Occasionally, certain areas in the Scenic Rim region are subject to flooding. Council has undertaken flood modelling to seek to identify areas in the region that are subject to riverine flooding and ensure that if these flood events occurs, we are well-informed and ready to take action.
Council has produced region-wide riverine flood mapping to assist the community's understanding of the flood risk to the region as a whole. These region-wide flood maps can be viewed at Riverine Flood Mapping.
The flood mapping only shows those key waterways of the region that are potentially impacted by riverine flooding. Riverine flooding occurs when excessive rainfall over an extended period of time causes a waterway to exceed its capacity resulting in flood waters spilling over its waterway banks and causing inundation.
Council's riverine flood mapping does not include all waterways. There may be small waterways, in particular intermittent waterways, that are not fully included in Council's flood models. These small waterways may experience flash flooding, causing short term overland flooding.
The flood mapping does not include local flooding. Local flooding is an intense burst of rainfall over a short period of time that may cause excessive run-off that builds up in a confined area and causes localised flooding. Inundation is expected to last only for a limited period of time until the run-off is able to drain away.
Council's riverine flood mapping is based on the 1% Annual Exceedance Probability (AEP) event. An 1% AEP flood event represents a flood that has a 1% chance of being equalled or exceeded in any year. Whilst the 1% AEP flood event is commonly used for urban planning purposes as the line of acceptable risk, there is always a possibility of having rainfalls beyond that contemplated by the 1% AEP event that may exceed the designated flood level. Rainfall events which cause floods are random and there is no guarantee when such a flood will occur, that it won't be much larger, or that it will only occur once in any year.
Council's flood mapping has been informed via flood models. A flood model is a computer simulation of a river or floodplain system to determine the magnitude, extent and depth of flooding; how fast floodwaters rise; and the implications for flood damage and emergency planning. As with all flood models, Council's flood models are an estimation of the flood event that is projected or anticipated to occur. The models are based on science, but similar to weather forecasting, flood modelling is not an exact science. It is instead an educated, fact-based indication of the likely outcome of particular rainfall events in specific catchment conditions. To improve the accuracy of Council's flood models, Council has compared the model outputs with historic flood events recorded across the catchments in the region.
Council has undertaken flood modelling of the key waterways of the region based on the 1% AEP event, which is shown in dark blue in the riverine flood mapping. There may be minor waterways not included in the flood mapping, in particular in the upper reaches of the catchments. The flood mapping contained within this website has also included State government mapping, shown in light blue, where this mapping is available. This information may include or be accompanied by specific disclaimers or limitations. Those disclaimers and limitations apply in addition to those outlined above.
It is everybody's responsibility to be aware of the risks and what to do in a flood emergency. Check the flood risk to your property by clicking on the link to the riverine flood mapping. If all or part of your property is shown as blue in the flood maps, it has been identified as at risk of being impacted by riverine flooding. To gain a clearer understanding of flooding hazard in the region, Council encourages you to review the Temporary Local Planning Instrument and Fact Sheet, or contact Council's Planning Section on 5440 5111.
Council's Disaster Management page provides important information about preparing for an emergency. It is important to be prepared for emergencies and you will need a plan for you and your family (including pets and livestock).