Flood classifications

River gauges assist the Bureau of Meteorology to communicate to an ‘at risk’ downstream community using flood descriptions or flood classifications of an event as ‘minor’, ‘moderate’ or ‘major’. These forecasts warn our communities about the approximate size of a flood and when it is likely to reach different locations so people know how to respond. Flood classifications are defined as:

• ‘Minor’ – Causes inconvenience. Low-lying areas next to water courses are inundated. Minor roads may be closed and low-level bridges submerged. In urban areas inundation may affect some backyards and buildings below the floor level as well as bicycle and pedestrian paths. In rural areas removal of stock and equipment may be required.
• ‘Moderate’– In addition to the minor flooding effects, the area of inundation is more substantial. Main traffic routes may be affected. Some buildings may be affected above the floor level. Evacuation of flood affected areas may be required. In rural areas removal of stock is required.
• ‘Major’ – In addition to the moderate flooding effects, extensive rural areas and/or urban areas are inundated. Many buildings may be affected above the floor level. Properties and towns are likely to be isolated and major rail and traffic routes closed. Evacuation of flood affected areas may be required. Utility services may be impacted.

For more information watch this 2 minute video from the Bureau of Meteorology video titled Understanding Flood Classifications.

More information

Find out more about flood classifications in Queensland.