REFERENCED DOCUMENT Flood Emergency Management Plan - MCU13/0064

Flood Classifications

At each flood warning river height station, the severity of flooding is described as minor, moderate or major
according to the effects caused in the local area or in nearby downstream areas.




Major Flooding: This causes inundation of large
areas, isolating towns and cities. Major
disruptions occur to road and rail links.
Evacuation of many houses and business
premises may be required. In rural areas
widespread flooding of farmland is likely.

Moderate Flooding: This causes the inundation
of low lying areas requiring the removal of stock
and/or the evacuation of some houses. Main
traffic bridges may be closed by floodwaters.

Minor Flooding: This causes inconvenience
such as closing of minor roads and the
submergence of low level bridges and makes the
removal of pumps located adjacent to the river
necessary.




The zero level of a river gauge ("gauge zero") is typically set at the low flow level of the stream, i.e. the water
level of the stream after a long dry spell. River heights are measured in metres above the gauge zero. For
example, a river height reading of 5 metres means that the water level has risen 5 metres above its lowest
level. In tidal areas, the gauge zero may be set at the mean tide level.

Each river height can be converted to its equivalent on Australian Height Datum (AHD) by applying the AHD
value of the gauge zero. Contact the Bureau of Meteorology if this is required.