1. The decision of the Responsible Authority is affirmed.
2. In permit application P09/2402 no permit is granted.

Mr Joseph Alesci, a solicitor from Urban Lawyers. He called the following witnesses:

• Mr Darren Powell, an engineer from Beveridge Williams Pty Ltd; and
• Mr David Kotsiakos (by summons) building surveyor from Mornington Peninsula Shire Council.

Mr Rory O'Connor, a solicitor from Norton Rose Lawyers. He called the following witnesses:

• Mr Andrew Clarke, town planner from Matrix Town Planning; and
• Mr Andrew Prout, an engineer from ENGENY Water Management.

A two storey dwelling is proposed to be constructed to the rear of an existing lot and the land subdivided. The subdivision would create a lot of 859m2 that would contain two double storey dwellings that have existing planning approval. A lot of 552m2would be created to the rear of this lot to contain the additional dwelling. The subdivision would create common property of 230m2 along the southern edge of the front lot to provide access to the approved two dwellings and the rear lot.

The additional dwelling would be supported by a series of pylons in order to sit above flood water levels. A garage attached to the dwelling and access would be similarly elevated.

Refusal to grant a permit pursuant to Section 77 Planning and Environment Act 1987.

Zone and Overlays applying under the Mornington Planning Scheme

Vegetation Protection Overlay (Clause 42.02 & Schedule 1).

Design and Development Overlay (Clause 43.02 & Schedule 1).

Planning permissions required under the Mornington Planning Scheme

Construction of two or more dwellings on a lot (Clause 32.01-4).

Construct a building and carry out works (Clauses 43.02-2, 44.03-1 and 44.04-1).

Subdivision of land (Clauses 32.01-2, 44.03-2, 4.04-2).

The subject land has an eastern frontage to Marchington Avenue of 20.8m, while the southern and northern boundaries are approximately 80m deep. The western boundary is along the banks of Tanti Creek. The lands lopes from east to west.

Surrounding land is residential with development to the north and south along Marchington Avenue.

A single storey dwelling currently occupies the eastern portion of the site, with a bungalow located on the lower, flat western portion near the creek.

1. M & H Curren Investments Pty Ltd is the owner of a lot at 3 Marchington Avenue Mornington. A planning permit has been issued that allows the construction of two dwellings on the eastern two thirds of this lot,[1] while leaving the rear third as open space. Curren Investments now seek to subdivide off this rear portion of the land and construct a further dwelling on it.
2. Tanti Creek lies along the western boundary of the subject lot. The fall of the land toward the creek is several metres and the proposed lot would be subject to flooding from this creek. In response to such risks, Curren Investments proposes to construct the dwelling on specially designed pylons and provide elevated access into and out of the garage and dwelling.
3. The Mornington Peninsula Shire Council believes that the flood risk is unacceptable and at first instance rejects the suitability of developing a dwelling on this portion of the land. Having regard to the development response of a raised dwelling, the Council also considers that the elevated built form fails to address neighbourhood character and other design outcomes applicable to this site.
4. For these reasons and the objection of Melbourne Water, the Council has refused to grant a planning permit.
5. Melbourne Water is the flood plain manager and is a referral authority for the purposes of the Planning Scheme.[2] It objects to the proposed subdivision and dwelling because it is of the opinion that the level of flood risk would be unacceptable.
6. Curren Investments argues that its design appropriately minimises the flood risk and presents an acceptable character outcome. It seeks a review of the Responsible Authority's decision on this basis.

1. The subdivision is subject to planning permissions under the Residential 1 Zone that applies to all of the land and the Flood and Land Subject to Inundation Overlays that apply to the rear part of the current lot. In fact, these overlays between them would cover the whole of the proposed second lot.
2. The proposed dwelling and use of the new lot would be as of right under the zone, however planning permission would still be required under the applicable flood overlays for the development of the dwelling.
3. Thus the two components of this application are caught up in a threshold issue about the flooding risks at this site. It is only if I were to be persuaded that the flood risk has been acceptably resolved that it would be necessary to consider the design and character issues that the Council's grounds also raise.
4. Having considered the submissions of the parties, the expert evidence and the applicable matters to be considered under the various planning controls, I have found it necessary to resolve the following questions:
   • What is the degree of flood risk?
   • Is the flood risk acceptable for residential land use and development?
   • What is the appropriate planning response to the level of flood risk?
5. In addressing these questions, it is first appropriate to set out the relevant planning and other relevant guidance applying to the use and development of flood prone land.

PLANNING AND OTHER GUIDANCE FOR THE USE AND DEVELOPMENT OF FLOOD PRONE LAND

1. A range of material has been put before me in respect to planning provisions and state planning policy contained in the Mornington Planning Scheme, planning practice notes, and guidelines relied upon by Melbourne Water.
2. I shall set out my considerations of each in turn in.

1. The subject site sits within a Residential 1 Zone. The relevant purposes of this zone that are in contention are:

To implement the State Planning Policy Framework and the Local Planning Policy Framework, including the Municipal Strategic Statement and local planning policies.

To provide for residential development at a range of densities with a variety of dwellings to meet the housing needs of all households.

1. These purposes and associated planning policies that address housing[3] encourage amongst other outcomes, housing diversity and consolidated use of existing residential land.
2. These outcomes are to be balanced with the Flood Overlay (FO) and Land Subject to Inundation (LSIO) controls applying to the land and planning policies that address flood and waterway management and broader goals of environmental and land use compatibility.[4]
3. The purposes of the FO are:

To implement the State Planning Policy Framework and the Local Planning Policy Framework, including the Municipal Strategic Statement and local planning policies.

To identify waterways, major floodpaths, drainage depressions and high hazard areas which have the greatest risk and frequency of being affected by flooding.

To ensure that any development maintains the free passage and temporary storage of floodwater, minimises flood damage and is compatible with flood hazard, local drainage conditions and the minimisation of soil erosion, sedimentation and silting.

There are other relevant purposes about environmental and water quality matters, that are not substantive to the issue of flood risks and hazards. I have therefore not considered these aspects of the controls further.

1. The purposes of the LSIO are expressed in similar terms to the FO save for the following:

To ensure that development maintains the free passage and temporary storage of floodwaters, minimises flood damage, is compatible with the flood hazard and local drainage conditions and will not cause any significant rise in flood level or flow velocity.

1. The differences between these two overlays can be seen to be essentially about the function of the land in its capacity to carry and transmit flood water. The LSIO is assigned to land that does not carry main flood flows, but rather lies at the fringe of floods, where flood flows are typically slower and shallower. Flood Overlay land will typically carry deeper, faster moving water, may be subject to more frequent inundation and under most circumstances would present a higher degree of risk.
2. Relevantly, the distinction between these two overlay controls carries through in terms of subdivision. Under both, a permit is required to subdivide land, however permission under the FO is conditional, and except under some circumstances not relevant to this application, a lot must not be created if it were to wholly lie within this overlay.
3. In this particular case, tabled plans indicate approximately half of the lot would fall within the FO, while the remainder of the lot is contained within the LSIO. The subdivision of this land is thus not prohibited under the terms of the Flood Overlay. It is of course an undisputed fact that the proposed lot would be wholly inundated in larger flood events, a fact that is relevant to the decision guidelines and the exercise of discretion.
4. The decision guidelines under each of these overlays require consideration of the following relevant matters:
   • State and local planning policy frameworks;
   • Any local floodplain management or in the absence of one, a flood risk report;
   • Comments from the relevant floodplain management authority;
   • The existing use and development of the land;
   • Whether the proposed use or development could be located on flood-free land or land with a lesser flood hazard outside this overlay;
   • The susceptibility of the development to flooding and flood damage;
   • The potential flood risk to life, health and safety associated with the development for occupants as well as emergency personnel; and
   • The obstructing effects of the development on floodwater storage, levels and velocities.
5. Mr Alesci is correct in observing that the overlay strategies do not require residential dwellings to be constructed outside of areas subject to the FO or LSIO. Having regard to the practice notes that guide the application of these overlays, it is apparent that this is due to the fact that these two overlays are applied to wide expanses of rural and urban land.[5] It is therefore a matter of exercising judicious discretion as to what is or isn't acceptable in the circumstances of each application.

1. The integrated decision making process set out under Clause.10.04 of the planning scheme requires various relevant planning policy objectives to be balanced to achieve an overall acceptable planning outcome. What will be acceptable is of course at the core of the dispute between the parties.
2. Current Investments argues that the subdivision and development accords with the zoning and relevant housing planning policies,[6] with the design of the dwelling and access addressing the needs for a safe living environment and an orderly outcome.
3. The Council and Melbourne Water say that the flood risk is unacceptable because the subdivision creates a lot wholly within the flood plain. It is also argued that this outcome is unnecessary when the current level of subdivision achieves the zone and housing policy objectives with no exposure of development to the flood risk. Melbourne Water submits that avoiding unacceptable levels of flood risk is a key policy outcome.
4. Clause 13.02 of the planning scheme addresses of flood risk. Specifically it is state policy for planning to:

• Life, property and community infrastructure from flood hazard.
• The natural flood carrying capacity of rivers, streams and floodways.
• The flood storage function of floodplains and waterways.
• Floodplain areas of environmental significance or of importance to river health.[7]

1. Strategies to address these objectives include amongst others, identifying land that is flood prone[8] and avoiding the intensification of 'the impacts of flooding through inappropriately located uses and developments'.
2. Responsible authorities are directed to consider a range of matters in addressing these objectives including but not limited to:

Any floodplain management manual of policy and practice, or catchment management, river health, wetland or floodplain management strategy adopted by the relevant responsible floodplain management authority.

Flood risk and guidance from the VPP Practice Notes

1. Melbourne Water has referred to the Victorian practice note for Applying for a planning permit under the flood provisions[9]. This practice note sets out that:

Flood risk must be considered in planning decisions to avoid intensifying the impact of flooding through inappropriately located uses and developments.

Land use planning is one mechanism that is used to minimise the risk of flooding to life and property.....

Each of the flood provisions provides differing degrees of flexibility for the development of flood-affected land directly related to the flood risk.

1. Such guidance reinforces the view expressed earlier about the operation of the overlays. Thus while not controlling land use per se this guidance supports a key principle in the overlays about achieving a level of intensification that is appropriate to the degree of flood risk. Moderating development to levels compatible with the degree of risk may of course, moderate the intensity of the use.
2. When considered in such terms, it should not be a surprise to find that the practice note highlights that: ..

Where possible, floodway land should be maintained in large parcels and not be fragmented by multiple property boundaries. The subdivision provisions aim to achieve this objective by not allowing new lots to be created in the UFZ or FO, other than to realign the boundaries of existing lots.

The creation of lots that are wholly within the UFZ or FO is also discouraged.

Subdivision provisions for the LSIO and the SBO are less stringent than for floodway areas. However, the intensification of development in flood storage areas or natural habitats should be discouraged. Any subdivision that could result in longterm intensification of development in flood-storage areas should be carefully assessed.

1. In my view, such guidance reinforces the message of the overlays and underpinning planning policy that:
   • Accommodation, including dwellings, within flood prone land that introduces a real and incremental increase of flood risk and hazards to life and property is to be strongly discouraged; and
   • Subdivision that would create a lot that is subject to flooding risks over all of its area or has insufficient area to accommodate development above the flood levels is strongly discouraged.

1. Messrs Prout and Powell variously refer to two sets of guidelines in assessing the level of flood hazard:
   • Guidelines for Development in Flood-prone Areas[10] (the MW Guidelines); and
   • Floodplain Management in Australia, Best Practice Principle and Guidelines, SCARM Report 73, 2000[11] (the SCARM 2000 guidelines).
2. Mr Alesci submits that it is the MW Guidelines that should have greatest weight as this document has been developed from a wide range of reference materials, including the SCARM 2000 guidelines which much of Mr Prout's assessment of flood hazard is based on, and broad industry consultation. Mr Alesci suggests that these guidelines represents Melbourne Water's 'current thinking'.
3. A stated purpose of the MW Guidelines is that it is consistent with 'best practice principles, policies and guidelines developed by State and Federal governments'. Commentary on floodplain management information includes references to the SCARM 2000 guidelines as well as a range of guidance material. I therefore accept that in the hierarchy of relevant considerations, the MW Guidelines have weight in this application.[12] The SCARM 2000 Guidelines has informed its development and from this point of view, the latter guidelines may be seen as a document that may assist in understanding the intent of the MW Guidelines.
4. Given its relevance, it is important to understand how the MW Guidelines operate. The actual 'guidelines' are set out under section 5 of the document. This section sets out by way of a table,[13] a series of development activities which are to be assessed against a series of 'necessary requirements' and 'additional considerations and comments'. Although not stated explicitly, it is clear that for the effective operation of the MW Guideline's it is necessary for a proposed development activity to satisfactorily address the core requirements and the additional considerations.
5. To paraphrase the MW Guidelines, the core requirements are:[14]
   • Flood flow - works or structure must not affect flood flow capacity;
   • Flood storage - flood storage must not be reduced by works or structures;
   • Freeboard - appropriate freeboards must be proposed;
   • Site safety - avoid development where 'the depth and flow of floodwater would create a hazard'; and
   • Access safety - avoid development where the depth and flow of floodwater affecting access to the property is hazardous.
6. These 'core requirements' are said to support the guiding principles of:
   • Minimising risk to people and property;
   • Identify and prevent potential for adverse impacts on adjacent, upstream or downstream areas;
   • Appropriate development within a flood prone area being designed accordingly; and
   • Reducing reliance on emergency service personnel in flooding events.[15]
7. Returning to the 'guidelines' proper, the relevant development activity and associated requirements are set out under Table 2 as follows:

Necessary Requirements - As per Section 5

Smaller urban resubdivisions (i.e. two-lot subdivisions; unit developments) and smaller urban developments.

• New buildings and/or lots located outside active flow areas.

• In existing urban areas, access safety requirements and smaller urban may be difficult or impossible to meet. Consideration of the proposal will only be provided where the other four requirements are fully achieved and there will be a reduction in overall risk in terms of access safety. All such cases, proposals should be discussed with Melbourne Water prior to the lodging of any formal application.
• It is not desirable for flows to penetrate sub-floor areas/voids below the 100-year flood level.
• Consult Melbourne Water's Land Development Manual to obtain standard main drainage design conditions. Special development conditions will be provided in the 'offer of drainage conditions', supplied by Melbourne Water after receipt of 'application for conditions'.

1. Having regard to these requirements, the proposed two lot subdivision and an additional dwelling should, if it is to satisfy the MW Guidelines:
   • Meet all of the necessary core requirements;
   • Avoid creating a lot in the active flow area;
   • Avoid developing a new building in the active flow area;
   • If site safety requirements cannot be met, the four other core requirements must be fully achieved along with a reduction in overall risk 'in terms of access safety'; and
   • Preferably, avoid the flow of flood waters from a 1:100 ARI events under or through sub-floor voids.

1. The subject land sits on the western side of Marchington Avenue in Mornington. The lot is approximately rectangular and extends from the street to Tanti Creek. Plans show that the land falls generally from east to west. Proposed lot 1 falls from approximately 10mAHD[16] to approximately 5.5m AHD, while proposed lot 2 falls from approximately 5.5m AHD to around 4m[17] AHD at the boundary with the Tanti Creek environs.
2. A current planning permit allows two dwellings to be constructed on what would be Lot 1. The new dwelling would be wholly contained within the proposed Lot 2, which I have noted earlier would be covered by a combination of the FO and LSIO.

1. In the vicinity of the subject site Tanti Creek's primary normal flow is contained within a narrow and shallow channel incised below the local land levels. Its broader flood plain is formed by rising land to the east and west, with the west being steeper that the east. In flood, water will tend to rise and spread further eastward than to the west.
2. The Tanti Creek catchment is not extensive, being some 600 hectares in area. It extends through the urban area of Mornington, with its headwaters in the vicinity of the Mornington Racecourse. It is subject to rapid flow generation from urban runoff, notwithstanding recent developments that include some retardation infrastructure, which Mr Prout and Mr Powell refer to. This infrastructure is located higher in the catchment where more recent urban development has occurred. Lower reaches of the catchment contribute flow in an uncontrolled manner such as described by Mr Kotsiakos along Morell Street.
3. Because of its urban nature, and the limited extent of flood control/stormwater retardation in the upper catchment, the experts agree that flood flows will be generated rapidly and from localised rainfall. Within the relatively narrow reach of the creek past the subject site, water can and has previously demonstrated an ability to rise rapidly.
4. Flow past the site passes beneath The Esplanade that lies to the south of the site via three large diameter culverts. Mr Prout's and Mr Kotsiakos' evidence is that these culverts restrict the flood flows, and if obstructed will cause flood waters to pond behind the embankment formed by this elevated roadway.
5. Melbourne Water has assessed the theoretical 1 in 100 ARI flood level to be between 5.1 and 5.3 metres AHD[18] at the subject site. If the culverts are partially blocked by flood debris, Mr Prout's evidence is that the flood water would rise until it overtops The Esplanade, i.e. just over 6metres AHD.
6. Mr Kotsiakos evidence is that the 1988 flood event, as well as during other flood events, blockage of the culverts resulted in these higher flood levels. Mr Kotsiakos described how the 1988 flood event followed a short but intense rainfall within the catchment. The Esplanade culvert was blocked by flood debris and water rose until it passed over The Esplanade. Ponding of floodwater extended upstream to Barkly Street, well past the subject site.
7. Because of this behaviour, Mr Kotsiakos advises that the more appropriate flood level to adopt is 6.1m AHD.
8. Whether at the level predicted by Melbourne Water or that observed by Mr Kotsiakos, 1:100 ARI flood event will inundate the whole of the proposed lot, will penetrate beneath the proposed dwelling and the partly suspended slab of the garage[19] as well as cover the dwelling entrance and driveway access. The relevant question is what hazard is generated by these flow, the answer to which is that it depends on the operability of the culverts beneath The Esplanade.
9. Based on the evidence of Mr Prout as supported by Mr Kotsiakos and the peculiar circumstances of this site, it is my view that it is prudent to adopt the higher flood level of 6.1m AHD.
10. At the theoretical 1 in 100 ARI event, Mr Prout calculates the depth of water extending across the site to range from zero at the north-east corner to 1.65m at the south-west corner. At the higher flood level of 6.1m AHD, adjusted depths would range from 0.5m up to 2.85m. Across the proposed building footprint the depth of flood waters would vary from 1.2m to 2.5m. Based on the application plans the depth of flow across access points would range up to 0.5m.[20]

1. The agreed evidence from Mr Powell and Mr Prout is that under a 1:100 ARI event, the velocity flood waters through the lot will be of the order of 0.5m/s up to 0.7m/s if the development does not cause any blockages. [21] If the dwelling were to result in full blockage of flow both experts adopt the advice of Melbourne Water that this velocity would rise to approximately 1m/s. [22]
2. Mr Kotsiakos observed that during the 1988 flood events, reasonably fast moving, sheet stormwater flow travelled down Morell Street into the creek. Mr Kotsiakos evidence is that this inflow of water affected the flow along the Tanti Creek flood channel, causing it to swirl. He suggested that under similar circumstances, floodwater would not necessarily follow the main channel, but swirl around the site.

1. It is apparent from reading the various decision guidelines and other relevant guidance that the term flood risks may have two interpretations.
2. The first is the risk of flooding occurring in any particular place. Melbourne Water and Victorian planning authorities rely on the 1 in 100 ARI event to define the extent of land that would be exposed to flooding that should be accounted for in planning and managing flood risks. In essence, this extent defines the risk of exposure to flooding.
3. It follows from the evidence of all the experts that this site is at risk to such flooding and there is no dispute about the application of the overlay controls to this land.
4. The second aspect of risk is the risk to human life and property. Such risks can be thought of as a product of an event's likelihood of occurring and its consequences as measured as the hazard to life and property.
5. The probability of a 1 in 100 year ARI event is sometimes misunderstood to mean that such an event may only occur once in every 100 years. This is not the case at all. A 1 in 100 year ARI event represents the extent of flooding that could be expected, on average, over a 100 year period. The probability of the 1:100 year extent of flooding occurring in any given year is 1%. However, as time goes on the probability of such event occurring increases. Over 70 years, a period said to represent an average lifespan, the probability of a 1 in 100 ARI event occurring in a flood plain is 50%, i.e. a 1 in 2 chance. The probability of being subject to two, such events over 70 years is approximately 16% (around a 1 in 6 chance).[23]
6. It would be fair to say then that over the life of a dwelling within the proposed lot there is an even chance of it being subject to a 1 in 100 ARI event and a reasonable likelihood of having two such events occur.
7. There is little doubt therefore that in terms of exposure, it can be said that there is a reasonable probability that proposed welling would be flooded to the extent indicated by the evidence of Mr Kotsiakos and Mr Prout.
8. Such a conclusion is not nor should it be controversial. It is the consequence of this exposure, i.e. the hazard and the way such a hazard is to be managed by the planning process, which is in dispute.
9. Mr Prout relies on the SCARM 2000 approach to define this level of hazard. Mr Powell relies on the MW Guidelines.
10. As I have noted earlier, Curren Investments dispute the reliance on the SCRAM 2000 approach, arguing that the MW Guidelines are more appropriate. For the reasons I have set out, I accept that the MW Guidelines are a distillation of a range of guidance and principles that Melbourne Water has prepared to guide applications such as these. I have therefore fore relied upon these guidelines in the first instance.
11. The core requirement at section 4.3.4 'Site Safety' of the MW Guidelines address the matter of hazard.
12. This requirement sets out that:

Development must not be allowed on properties where the depth and flow of floodwaters would create a hazard.

1. Like the disputed SCARM 2000 approach, this core requirement relies on an assessment of flow velocity and depth to determine whether there is a hazard. The determining criteria are:

The product of depth (in m) and velocity of flow (in m/s) should be no more than 0.35m2/s.

1. As cumulative criteria, they would all need to be satisfied to indicate no hazard.[24]
2. While the predicted flood flow velocities set out earlier are below the MW Guideline criteria, the potential ranges in depth beneath the building and over proposed access levels are not. The product of the flow and depth also exceeds the criteria. This assessment therefore would indicate the existence of an unacceptable hazard to persons and an unacceptable level of site safety.
3. Mr Prout's SCRAM analysis, which similarly relies on a combination of depth and flow velocity, indicates an extreme to high hazard. Essentially the two methods arrive at the same conclusion.
4. The MW Guidelines highlight that in terms of assessing hazard:

• building entrance/exit points and their surrounds;

• connecting routes to outbuildings or car parking areas; and

1. The depth of flow exceeds the criteria applicable to flow across the property and over access and driveway levels. While Mr Powell's evidence is that the access ways and front entrance can be raised to achieve lesser depths over such access, the fact remains that the hazard is still present by way of flow around or beneath such access.
2. Given that the degree of flooding presents a hazard in combination with the probabilities of the such flood events occurring, I conclude the that land is subject to a level of flood risk that the planning scheme seeks to address through the underlying principles of land use planning and development that I have set out earlier. For reasons that I will address later, the proposed engineering response put forward by Curren Investments is an unacceptable response to such principles.

1. Mr Alseci submits that the MW Guidelines, the overlays and other planning policy guidance do not prohibit development. It is contended that the combined import of the planning and other relevant guidance is to 'ensure urban development and redevelopment is compatible with any flood risk'. Curren Investments contends that the compatible flood risk can be addressed by adopting engineering responses that:
   • Elevate the building and dwelling access above flood levels, thereby reducing the hazard.
   • Relies on specially designed pylons that reduce the risk of debris being caught within the dwellings pylon substructure and so reduce the impacts on flood flow levels and velocities and reduce the risk of property damage.
2. Such a response diverts attention from the underlying planning principles that distil from the earlier consideration of the various policies and guidelines. A key principle for planning is that if development can avoid occurring within flood prone land then it should. In line with such a principle, a more orderly planning outcome will be achieved by creating a lot that would not be wholly subject to flooding so land use and / or development is not constrained. This principle and the outcomes are consistent with a number of decisions by other divisions of the Tribunal referred to be Melbourne Water.[25]
3. Clearly this proposal fails to address these important principles. It seeks to address the flood risks through an engineering response.
4. Even if I were to be persuaded that there was some planning imperative to place less weight on flood plain planning principles in order to increase the intensity of residential land use at this location, on merit, I am not satisfied that the engineering response is satisfactory.
5. The evidence highlights that:
   • The flood flows may not behave in the manner assumed and relied upon in the design and location of the pylon system.
   • The urban character of the catchment means a high likelihood of rapidly rising flood levels with little response time for occupants to react and prepare.
   • The ongoing maintenance requirements of the pylons, footings and void areas beneath the dwelling to ensure clear flow of flood waters and security of the pylon system is an unreasonable impost and constraint on the residential use of the land.
   • The site remains subject to flows that present an inherent hazard to persons and property.
6. Further it is evident that having a dwelling located over flood flows and allowing some flow over or beneath its access does nothing to address the psychological impact for occupants that such a situation may bring. Clearly, occupants would need to evacuate the dwelling, causing stress, possibly alarm and perhaps financial imposts. The hazard remains and occupants would need to respond as would emergency worker if an issue arose.
7. At best the engineering response may provide a sense of security for property, but does nothing to redress the hazard, financial and other hardship impacts to occupants that arise from evacuating a dwelling.
8. In all of this, the question that must be asked is whether this a fair, orderly and reasonable outcome for future owners and occupants given:
   • an absence of a higher planning imperative to create the additional lot and dwelling; and
   • the fact that the balance of flood plain management policy and guidance directs an outcome toward this land being better managed as part of a larger lot that can achieve, as a larger entity, other residential zone and policy objectives.
9. The answer quite plainly in my view is it would not be fair, it would not be reasonable and it would not be an orderly planning outcome.

1. Curren Investments argues that its design and engineering response to the level of flooding and hazard successful addresses the requirements of the MW Guidelines. I do not accept that this is the case.
2. Curren Investments response to the MW Guidelines is to focus on the principles and the core requirements. It argues that it has identified and minimised the risk by an appropriate design response in satisfaction of the principles. It says that the design response provides appropriate free board, does not affect flow and storage capacity and thereby removes (or reduces) the hazard.
3. Applying the guidelines proper to this proposal in the manner I set out earlier, it is not enough to address only the core requirements. The guidelines proper have additional requirements and considerations that must be satisfied.
4. Having regard to the flood risk and inherent hazard to site and access safety, I find that the proposal fails the test of meeting the necessary core requirements and satisfactorily addressing the additional considerations because:
   • The proposed access ways, either as proposed or further elevated, exposes people to an unacceptable level of hazard from flows over or beneath the access, failing to meet the core requirement for safe access.
   • The development occurs on land that would be subject to hazardous flood flows, which is contrary to site safety core requirement to avoid development on such land.
   • It creates a lot that is wholly contained within an active flow area, contrary to the additional considerations of the guidelines.
   • The building of the structure over the flood water flows results in sub-floor areas and voids that would be flooded, a response that is undesirable under the guidelines.
5. The failure to address the MW Guidelines in an acceptable manner weighs heavily against this proposal.

1. It follows from a consideration of the flooding regime of this location, the corresponding level of risk, hazard to people and property and the balance of planning policy and other guidance that this proposal is unacceptable.
2. The level of flood risks is one that planning policy and the corresponding controls seek to avoid at first instance rather than engineer away. Creating a lot that is wholly subject to such risks and the unavoidable need to engineer them away in order to develop the land is contrary to an orderly planning outcome.
3. Curren Investments response to the flood risk fails to recognise and take account of planning policy and other guidance to avoid the need for 'engineering away' such risks. It is clear from a consideration of the applicable planning provisions, policies and other relevant material such as the MW Guidelines that if development can avoid flood prone land that presents unacceptable levels of risk, it should do so.
4. The MW Guidelines usefully summarise the clear principle that:

Good planning is the key to minimising long-term risks of damage from flooding. The principle is simple - plan and develop properties, buildings and structures so that they are safe from flooding from the outset without compromising the safety of other properties. Prevention is far cheaper than the cure.

1. I am not persuaded that 'advances in engineering' as put by Curren Investments overcomes the clear intent of planning to avoid the need for such engineering in the first instance.
2. Quite simply the creation of a separate lot of residentially zoned land that is so constrained as to require the engineering response proposed by Curren Investments lies at the root of the matter. The subdivision does not result in an orderly planning outcome. It results in an outcome that planning and other flood plain management policy seeks for the most part to avoid at first instance. The proposal to then build a residence on such a lot further compounds the unacceptable nature of this outcome.
3. Amongst the matters to be considered under the decision guidelines, is a question about the existing use and development of the land. The fact is that the existing lot is capable of accommodating appropriate levels of residential development, as demonstrated by the current planning approvals, without the need to encroach into the flood prone land. Such development achieves the balance of the zone objectives, housing policy and flood plain management outcomes sought under the planning scheme.
4. For these reasons, I conclude that the decision of the Responsible Authority should be affirmed and direct that no permit be granted.

[1] Permit No P08/1870 issued on 25 June 2009.

[2] As per Clauses 66.01 & 66.03 of the Mornington Planning Scheme and s. 52 of the Planning and Environment Act 1987.

[5] Applying the flood provisions in planning schemes - A guide for councils Victorian Planning Practice Note 12, August 2000.

[8] In planning policy terms flood prone is land which may be subject to inundation up to and including a 1:100year ARI event.

[9] Victorian Planning Practice Note 11, August 2000.

[10] Version 1.1, October 2008. Melbourne Water

[11] CSIRO Publishing acting on behalf of the Agriculture and Resource Management Council of Australia and New Zealand - Standing Committee on Agriculture and Resource Management.

[12] As per ss.60(1A) (g) and 84B of the Planning & Environment Act 1987.

[14] While referring to necessary requirements as being under section 5 of the document, it is clear that this is a reference to the 'core requirements' of section 4.

[15] At s.4.2 (p10) of the MW Guidelines.

[17] Around 3.6m in the south-west corner.

[19] The application plans showed the access and garage to be placed on filled land. Mr Powell recommended that a suspended slab arrangement as a better response over filling the land.

[20] The plans show an access level of 5.64m AHD.

[21] Email from Keith Boniface of Melbourne Water to David Kotsiakos dated 29 September 2010.

[22] The specific value advised by Melbourne Water is 1.07m/s. I have rounded this value, given the likely levels of accuracy in the modelling which relay upon a range of ground conditions being maintained along the creek valley.

[24] I note that these criteria are not hard and fast rules. The MW Guidelines direct attention to the 'Floodway Safety Criteria Guidelines ...documented...in Appendix G of the Design Guide in Melbourne Water's Land Development Manual'. Neither expert referred to the Floodway Safety Criteria Guidelines but preferred to rely on the calculation of depth and velocities as I have set out.

[25] Whelan v Maribyrnong CC [2009] VCAT 2681, Davies v Moira SC [2011] VCAT 452 and Lourey v Yarra CC (Application P1365/2011 - 1 December 2011).