AT THE POINT
Location: This confluence point is located close to Dry Creek on the lower western slopes of the Shotover Range and around 18 km east of the South Blackall coal mine. The closest settlement is Blackwater about 49 km to the north-north-west. The site lies within the Central Highlands Regional Council area. The site has not yet been visited on the ground.
The Landscape: The point is about 300 m ASL on the lower slopes of the outwash fand that sit below the western scarp of the Shotover Range. The underlying geology is sandstone of Triassic age (251 to205 million years. The vegetation is pasture or grassland and land use is cattle grazing. Dry Creek flows to the Comet River which is a tributary of the Mackenzie and Fitzroy Rivers.
Point information and photos: Ken Granger, Google Earth, 2009
IN THE DEGREE SQUARE
The Country: The landscape of the square is dominated by the Blackdown Tableland and the Shotover, Dawson and Expedition Ranges that run from it. These have a maximum elevation of 946 m ASL whereas the surrounding lowlands have a general elevation of around 300 m ASL. The lowest point in the square is around 75 m where Springton Creek leaves the square to the north.
The mountain block is composed of sandstone of Early Triassic age (230 to 205 million years). In the low ridge that runs north-west from the point there is lateritic duricrust of Quaternary age (less than 1.6 million years). The streams that flow off the Blackdown Tableland complex have several waterfalls, such as Gudda Gumoo (Rainbow Waters) on Mimosa Creek, during periods of good rainfall.
The lowlands are relatively flat and are composed mostly of mudstone and coal of Middle Eocene age (around 40 million years). It is in these formations that several very large open cut coal mines are located.
Looking across the lowlands from the Expedition Range (KG, 2008)
The drainage in the square is dominated by the Comet River and its tributaries including Humboldt, Planet and Springton Creeks. The Comet is part of the Fitzroy catchment, the second largest catchment in Australia after the Murray-Darling. In the main drainage channels there is alluvium also of Quaternary age.
A small weir has been constructed on the Mackenzie River just north of Blackwater to supply the town and the local coal mines.
The vegetation on the tableland and ranges is quite diverse with dry eucalypt forest, moist pockets of ferns and orchids and dry heath country. Its isolation has preserved several endemic species such as the Blackdown wattle and Rainbow Falls callistemon. This vegetation supports a varied fauna with an abundant bird life including the endangers Glossy Black Cockatoo which feeds exclusively on Casuarina nuts.
On the open plains there are remnants of the original eucalypt woodland but much of the native vegetation has been cleared for grazing and more recently for open cut mining. Cattle grazing remains the main form of land use.
The Climate: The climate of the area is classified as sub tropical with a moderately dry winter. The Bureau of Meteorology climate station at Emerald Post Office to the west of the square provides representative statistics. It has an elevation of 179 m, and has recorded data from 1882-1992.
The highest temperature ever recorded in Emerald was 46.2°C in December 1919 while the lowest temperature was -5.6°C in July 1899. Rainfalls also vary greatly. The highest total of 1 407.2 mm was recorded in 1956 and the lowest total of 205.6 mm in 1919. These and other climate statistics for Emerald can be found at on the Australian Bureau of Meteorology website, http://www.bom.gov.au/climate/averages/tables/cw_035027_All.shtml.
Extremes of Nature: The area is prone to the impact of tropical cyclones. The database maintained by the Bureau of Meteorology shows 23 cyclones have passed within 200 km of the point in the 101 years from 1906-7 to 2006-7. Of these four passed within 50 km of the point. They were: an unnamed cyclone in February 1911, an unnamed cyclone of January 1934, an unnamed cyclone in February 1959, and TC Una in December 1973. These cyclones bring destructive winds and intense rainfall that can produce wide-spread flooding. Cyclone information for this area and all of Australia can be found at the Australian Bureau of Meteorology website, http://www.bom.gov.au/cgi-bin/silo/cyclones.cgi.
Cyclone tracks that passed within 200 km of the confluence point 1906-2006 (BoM web site)
Floods in the Comet and Mackenzie catchments are relatively common but tend not to impact of the settlements in the square. The most recent episode was in 2008 when an intense rainfall episode caused major flooding in the Emerald and Blackwater area, including flooding of several major open cut mines. The de-watering of these mines has caused ongoing rises in river levels at places such as the Bedford Weir and the flood scars from that flooding were clearly evident for some time after.
The area experiences around 20 to 25 thunder days each year. Such storms can bring intense rainfall leading to flash flooding. They can also bring strong winds, hail and lightning strikes. Lightning can start bushfires if there is sufficient fuel to sustain a fire.
Bushfires in the rural areas can be difficult to control but are unlikely to do significant damage. Stock and fencing losses are likely.
The area can experience extreme heat throughout some of the year, with Emerald having an average of 62 days annually with maximum temperatures equal to or over 35°C and 5 days with temperatures of 40°C. Such extreme temperatures can cause heat stroke and death if appropriate measures are not taken such as avoiding strenuous physical effort, keeping as cool as possible and drinking lots of water. Heat waves kill more people in Australia than all other natural hazards combined.
By contrast Emerald also has an average of 10 days a year with temperatures of 2°C or less and 4 days of zero or less.
The National Earthquake Database maintained by Geoscience Australia contains no earthquake epicentres within the degree square.
The Indigenous Story: The land within the square is the traditional country of the Gangulu people. The Aboriginal art sites that are located in the Blackdown Tableland National Park is evidence of their long term occupation of country.
Woorabinda was first established in 1927 as a replacement for the Aboriginal camp at Taroom. People from at least 17 different language groups were forcibly placed in the camp and were under the control of the Chief Protector of Aborigines.
In 1942, during World War II, a Lutheran Aboriginal mission at Cape Bedford on Cape York in far North Queensland was closed and the Aboriginal people were forcibly relocated to Woorabinda. Many died from sickness due to the poor sanitation and inadequate shelter from the frost and cold winter nights of the inland climate. One estimate puts the number of deaths of Bedford people during this period at 235. The survivors were allowed to return to Cape Bedford in 1949 to what is now known as Hopevale.
The Woorabinda community is the only Deed of Grant in Trust (DOGIT) Aboriginal community within the Central Queensland region. DOGIT communities have a special type of land tenure which applies only to former Aboriginal reserves. The land title is a system of community level land trusts, owned and administered by the local council.
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European Exploration and Settlement: The first Europeans to pass through the area were Ludwig Leichhardt and his party in 1844 on the expedition from the darling Downs to Port Essington. Leichhardt named the Comet River and other features in the area. Leichhardt was the first to report the coal deposits of the area. Twenty-seven kilometres from the present site of Blackwater, Leichhardt observed 'beds of coal indistinguishable from those on the Hunter at Newcastle'.
Settlers began entering the area by the 1860s, mostly bring sheep and cattle. William Yaldwin settled the area to the north of the Blackdown Tableland in 1869. He named the mountains after his family home in Essex. His attempts to graze cattle in the area were thwarted by the phosphorus-deficient soils of the area which caused his cattle to develop chalky bones.
The first attempt to mine coal in the Bowen Basin was in 1892/93 at Tolmies, near Blackwater, but the workings were abandoned in 1900. It was not until the early 1960s that coal exploration was conducted in the Bowen Basin on a large scale.
It wasn't until the early 1960s that the town really started to develop. In 1959-60 coking coal was found to the south of the town. A mining lease was granted in 1965 and in 1967 the first mine in the area started operating. It is claimed that in 1962 the town's population was only 25. Twenty years later it had grown to over 8000.
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The total population of the degree square at the 2011 national Census was 6851.
The gradual decline in population probably reflects the shift from the construction phase of the local coal mines to the operational status. At the 2011 national census the population of Blackwater was 4834, down from 5036 in 2006, while the Aboriginal community of Woorabinda had a population of 935, an increase from the 2006 population of 851.
Blackwater is the main service centre for the surrounding coal fields that include South Blackwater, Kinrola and Curragh. It has a good range of commercial and community services. The recently opened Blackwater International Coal Centre provides visitor information on the district as well as highlighting the local coal industry and the equipment it employs.
Blackwater (Google Earth image)
Blackwater park (KG, 2008)
he Aboriginal community of Woorabinda has a limited range of commercial and community services. It is located on the banks of Davy Creek.
Woorabinda (Google Earth image)
There is considerable infrastructure within the square much of it supporting the various large open cut coal mines and the gas fields in the area. Several mines have dedicated rail spurs that link them to the main rail link to the export facilities at Gladstone. The gas fields along the western side of the square are linked by an underground pipeline to Wallumbilla to Gladstone gas pipeline. The Capricorn Highway is the main public road in the square and it carries a large amount of heavy transport including material for the coal mines. In all, the square has a total of around 1975 km of public roads.
Heavy transport on the Capricorn Highway (KG, 2008)
Apart from the small Woorabinda Sire, the square is within the Central Highlands Regional Council area. There are three national and conservation parks in the square: Blackdown Tableland National Park, Blackwater Conservation Park and Taunton National Park. They have a combined area of around 350 000 ha.
Compiler: Ken Granger, 2009
Edited by: Hayley Freemantle
Various web sites including EPA, local governments, tourist industry and Bureau of Meteorology.