MBRC Planning Scheme - Coastal hazard overlays

Under state government requirements, planning schemes must identify areas at risk of coastal hazard. In the MBRC planning scheme, the Coastal hazard overlays are used to identify areas impacted by storm tide and erosion hazards that pose a potential risk to people and property.

Coastal hazards include storm tide inundation (i.e. sea water flooding from storm or cyclone events) and erosion of land. It is important to address the risk these hazards present when assessing new development.

What is an overlay map?

An overlay map shows the location and extent of special features such as where land may be subject to hazards or other impacts. Overlays may apply to all or part of your property and your property may be affected by more than one overlay. Having an overlay on your property may affect the type of development that can occur, building controls and whether approval from Council is required.

What is the coastal hazard overlay code?

The Coastal hazard overlay code contains the planning, building and engineering requirements relevant to development in the Coastal planning area. The code provides additional assessment benchmarks and development requirements over and above the "normal" zoning or use requirements in other parts of the planning scheme. These additional requirements are placed on development in these risk areas to ensure that development that occurs within the area is compatible with the risk presented by the hazard.

What is a coastal planning area?

Under state government requirements, planning schemes must identify an area where coastal hazard planning controls apply. The Coastal hazard overlay maps show this as Coastal planning areas and comprise all land subject to coastal hazards including storm tide inundation and coastal erosion.

What is a storm tide inundation risk area?

Coastal hazard mapping shows areas considered at risk of inundation from storm tide events. Storm tides typically occur in low-lying coastal locations and are generally caused by extreme weather events such as cyclones. Significant storm tides are reported to have occurred historically in the Moreton Bay Region in 1931, 1954, 1967 (Cyclone Dinah), 1972 (Cyclone Daisy), 1974 (Cyclone Pam), 1976 (Cyclone David) and 2004 .

The Coastal hazard (Storm tide inundation) overlay map is based on the latest storm tide information available to Council and does not include the effects of climate change. This includes areas of High and Medium storm tide inundation. The storm tide inundation risk areas have been mapped using information on the depth and velocity of sea water during storm tide events. In some cases the depth of water is sufficient to result in a high risk classification even if the velocity is small (for example a canal or waterway).

The Balance coastal planning area includes all land outside the High and Medium storm tide inundation risk areas is considered to have a low to negligible risk.

Recent approved filling and other modifications to the ground surface may not be reflected in the current mapping.

What is an erosion prone area?

The Department of Environment and Science is responsible for declaring erosion prone areas for the Queensland coast. The erosion prone area is the width of the coast that is considered to be vulnerable to coastal erosion and tidal inundation. The calculation of the erosion prone area is based on:

  • a short-term erosion component from extreme storm events
  • a long-term erosion component where gradual erosion is occurring commonly from channel migration or a sediment supply deficit
  • a dune scarp component, where slumping of the scarp face occurs following erosion;
  • erosion risk due to future sea level rise from climate change both by permanent inundation of land by tidal water and the morphological response of the coast to elevated water level
  • a 40% safety factor.

Under state government requirements, planning schemes must identify an area where erosion prone planning controls apply. The Coastal hazard (Erosion prone area) overlay map shows all land subject to coastal erosion. This mapping is based on information dated 21 January 2015 and does not reflect the new Erosion Prone Areas which were declared on 8 July 2015. The majority of Erosion Prone Areas are still located within Council’s coastal planning area and are therefore subject to assessment against this code. If you are unsure as to whether your property is identified in an Erosion Prone Area you can undertake a property report by visiting request a coastal hazard map.

Council committed to undertake a localised erosion prone area study which commenced in 2016. As a result a number of shoreline erosion management plans for at risk areas are now available to view:

How do I find out if my property is mapped in this overlay?

If you are planning to build on, or develop your property, use the free online My Property Look Up. If there is no reference to the overlays, then they do not apply to your property.

How does this affect my property?

The Coastal hazard overlays only impact your property if it is identified in the mapping, and you wish to develop. Under state government regulations, development is then subject to building controls and safety requirements to help protect property owners and residents living in these areas.

For further information about flood behaviour, download a free Flood Check Property Report. Flood Check Property Reports map frequency and depth of floods, they do not map risks associated with development and therefore cannot be directly compared to the mapping shown on any overlay.