The State Emergency Service (SES), with support from external engineering specialists, has developed the Tasmanian Strategic Flood Maps. The project was jointly funded by the Tasmanian and Australian Governments. The mapping is based on robust methods that align with national and international standards.
These maps are produced using computer flood models, which provide the best available estimates of flooding based on current data, though they are simplified representations of real-world conditions.
Flood Models and Flood Maps
The flood modelling assesses both the current flood risk and the projected risk for the year 2100. The 2100 modelling takes into account the expected impacts of climate change, including shifts in annual rainfall patterns and increases in storm intensity.
Flood maps have been created for the following scenarios:
• 2%, 1%, and 0.5% annual chance of occurrence (Annual Exceedance Probability – AEP) based on historical rainfall records
• 1% annual chance of occurrence under the climate conditions projected for 2100
The mapping can be accessed via the following link:
The maps show the predicted extent of floodwaters. Additional information can be accessed using the Add Layer button, searching for ‘flood’ and selecting additional layers under the Statewide Flood Hazard category. These additional layers include the 2% and 0.5% AEP as well as water level and water velocity maps.
Where an area is predicted to be impacted by flooding on these maps, it may be subject to the Flood-Prone Areas Hazard Code in the Tasmanian Planning Scheme – State Planning Provisions.
It’s important to note that actual flood events may differ from model predictions due to natural variations such as:
• uneven rainfall distribution across a catchment
• prior river levels and soil saturation before a flood event
• tidal influences or storm surges in coastal areas