What the Flood Overlay shows
The Flood Overlay forms part of the Noosa Plan 2020. It identifies areas potentially affected by flooding or inundation during a modelled event with a 1 per cent annual exceedance probability for the year 2100.
A 1 per cent annual exceedance probability means there is a one in 100 chance of an event of that size or larger occurring in any year. It does not mean such an event will happen only once every 100 years.
The mapping incorporates modelling assumptions and is used to help assess development. Noosa Council describes it as indicative. It does not capture every possible flood scenario, and larger or less frequent events may extend beyond the mapped area.
Flood Overlay mapping is intended to support development assessment. It should not be used by itself to decide whether a property is suitable to buy.
What the mapping does not tell you
The overlay does not confirm whether a particular building has flooded, how deep water may have reached during a previous event or whether access to the property has been affected.
A property may be mapped even if the existing building has no known history of inundation. A property outside the overlay may still experience local drainage, overland flow or flooding during an event that is different from the modelled scenario.
The mapping also does not replace an assessment of the building, surrounding land, drainage, access, services or the buyer's intended use of the property.
Queensland's seller disclosure statement does not provide a property's flooding history or every restriction imposed by planning laws. Buyers are encouraged to make their own enquiries before signing a contract.
How the overlay may affect future plans
The Flood Overlay can trigger assessment against the Flood Hazard Overlay Code when development is proposed. The purpose is to manage risks to people, property, infrastructure and the environment without increasing flood impacts elsewhere.
Depending on the property and proposed work, relevant matters may include:
Floor levels
Minimum finished floor levels may apply to new habitable rooms or other proposed work.
Building design
Materials, services and construction details may need to respond to the expected depth, velocity or duration of flooding.
Access
Safe access, evacuation and the ability to reach the property during a flood event may need consideration.
Flood storage and flow
Filling, structures and changes to the land may need assessment to avoid redirecting water or reducing flood storage.
Proposed use
Requirements can differ according to the type of development and how the property will be occupied.
Approval pathway
Some work may require planning or building approval, while other work may be subject to different requirements or exceptions.
Being within the overlay does not automatically prevent development. The assessment pathway and applicable requirements depend on the site, proposed work and current planning and building rules.
Before relying on renovation, extension, rebuilding or subdivision potential, obtain property specific advice from Noosa Council and appropriately qualified planning, building or engineering professionals.
What to check for a specific property
Council mapping provides an initial view of whether the Flood Overlay applies. More detailed information may be available through Noosa Council's property searches.
A Flood Search Certificate may provide:
Overlay status
Whether the property is mapped within the Flood Hazard Overlay.
Modelled flood levels
Available flood levels produced through Council's modelling.
Historical information
Historical flood levels where Council holds relevant information.
Minimum floor levels
The minimum finished floor level that may apply to new habitable rooms.
Flood velocity
Available information about the expected movement of floodwater.
For larger sites, multiple lots or more complex development, Council also offers an Advanced Flood Search Certificate.
Useful starting points include Noosa Council's Flood Mapping page, the Noosa Plan 2020 site report and a Flood Search Certificate. Disaster management maps and coastal hazard maps serve different purposes and should not be treated as substitutes for the planning scheme Flood Overlay.
Look beyond the mapped boundary
How the land and existing improvements respond to water can matter as much as the mapped overlay.
Relevant questions may include:
What are the floor levels of the habitable rooms?
Are garages, storage areas or other lower spaces below the relevant flood level?
Is there evidence of previous water entry, moisture damage or repairs?
How does water move across or around the site?
Can the property be accessed safely during significant rainfall or flooding?
Are electrical equipment, services and essential systems located above likely flood levels?
Have previous additions or enclosed lower areas received the required approvals?
Could proposed work affect flood flow, storage or neighbouring property?
A building and pest inspection may identify moisture, deterioration or visible signs of water entry. It does not determine the full flood risk, confirm planning requirements or replace specialist flood advice.
Insurance and lendingConfirm the practical costs early
Flood exposure can affect insurance availability, premiums, excesses and policy terms. The result varies between insurers and properties.
Obtain quotations for the specific address before signing the contract. Check whether flood is included, how the policy defines flood, which exclusions or limits apply and whether the proposed sum insured is adequate.
A lender may also consider the property valuation, insurance availability and whether the property provides acceptable security. Requirements vary between lenders and loan products.
An insurance quotation is more useful than a general assumption about flood affected property. Confirm the cover, premium, excess and policy terms for the individual address.
If finance is required, discuss the property with the lender or mortgage broker early. A solicitor or law practice should advise on the contract and any conditions or deadlines.
Noosa contextUse the right mapping for the question
Noosa Council provides several types of flood and hazard mapping. Each serves a different purpose.
The Flood Overlay in the Noosa Plan 2020 is used for planning and development assessment. Council's disaster management mapping provides information for emergency planning and particular flood scenarios. Coastal hazard mapping addresses matters including coastal erosion and storm tide inundation.
These mapping systems should be reviewed separately. A property may be affected by more than one hazard or mapping layer.
Properties outside the Noosa Shire local government area may fall under the Sunshine Coast Planning Scheme and different council information or requirements. Confirm which local government and planning scheme apply before relying on any mapping.
A mapped overlay is a reason to investigate the property more closely, not an automatic reason to dismiss it. The useful questions are what type of flooding is being modelled, how the building and access may be affected, what information is available for the site and whether the property still suits the buyer's plans.