This brochure describes
the flood warning system operated by the Australian Government, Bureau
of Meteorology for the Barron River. It includes reference information
which will be useful for understanding Flood Warnings and River Height
Bulletins issued by the Bureau's Flood Warning Centre during periods of
high rainfall and flooding.
The Barron River has a catchment area of about 2100 square kilometres above Kamerunga at the mouth of the delta and has its headwaters in the area immediately east of Atherton. From this area, the river flows north to Tinaroo Falls Dam which has a catchment area of 550 square kilometres which is only about 25% of the total catchment area. The Barron River continues in a northerly direction through Mareeba before it takes an easterly turn near Bilwon and flows generally eastward to the Barron River delta.
There is a strong rainfall gradient across the catchment with the heaviest rain typically falling along the coastal strip around Cairns and Kuranda. In the western area of the catchment, rainfall totals tend to be significantly less. Heavy localised rainfall along the coastal strip up to Kuranda can cause rapid river rises in the lower Barron River around Kamerunga although larger floods tend to be associated with catchment wide heavy rainfalls.
The Barron River delta area can be subject to major flooding with low lying areas being susceptible. Large areas of agricultural areas can be inundated and residential areas affected. Tides can have a significant impact on the smaller floods near the river mouth but little effect in larger floods.
The Barron River has a quite well recorded flood history with documented evidence of flooding as far back as the early 1900's. Records at the key reference gauge at Myola show that the largest flood occurred in early 1911 and significant floods have occurred in the late 1970's and in 1999.
Tinaroo Falls Dams, constructed in 1958, has little effect on large floods in the Barron River.
The Bureau of Meteorology operates a flood warning system for the Barron River catchment based on a rainfall and river height observations network shown on the map. In consultation with the Cairns Regional Council, the Bureau issues flood warnings whenever the Barron River at Kamerunga is expected to exceed 5 metres. The target lead time is to provide 6 hours warning of flood heights exceeding this level. These warnings are updated up to every three hours during flood events.
The real time ALERT flood reporting network in the Barron River enables flood predictions to be made earlier and with more accuracy.
The Bureau's Flood Warning Centre issues Flood Warnings and River Height Bulletins for the Barron River catchment during flood events. River height predictions are given when moderate flood levels are likely to be exceeded.
The Cairns Regional Council and the Mareeba Shire Council are able to provide further information on flooding in the area of the Barron River catchment.
Barron ALERT System
The Barron River ALERT flood warning system was installed in 1995 as a cooperative project between the Bureau of Meteorology, the City of Cairns and the Cairns Port Authority. The system comprises a network of rainfall and river height field stations which report via VHF radio to base station computers in Cairns.
The field stations send reports for every one millimetre of rainfall and every 50 millimetre change in river height. The Barron network has a total of 17 field stations of which nine measure rainfall and river height, six measure rainfall only and two monitor water level only.
The base station computer in the Cairns Regional Council offices collects the data and has software that displays it in graphical and tabular form. The data is also received by the Bureau's Flood Warning Centre where it is used in hydrologic models to assist in formulating river height predictions.
Flood Warnings and Bulletins
The Bureau of Meteorology issues Flood Warnings and River Height Bulletins for the Barron River catchment regularly during floods. They are sent to radio stations for broadcast, and to local Councils, emergency services and a large number of other agencies involved in managing flood response activities.
Flood Warnings and River Height Bulletins are available via :
Internet/World Wide Web
Interpreting Flood Warnings and River Height Bulletins
Flood Warnings and River Height Bulletins contain observed river heights for a selection of the river height monitoring locations. The time at which the river reading has been taken is given together with its tendency (e.g. rising, falling, steady or at its peak). The Flood Warnings may also contain predictions in the form of minor, moderate or major flooding for a period in the future. River Height Bulletins also give the height above or below the road bridge or causeway for each river station located near a road crossing.
One of the simplest ways of understanding what the actual or predicted river height means is to compare the height given in the Warning or Bulletin with the height of previous floods at that location.
The table below summarises the flood history of the forecast locations in the Barron River catchment. Note that all heights are in metres on flood gauges.
[*] These heights are taken at old gauge sites and may not relate to flood levels from existing gauges sites.
Historical flood heights for all stations in the Barron River flood warning network, as shown on the map, are available from the Bureau of Meteorology upon request.
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. Terms used in Flood Warnings are based on the following definitions.
Each river height station has a pre-determined flood classification which details heights on gauges at which minor, moderate and major flooding commences. Other flood heights may also be defined which indicate at what height the local road crossing or town becomes affected by floodwaters.
The table below shows the flood classifications for selected river height stations in the Barron River catchment.
All heights are in metres on flood gauges.
(B) = Bridge (S) =Spillway
The above details are correct at the time of preparing this document. Up-to-date flood classifications and other details for all flood warning stations in the network are at:
Flood gauge information
For the latest rainfall and river height conditions please use the following link:
Latest rainfall and river heights
For the latest rainfall and river height network map please use the following link:Network maps
For further information, contact:
Regional Hydrology Manager, Bureau of
GPO Box 413, Brisbane Q 4001