MBRC Planning Scheme - Dwelling houses in Coastal hazard areas

The Coastal hazard overlay maps only impacts you if your property is identified in the mapping and you wish to develop (i.e. building or extending, changing use, subdividing, clearing vegetation, filling or excavation).

The Coastal Hazard overlay maps identify land subject to risks from storm tide inundation and erosion from coastal processes. The Coastal Hazard overlay code is found in section 8.2.1 of the planning scheme and includes the requirements for development occurring on land identified on the overlay maps according to their level of risk.

The overlay maps and code are designed to ensure people and property in these areas are safe from storm tide and erosion events.

There are three areas that make up the Coastal planning area shown on Overlay map - Coastal hazard (Storm tide inundation):

  1. Balance coastal planning area
  2. High risk storm tide inundation area
  3. Medium risk storm tide inundation

Overlay map - Coastal hazard (Erosion prone area) identifies the Erosion prone areas.

For further information about these overlay maps, see the information sheets.

This information sheet provides a summary of the requirements for building or extending a Dwelling house (including Domestic outbuildings and Secondary dwellings) in areas identified on the Coastal hazard overlay maps. The requirements vary depending on which area the proposed house is located.

Dwelling houses in the Balance coastal planning area

If your property is mapped in the Balance coastal planning area (outside the High and Medium risk storm tide inundation areas and Erosion prone areas), building a new Dwelling house or extending will be either accepted development or accepted development subject to requirements.

Extending an existing Dwelling house by 50m2 or less is accepted development, meaning there are no planning scheme requirements provided the building work satisfies the circumstances for being accepted development in Table 1.7.7.1 Accepted development of the planning scheme.

Building a new Dwelling house or extending an existing Dwelling house by more than 50m2 (including domestic outbuilding and secondary dwelling) in the Balance coastal planning area is self-assessable development, meaning it must comply with the requirements in the Coastal hazard overlay code. The requirements include:

  1. Build to minimum habitable floor level1;
  2. Use waterproof materials below the minimum habitable floor level;
  3. Locate essential electrical services above the Defined Flood Event level;
  4. Ensure filling does not impact on water flows or other properties during the Defined Flood Event2. Filling is required in the Balance coastal planning area to achieve the flood planning level as a minimum; and
  5. Hazardous chemicals are located and stored at or above the minimum habitable floor level1.

In the event you do not comply with these requirements, a development approval is required from Council.

These requirements are summarised from RAD1 to RAD8 of the Coastal hazard overlay code.

Dwelling houses in Medium and High risk areas (Storm tide inundation)

Building a new Dwelling house or extending a Dwelling house by more than 50m2 in the Medium and High risk storm time inundation areas requires development approval from Council. The assessable (code assessment) application will need to demonstrate how the proposal is designed to mitigate the risks in accordance with the Coastal hazard overlay code.

The following requirements apply to both building new Dwelling houses and extensions (including domestic outbuilding and secondary dwelling) in the risk areas:

  1. Build to minimum habitable floor level1;
  2. Use waterproof materials below the minimum habitable floor level;
  3. Undertake structural design of the dwelling using a suitable engineer;
  4. Utilise pier and pole constructions to achieve minimum floor levels;
  5. Provide a coastal engineering report;
  6. Ensure the building work and earthworks are capable of withstanding the coastal hazard events;
  7. Filling is only permitted in the Medium risk storm tide inundation area as a minimum to the Year 2100 Highest Astronomical Tide level;
  8. Locate essential electrical services above the Defined Flood Event level;
  9. Ensure building design addresses the street; and
  10. Ensure fencing is at least 50% permeable.

These requirement are summarised from performance outcomes PO1 to PO7 of the Coastal hazard overlay code.

Dwelling houses in the Erosion prone area

Under state government requirements new development, including building work, is significantly restricted in this area. Building a new Dwelling house is generally not permitted unless it can be demonstrated that the development can mitigate the coastal erosion risk without adversely affecting private and public land and infrastructure in the locality.

Building a new Dwelling house in the Erosion prone area will require a development approval from Council. The required application will be subject to an assessable (code assessment) application will be assessed against Table 8.2.1.2 of the Coastal hazard overlay code.

Extending an existing Dwelling house (including domestic outbuilding and secondary dwelling) in the Erosion prone area will only require a development approval from Council if the gross floor area of the extension or addition exceeds 50m2.

All new works for either building a new or extending a dwelling house must be built to the minimum habitable floor level, identified in Table 8.2.1.3 Flood planning level for a habitable floor (residential development) and a non-habitable floor (non-residential development) and levels for hazardous chemicals.

Filling is not permitted on land in the Erosion prone area.

Note: If the Dwelling house is within the Coastal management district and has a gross floor area greater than 1,000m2, referral to the State Government is required in accordance with the Planning Regulation 2017 Schedule 10, Table 6.

How do I find out if my property is included in the Coastal hazard overlay maps?

Use the free online My Property Look Up. If there is no reference to the overlay or a Drainage Investigation Area (DIA) then it does not apply to your property. The Coastal hazard overlay maps only impact your property if it is identified in the mapping and you wish to develop.

For more information

View information sheets:

Information about the Defined Flood Event and Flood Planning Level can be obtained via a Flood Check Development Report.

For further information about flood behaviour, download a free Flood Check Report. A Flood Check Property Report will provide information on the extent and depth for a number of flood and storm tide events relevant to your property of interest. A Flood Check Development Report will provide information required to support the planning scheme for the Flood and Coastal hazard overlays. These reports do not map risks associated with development and therefore cannot be directly compared to the mapping shown on any overlay.

1. Minimum habitable floor heights are located, designed and constructed to:

  • 300mm above the Defined Flood Event (DFE) where within the Erosion Prone Area; or
  • 500mm above the Defined Flood Event (DFE) where not within the Erosion Prone Area.

2. The Defined Flood Event (DFE) is the event used to determine the flood level for planning and development purposes.

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