FLOOD WARNING SYSTEM
This brochure describes the flood
warning system operated by the Australian Government, Bureau of
Meteorology for the Nebine, Mungallala and Nebine Creeks . 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.
Wallam Creek at Homeboin
|Contained in this
document is information about:
(Last updated April 2014)
The Nebine, Mungallala and Wallam Creek catchments are located about 100 to 150 kilometres west of St George in southwestern Queensland and drain an area of approximately 36,000 square kilometres. Mungallala Creek rises in the Chesterton Ranges 50 kilometres northwest of Mitchell. The Nebine and Wallam Creeks rise in an area south of a line between Mitchell and Morven. The small townships of Bollon and Mungallala are the only towns in the catchment.
All three creek systems flow in a southerly direction, parallel to each other for some 250 to 300 kilometres, before crossing the Queensland and New South Wales border west of the town of Hebel. They join the Culgoa River prior to entering the Darling River system upstream of Bourke.
Floods normally develop in the headwaters area of Nebine, Mungallala and Wallam Creeks. However, general heavy rainfall situations may occur throughout these vast catchments. In recent years, the catchments have seen extensive flooding particularly in May 1983, April 1990, February 1997 and in March 2010. The flood of March 2010 produced large scale traffic disruption and residential area inundation. There were also localised communities that required evacutation.
Previous flood information for the Nebine, Mungallala and Wallam Creek catchments are well documented, with river height records for Homeboin and Tomoo dating back to the 1950's. The record major flood of March 2010 caused widespread traffic difficulties and property inundation.
The Bureau of Meteorology operates a flood warning system for the Nebine, Mungallala and Wallam Creeks based on a rainfall and river height observations network shown on the map. The network consists of a number of volunteer rainfall and river height observers who forward observations by telephone when the initial flood height has been exceeded at their station.
The Bureau's Flood Warning Centre issues Flood Warnings and River Height Bulletins for the Nebine, Mungallala and Wallam Creeks during flood events. Qualitative flood forecasts are issued when moderate flood levels are likely to be exceeded.
Local Council's throughout the Nebine, Mungallala and Wallam Creek catchments may be able to provide further details of flooding in your area.
The Bureau of Meteorology issues Flood Warnings and River Height Bulletins for the Nebine, Mungallala and Wallam Creek catchments 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 :
Radio stations, particularly the local ABC, and local commercial stations, broadcast Flood Warnings and River Height Bulletins soon after issue.
These include the Councils, Police, and State Emergency Services in the local area.
Internet/World Wide Web
Flood Warnings, River Height Bulletins and other weather related data is available on the Bureau's Web page at http://www.bom.gov.au . The Queensland Flood Warning Centre website is http://www.bom.gov.au/qld/flood .
Flood Warnings are available through a recorded voice retrieval system, along with a wide range of other weather related and climate information.
|Main Directory||Phone||1900 955 360|
|Flood Warnings||Phone||1300 659 219|
Telephone Weather Services Call Charges:
1900 numbers: 77c per minute incl. GST; 1300 numbers: Low call cost - around 27.5c incl. GST.
(More from international, satellite, mobile or public phones)
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 Nebine, Mungallala and Wallam Creek catchments - it contains the flood gauge heights of the more significant recent floods.
|River height station||Homeboin||Bollon||Mungallala||Tomoo||Deelamon|
Historical flood heights for all river stations in the Nebine, Mungallala and Wallam Creek catchments Floodwarning network, as shown on the map, are available from the Bureau of Meteorology upon request.
NEBINE, MUNGALLALA AND WALLAM CREEK CATCHMENTS - ASSESSMENT OF THE FLOOD POTENTIAL
Major flooding requires a large scale rainfall situation over the Nebine, Mungallala and Wallam Creek catchments. The following can be used as a rough guide to the likelihood of flooding in the catchment :
Average catchment rainfalls in excess of 25mm, with isolated 50mm falls, in 24 hours may result in stream rises and the possibility of minor flooding and local traffic disabilities. If rainfalls have been recorded in the previous 2 to 3 days, then moderate to major flooding may develop.
Average catchment rainfalls in excess of 50mm, with isolated 75 to 100mm falls, in 24 hours may result in significant stream stream rises with the possibility of moderate to major flooding developing, particularly in the lower reaches of all three catchments and extending downstream to the Queensland and New South Wales border.
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.
|Minor Flooding :
Causes inconvenience. Low-lying areas next to watercourses 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 Flooding :In addition to the above, the area of inundation is more substantial. Main traffic routes may be affected. Some buidlings may be affected above the floor level. Evacuation of flood affected areas may be required. In rural areas removal of stock is required.
Major Flooding :In addition to the above, 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.
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 Nebine, Mungallala and Wallam Creek catchments.
River Height Station
First Report Height
Minor Flood Level
Crops & Grazing
Moderate Flood Level
Towns and Houses
Major Flood Level
All heights are in metres on flood gauges.
(B) = Bridge (C) = Causeway (X) = Crossing
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:
For the latest rainfall and river height conditions please use the following link:
For the latest rainfall and river height network map please use the following link:Network maps
For further information, contact:
The Regional Hydrology Manager, Bureau of Meteorology, GPO Box 413, Brisbane Q 4001