this conclusion was that the grid size of the model must be small enough to accurately represent flow paths between buildings. Smith and Wasko reported that this was up to a 2 by 2 metre grid. The municipal wide modelling used a 3 by 3 metre grid, consistent with the Melbourne Water Technical Specification and standard industry practice. Mr Ottrey's evidence was that anything smaller than a 3 by 3 metre grid was not practical due to the impacts on model run times.

Relying on Mr Ottrey's evidence, Council submitted that the roughness approach is the appropriate way to model the obstructions caused by fences and buildings.

The Panel is satisfied that the roughness approach to account for the flow obstructions caused by buildings and fences is appropriate for catchment wide modelling. Both experts agreed that the roughness approach for catchment wide modelling is consistent with industry practice. This approach is also consistent with Melbourne Water guidelines and the Technical Specification.

While the Smith and Wasko research supports the case for using the block out approach when grid sizes smaller than a 3 by 3 metre grid can be applied, a smaller grid size for this municipal wide project would not be practical.

The Panel accepts that there may be instances where the block out approach would be more accurate in modelling the impact of buildings and fences at a localised level. Mr Moret suggested that 142 Dawson Street may be one such case. The block out approach could be applied to this site at the permit application stage to determine flood levels for the purposes of building design for any redevelopment of the site.

However, there is no evidence before the Panel to suggest that applying the block out approach to account for the flow impacts of all substantial buildings and fences across the entire municipality is justified, or would result in more accurate flood mapping when modelling at a catchment level.

• the impact of fences and buildings on overland flows has been modelled appropriately.

The issues are whether the following properties should be included in the SBO2:

• 24 Post Office Place, Glenroy
• 39A Everard Street, Glenroy
• 1 Champ Street, Coburg
• 142 Dawson Street, Brunswick West
• 41 and 41A Lytton Street, Fawkner.

These are the properties of the parties to the Hearing (including those who did not appear), who presented site specific information to the Panel that allowed an assessment of whether the outcome of the modelling for those sites were sufficiently robust and accurate to justify the retention of the SBO2. For other sites, the Panel had no information before it to suggest the modelling was inaccurate and the SBO2 should not be applied.

Submitter 21 objected to 24 Post Office Place Glenroy being included in the SBO2 on the basis that:[3]

• the mapping does not reflect the topography of the land and the existing drainage infrastructure
• footpath and roadway levels would direct overland flows from the north, down Pascoe Vale Road away from Post Office Place
• no detailed feature and level survey has been undertaken to find the true relative levels of the building entries
• there have been no issues with stormwater flow on the property in the past.

• the responsibilities of developers to reduce stormwater runoff upstream
• what intervention measures are being undertaken by Council to mitigate flooding that may occur due to future development.

These last two points are not relevant to the question of whether the Amendment should be supported, for the reasons set out in Chapter 1.4.

Engeny undertook a site visit and reviewed the site's inclusion in the SBO2 in response to Submission 21. Mr Ottrey's evidence described the outcomes of the site visit and review:

• The modelling shows water levels in a 1 percent AEP event with climate change of up to 94.34 metres Australian Height Datum (AHD) at the north western corner of the property and 94.18 metres AHD at the south western corner of the property.
• These modelled flood levels are both higher than the building entry levels at the respective points.
• Some changes had occurred in the vicinity of the property since the LiDAR data used in the modelling was captured:
  • - footpaths had been replaced but the design intent was to match the existing footpath levels
  • - a raised crossing has been constructed across Post Office Place at the intersection with Pascoe Vale Road.
• The raised crossing will likely reduce the ability of overland flows to enter Post Office Place which may slightly increase water levels within Pascoe Vale Road and impacting on 24 Post Office Place, but this is not expected to be a significant change.

Mr Ottrey considered there is no justification to amend the SBO2 mapping in respect of the property at 24 Post Office Place, Glenroy based on site specific conditions.

The Panel accepts that Engeny undertook a sufficiently robust investigation of the site specific conditions, and is satisfied based on those investigations that the site specific conditions are sufficiently close to the modelled inputs to make the model reasonably accurate in terms of the potential for the property to be inundated in the 1 percent AEP event.

As noted above, no past flooding is not a reasonable basis on which to remove a property from the modelled flood extent where that modelled extent is found to be reasonably accurate based on reasonably accurate inputs.

• There is no justification for removing 24 Post Office Place Glenroy from the SBO2.

Submitter 24 objected to 39A Everard Street Glenroy being included in the SBO2 on the basis that:

• the conditions on the property minimise the need for the SBO2
• nearby development and landscaping is to blame for flooding impacts
• Council should be maintaining its drainage infrastructure to avoid flooding impacts from overland flows
• the application of the SBO2 will increase insurance costs and limit development opportunities
• the modelling and mapping represents one means of assessing floodwater impacts and is "not a method of management in mitigation".

The further submission from the owners of 39A Everard Street (D26) makes mention of being denied permission for a garage on their boundary. It is not clear on what basis permission was denied, and in any event this is not a matter before the Panel.

Engeny undertook a site visit and reviewed the site's inclusion in the SBO2 in response to the site specific concern raised in Submission 24. Mr Ottrey's evidence described the outcomes of the site visit and review:

• on ground flow depths may differ slightly from modelled depths, which could impact on flow depths within a very localised area
• the resident confirmed a history of water inundating the property and had taken proactive steps to help minimise the damage to their property because of the past inundation events
• the allowance of open flow paths around the dwelling (east side and west side) will help to allow water to flow through the property and minimise the risk of above-floor level flooding, but the property is still likely to be inundated in a 1 percent AEP event.

Based on the above, the Panel does not consider there is any justification for removing 39A Everard Street from the SBO2 extent based on site specific conditions. Any future permit application for development on 39A Everard Street Glenroy will need to respond to the identified flood risk. Site specific conditions and how they influence overland flows will be further assessed at the permit application stage in the context of the proposed development.

The other issues raised by Submitter 24 are not relevant for the reasons set out in Chapter 1.4.

• There is no justification for removing 39A Everard Street Glenroy from the SBO2.

Submitter 28 objected to 1 Champ Street Coburg being included in the SBO2 on the basis that the site accommodates existing development associated with the former Pentridge Prison, including significant bluestone walls that exist in the north-west corner of the site, that protect the land within the walls from overland flows.

Engeny undertook a site visit and reviewed the site's inclusion in the SBO2 in response to the site specific concern raised in Submission 28. Mr Ottrey's evidence explained that a structural engineering report was provided that confirms that the wall can resist the expected flows in the 1 percent AEP storm event (which the modelling predicts to be less than 300 millimetres). It also provides details on the long term maintenance requirements of the wall to continue resisting flows. On that basis, Engeny recommended removing the SBO from the area inside the bluestone wall.

Council supported removing properties within the bluestone wall from the SBO2 on the basis that:

• the wall is an effective barrier to the flow of water due to its size and construction
• the wall is heritage listed and is highly unlikely to be removed
• the owner has signed a statutory declaration that states they will not remove the wall while they are the owners of the property.

The Panel agrees, and supports the proposed change (reflected in the Day 1 SBO2 map) to remove 1 Champ Street Coburg from the SBO2.

Builtmore objected to 142 Dawson Street Brunswick West being included in the SBO2 on the basis that:

• there has been no previous issues with flooding on the site
• the site conditions, including the existing structures and drains on the site, already manage stormwater risk
• the proposed SBO appears to rely on broad modelling rather than site-specific hydrological evidence
• the modelling relied on LiDAR data rather than site specific survey information which is more accurate than the LiDAR data
• there is no evidence that Council has exhausted alternatives such as public land mitigation before deciding to apply the SBO2 over private property
• the application of the SBO2 places unjustified constraints on the future development of the site
• the SBO2 will restrict the future use and development of the land.

Builtmore presented evidence from Mr Moret in support of the removal of the SBO2 from the site. He highlighted site specific conditions which had not been factored into the model and which he considered called into question the suitability of the application of the SBO2:

• the impact of the existing building on overland flows across the site
• potential localised smoothing of topographic detail in the LiDAR data
• the impact of the grated pits within the carpark area on overland flows across the site
• a proposed wetland project to be developed in the park to the north of the property, which he said may retard or retain stormwater that would otherwise divert to 142 Dawson Street.

Mr Moret did not contest the fact that overland stormwater flows will enter the site during the 1 percent AEP event. Rather, he considered the site conditions would influence the movement of stormwater through the site.

Engeny undertook a site visit and reviewed the site's inclusion in the SBO2 in response to the site specific concern raised in Submission 42. Mr Ottrey's evidence indicated that the LiDAR data used to represent the ground levels at the site in the model appears to be a good match to what was observed on and immediately surrounding the site, including the levels of the park to the rear of the site.

Mr Ottrey responded to Mr Moret's evidence in detail in D35. His responses to the modelling issues raised by Mr Moret are discussed in Chapter 3. This includes the 'block out' and 'roughness' approaches to representing buildings in the modelling (discussed in more detail in Chapter 3.1). On the site specific issues raised by Mr Moret, Mr Ottrey responded:

• The modelling shows that an overland flow of water reaches the northern edge of 142 Dawson Street which places it at risk of inundation. Without a physical barrier, overland flow will enter the site.
• While the existing building on the site is a physical barrier across the northern boundary, it is not designed and may not be maintained as a physical barrier to overland flows.
• It is likely overland flows will enter onto the site from the east and west boundaries, and could enter the site from the south, resulting in inundation of at least part of the site notwithstanding the existing building.
• The pits are most likely private drainage assets which are used to drain rainfall from the site. No private drainage assets are included in the model, because:
  • - Council does not have accurate records of where all private pits, pipes and drains are located
  • - Council is not responsible for maintaining these drains
  • - they are generally designed to drain runoff from the site to the legal point of discharge, not to manage additional flows onto the site
  • - the Council drains that these pits and pipes would connect to would be full in the 1 percent AEP event (inclusive of climate change), so there is no additional capacity available for the private drains to discharge to.

On this basis, Mr Ottrey did not consider any changes to the SBO2 in relation to 142 Dawson Street are appropriate.

• no evidence has been provided by Mr Moret that the current building is 'flood proof' or will prevent flows in a future 1 percent AEP scenario
• the on-site grates to drain the rear carpark will do little to alleviate the effects of stormwater flooding in a 1 percent AEP event
• the topographical issues highlighted by Mr Moret about potential localised 'smoothing' will not change the outcome that overland stormwater will enter the site during the 1 percent AEP event
• the proposed wetland in the park to the north is not being designed as a retention or retarding basin for stormwater, and in any event there is no certainty about whether or when the wetland project will go ahead.

The Panel is not persuaded that there is any justification for removing the SBO2 from 142 Dawson Street based on site specific conditions. The remaining issues raised by Builtmore are not relevant considerations for the Amendment, for the reasons set out in Chapter 1.4.

• There is no justification for removing 142 Dawson Street Brunswick West from the SBO2.

Submitter 90 objected to 41 and 41A Lytton Street Fawkner being included in the SBO2 on the basis that:

• drainage works had been undertaken on the site in 2022 and 2023
• extensive upgrades had occurred in recent years to the drains in Lytton Street and surrounding streets
• the poor condition of Council's drainage infrastructure is the main contributor to stormwater issues.

Engeny undertook a site visit and reviewed the site's inclusion in the SBO2 in response to the site specific concern raised in Submission 90. Mr Ottrey's evidence described the outcomes of the site visit and review:

• The LiDAR shows that the low point in Lytton Street in front of the site is approximately 300 millimetres below the footpath level, which matches what was observed on-site.
• The LiDAR shows a gradual fall from the corner of William Street and Lytton Street back to the site within the road pavement area (levels range from 92.8 metres AHD to 92.0 metres AHD over a distance of approximately 200 metres).
• The modelling shows that shallow sheet flow from the low point in Clovelly Avenue will reach Lytton Street in a 1 percent AEP event including climate change.
• This flow path is not included in the map as it does not meet the inclusion criteria (being too shallow), however it is still a source of runoff contributing to the water levels in the low point in Lytton Street in a 1 percent AEP event.
• The model shows that in a 1 percent AEP event, runoff will pond in Lytton Street once the capacity of the underground drainage is exceeded and the water level will build up until the footpath is overtopped, resulting in inundation of the site (and other properties in Lytton Street).

On this basis, Mr Ottrey did not consider any changes to the SBO2 in relation to 41 and 41A Lytton Street Fawkner are appropriate. Council agreed, and so does the Panel, noting that the various levels and overland flow behaviours in Lytton Street appear to have been extensively investigated and modelled by Engeny, and nothing observed on site by Engeny suggested the model is likely to be inaccurate.

• There is no justification for removing 41 and 41A Lytton Street Fawkner from the SBO2.

Request for Panel Direction on hydrological modelling

Response to Panel Direction on hydrological modelling:

• - Covering letter
• - Memo from Engeny on calibration and validation data
• - Attachment to Engeny memo: Historic flooding presentation

Municipality map with submitter locations [CONFIDENTIAL]

Municipality map showing extent of Special Building Overlay mapping

Individual grid maps showing extent of the Special Building Overlay and submitter locations [CONFIDENTIAL]

• - Attachment 1 - Email from Mr Moret to Mr Farah requesting further data

Email to Panel - request for clarification on scope for Glenn Ottrey evidence presentation

Expert Evidence statement of Glenn Ottrey (drainage engineering)

Response to Builtmore Investments request for extension to submit evidence

Letter to Panel - procedural fairness and expert evidence

Response to Builtmore Investments request for extension to submit evidence and Distribution List version 3

• - Attachment 1 - Email from Mr Moret to Mr Farah requesting further data (note: same as Document 13 and 13a)

Email to Panel - Support for Builtmore Investments request for extension to submit evidence

Letter to Panel - Information requests and proposal for Hearing dates

Email to Panel - Information requested from Council

Response to alternative Hearing dates proposed by Council

• - Attachment 1 - Response from Council dated 16 July 2024
• - Attachment 2 - Post Office Place photos
• - Attachment 3 - Response to submission from Council dated 17 June 2024

Expert Evidence statement of David Moret (hydraulics engineering)

Memorandum from Engeny - Model versions for Merri-bek SBO

Drainage Asset Management Plan 2020 (Moreland City Council)

• - Appendix 1 - Melbourne Water letter to Council's CEO 8 May 2025
• - Appendix 2 - Email from Melbourne Water dated 29 May 2025
• - Appendix 3 - Drainage infrastructure requests - Summary table
• - Appendix 4 - Drainage maintenance requests - Summary table
• - Appendix 5 - Banyule C6 Panel Report
• - Appendix 6 - Banyule C101 Panel Report
• - Appendix 7 - Bayside C153 Panel Report
• - Appendix 8 - Melbourne C384melb Panel Report
• - Appendix 9 - Moreland C50 Panel Report
• - Appendix 10 - Port Phillip C111 Panel Report
• - Appendix 11 - Yarra C210 Panel Report

Memorandum from Engeny - Response to evidence from David Moret of DPM Consulting Group and written submissions to the Panel

PowerPoint presentation from Glenn Ottrey (drainage engineering)

• - Map of Glenroy area showing flood modelling
• - Image of Glenroy NE
• - Image of Glenroy NW
• - Image of Glenroy SE
• - Image of Glenroy SW

Email to Panel - Updates to presentation from Glenn Ottrey (drainage engineering)

Updated PowerPoint presentation from Glenn Ottrey (drainage engineering)

PowerPoint presentation from David Moret (hydraulics engineering)

[1] The Day 1 SBO2 map is attached to a memo prepared by Engeny which explains the process and outcomes of the reviews in response to submissions. It is part of D10.

[2] Representations of buildings in two-dimensional numerical flood models. Australian Rainfall and Runoff Revision Project, Engineers Australia (2012)

[3] Submitter 21's concerns are outlined in her original submission (S21) and a further written submission to the Panel (D25)