Headline-grabbing floods in towns like Roma, Charleville and St George have slightly obscured a massive water event that has been quietly snaking its way through far western Queensland. This week Adam Kerezsy flew over flooded Central Australia and has this report on one of the biggest ecological stories this year.

Story and pictures Adam Kerezsy

In late February and early March torrential rain fell in the desert and channel country in far western Queensland. Daily rainfall records tumbled in places like Birdsville and Windorah, and many districts in central Australia received their average annual rainfall in a single event. Coming on the heels of an already wet summer, there was nowhere for the water to go but over the banks of channels, out onto the floodplain and slowly down towards South Australia and Lake Eyre.

The Georgina is the most westerly river that is characterised by what is commonly known as ‘channel country’, a complex system of river channels that are mostly dry, occasionally wet, ever-changing and generally unpredictable. But to the west of the Georgina, the big low that was generating the rain was also letting go over one of the driest areas of Australia – the Simpson Desert.

Bush Heritage Australia – a private not-for-profit conservation company – owns two properties in the east Simpson, and both Craven’s Peak and Ethabuka hug the Queensland/Territory border. The Mulligan River – mostly a dry sandy channel – forms the north-eastern boundary of the Simpson Desert, and flows down through these and other private and company-owned areas before finally – occasionally – meeting the Georgina system at Eyre Creek.

Max Tischler and I have both been working for Bush Heritage Australia as ecologists, and prior to this both have been crawling around this particular part of Australia for a little longer than most people would consider sensible. Max generally stays out of the water and keeps an eye on birds and reptiles and mammals, whereas I’ve been tracking fish movement into the Mulligan since 2006. A strange obsession, it must be admitted, for deserts and fish are not the most obvious bedfellows.

Desert ecosystems are boom-bust. Mostly bust – when its dry, everything just hangs on. Occasionally boom. And 2010 is going to be a massive, massive boom. So when we started receiving the ‘9 inches overnight!!’ rainfall stories we knew it’d be a long time before we could get out and get dirty again, knew it’d be extremely interesting once we finally did, and started wondering just what Bush Heritage’s desert reserves were actually looking like. There was only one way to find out, because unlike Charleville or Roma, there aren’t any population centres in the east Simpson.

A week after the big rains hit we were at 500 feet, heading south from Mt Isa, and properly excited about just how much water we might see. The folded and sometimes jagged countryside south-west of the Isa was uncharacteristically green, but it wasn’t until we hit the Georgina that we realised just what a big year 2010 will be. As the Georgina headed east and then south like a giant, distended snake, we kept flying west into the desert. In the swales in-between sand dunes were huge dollops of water. The roads we normally drive down disappeared abruptly into vast expanses of muddy central Australian wetland. We picked out the landmarks we knew that were tall enough to protrude through the floodwaters and directed the pilot south. This was the Mulligan – formerly a sandy channel you hardly notice you’ve crossed, now a massive inundated floodplain many kilometres across and broken only by dune crests and the tops of gidgee trees. Following the 2007 flood seven fish species migrated up to 300 kilometres to enjoy a temporary – and ultimately fatal – stay in the fickle Mulligan on Ethabuka and Craven’s Peak. By early 2008 they were all gone as the river evaporated into the deep blue sky. In 2009, another flood year, we picked up an extra species – a hardyhead that was previously only known from the Lake Eyre region in South Australia. Our minds boggled at what might cruise up the Mulligan in 2010.

As you push further into the desert the dunes become closer, and they run in a parallel north-west to south-east orientation. Max had a particular goal in mind – to check whether the extremely remote Field River had also received the rain. The Field is nothing more than a swale with a few more trees than the swales on either side. A true desert river. Max has been chasing rats and lizards out there for years. Sure enough, as we approached the Field, we noticed the sun reflecting off a mobile surface, and realised that we were part of an extremely elite club – people who had actually witnessed the Field River flowing.

So there’ll be an explosion of life on Ethabuka and Craven’s Peak this year – both properties smack-bang in some of the harshest country Australia dishes up. The boom is most definitely just about to happen, and with a bit of luck we’ll be able to track the population changes in the plants, rats, reptiles, frogs and fish that either call the Simpson home or take their chances on the unpredictable floods and head north into the wet desert.

There’ll probably never be a better year to measure just how bountiful the boom can be.