AT THE POINT
Location: The point is located within the road reserve of the Bulloo Development Road about 17 km east of Thargomindah. The site was located accurately by GPS with access by road and on foot. It is located in Bulloo Shire.
The Landscape: The topography around the site is low-lying and generally flat outwash country that flanks the floodplain of the Bulloo River. Soils are sandy and the geology is Late Cainozoic aged (around 1 million years) unconsolidated sediments.
The vegetation is predominantly low open woodland of gidgee (Acacia cambagei) and mulga (Acacia aneura) with a sparse ground cover of tussock grasses. The land around the site is used for cattle grazing.
Reading the GPS
Col Grant: Observations carried out at exact degree confluence. This confluence is 17km E of Thargomindah, in the Bulloo catchment.
Point information and photos: Jane Terrell-Payne and Les Payne. Additional information by Col Grant (Authors email: email@example.com)
IN THE DEGREE SQUARE
The Country: The land within the degree square is dominated by the floodplain of the Bulloo River, with its braided course, and the low country that flanks the floodplain. Elevations range from around 100 m ASL to not much more than 200 m ASL throughout. The vegetation throughout the square is very similar to that at the confluence point.
Geology is either alluvium in the river floodplains or sedimentary rocks across the rest of the square. The oldest sediments are the Cretaceous age (141 to 65 million years) Winton formation sandstones and mudstones in the north-west and north-east corners of the square.
Col Grant: Bulloo River
The Bulloo River flows south for about 500 km along the eastern side of the Grey Range through several Qld degree squares. while the river flows here, it is destined to come to an end before it reaches the Qld-NSw border, disappearing into a series of lakes, swamps and overflow areas.
Bulloo River, Col Grant 2008
Underlying much of the central and western Qld (and adjacent areas of NSW and SA) is a vast underground water source. The porous sandstone of the Great Artesion Basin holds water that is extracted by the use of bores. Thargomindah is supplied with hot water and previously, hydro-power for street lighting from the Old Bore. A new bore will soon replace this uncapped one.
Old Bore, Col Grant, 2008
The Climate: The area has a desert climate with persistently dry and hot conditions. The Thargomindah Post Office is the most representative climate station. The desert climate is renowned for extremes of temperature. The highest maximum on record was 47.7°C in January 2003 while the lowest minimum recorded was -2.2°C in July 1959. Rainfall can also vary greatly. The highest annual rainfall on record was 740.6mm in 1956 and the lowest annual rainfall was 50.3mm in 1937.
Thargomindah Post Office (045017) 1879-2005
Extremes of Nature: In spite of its distance from the coast at least one tropical cyclone has penetrated into the degree square. TC Agnes which crossed the coast at Townsville in March 1956 was still a Category 1 storm when it passed to the west of Thargomindah.
Cyclone tracks within 200 km of the confluence, 1906 to 2006 (Bureau of Meteorology web site)
The Bulloo River has a record of major floods with that of January 1974 being the greatest recent flood with a gauge height at Thargomindah of 6.78 m. Floods of 6.0 m or more have been experienced six times since 1963, the most recent being in January 2008 (6.07 m). Major flooding such as this requires large scale rainfall over the upper Bulloo catchment - 100mm in 24 hours is sufficient to produce such flooding. Flood waters tend to move slowly, spread across wide areas and have relatively low velocities. They can, however, isolate areas for many weeks and cause extensive stock losses.
Only one small earthquake has been recorded within the degree square, a ML 2.7 event of 26 September 1999 located on the western edge of Lake Bindegolly about 30 km east of Thargomindah.
By far the most common extremes are drought and heatwave.
The Indigenous Story: The degree square straddles the country of the Wangkumara (the north-west), Margany (north-east), Kullilla (south-west) and Budjari (south-east) language groups.
European Exploration and Settlement: The first known Europeans to pass through the area was the party led by William Brahe on their way back to Melbourne after they had buried supplies for the Bourke and Wills expedition at the 'Dig Tree' in 1861. Pastoral development began in 1864 and the wool industry dominated for many years. The town of Thargomindah was gazetted in 1874.
The artesian bore sunk in 1893 was harnessed to provide energy for the world's third (behind London and Paris) and Australia's first municipally-operated electric street lighting.
Today: At the national census of 2011 Thargomindah township had a population of 206, the bulk of it living in Thargomindah. The population across the degree square has been steadily declining for at least the past decade.
The major industry in the area has been cattle grazing, but the mining industry is now becoming dominant with gas and oil fields being tapped within the degree square. Oil production is rapidly being overtaken by the production of natural gas. The Ballera Gas Centre is linked to Moomba in South Australia, and together they supply Adelaide, Melbourne and Sydney and shortly will supply Brisbane, Gladstone and Mt Isa, with gas produced from the Cooper Basin.
The Moomba to Brisbane gas pipeline passes through the square from west to east more-or-less paralleling the Bulloo Development Road - the main access route through the area.
Opals are also found in the area.
The Lake Bindegolly National Park is located about 56 km east of Thargomindah and is recognised as one of the most important inland wetland systems in south-west Queensland. It features three major lakes - Lake Bindegolly (saline), Lake Tamaroo (saline) and Lake Hutchinson (freshwater). More than 190 species of birds have been recorded in the park including Pink-eared, Blue Bill and Black ducks. The park conserves one of only two known populations of the endangered wattle Acacia ammophila.
Compiled by: Jane Terrell-Payne and Les Payne with additional material from Ken Granger 2008 and Col Grant 2008.
Edited by: Hayley Freemantle
Sources: Queensland Museum, 2003: Discovery guide to outback Queensland, Queensland Museum, Brisbane.
Philip Moore, 2005: A guide to the plants of inland Australia, New Holland, Sydney.