Cooper Creek

Cooper Creek is a significant river system in Australia. It spans the states of Queensland and South Australia. This waterway is a vital part of the Lake Eyre basin. It serves as one of three major Queensland river systems that feed into that basin. Most of the time, the creek is ephemeral. This means it does not have a constant flow of water. Instead, its movement depends on monsoonal rains. These rains often fall months earlier in eastern Queensland. The creek's behavior is defined by these distant weather patterns.

The river has a unique way of beginning its journey. It rises west of the Great Dividing Range on low ground. It starts as two distinct central Queensland rivers. One is the Thomson River, located between Longreach and Charters Towers. The other is the Barcoo River, found east of Tambo. This is believed to be the only instance in the world where two rivers flow into a single creek. From there, the water spreads into a vast area. It forms many anastomosing channels. These are interconnected, branching channels that weave through the landscape. The creek moves south through the Channel Country. It eventually turns west into South Australia toward Lake Eyre.

Water movement in the Cooper Creek is highly irregular. In most years, the water is absorbed into the earth. It may fill various permanent waterholes or lakes like Lake Yamma Yamma. Sometimes, the water simply evaporates before reaching its destination. However, very wet years change the landscape entirely. During these times, the creek floods the entire Channel Country. The water travels through the Strzelecki Desert, the Sturt Stony Desert, and the Tirari Desert. In 1940, a massive flood occurred. A vast area around the creek was underwater. During such events, the river upstream of Windorah can become very wide.

The history of this region is very deep. Aboriginal Australians have inhabited this area for over 20,000 years. In the Channel Country alone, more than 25 tribal groups lived. They maintained a vast trade network stretching from north to south. They moved goods like ochre to the north. They also moved shells and pituri to the south. Birdsville served as a major meeting place for trade and ceremonies. Later, European explorers arrived in the mid-1800s. Charles Sturt named the river in 1845. He named it after Charles Cooper, the Chief Justice of South Australia.

Famous explorers also left their mark on this creek. In 1861, the explorers Burke and Wills died here. Only John King survived the expedition. He survived because of the help of friendly Aboriginal people. Ten years after their deaths, people began building homesteads. Innamincka became the first permanent settlement in the area. By 1880, the water source attracted many more settlers. They brought cattle and sheep to the region. This caused the displacement of local Aboriginal people from their lands. By 1900, the local population had dropped to only 30 survivors. This was only 10% of the original number. Diseases like influenza and measles caused this loss.

Scientific studies show interesting facts about the river's flow. The Cooper carries a lot of runoff. It carries twice as much runoff as the Diamantina River. It also carries three times as much as the Georgina River. However, it reaches Lake Eyre much less frequently than those rivers. This happens because much more water is absorbed along its course. There may also be long cycles of wet and dry periods in these basins. Some evidence suggests these cycles occurred during the Medieval Warm Period. This shows how long-term climate changes affect the river's reach.

Today, the land around the creek is used for specific purposes. Most of the basin is used for grazing sheep and cattle. This happens on natural grasslands. The rainfall in the area is very erratic. For example, Blackall receives over 500 mm of rain. However, the rain is too unpredictable for growing crops. The soil in the region is mostly Vertisols or Vertic Torrifluvents. These soils are quite fertile. However, they have a heavy texture. Because the rainfall is so erratic, these soils have a strong tendency to crack. This makes the landscape look very distinct to anyone visiting.