1. The Applicant filed in the proceeding a letter dated 30 November 2023 from the Interested Party which states:

Flooding may be associated with the Melbourne Water regional drainage system and/or the local Council drainage systems. Information available at Melbourne Water indicates that the property is not subject to flooding from Melbourne Water's drainage system, based on a rainfall event which has a 1% Annual Exceedance Probability (AEP), that is, a 1% probability of being equalled or exceeded in any one year. To determine if a property is subject to flooding from the local Council drainage system you will need to contact the relevant Council for flood information.

For the purposes of the Building Code of Australia - Building in Flood Hazard Areas, there is no applicable flow rate velocity associated with the above property. Melbourne Water does not have any information in relation to flow velocities associated with the local Council drainage system.

The Victorian Marine and Coastal Policy 2020 identifies the need to plan for sea level rise of not less than 0.8 metres by 2100 when assessing risks and impacts associated with climate change. Melbourne Water, as the relevant floodplain management authority has identified that this property may be affected by increases to the mean sea level of Port Phillip Bay / Western Port.

1. The Applicant also filed in the proceeding another letter dated 8 February 2024 from the Interested Party which states:

The Victorian Marine and Coastal Policy 2020 identifies the need to plan for sea level rise of not less than 0.8 metres by 2100 when assessing risks and impacts associated with climate change. Melbourne Water, as the relevant floodplain management authority has identified that this property may be affected by increases to the mean sea level of Port Phillip Bay / Western Port.

1. A further letter dated 21 May 2024 from the Respondent was tendered by the Applicant which states:

Melbourne Water notes that the land is not covered by either a Land Subject to Inundation Overlay (LSIO) or a Special Building Overlay (SBO) therefore, Melbourne Water does not consider that it is a Determining Referral Authority for this development.

Melbourne Water has reviewed the proposal and advises that pursuant to Section 52 of the Planning and Environment Act 1987, the following recommendations are applicable:

1. It is recommended that the finished floor level for the extension is set no lower than 600mm above the applicable flood level of 2.4m AHD.

The above requirement is in accordance with "Table 5: Floor level requirements for dwelling extensions with existing floor levels below the 1% AEP flood level" of the adopted 'Guidelines for Development in Flood Affected Areas' (DELWP).

The current proposal is not supported by Melbourne Water as it is proposed with finished floor levels below the applicable flood level of 2.4m AHD, resulting in the new floor space being susceptible to flood damage. At a minimum, any new ground floor extension with an area greater than 20m2 should be raised up to the flood level.

1. A further letter dated 19 March 2025 from the Respondent was filed in the proceeding by the Applicant which provides the following:

Pursuant to Regulation 153(6)(a) of the Building Regulations 2018 Melbourne Water advises:

• The applicable 1% Annual Exceedance Probability (AEP) flood level for the property is 2.4 metres to Australian Height Datum (AHD).
• It is recommended that the finished floor level for the proposed extension is set no lower than 600mm above the applicable flood level of 2.4 metres to AHD.
• The submitted plans do not comply with the above recommendations.
• Pursuant to Regulation 153(6)(b), Melbourne Water does not consent to the finished floor level being set less than 300mm above the applicable flood level.

This property is subject to flooding as a result of coastal inundation associated with predicted mean sea level rise by the 2100 due to climate change. The applicable 1% Annual Exceedance Probability (AEP) flood level for the property, being the 1% probability in any one calendar year, is 2.4 metres to Australian Height Datum (AHD). Accordingly, the applicable Nominal Flood Protection level (NFPL) for the site is 3.0 metres AHD which includes a 600 mm freeboard.

1. The Applicant relies on expert opinion of Ms Tsioulos, a Senior Flood Risk Management Engineer - HARC (HARC Report) who provided the following opinion:

This overlay does not have any specific requirements; however, it indicates that an application will be considered by the City of Port Phillip as the responsibility for local drains. There are no Melbourne Water regional drains or waterways.

Melbourne Water have previously adopted 1.6m AHD as the 1% AEP storm surge flood level. This has been revised to 2.4m AHD with the adoption of a 0.8m sea level rise applicable by 2100. The Port Phillip Bay (PPB) Coastal Hazard Assessment (CSIRO 2022). indicates that the levels adopted by Melbourne Water are likely higher than the most likely 0.8m sea level rise levels in PPB. For all future scenarios investigated in the PPB Coastal Hazard Assessment, the 1% AEP flood level will not exceed 1.86m AHD (the current floor level of the dwelling) until beyond 2070 as shown below in Figure 7-5. There have been a number of modelled future climate change scenarios all have inherent

levels of uncertainty not only in the climate scenarios but also how those scenarios are translated into flood models and flood levels.

Melbourne Water have indicated that the property is subject to flooding as a result of coastal inundation associated with predicted mean sea level rise by 2100 due to climate change. The applicable 1% AEP flood level for the property is 2.4m AHD and the applicable NFPL for the site is 3.0 metres AHD which includes a 600mm freeboard. The future coastal inundation will occur due to overtopping of the shoreline and coastal sea walls and potential backflooding through local drainage systems. Figure 7-6 shows the future 1% AEP storm tide inundation extents from Port Phillip Bay as it affects the subject site in 2070 and 2100 (CoastKit access May 2025).

Spot level survey data in Figure 7-8 below indicates that the topography of the site at the location of the building envelope grades from around 1.40m AHD at the south-western corner of the property (Page St frontage) up to 1.73m AHD the rear of the property. The finished floor level of the existing property is 1.86m AHD and with no existing garage, however rear land access is available to the property.

Melbourne Water have advised that the property is not subject to flooding from regional stormwater drainage or waterway assets and that there is no current applicable flood. As such, there is no current flood risk under existing and developed conditions. The future 2100 1% storm tide flood level of 2.4m AHD (based on the state dataset and as advised by Melbourne Water), will see the potential for flood depths of between 0.6-0.98. This is considered a low-moderate hazard for adults. The Safety Criteria in Figure 7-9 below from AR&R 2019 illustrates the level of hazard associated with the depth and velocity of floodwaters. The velocities associated with both coastal flooding and overland flow in this area would be close to zero.

I have considered the post development flood risk, taking into consideration the existing development, the current flood conditions, the future development conditions and the future flood conditions.

Under existing conditions, the site is not considered to be subject to flooding. The future flooding associated with both the underground drainage and storm surge is considered low-moderate hazard, due to its low velocity x depth product as per the AR&R 2019 Safety Criteria and would be low hazard inside the building. The flood hazard does not change or increase as a result of the proposed development under the 1% AEP under 2100 future flood conditions.

The existing dwelling has three (3) bedrooms, a living room, dining room and kitchen - which is a total of six (6) habitable rooms on the ground floor plus non-habitable rooms of the bathroom, toilet and laundry.

The proposed development has two (2) bedrooms, an office, a living and dining room and a kitchen on the ground floor- which is also a total of six (6) habitable rooms on the ground floor plus a laundry, bathroom and ensuite. There are two (2) habitable rooms located on the first floor above the flood level. There is no change in the number of habitable rooms on the ground floor below flood level.

However, of note, is the reduction in the number of bedrooms located below flood level. Bedrooms are typically considered to be a greater risk than other habitable rooms because they are passive areas in which residents sleep and rest.

It is also important to note, that simply having a first floor in which residents can seek shelter and safe refuge until flood conditions recede is a better outcome than having no means to seek safe ground. I am of the opinion that overall, the proposed development sees a reduction in flood risk to life, health

and safety, as the upstairs area provides a flood free refuge.

It is proposed to maintain the floor level of the ground floor and extension at the current level of 1.86m AHD. Buildings covered by Heritage Overlays face significant constraints in elevating floor levels to minimise the potential for flood damages.

When we then consider the consequences, factoring in:

▪ That under the 2100 sea level rise conditions the flood hazard (safety) of the floor level is be considered low for adults,

▪ The maximum flood level would only last for a few hours before receding,

▪ There would be very little velocity or wave action due to the type of inundation and the location of the property,

▪ The dwelling has a first floor that also acts as an additional refuge,

then the consequences of a 1% AEP storm tide event in 2100 would be categorised as minor (on the basis that the flood hazard is minor inside the building and water damage would be minor). This risk associated with this development an overall rating of LOW in relation to flood damages and life, health and safety.

'Developers may need to comply with other legislation, where there are potential impacts on environmental, cultural and landscape values.'

This would include Heritage protection requirements. In the Introduction of the DELWP Guidelines, when discussing the purpose of the guidelines to 'provide a clear, consistent and transparent process for managing land use and development in flood affected areas', it also says, ' the guidelines cannot cover all the circumstances and aspects of flood behaviour' and that 'Floodplain managers have discretion to vary from the guidelines, considering local circumstances, the nature of the development

Council has obligations to adhere to both flooding, amenity and heritage policy needs. It therefore becomes incumbent on authorities such as Melbourne Water to determine if the flood risk on a property and its intended development is deemed tolerable. In assessing this risk, Melbourne Water consider the DELWP Guidelines but also have the power to apply discretion.

The have been two cases similar to this appeal to the Building Appeals Board in the last 12 months in relation to a refusal under Building Regulation 153 for development in land liable to flooding; Tsandefskis V Port Phillip City Council BAB No.455823 and Syme V Port Phillip City Council BAB No.455966.

In both cases, the Board acknowledged that Sub-regulation 153(4) of the Regulations states that the Council 'must not' grant consent if it is of the opinion that there is 'likely to be a danger to the life, health or safety of the occupants of the building due to flooding of the site'. The corollary of this sub-regulation is that Council may grant consent if it is not of the opinion that there is likely to be a danger to the life, health or safety of the building's occupants due to flooding. In both cases, there was not deemed to be a likely danger to life, health and safety.

Although no evidence was presented in relation to the likely service life of the proposed dwelling in Syme V City of Port Phillip were presented in evidence, the Board noted the general context that houses of around 50 years old are typically at the end of their service life and that it is possible that in 76 years (2100) the proposed dwelling may no longer be in service in its designed form or at all.

This site has a low-moderate flood hazard classification for adults under future 2100 coastal inundation conditions due to the low velocities of floodwater at the site.

The future flooding inside the dwelling is low flood hazard for children classification as per the AIDR 2017 and AR&R 2019 Safety Criteria.

The provision of a second storey provides a place of safe refuge in times of flood.

The proposed development at the site reduces the current risk to life, health and safety by reducing the number of bedrooms on the ground floor below flood level and sees no change in the

overall number of habitable rooms on the ground floor.

The proposed development does not alter or change the flood hazard on the subject land. It does not increase flood levels, change flood behaviour, duration or velocities.[2]

1. The Applicant contends that there is no evidence to dispute the matters set out in the report provided by Ms Tsioulos.
2. During the hearing the Applicant submitted that the declaration of flood levels is prescribed by s 203 of the Water Act and contends that the Interested Party has accepted the flood level has not been declared. Although the Applicant accepts that the Water Act provides a specific process for determining flood levels, it could not be the intention of the legislature to refer to a broad power when referencing flood levels.
3. The Applicants also made the following submissions in response to the Interested Party's submissions on the application of the regulation:

(a) The flood level is defined in the Water Act. There is no other definition for it.

(b) Reg 153(5) of the Regulations uses the term 'may' rather than 'must'. Pursuant to s 45(1) of the Interpretation of Legislation Act 1984 (ILA) where a statute uses the word 'may' the power may be exercised or not with discretion.

(c) In relation to reg 153(6)(b) of the Regulations regarding the 300mm above the flood level or otherwise determined, there is no alternative mechanism for the declaration of a flood level. The phrase 'otherwise determined' should be read as a reference to the 300mm in the first part of the sentence rather than providing a determination of a flood level. There is discretion in relation to 300mm rather than an alternative mechanism to determine a flood level. There is a definition of a flood level and it cannot be altered by 'otherwise determined by' in a manner that allows for a secondary mechanism.

1. The Council provided the following submissions:

(a) The planning permit did not regulate the finished floor level of the building and so the exemption to obtain report and consent under reg 153(3) of the Regulations does not apply.

(b) There was no evidence that the construction would not be a danger to life, health or safety of the occupants of the building due to flooding at the site.

(c) Under reg 153(4) of the Regulations the Council cannot give consent if it forms the opinion there is likely to be a danger to life, health or safety of the occupants of the building due to flooding at the site.

(d) Whilst the Respondent has not done its own flood modelling, as Melbourne Water is the relevant floodplain manager with a flood management function and flood modelling expertise, the Council submits it is reasonable to rely upon the advice of Melbourne Water. The Council, it contends is not in a position to technically depart from the flood modelling advice of Melbourne Water and considers it is reasonable and appropriate to rely upon Melbourne Water's expertise.

(e) Although the Council may consider report and consent under reg 153 of the Regulations without consulting with Melbourne Water in circumstances where the Council does not set a minimum floor level in its report under sub-reg (2), it considers given Melbourne Water's floodplain management functions and expertise it is prudent for the Council to consult with Melbourne Water in relation to all applications under reg 153.

(f) As Melbourne Water had advised that the declared flood level for the site was 2.4m AHD, reg 153(6)(b) required that the Council must specify in its consent a level at least 300mm above any flood level declared for the site.

(g) The ground floor level of the dwelling on the drawings submitted as part of the application is nominated to be constructed at 1.86m AHD, which is 540mm lower than the applicable flood level for the property.

(h) The floor level of the proposed building work is 840mm below the level that the Council could consent to without the consent of Melbourne Water under reg 153(6)(b).

1. In response to questioning at the hearing, the Council confirmed that it did not form a view whether there was a danger posed to occupants.

1. The Interested Party provided the following submissions:

(a) The Interested Party reviewed the planning permit application and confirmed that it did not support it. The Interested Party recommended that the finished floor level for the extension is set no lower than 600mm above the applicable flood level of 2.4mAHD.

(b) That is, in its letter of 19 March 2025, Melbourne Water notified the Council that the flood level for the Subject Property was 2.4 metres to AHD and that Melbourne Water did not consent to the finished floor level of the proposed works being set to less than 2.7 meters to AHD, being 300mm above the flood level.

(c) The term 'area liable to flooding' is only used in sub-reg 5(1) in the definition of 'special designated area'. That term is not used in reg 153(2). However, Melbourne Water contends that the definition of 'area liable to flooding' set out in reg 153(2) should, in the absence of any other definition of that term in the Regulations or the Building Act, apply to the use of that term in reg 153(2).

(d) Melbourne Water says that the Subject Land is liable to flooding for the purpose of reg 153(2) because the Subject Land was determined, by or under the Water Act, that it was liable to flooding (see regulation 5(2)(a) above). Importantly, regulation 5(2)(a) does not require that the 'determination' be given in any particular terms. It is only necessary that the Subject Land be determined, by or under the operation of the Water Act, to be liable to flooding, however expressed.

(e) The Interested Party relies on sections 201-205 of the Water Act.

(f) The Interested Party acknowledges that the flood level for the Subject Land is not published in the Government Gazette.

(g) The Interested Party's functions under the Water Act include finding out how far floodwaters are likely to extend and how high they are likely to rise, declaring flood levels, to develop and implement plans and to take any action necessary to minimise flooding and flood damage, to control developments that have occurred or that may be proposed for land adjoining waterways, and to provide advice about flooding and controls on development to local councils. Those functions are broad. Notwithstanding that the declaration of a flood level is required to follow the process in section 203(2) of the Water Act, that same requirement does not apply to the other functions exercised by Melbourne Water or to the 'determination' of a flood level in broader terms. Melbourne Water contends that the general power to determine a flood level is not the same as the exercise of the power to formally declare a flood level under the Water Act, to which very specific processes and consequences apply.

(h) The existence of a right to 'determine' a flood level from time to time is consistent with the practical discharge of Melbourne Water's functions.

(i) Melbourne Water contends that this is necessary to enable it to effectively minimise flooding and flood damage in circumstances where it has not formally declared the flood level for a building or site. That is, to protect individuals and property, and to inform councils as a means to do so is an extension of the function under section 202(2)(f) of the Water Act. Melbourne Water contends this is consistent with the deliberate broad wording of regulation 5(2)(a), in conjunction with the broad determination wording in regulation 153(6).

(j) Accordingly, in its letter to Council dated 19 March 2025, Melbourne Water determined that the flood level for the Subject Land is 2.4 metres AHD.

(k) The Board must refuse the application if the Board concludes that, if the proposed works are constructed, there is likely to be a danger to the life, health or safety of the occupants (regulation 153(4))

(l) The Board, if it was minded to grant consent, should, in Melbourne Water's view, specify a level for the surface of the lowest floor of a building on the site for the purpose of regulation 153(5). Where a lot is within an area liable to flooding and therefore consent is required from the relevant council prior to obtaining a building permit, it follows that any consent should set the minimum floor level. In Melbourne Water's view, the use of the word 'may' in regulation 153(5) does not give the relevant Council or the Board the power to decline to set a minimum floor level where consent is granted - rather it leaves open the possibility that the application for report and consent will be refused, therefore removing the need to set a minimum floor level at all.

(m) The Interested Party considers that the BAB should specify a floor level of 2.7mAHD. Melbourne Water does not contend that a flood level has been declared for the Subject Site under the formal process for flood level declaration under the Water Act. However, such a formal declaration of a flood level is unnecessary for the purpose of regulation 153(6)(b). That regulation expressly confirms that a flood level can be 'otherwise determined'. That is, determined by Melbourne Water in a manner other than under the formal process under the Water Act. In this case, 2.4mAHD with 300mm freeboard added this comes to 2.7mAHD.

(n) The Interested Party has relied on the High Court decision in Frugtniet v ASIC as a principle that the BAB stands in the shoes of the primary decision maker and is subject to the same constraints unless the contrary legislative intent is expressed.

(o) The Interested Party acknowledges its prior advice changed over time and notes they were correct based on information at the time. While the certificates may help an applicant for a planning permit or building permit plan their development, it does not constitute any authority for a proposed development and that is indeed specifically disclaimed in the certificates themselves. In addition, the certificates provided to the Applicants do not constitute 'consultation' between Council and Melbourne Water for the purpose of reg 153 of the Building Regulations.

(p) The flood level of 2.4 metres has not been gazetted. Section 203(1) of the Water Act provides that an Authority may declare a flood level in relation to a specified area, and if it chooses to do so, must publish that declaration in the Gazette. There is no obligation for Melbourne Water to determine a flood level (being the power referred to in regulation 153(6)) in this way.

(q) Any absence of a publication in the Gazette as to a declaration does not of itself invalidate a determination. Notwithstanding the procedures specified for making a declaration under section 203 of the Water Act, the absence of a notice published in the Gazette does not affect the validity, operation or effect of an instrument. The Water Act does not specify that a declaration under section 203 is contingent on, or takes effect on, the publication of the declaration in the Gazette. This can be contrasted with section 205 of the Water Act which specifies that the declaration of an area liable to flooding made by the Minister is so declared by Order in the Gazette.

(r) While section 205 of the Water Act makes provision for areas of land liable to flooding, as declared by an Order of the Minister published in the Gazette, the Building Regulations are not confined to declarations made under section 205 of the Water Act.

(s) Regulation 5(2) of the Regulations provides a number of ways in which land is, for the purposes of the Regulations, in an area liable to flooding (and accordingly, land to which regulation 153 applies). It relevantly includes an area which is determined as being liable to flooding under the Water Act, however expressed.

(t) The Regulations do not confine regulation 5(2)(a) to land which is declared by the Minister under s 205 of the Water Act. If it was Parliament's intention to limit the application of the Building Regulations in that way, it could have done so.

(u) The Interested Party's powers under s 202(2) of the Water Act are broad.

(v) The Interested Party also considers that the BAB cannot look behind the floor levels and adequacy of the Interested Party's water flood mapping methodology. Further, that the expert report cannot be considered under reg 153(6) of the Regulations.

1. During the hearing, the Interested Party noted there was no dispute that the allotment was in an area liable to flooding. Further that there was no declared flood level - rather the Interested Party relied on the phrasing 'otherwise determined' contained in reg 153 of the Regulations.
2. Further, the use of the wording 'recommend' rather than determine in the prior letters should not be given too much weight as those prior letters were not provided under reg 153 of the Regulations.
3. The Interested Party further states that the prior BAB cases relied on by the Applicants were in error as they stopped at reg 153(4) of the Regulations and were required to go further.
4. The words 'otherwise determined' would have no work to do if simply ignored. It was open for the Council to consult with the Interested Party to provide information.
5. The application of s 45(1) of the ILA does use the term 'may' but in context reg 153 cannot have intended to leave the minimum finished floor level unspecified. It is required in the report and consent to state a finished floor level. The building may be safe for occupants but still create potential damage to property of the building site or others. In context is still requires the Respondent to state the minimum floor level.

1. The appeal has been brought pursuant to s 144(1)(a) of the Act. Under s 148 of the Act, the BAB stands in the shoes of the decision maker and has de novo jurisdiction to hear the matter.
2. In the current context of the appeal, this means that we must consider whether it is appropriate to grant consent to the proposed alterations and additions pursuant to reg 153 of the Regulations.
3. The parties have raised a number of issues including the statutory context in which the report and consent under reg 153 of the Regulations occurs. We will have regard to this before determining whether the report and consent should be granted.

Statutory Context of reg 153 of the Regulations

1. Regulation 153 of the Regulations has been extracted in full above in this Determination.
2. The parties do not contest that the building:

(a) is not a class 10 and is not unenclosed floor area;

(b) Is not an alteration to an existing building of less than 20m²;

(c) the planning scheme also does not regulate the level of the lowest floor level of the building in relation to any flood level declared by the Water Act or otherwise determined by the floodplain management authority or the relevant council.

Given this, a report and consent is required for a building permit of a site on an allotment that is in an area liable to flooding, which is also not contested.

1. Under reg 153(4) of the Regulations the Council (Respondent) may not give its consent under reg 153(2) of the Regulations if it is of the opinion that there is likely to be a danger to the life, health or safety of the occupants of the building due to the flooding of the site.
2. Regulation 153(5) provides that the Council, in its report under sub-reg (2), may specify a level for the surface of the lowest floor of a building on site. The parties accept that the ILA states the reference to 'may' means the exercise of power that may or may not be exercised. The use of the term 'may' is significant given the use of 'must' in other sub-regs under reg 153 of the Regulations. It suggests an interpretation that there is no mandatory requirement or imperative direction for the Council to specify the level for the surface of the lowest floor of a building on the site. The power is discretionary.
3. Further, reg 153(6) of the Regulations states that before specifying a floor level under reg 153(5) of the Regulations the relevant council must:

(a) Consult with the floodplain management authority for that site; and

(b) Specify a level at least 300mm above any flood levels declared under the Water Act or otherwise determined by the floodplain management authority, unless the floodplain a management authority consents to a lower floor level.

1. However, if the Council has elected not to exercise its power to specify a level for the surface of the lowest floor of a building, then it would not appear that reg 153(6) of the Regulations could apply. This is because reg 153(6) is first conditional on the Council electing to exercise its power under reg 153(5) of the Regulations to specify a level for the surface of the lowest floor of a building on the site.
2. If the Council has elected to exercise its power to specify a level for the surface of the lowest floor of a building on the site, then reg 153(6) of the Regulations applies. The question then becomes how to apply reg 153(6)(b) in those circumstances.
3. Regulation 153(6)(b) suggests that a level of 300mm above any flood levels declared under the Water Act or otherwise determined by the floodplain management authority (unless the floodplain management authority consent to a lower floor level).
4. We are tasked with considering how the term 'otherwise determined' should be applied in this context. The parties were unable to cite any relevant case law to assist us in interpreting these words.
5. In the decision in Project Blue Sky Inc v Australian Broadcasting Authority[3] [1998] HCA 28 it was stated: '... In determining the question of purpose, regard must be had to the language of the relevant provision and the scope and object of the whole statute'.[4]
6. In having regard to the provision, we consider it appropriate to have regard to the Water Act.
7. Regulation 153(6) of the Regulations reference 'flood level declared by the Water Act'. The Water Act also defines a flood level specifically as a flood level that is declared by an authority under section 203(1) of the Water Act. Accordingly, a flood level is defined as a flood level declared pursuant to s 203 of the Water Act.
8. Section 203 of the Water Act provides a process for declaring a flood level, a flood fringe area or a building line. The process requires receiving submissions from any person and publishing in the Government Gazette.
9. There is no other process outlined in relation to a 'flood level' or 'flood level declared by the Water Act' under the Water Act. Regulation 153(6) of the Regulations outlines a level which may be 'otherwise determined' by the floodplain management authority. There is no apparent power donated by the Water Act to declare a flood level by way of an alternative mechanism of 'otherwise determined'.
10. We accept the Applicants' submission relying on the decision in Anthony Hordern & Sons Ltd v Amalgamated Clothing and Allied Trades Union of Australia[5] where it states:

When the Legislature explicitly gives a power by a particular provision which prescribes the mode in which it shall be exercised and the conditions and restrictions which must be observed, it excludes the operation of general expressions in the same instrument which might otherwise have been relied upon for the same power.

The specific power to declare a flood level cannot be altered by any other general power provided under the Water Act even if one can be said to exist. [6]

1. We also accept the Interested Party's submission that the words 'otherwise determined' must have a meaning different to a declared flood level otherwise there would be no reason for those words to be in the provision. We also accept that general principles of statutory interpretation require us to give weight to all the words contained in the provision.
2. We note that reg 153(6)(b) of the Regulations uses the conjunction 'or' between flood levels declared under the Water Act and 'otherwise determined'. In our view this suggests a process separate and distinct from a declared flood level and should not be read as the same process. This also prevents any contradiction with the process set out under the Water Act for declared flood levels.
3. Section 202 of the Water Act does provide a list of the functions of the water management authority which includes finding out how far floodwaters are likely to extend and how they are likely to rise. The context of the existing powers under the Water Act do not provide for setting flood levels in any other way except by declaration.
4. As a matter of statutory interpretation, we accept that all words in the section should be given weight to apply the appropriate meaning. We also note that under the ILA[7] it is permissible to seek to review additional material such as explanatory memorandums and Regulatory Impact Statements to properly construe the provision in question. It is also appropriate to give the plain English construction to the words in the provision.
5. A review of the explanatory memorandums for both the Water Act and the Regulatory Impact Statement for the Regulations do not shed much further light on this issue of 'otherwise determined'.
6. The Water Bill 1989 explanatory memorandum simply summarises the provisions as follows:

1. The Regulatory Impact Statement for the Regulations (RIS) notes the structure is to provide additional oversight for flood areas. Part B of the RIS states that the report and consent process was designed to provide both oversight and flexibility. In particular, reg 153 of the current Regulations was described as:

In giving its consent to construct on flood-prone land, council will assess the proposal taking into account danger to the life, health or safety of occupants of the building due to flooding of the site.

Council will refer the application to the floodplain management authority. This process also allows council to determine the allowable minimum floor level of the building. Council is also required to inform the floodplain management authority and sewerage authority of the floor level for the site.

The RIS considers that flexibility and oversight are important, but that consent may still be given to construct on flood prone land.

1. The Macquarie Dictionary defines the word 'Determine' as follows:

-verb (t) 1. to settle or decide (a dispute, question, etc.) by an authoritative decision. 2. to conclude or ascertain, as after reasoning, observation, etc. 3. Geometry to fix the position of. 4. to fix or decide causally; condition: demand determines supply. 5. to give direction or tendency to; impel. 6. Logic to limit, as an idea, by adding differentiating characters. 7. Chiefly Law to put an end to; terminate. 8. to lead or bring (a person) to a decision: it finally determined her to do it. 9. to decide upon -verb (i) 10. to come to a decision or resolution; decide. 11. Chiefly Law to come to an end.

1. The plain English meaning of 'Determine' means to decide, conclude or ascertain (as after reasoning observation). It may also simply mean give direction.
2. The RIS and the Regulations suggests that the 'otherwise determined' is more akin to advice or a recommendation by the flood management authority after being consulted by a Council.
3. It is questionable whether the words 'otherwise determined' by a floodplain management authority would reach the level of a reviewable decision in and of itself in accordance with the decision in Australian Broadcasting Tribunal v Bond [1990] HCA 33 case. This is because a reviewable decision is one for which provision is made by or under statute law. Based on the Water Act 1989, the decision is not being made under that enactment and further there is no review or appeal of that decision in the same way a party could appeal a declared flood level pursuant to s 207 of the Water Act. Further, the Regulations make it clear that it is the Council who provides the final operable decision which can be appealed to the Building Appeals Board.
4. Such an interpretation is consistent with the RIS. The Regulations are providing more flexibility in approach which suggests that the words 'otherwise determined' may not be a formal determination in the context of the Water Act and Regulations.
5. The Regulations require, pursuant to reg 153(2), for a building site owner to seek the report and consent of the Council for a building permit if the site is on an allotment that is in an area liable to flooding. Under reg 153(4) the Council can not provide consent if it is of the opinion that there is likely to be a danger to the life, health and safety of the occupants of the building due to flooding of the site. Accordingly, it appears that if the Council does not hold such a concern that it can provide consent to the application.
6. Reg 153(5) of the Regulations then provides the Council with the discretion to specify a level for the surface of the lowest floor of a building on the site. If the Council exercises such a discretion, then it must follow the process set out in reg 156 (6) of the Regulations.
7. The language of the provision as set out in reg 153(6) of the Regulations refers to 'consult with' the floodplain management authority before the Council makes any decision under reg 153(5) and 153(6) of the Regulations. This suggests it is a consultation process in which it may take an advice or opinion on flood levels which have not been declared. The Council is to then consider this advice or position put forward by the floodplain management authority prior to making its decision. If the Council does exercise its discretion to set a floor level, then it must consult with the Council and then must specify a level 300mm higher than the either the declared flood or the flood level otherwise determined by the authority.
8. In addition to the above, we note the Council is required to determine the report and consent subject of the appeal. Regulations 153(5) and 153(6) consistently state the exercise of power to specify a level for the surface of the lowest floor of a building on the site is held by the Council rather than the floodplain management authority. If the Council elects to use this power, then the Council is required to consult and utilise information obtained from the floodplain management authority to make its decision.

Whether the report and consent should be granted

1. As noted above, it is agreed between the parties that there is no exemption to the requirement to apply for a report and consent. Further, the parties do not dispute that the allotment is in an area liable to flooding and that the report and consent is required. This addresses the factual matters relevant to reg 153(1) and (2) of the Regulations.
2. The evidence further supports a finding that the planning scheme does not regulate the level of the lowest floor of the building in relation to any flood level declared under the Water Act or otherwise determined by the floodplain management authority or the relevant Council. This means that the report and consent is required as the exemption provided under reg 153(3) of the Regulations does not apply in these circumstances.
3. Under reg 153(4) of the Regulations, the relevant Council must not give its consent under the report and consent process if it is of the opinion that there is likely to be a danger to the life, health or safety of the occupants of the building due to flooding of the site.
4. The evidence provided by the Council is that it had not formed a view that there was a danger to the life, health or safety of the occupants of the building due to flooding of the site.
5. Conversely, the Applicants provided expert evidence regarding the proposed dwelling, estimation of current and future flood levels and the overall danger to life, health or safety of the occupants of the building due to the flooding of the site. We consider that for the purpose of reg 153(4) of the Regulations that we should have regard to these factors to determine the overall risk of danger to life, health or safety of the occupants of the building due to the flooding of the site.

1. The evidence provided by the Applicants indicate that the current dwelling is subject to heritage overlays. The heritage overlay creates a number of planning considerations for the proposed alterations and additions to the building.
2. Uncontested evidence was tendered to establish that the suggested floor level provided by the Interested Party, if complied with, would cause the alterations and additions to be in breach of several building regulations as well as heritage protections.
3. The Applicants' expert also notes in her report[8] that the Guidelines For Development in Flood Affected Areas (DELWP[9] Guidelines) at page 37 confirm that the freeboard requirements can be relaxed for a minor development:

Where the cost and inconvenience of raising floors for building extensions is disproportionate to the benefits.

1. The Applicants' expert also noted the Council has the requirement to adhere to flooding, amenity and heritage policy requirements. Further, Ms Tsioulos, the Applicant's expert, noted that:

It therefore becomes incumbent on authorities such as Melbourne Water to determine if the flood risk on a property and its intended development is deemed tolerable. In assessing this risk, Melbourne Water consider the DELWP Guidelines but also have the power to apply discretion.

1. The proposed alterations and additions reduce the number of bedrooms on the ground floor of the dwelling. We find that reducing the number of bedrooms on the ground floor is considered beneficial because there are less rooms where an occupant may be sleeping on the ground floor which could potentially be impacted by flood. Further, the additions and extension would provide an upstairs refuge from potential floodwater.
2. We also note the findings of the BAB in Symes v Port Philip City Council [2024] VBAB 142 which confirms the general context of dwellings is that dwellings of around 50 years old are typically at the end of their service life. In that decision it was also concluded that consideration should be given to the service lifespan of a home and the imposition of speculative flood conditions at the extreme end of the potential service life.[10]

1. The uncontested evidence of the Applicants' expert, Ms Tsioulos, states:

Melbourne Water have advised that the property is not subject to flooding from regional stormwater drainage or waterway assets and that there is no current applicable flood. As such, there is no current flood risk under existing and developed conditions.[11]

1. The issue before us does not relate to current but potential future flooding. The Interested Party, Melbourne Water, has revised its previously adopted 1.6mAHD for the 1% AEP storm surge level to 2.4mAHD for the 1% AEP storm surge level for the year 2100.
2. Ms Tsioulos's expert evidence goes on to opine:

The Port Phillip Bay (PPB) Coastal Hazard Assessment (CSIRO 2022). indicates that the levels adopted by Melbourne Water are likely higher than the most likely 0.8m sea level rise levels in PPB. For all future scenarios investigated in the PPB Coastal Hazard Assessment, the 1% AEP flood level will not exceed 1.86m AHD (the current floor level of the dwelling) until beyond 2070 as shown below in Figure 7-5. There have been a number of modelled future climate change scenarios all have inherent levels of uncertainty not only in the climate scenarios but also how those scenarios are translated into flood models and flood levels.

1. Ms Tsioulos further provides evidence that the depth of overfloor flooding may be up to 540mm in depth but the risk of overfloor flooding in 2100 is low and imbued with uncertainty in both climate scenarios and how those scenarios translate into flood models and flood levels.
2. The Interested Party did not contest this evidence regarding the statements made by Ms Tsioulos as to the uncertainty in modelling future climate change scenarios. There is no information provided by the Interested Party to demonstrate or verify the likely rise in sea levels which is considered to be the likely source of flooding on which its position is based.
3. It is further unknown whether the Council will undertake flood mitigation works to account for the potential rise in sea levels. This may include works to prevent backflow stops on drainage pipes (such as those completed by many municipalities in Queensland flood prone areas) or seawalls.
4. There is therefore some doubt introduced regarding the actual flood levels on which the recommendation provided by the Interested Party is based.

1. The uncontested expert evidence of Ms Tsioulos considered that the consequences of a 1% AEP storm tide event in 2100 would be categorised as minor (on the basis that the flood hazard is minor inside the building and water damage would be minor). The risk associated with the proposed development would have an overall rating of low in relation to flood damages and danger to life, health and safety of occupants. The factors on which this rating was based were:

(a) that under 2100 sea level risk conditions the flood hazard (safety) of the floor level is to be considered low for adults

(b) The maximum flood level would only last for a few hours before receding

(c) There would be very little velocity or wave action due to the type of inundation and the location of the property

(d) The dwelling has a first floor that also acts as an additional refuge.

1. Based on the evidence and material provided, we cannot conclude that the proposed dwelling extension and alteration would be a danger to the life, health and safety of occupants for the purpose of reg 153(4) of the Regulations.
2. We then need to consider whether we are required to specify a level for the surface of the lowest floor of a building on the site for the purpose of reg 153(5) and 153(6) of the Regulations. In our view, the Council can choose whether to exercise its discretion under reg 153(5) of the Regulations (for reasons stated above) or not.
3. Given this, we have had regard to the wording of the report and consent refusal. In doing so, we note the wording is as follows:

Should Council have decided to specify a floor level for the surface of the lowest floor of the building, Regulation 153(6) requires that Council consults the floodplain management authority for that site, and specify a floor level of at least 300mm above the flood level declared for that site by the floodplain management authority (unless the floodplain management authority consents to a lower floor level). The floodplain management authority were consulted, specified a flood level of 2.40m AHD for the site, and did not consent to a lower floor level. Should Council have decided to specify a floor level, the minimum level able to be specified would have been 2.70m AHD, which is 840mm higher than the proposed floor level of the building.

1. The word choice for the refusal of the report and consent is interesting in that it states, 'Should Council have decided to specify...' and further '...Should Council have decided to specify a floor level, the minimum level able to be specified would have been'.
2. The wording does not indicate a definitive decision or specification of the floor level by the Council. It suggests to the contrary, that Council has elected not to specify as the statement is speculative regarding what the Council may have done if it had decided to specify the floor level.
3. In these circumstances, we cannot interpret the report and consent refusal as an election to exercise the discretionary power of the Council under reg 153(5) of the Regulations. In any event, this is a hearing de novo and not a judicial review. This means that the BAB review the matter afresh and adopt a pathway that does not require the specification of the floor level.
4. Whilst the BAB stands in the shoes of the decision maker and therefore has a similar discretion, we do not consider that it would be appropriate for that discretion to be exercised specifying the floor level under reg 153(5) and 153(6) of the Regulations. There is potentially more information available that has not been provided to permit us to assess and properly determine the floor level.
5. We will make an order that reflects our findings.

[1] Clause 17 of Schedule 3 to the Building Act 1993 provides: 'Unless the Building Appeals Board otherwise determines, a party to a proceeding before the Board must bear his, her or its own costs'.

[3] [1998] HCA 28.

[5] [1932] HCA 9; (1932) 47 CLR 1.

[7] Section 35.

[9] Department of Environment, Land, Water and Planning as it was then known.

[10] Symes v Port Philip City Council [2024] VBAB 142 [20-21]

[11] See page 18 paragraph 7.4.1 of the Expert Evidence Statement of Carolyn Tsioulos dated 15 May 2025.