One in 100-year floods could instead become annual events among new predictions for how rising sea levels will affect Brisbane over the rest of this century.
Maps released this week show low-lying Brisbane suburbs, including Hemmant, Northgate, Strathpine, Bald Hills and Tingalpa, are most likely to be affected by sea level rises by the year 2100.
Suburbs along the Brisbane River, including Bulimba, New Farm and Woolloongabba, are also at risk of being flooded more frequently.
The maps calculated future water levels across all major capital cities with the use of laser technology, and were developed by the federal Department of Climate Change and the Co-operative Research Centre for Spatial Information.
See the maps in full:
- Brisbane's northern suburbs
- Brisbane's inner northern suburbs
- Brisbane's eastern suburbs
- Brisbane's bayside suburbs
- Brisbane's southern suburbs
The projections measured the impact of high tides resulting from seas rising various levels between 0.5 metres by 2100, which is considered unavoidable, and 1.1 metres.
The maps show low-lying suburbs alongside Brisbane's creeks and lakes are most at risk of being inundated by king tides, rather than oceanfront areas.
While the ocean is shown to encroach on some bayside suburbs, areas between Hemmant, Murarrie and Tingalpa are completely underwater.
Most of Brisbane Airport could also be regularly submerged by the end of the century, according to the maps.
Bruce Thom, the chairman of the Australian Coastal Society, said the impact of sea-level rises would be similar to the "Venice effect".
"You do not see one big flood, but a greater frequency of inundation due to high tides," he said.
"Seventy years ago St Mark's Square in Venice, Italy, would only be flooded just a few times a year. Now the square is flooded a couple of hundred times a year."
We have had a lot of people move to Brisbane and they have chosen to live near this beautiful, idyllic little creek in suburbia. I'm afraid they don't know that it could turn into a raging torrent
Research centre chief executive Peter Woodgate warned the maps were only showing the predicted tidal rise and did not take into account the impact of flooding rains and storms, which would occur much more regularly.
“One in 100 year [flooding] events would be occurring once a year,” Dr Woodgate said.
"... If you get flooding coinciding with a high tide, as we do, then the impact will be even worse."
Dr Woodgate said he hoped that within two years the centre would be able to predict flooding levels for every backyard in high-risk Brisbane suburbs.
"We will be able to go door-to-door and talk to residents about what the implications are and what needs to be done," he said.
"It may show that there are homes which are [unsustainable] but we cannot reach that conclusion until will do further detailed analysis.
"We need to think about the protective infrastructure we can put in place, for example, higher levy banks, better drainage systems and different building materials."
Lord Mayor Campbell Newman again warned new residents yesterday of the flooding risks in the city.
"My concern is that over the last 15 years we have had a very dry period and we are now seeing a return to the conditions that prevailed during the 60s and 70s," he told 4BC Radio.
"Since then we have had a lot of people [move to Brisbane] and they have chosen to live near this beautiful, idyllic little creek in suburbia. I'm afraid they don't know that it could turn into a raging torrent and it could actually threaten their property."
Cr Newman encouraged residents to make themselves aware of the flooding risk to their property and take out adequate flood insurance.