The lowest point in Australia fills with water only a few times per century. When it floods, pelicans appear from nowhere in the desert to breed on a temporary lake.
Phanly, CC BY 3.0
A basin below the sea
Kati Thanda-Lake Eyre is the focal point of one of the world's largest internally draining river systems, the Lake Eyre Basin, which covers about 1.2 million square kilometers, or nearly one-sixth of Australia. The lake is an enormous salt pan, or playa, and its deepest point sits approximately 15 meters below sea level, making it the lowest point on the continent. This depression is a result of tectonic downfaulting that occurred around 30,000 years ago, cutting off a previous outlet to the sea.
The lake bed is a dry, shimmering expanse of salt. Evaporation rates are extreme, averaging between 2,500 and 3,500 millimeters annually. This intense evaporation concentrates salts, leaving a crust that can be up to 50 centimeters thick in the southern sub-basins of Lake Eyre North. The water that does reach the lake is often already saline, and as it evaporates, the lake becomes hypersaline. When full, its salinity is comparable to seawater, but this concentration increases dramatically as the water disappears.
Boom and bust ecosystem
Full flooding of Kati Thanda-Lake Eyre is a rare event, happening only a handful of times per century; major fillings were recorded in 1950, 1974, and 1984. Minor floods that fill a portion of the lake occur roughly every three years, while more significant fillings happen about once a decade. The water originates not from local rain; the area receives less than 150 mm annually, but from monsoonal rains that fall thousands of kilometers away in Queensland. This water slowly travels south through a network of braided channels and floodplains known as the Channel Country, a process that can take months.
When the floodwaters arrive, they trigger a dramatic biological transformation. Dormant eggs of brine shrimp (Parartemia) and shield shrimp hatch in the revitalized lake bed. This explosion of crustaceans provides a massive food source for fish, like the Lake Eyre hardyhead, that are carried down by the floodwaters. This, in turn, attracts immense flocks of waterbirds. In the 1989-1990 flood, an estimated 200,000 Australian pelicans (Pelecanus conspicillatus), representing about 80% of the country's total population, arrived to breed. How these birds, from coastal areas thousands of kilometers away, sense the lake has water is not fully understood. Theories suggest they may detect atmospheric changes associated with distant, large-scale rainfall. The birds must breed quickly, as the lake begins to evaporate almost immediately, and a complete filling can dry up in about two years.
💡Fun Facts
The lake’s official name, Kati Thanda–Lake Eyre, was adopted in 2012 to incorporate the name used by the local Arabana people.
In 1964, Donald Campbell set a world land-speed record of 403.10 mph (648.73 km/h) on the lake's salt flats in his wheel-driven car, Bluebird CN7.
When the lake is full, it covers an area of up to 9,500 square kilometers, making it the largest lake in Australia.
The Lake Eyre Basin has fish species that can reportedly live for up to 80 years, surviving in isolated waterholes during dry periods.
The park is accessible 24/7, but public access routes are often closed during the summer from December to mid-March due to extreme heat. Always check the Desert Parks Bulletin for current conditions.
Admission
A vehicle entry fee is required. Camping fees also apply for overnight stays at designated campgrounds.
Accessibility
Access is via remote tracks suitable for 4WD vehicles only. The terrain is flat but can become impassable after rain. Recreational access to the lake bed itself (walking, driving) is not permitted to protect the fragile environment and for safety. Viewing is from designated lookouts.
