Cooper Creek, 2004. Photo: V Norris
The drainage basin of the Cooper Creek covers 297,000 km2, making up almost a quarter of the LEB. Around 80 percent of it lies in Queensland, with close to 18 percent in South Australia and just over 2 percent in New South Wales. The Cooper is Australia's largest braided stream, best demonstrated in the vast section of 'Channel Country' which occurs across the low lying areas along 400 kilometres of river channel from just north of Windorah to the South Australian border. The greatest length measured for the Cooper is 1,523km, and except for the headwater areas, much of the catchment has little relief, with very low slopes of only a few centimetres per kilometre. More rain (400-600 mm/yr) falls in the north, with only 50-100 mm/yr on average falling in the arid south.
- Two major rivers come together to form the Cooper - the Thomson River from the Desert Uplands and some of the Mitchell Grass Downs in the north, and the Barcoo River from the north-east.
- Downstream from the junction of the Barcoo and the Thomson near Windorah, the Cooper usually floods out slowly between sand dunes, across gibber plains and into wetlands and waterholes.
- The only major water storages are waterholes, 6-25km long and 7-10m deep on average. Seven large waterholes make up half the estimated volume of waterhole capacity on the Cooper floodplain.
Major flood events
- In major floods, the Cooper can be many kilometres wide, which prevents accurate gauging of high flows, but this can sometimes be done near Innamincka where the Cooper cuts through a range of hills.
- Downstream from Innamincka, the Cooper divides into the main branch and a north-west branch. In a major flood, the north-west branch delivers water to the extensive
Coongie Lakes system, which supports thousands of breeding waterbirds.
- The Cooper is the most variable river in the world so although Lake Coongie itself rarely dries out, the whole system only fills occasionally.
- Only rarely, about once every 10 years, does the Cooper actually reach Kati Thanda-Lake Eyre, sometimes as long as 10 months after tropical monsoonal deluges fall in the northern part of the catchment.
- In 2011, the Cooper flowed the entire length of its catchment from its source in the White Mountains, 220km south-west of Townsville, to its mouth on the eastern shore of Kati Thanda-Lake Eyre.
- A variety of landscapes are found in the Cooper Creek catchment - channel country (predominates), Mitchell Grass plains, sand dunes, spinifex grasslands, gibber deserts, stony plains and acacia woodlands.
- Some of the areas near stock routes have been designated as biodiversity hotspots e.g. Cooper Creek Waterhole near Windorah.
Demographic and land use features
- About 12,000 people (ABS 2001) live in the Cooper catchment, with most concentrated in the north, where Longreach is the largest town with just over 4,100 people in the local government area (ABS 2011).
- Mining (primarily oil and gas in the Cooper/Eromanga Basin) contributes most to the economy, but the major land use is grazing.
- Tourism and unconventional gas are the fastest growing industries in the region.
- the Moomba gas fields
- Longreach - the birthplace of QANTAS
- The National Stockman's Hall of Fame (also in Longreach)
- The many lakes and waterholes that host thousands of breeding birds after heavy rains
- The Strzelecki Desert, a magnet for 4WD camping enthusiasts