Kati Thanda-Lake Eyre

The rare flooding of Kati Thanda-Lake Eyre

The spectacularly rare sight of Kati Thanda-Lake Eyre full of water and teeming with fish and birdlife is on full display for anyone who can get to northern South Australia in the next few weeks. It’s the largest salt lake in the country, and it’s only reached capacity 3 times in the past 160 years - but locals have warned the show won’t last long… So in this Squiz Shortcut, we’ll take a look at:

• why the lake is unique

• what’s caused the temporary oasis to spring up

• and the impacts climate change might have on it in the future...

Prefer to listen or watch?

Listen to Andrew Williams and Claire Kimball cover this topic in this Squiz Shortcut podcast episode, or check it out on YouTube - and hit subscribe while you’re at it.

Listen time: 13 minutes

Squiz the Shortcut

Why are you telling me about a big lake?
There’s a good reason, we promise… There’s a really rare event happening at the moment in South Australia that not many people have ever seen - even Aussies - and that’s the sight of Kati Thanda-Lake Eyre full of water. 

What’s special about that?
This isn’t just any lake. Kati Thanda-Lake Eyre is one of the largest salt lakes in the world - it’s 9,700km2 - and it draws from a catchment area that’s 5 times the size of the UK. But why this flooding event is news, is because the lake is usually bone-dry - and all of this water has brought lots of little fish, which in turn attract millions of birds, so the whole area has been transformed into a beautiful desert oasis… 

Let’s get our bearings… Where exactly is it?
It’s in the South Australian outback, around 700km north of Adelaide and 300km from the nearest coast. At 15.2 metres below sea level, it’s the lowest point in the country, and it’s fed by 2 main river systems…

Which ones are they?
The Georgina-Diamantina Rivers, and Cooper Creek… They flow south from Queensland into the Kati Thanda-Lake Eyre basin which essentially forms a giant drainage system.

How does that work?
The lake is an ‘ephemeral’ or 'terminal lake', meaning the water evaporates instead of running out to sea. And where it’s located in the outback, temperatures get real hot, real quick. That’s why there’s only a few more weeks to take in the sight of the full lake… 

What happens after that?
Locals are reporting that the water has peaked, so there’s a “hard cut-off” to see it by air because when we get into November, temperatures there hit 40 degrees and over, putting people’s safety at risk. And once the water starts evaporating, the lake becomes even more of a showstopper.

Why is that?
It turns a vivid pink colour which is caused by a pigment found in a type of salt-loving algae. The photos are very pretty - we’ll include a link in our recommendations… 

So, why has the lake filled up now?
It’s because floodwaters from the very heavy rains and monsoonal conditions that followed Tropical Cyclone Alfred earlier this year in Queensland have made their way down through that drainage system. Side note: the lake is thought to be around 200 million years old and the natural depression was formed by tectonic movement.  

What’s the story behind its name?
The first European recorded to have to set eyes on the lake was the explorer Edward John Eyre, and he called the region “inhospitable and impracticable” country. He saw the lake as a huge barrier in his way which he was forced to go around…

Quite the detour… 
Sure was… So that was back in 1840, and after his first sighting of the lake, the government named it after him as Lake Eyre. But it’s an area of cultural significance to the Indigenous Arabana and Dieri people who, far from finding it inhospitable, lived and thrived in the desert landscape well before Eyre spied it…

Do they still live there?
Yep… The Arabana lodged a native title claim over the area in 2012, and in December that year the lake was renamed Kati Thanda–Lake Eyre to reflect the traditional name, which the Arabana Aboriginal Corporation says means ‘the name of the lake which was formed after the skin of a kangaroo was spread over the ground’... 

So it’s quite important to them?
Yes… The story is part of Aboriginal cultural mapping, and the lake is a sacred Indigenous site… But the story of how the lake floods, and the changes it brings to the desert when it does, has long enthralled Aussies from all walks of life - particularly scientists… 

When did it last fill up?
Back when Australia had its wettest year on record in 1974 - we’ll do the maths for you, that’s 51 years ago, so it’s a long time between drinks…

Has this year been similar to 1974?
In 2025, northern Australia has experienced even more rainfall than 1974, while parts of southern Australia have been in drought… But where Kati Thanda-Lake Eyre is concerned, the heavy rains in southwest Queensland in the wake of Tropical Cyclone Alfred back in March caused devastating flooding in what’s known as Channel Country. There were huge losses of crops and livestock; whole farms went under… And as the floodwaters flowed south, from May there were predictions that the lake would fill. 

And they were right?
Yep… The water was slow-moving but it travelled over 600km, and according to reports from local pilots, it’s now reached all parts of the lake, bringing a heap of wildlife with it.

Tell me more about that… 
The life cycle of the animals that survive there is fascinating. It’s a dry, flat salt bed most of the time, but when it rains, or on the rare occasions that it floods, wildflowers cover the desert plains and millions of tiny brine shrimp hatch from eggs in the lake bed. The fish that are carried downstream by the floodwaters eat the shrimp, and all of that food then attracts waterbirds in their millions. One report says pelicans, stilts and other waterbirds find their way there from as far away as China and Japan..…

Are there other species too?
Yep… They’ve evolved and adapted to having no water for large periods of time - like inland crabs and shield shrimps (they lay eggs that dry out and can survive for up to 7 years until the next deluge, when they’ll hatch and repeat the whole cycle). So, this flood event is rare, but climate experts predict that warming ocean temperatures and changing climate conditions will start to have an impact…

How so?
They say those warming sea temps are starting to cause more frequent extreme weather events like cyclones that bring with them heavy rains, which in turn cause floods like we saw in Queensland earlier this year. And with all of that, the lake is likely to fill more often, but on the flip side, hotter temperatures could have an effect on the lake’s fragile ecosystem.

Just explain that a bit more…
Studies from the University of Adelaide have found that rising temperatures have already increased salinity and algae levels in the lake. And more intense evaporation is another factor that’s changing the habitat for the species there, increasing vulnerability for many of them… Then there’s another sort of threat - humans.

How are humans a threat?
Even though the lake’s remoteness serves as some protection - it’s a long drive to get there - this latest flood and the free promotion that comes with so many people posting images of it on social media, has brought an influx of tourists to the area. And with them has come pollution, rubbish and foot traffic around the lake’s shore. 

How popular is it?
Local pilot Trevor Wright reckons it’s a top 10 bucket-list item for baby boomers with the time and money to travel, so on the bright side, there’s money coming into the local economy too. But to manage it all, the South Oz Government has had to take some measures…

What sort of measures?
They’ve banned visitors from walking on the lake bed to protect the salt crust and out of respect for the Arabana people who consider it sacred… That was back in February when it was still dry. It’s a far cry from 1964 when British speed racer Donald Campbell used the salt flats as a racetrack to break the world land speed record. But soon enough, the lake will return to that dry state. 

How long is the water likely to last?
Wright says it could hang around for up to a year before it completely goes - but between December and March, the national park is closed because temps during the day reach 50 degrees and over…

Yikes…
Exactly… So if you miss it now, you won’t get another chance for a while.

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Onto our Recommendations

Reading: This piece published in The Guardian about the effects of climate change on the lake and how it stands to impact the Arabana people.

Watching: An ABC documentary called Lake Eyre… It’s all about the lake and its ecology when it floods, and it’s billed as one of the most extensive coverages of the cycle of life in the desert. Tragically, ABC journalist Paul Lockyer, cinematographer John Bean, and pilot Gary Ticehurst died in a helicopter crash while filming the documentary back in 2011… The ABC has put out a commemorative edition in tribute to the crew, and it’s available on iView.

Perusing: And here are some of the latest images of the full lake taken by local pilot Trevor Wright.

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