This dataset, created in June 2013, provides an indication of areas subject to overland flow flooding inside the Brisbane City Council local government area.
The overall overland flow layer consists of the 1% Annual Exceedance Probability (AEP) (100 year Average Recurrence Interval (ARI)) flood extent sourced from the Citywide Creek and Overland Flow Path mapping study (GHD, 2017).
High impact area:
In high impact areas, overland flow is almost certain to occur during a single lifetime (70 years). An event of this size or larger has a 5% chance of occurring in any year. The overland flow is generally unsafe for people, vehicles and buildings.
Medium impact area:
For the majority of medium impact areas, overland flow is very likely to occur during a single lifetime (70 years). An event of this size or larger has a 2% chance of occurring in any year. The overland flow is generally unsafe for people, vehicles and buildings, however these hazards are experienced less frequently than in high impact areas.
Low impact area:
For the majority of low impact areas, overland flow is likely to occur during a single lifetime (70 years). An event of this size or larger has a 1% chance of occurring in any year. The overland flow is generally safe for people, vehicles and buildings; however, certain areas can experience greater hazards.