The City of Gold Coast publishes flood maps that show whether a property sits in a flood risk or flood affected area, and it sells a flood level search report that gives a property’s designated flood level and ground level. Neither arrives with the seller disclosure statement, which does not have to cover a property’s flooding history, so a buyer looks them up separately.
General information, not advice. This guide is published by Dotto and does not arrange loans, insurance or advice. The official place to check is the City of Gold Coast’s flood maps page. The City says these maps are not for use during a flood; in a rain or flood event it points to its emergency dashboard.
Why this is the buyer’s to check
The City of Gold Coast describes the city as prone to flooding, like many coastal cities, and says past floods have caused moderate to extensive damage to private property. Queensland’s seller disclosure scheme lists flooding history among the things a seller does not have to include. The warning the Property Law Regulation 2024 puts on the disclosure statement encourages buyers to make their own inquiries about flooding history before signing, and says a buyer may not be able to end the contract if it is discovered after signing. More on the statement is in guide 1.
The City’s three maps
The City publishes three online flood maps. It says they inform its planning scheme, City Plan, and its rules for building and development, and that they are best viewed on a larger screen.
The City of Gold Coast’s flood maps, as the City describes them
Map
What it shows
What the City says it is for
Flood risk awareness map
The City’s newest citywide map, from its latest flood modelling, sorting land into risk categories from the likelihood of flooding and how hazardous the water would be.
Flood risk awareness only. The State Government is reviewing it as part of the proposed Designing for Flood update to City Plan.
Flood insurance map
Whether a property could be flooded in five scenarios, from frequent to extremely rare (a 20% to a 0.05% chance in a year), as at present, without future climate change factors.
A starting point for talking with an insurer about flood cover. The City has given this mapping to the Insurance Council of Australia.
Flood depth map
Approximate flood depth in a flood with a 1% chance in a year, worked out from the defined flood level and estimated ground level in City Plan, with the defined flood level for each property.
Seeing whether a property is in a flood affected area, for someone buying, building or developing.
On the awareness map, the outermost band is the maximum regional flood extent, reached only in very rare to extreme floods. Inside it, the City grades land as low, medium, high or very high risk. In short: low risk land meets lower hazards in frequent or infrequent floods; at the high and very high end, floods are both more frequent and usually more hazardous, and the City describes the water there as unsafe for people and able to damage vehicles and buildings. The map key on the City’s page gives the exact wording for each band.
The flood level search report
Beyond the maps, the City sells a flood level search report for a single property. It summarises the flood information the City holds: an estimated designated flood level, which is used to set floor levels, and the ground level at the centre of the property. It does not show how far a flood would spread across the land.
The unit. Results are given in metres AHD, the Australian Height Datum, where 0.0 metres is close to mean sea level.
The flood behind it. For most areas, the designated flood level reflects rain with at least a 1% chance of happening in a year, arriving together with a storm tide.
What it leaves out. It covers riverine or regional flooding only, the kind caused by long rain over whole catchments, and not local flash flooding.
The floor rule. The City requires habitable floors in homes to be at or above the combined defined flood level plus a minimum freeboard of 300 millimetres, under City Plan’s flood overlay code and the Building Regulation 2006.
Precision. The City recommends a licensed surveyor to find accurate property and floor levels.
The report can be requested online, at a customer service centre or by post, for an administrative fee listed in the City’s register of fees and charges. The details are on the City’s flood level search page, which also links an example report.
1Ground level at the centre of the lot, as given in the report.
2The designated flood level, in metres AHD.
3Freeboard: at least 300 millimetres for homes, under the City’s rules.
4The habitable floor level, required to be at or above the flood level plus freeboard.
An illustration of the terms, drawn for this guide and not to scale. The real levels for a property come from the City’s report or a licensed surveyor.
Reading the odds
What a 1% flood does and does not mean
The City explains a flood the size of a 100-year average recurrence interval as one with a 1 in 100 chance of happening in any one year. It adds that there is no guarantee about when such a flood will come, that a flood will not be much bigger, or that only one will happen in a year. A property that is not below the designated flood level may still be affected by extremely rare floods.
Building or renovating
For land in a flood risk area, provisions in City Plan’s flood overlay code may apply to building and development. The City also publishes a flood resilient design guideline for people building or renovating there. The City Plan interactive mapping shows the planning layers for a property.
Where a loan comes in
One place flood information meets the money side is insurance. The City offers its flood insurance map for talking through suitable flood cover with an insurer, and suggests asking the insurer or the Insurance Council of Australia about flood insurance itself. Boost to Buy writes cover into its rules: under that scheme, the home must always be insured against damage and destruction, flood included, and against any other risk the lender requires. More on that scheme is in guide 5.