The overland water flows responsible for unexpectedly flooding thousands of homes in February this year have been added to a new flood map for Brisbane.
Brisbane City Council's new Flood Information Online tool provides an interactive online flood tool designed to make finding information easier.
Brisbane Lord Mayor Adrian Schrinner said about 1,100 ground surveys, 21 hydrology models and 21 hydraulic models were used to generate the new maps.
Flood levels were also surveyed at more than 550 locations and gauges inspected at more than 450 locations.
Surveyors also recorded debris markings at more than 90 locations.
The new maps show overland flow more significantly impacted northside suburbs Albion, Windsor, Wilston and Newmarket in 2022, compared to 2011.
In the flood-prone southern suburbs Oxley, Rocklea, Yeronga, Tennyson, Graceville and Chelmer, 2011's floods affected a far bigger area.
The maps show how overland flow inundated Toombul Shopping Centre, as well as Albion's Sandgate, Crosby and Abbotsford roads and New Farm's James, Browne and Clay streets.
"The new Flood Awareness Map has been updated to better display information with clearer navigation, simpler language, and improved functionality across devices," he said.
"The online tool also includes a new historic flood layer displaying the extent of the February 2022 flood with mapping for both river and creek flooding included."
The updated FloodWise Property Report also makes it easier for residents to visually understand how flooding may affect a property for building and development.
"More than 540,000 residents downloaded property reports between January and May this year so we know this update will be a popular feature for residents wanting to be better prepared," Cr Schrinner said.
App competition extended
Cr Schrinner also urged residents to sign up for the free Brisbane Severe Weather Alerts app.
"More than 11,750 residents have signed up for the free alerts since the February flood event, but it remains important if you're not registered to sign up so you can be prepared," he said.
Labor council opposition leader Jared Cassidy said despite a competition encouraging residents to download the app during September, only 3,000 people had done so, taking total subscribers to just over 176,000.
At the end of August, Cr Schrinner said about 8,000 had signed up since February this year.
The competition, offering a range of prizes including a family trip to Tangalooma, has been extended to anyone who signs up before December 1, 2022.
