Erosion, storm tide inundation and permanent inundation
Coastal hazards are generally considered through three related forms of mapping. Each represents a different process and can have different implications for planning, development and ownership.
Coastal erosion
Coastal erosion is the loss or movement of land caused by waves, storms, currents, sediment movement and longer term shoreline change.
An Erosion Prone Area identifies land considered vulnerable to coastal erosion or permanent tidal inundation over the relevant planning period. The mapped area is intended to support planning and development decisions. It does not predict exactly when or how erosion will affect an individual property.
Storm tide inundation
A storm tide occurs when normal tidal conditions combine with the effects of severe weather, including storm surge and wave activity.
Storm tide inundation mapping identifies low lying land that may be temporarily covered by water during a defined event. The expected depth and extent vary by location and event.
Permanent inundation and sea level rise
Permanent tidal inundation refers to the expansion of tidal areas as sea levels rise.
Noosa Council's coastal hazard mapping considers current conditions and future planning horizons including 2040, 2070 and 2100. The appropriate horizon depends on the decision or development being considered.
Coastal hazard maps are useful screening tools, but they are not a substitute for property specific planning, surveying, engineering or coastal advice where detailed decisions are involved.
Different maps answer different questions
Coastal hazard information for a Noosa property may appear across state mapping, Noosa Plan 2020 mapping and Council's Coastal Hazards Adaptation Plan mapping.
Under Noosa Plan 2020, erosion prone areas and coastal building lines are addressed through the Coastal Protection and Scenic Amenity Overlay. Storm tide inundation is addressed through the Flood Hazard Overlay.
Noosa Council also provides Coastal Hazards Adaptation Plan mapping showing possible changes in coastal erosion, storm tide inundation and permanent inundation across current and future planning horizons.
These layers serve different purposes. Buyers should confirm which planning scheme provisions currently apply to the property and avoid relying on one map in isolation.
The applicable planning scheme depends on the property's location. Noosa Shire Council and Sunshine Coast Council use different planning schemes, overlays and assessment requirements.
Development, ownership and insurance considerations
Development
Coastal hazard mapping can affect how proposed building work or development is assessed. Depending on the property and proposal, relevant matters may include building location, floor levels, setbacks, coastal processes, evacuation, access and engineering requirements.
A mapped hazard does not automatically prevent development. It does mean that a buyer with plans to build, extend, renovate or redevelop should confirm the applicable requirements before relying on those plans.
Existing homes
For an existing home, the mapping should be considered alongside the building's location, elevation, construction, approvals and condition.
The presence of a mapped hazard does not establish that the home has previously been damaged or will be affected by a particular event. Equally, the absence of visible damage does not remove the need to understand the available mapping and property records.
Insurance
Insurance availability, premiums, excesses and exclusions can vary between properties and insurers. Where coastal erosion, storm tide inundation or another hazard may be relevant, obtain property specific quotes and read the proposed cover before committing to the purchase.
Long term considerations
Planning and hazard mapping can change as information, modelling and planning policies are updated. Buyers considering long term ownership or future development should understand both the current requirements and the limits of relying on present day mapping.
Noosa Main Beach and some sections of the Noosa North Shore have experienced periodic coastal erosion. The Noosa River entrance area is also subject to shifting sand movement. These dynamics are managed through ongoing coastal monitoring and periodic beach nourishment programs.
Coastal hazards across the Noosa region
Conditions vary substantially across the Noosa region. Open coast beaches, the Noosa River entrance, tidal waterways, canal areas and Noosa North Shore are affected by different coastal processes.
A property's exposure cannot be determined reliably from the suburb name or its apparent distance from the beach. Current mapping and property specific information should be checked for the individual site.
Properties in the Noosa Shire Council and Sunshine Coast Council areas are subject to different planning schemes. Planning provisions and assessment requirements differ between the two schemes. Confirm which planning scheme applies to the specific property you are assessing.
Noosa North Shore has a distinct coastal setting, with low lying land, ocean and river influences and limited access. Buyers considering property there should obtain advice suited to the particular site and their intended use.
Riverfront and canal properties may be affected by both flood and coastal hazard considerations. River flooding, storm tide inundation and permanent tidal inundation are different processes and may appear in different mapping layers.
What to checkQuestions for a coastal property
Coastal hazard mapping can look confronting when it first appears in a property search. Its presence does not provide a simple answer about whether the property is suitable.
The useful questions are what process is being mapped, which requirements apply today and whether the result affects the buyer's intended use of the property. Those questions need to be answered for the individual site rather than the suburb as a whole.