AT THE POINT
Students from Eromanga State School mark the confluence point. (Photo by Eromanga SS, 2008)
Location: This confluence point is located 3.4 km east of the Cooper Developmental Road, between Moorinah and Tintaburra Creeks which are tributaries of the Wilson River. The point is located on Mt Margaret Station within Quilpie Shire. The nearest town is Eromanga, 44.5 km to the north-east. The point was reached by road and then on foot with several channel crossings required. The point was accurately located using GPS.
The Wilson River and its tributaries drain to Cooper Creek and ultimately to Lake Eyre.
Vegetation across the area is generally similar to that at the confluence point with Mulga and Gidgee (Acacia cambagei) the most prominent shrubs. Ground cover ranges from tussock grasses to saltbush on some of the higher country. Lignum thickets are common along the drainage lines. Coolibah (Eucalyptus coolabah) and River Red Gum (E. camaldulensis) are often found along the levees of the main drainage channels.
Fauna and land use is fairly similar across the square as that found at the confluence point.
The Climate: The climate of the area is classified as persistently dry desert. The nearest climate station included in the Bureau of Meteorology's web site is Quilpie, about 130 km to the east.
Quilpie Airport (site 045015 1917-2008 (elevation 200 m ASL)
The highest temperature ever recorded in Quilpie was 46.5°C in January 1973 while the lowest temperature was -2.3°C in July 1977. Rainfalls also vary greatly. The highest total of 919.3 mm was recorded in 1950 and the lowest total of 91.4 mm in 1937. Temperatures in the degree square may be slightly hotter in the summer and colder in the winter than Quilpie and rainfall is likely to be marginally lower.
Extremes of Nature: In spite of its remoteness from the coast the area has been subject to the impact of cyclones. The database maintained by the Bureau of Meteorology shows that four cyclones have tracked within 200 km of the confluence point since 1906. TC Agnes formed out in the Pacific near Fiji in March 1956, TC Audrey formed in the Gulf in January 1965, TC David formed near Vanuatu in January 1976 and TC Gertie formed in the Timor Sea in December 1995.
Cyclones like these, as well as cyclones that pass much further to the north, bring heavy rain with serious floods. In the Channel Country such floods can spread many tens of kilometres from the main streams and inundation can last for many weeks. Towns like Eromanga can be isolated for weeks on end in a big flood. Generally, however, floods in these areas can take weeks to flow through the catchments and there is generally plenty of time to move stock and other possessions to safe places before the flood peak arrives.
Unlike floods in coastal rivers, floods in the interior are more welcomed than feared because they replenish soil moisture, surface water storages and replenish the vegetation. Trees such as the Coolibah and River Red Gum, for example, need such floods to germinate their seeds and thus maintain their species.
The area experiences between 15 and 20 thunder days each year. These storms can bring destructive winds and flash flooding, however, the major threat is from bushfires that can be sparked by lightning strike if there is sufficient fuel for the fire to spread.
Drought is undoubtedly the most destructive of all natural hazards in this region. The climate data for Quilpie shows that zero rainfall has been experienced at least once in every month of the year since 1917. During periods of drought sand storms can be an additional hazard bringing reduced visibility and causing people with respiratory illness great distress.
Tracks of cyclones that passed within 200 km of the confluence point (Bureau of Meteorology web site)
Extreme heat is also a serious issue. The climate records for Quilpie show that on average (over 52 years of records) the area experiences 98 days a year with temperatures over 35°C and 20 days a year with temperatures over 40°C. Such extreme temperatures can cause heat stroke and death if appropriate measures are 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.
The National Earthquake Database maintained by Geoscience Australia contains no earthquake epicentres within the degree square. The nearest epicentres were located at about 125 km distance; one to the south near Murrawarra Creek and to other the north-east in the middle of the Cooper Creek's braided channel. The southern event occurred on 30 July 1970 and had a magnitude of ML 3.2; the north-eastern event was on 23 September 2002 and had a magnitude of ML 2.3. No damage was recorded from either event.
The Indigenous Story: The area is the traditional home of the Wangkumara people. The name Eromanga is said to be an Aboriginal word meaning 'windy plains'.
MORE INFORMATION WELCOME
European Exploration and Settlement: The earliest explorers to penetrate this area were Edmund Kennedy in 1847, Augustus Gregory in 1858, Burke and Wills in 1859 and Alfred Howitt (searching for the Burke and Wills party) in 1861. Graziers, such as the Duracks, followed bringing sheep flocks to the great sandy plains. They were followed in the 1870s by prospectors. The first freehold opal leases were granted in 1875 and the town was named and gazetted 1879. Opal mining was so significant that by the early 1880s the town was known as 'Opalopolis'. By 1883 Eromanga had a population of around 500 and its first hotel had been built. The Royal Hotel became a Cobb and Co staging post. The decline in opal mining, the vagaries of the climate and their impact on the grazing industry and the development of roads led to a decline in the town's population.
In the 1980s the area became the focus for oil and gas exploration and most exploratory wells showed hydrocarbons. In 1985 a small oil refinery was built near Eromanga to exploit crude oil from the Kenmore field and to produce automotive distillates, jet fuel, special solvents and specialist chemicals.
Today: The total population of the degree square at the 2011 national census was around 50 with the bulk of then living in Eromanga. The population has been in decline over the past decade. The peak of 154 was recorded at the height of the oil exploration stage and was made up largely of male oil and construction workers. The rural population has remained fairly constant though it too is in decline.
The dominant land use across the area remains the grazing of sheep and cattle, though the grazing industry is regularly impacted by drought, floods and plagues of grass hoppers.
The search for alternative sources of energy to replace fossil fuels has again brought a focus on the Cooper and Eromanga Basins where the potential for geothermal energy is believed to be significant.
Eromanga is reputed to be the town furthest from the sea in Australia.
Edited by: Hayley Freemantle
Compilers: Ken Granger, 2008
References: various web sites including EPA, local governments and Bureau of Meteorology.
Queensland Museum, 2003: Discovery guide to outback Queensland, Queensland Museum, Brisbane.