The Phenomenon of Lake Eyre
Kati Thanda-Lake Eyre, in Central Australia, is the largest salt lake on the continent. It’s often dry, but on rare occasions it fills. So why does it flood?
WORDS Shaney Hudson
Kati Thanda-Lake Eyre is located in the heart of Australia’s centre in South Australia. Here, the red sand of the Simpson Desert is juxtaposed with the colourful water that has filled and emptied its basin for more than 200 million years.
While the native title holders and traditional custodians of the land, the Arabana people, would have seen the lake fill and dry for thousands of years, until 2012, the lake was named after English explorer Edward John Eyre, who crossed the interior of Australia in 1840. In 2012, it was officially dual-named with its traditional Indigenous name: Kati Thanda.
WHERE THE WATER FLOWS
Marking Australia’s lowest point at 15 metres below sea level, Kati Thanda-Lake Eyre acts as a drainage basin for one-sixth of Australia’s land mass. Known as an endorheic basin, it is one of the world’s largest internally draining river systems, meaning there is no outflow to other external bodies of water, such as rivers or oceans. Instead, the waters evaporate under the harsh desert heat, leaving behind a large salt pan.
Rainfall from the Flinders Ranges (Ikara-Flinders), Simpson Desert (Munga-Thirri-Simpson) and Western Plateau empty into Kati Thanda-Lake Eyre, and even minimal bursts of local rainfall can transform the lake. But the big water, when it arrives, travels a magnificent distance, mainly from monsoonal rain and floods in Queensland, but also overflowing from the Northern Territory and South Australia.
It’s a journey that transforms the interior of the country. The bulk of the rainwaters cascade down the Diamantina and Warburton River systems, snaking its way across the desert, leaving a veil of vibrant native wildflowers in its wake.
Tours from above show Kati Thanda-Lake Eyre’s glory in its fullness, including its vibrant rivers and the diverse waterbirds that call it home.
WATER WORLD
While a small amount of water is always scattered in the lake basin, being able to catch the lake in its full aquatic splendour is unpredictable. A small flood occurs on average every three years, a larger one every decade, and Kati Thanda-Lake Eyre has filled to capacity a mere three times in the past 160 years.
When the lake does fill, it becomes the 13th biggest lake in the world and it’s then the party gets started. The waterbirds come in their thousands: pelicans and banded stilts, the desert-dwelling galahs and shorebirds: silver gulls, pink-eared ducks, grey teals and whiskered terns. It’s estimated more than 80 bird species descend on the lake to roost, breed and feed. First, they feast on the fish carried hundreds of kilometres through the river system into the lake. Then, as the water recedes and becomes salty, the birds snack on the brine shrimp that hatch in the waterways. The birds are not the only ones to show up. Scientists, professional ornithologists, amateur twitchers and of course, tourists, descend in flocks almost as great as the birds. There’s even a yacht club committed to sailing the waters when they reach a suitable depth.
“ When the lake does fill, it becomes the 13th biggest lake in the world and it’s then the party gets started.”
BIRD’S-EYE VIEW
The best way to see Kati Thanda-Lake Eyre is from above. Scenic flights over the lake leave daily, crossing the waterway in its various states of aquatic dress, and undress.
Whether it is brimming with water or bone dry, the lake tells a different story from the air. When Kati Thanda-Lake Eyre is filled with water, the area around it, and the channels that feed it are lush and green. When it is full, the view is of glistening splendour, the birdlife and colours giving rise to a thriving inland sea.
As the lake recedes, it becomes hypersaline, and if the conditions are right, begins to be fringed with pink hues reminiscent of a watercolour painting. This phenomenon is caused by the presence of halophilic microorganisms, which thrive in the intensifying saltiness of the water. These small creatures produce beta-carotene, the reddish pigment that gives the lake a serene pink tinge.
As the last water evaporates, the surface becomes a crystallised, bone-white colour, leaving a harvestable commodity mined by mineral companies, a favoured racetrack for land speed records, and from above, an otherworldly area that looks like the surface of the moon.
Like an abstract painting coming into focus, it’s only when you view Kati Thanda-Lake Eyre from above that you can truly appreciate how much beauty and natural science lies hidden in the outback.
Experience a Natural Wonder
See Kati Thanda-Lake Eyre in all its glory on a 14-day Outback South Australia & Kangaroo Island tour with Outback Spirit. This small-group all-inclusive adventure takes you through the most-spectacular sights in South Australia. Starting from $8,675 pp twin share, 2024 tours will operate from April-October, book now to secure your spot.