Cooper Creek does not behave like an ordinary river. It is ephemeral, dry for long stretches, and it has no urgency about reaching the sea. Flowing out of Queensland into the Lake Eyre Basin, it spreads and braids across almost flat country, and on the lower floodplain it fans out into the lakes and channels of the Coongie system. Only after the rarest and largest floods does any of this water push all the way down to Lake Eyre. Most years it simply pools, soaks and evaporates here, in a triangular wetland whose management boundary runs from Lake Moorayepe in the north down toward Marion Hill, with its eastern edge brushing the South Australia border just past Innamincka.

Life in this country runs on a switch. For years the lakes may shrink and the channels crack into dry mud. Then a flood arrives from the north, and within weeks the desert detonates into growth. Plants race to seed, fish surge through the filling channels, and waterbirds pour in from across the continent. Coongie Lakes regularly supports more than twenty thousand waterbirds - ducks, cormorants, pelicans, ibises, spoonbills, herons and waders - which gather here to feed and breed before scattering again as the water falls away. This boom-and-bust rhythm, driven by a free-flowing desert river, is a phenomenon rarely seen anywhere else on Earth, and it is why the system is recognised internationally.

The vegetation maps the water with precision. Along the creek banks and the regularly flooded ground stand river red gums and coolibahs, often over a dense tangled understorey of lignum. Step away from the channels and the world changes abruptly: the gibber plains, paved with wind-polished stones, carry only a scatter of Mitchell grass, while the surrounding dune country grows hardy desert specialists - sandhill wattle, sandhill canegrass and species of Dodonaea. In a single short walk you can pass from shaded riverine forest to open desert, the entire transition compressed into a few hundred metres by the simple presence or absence of floodwater.

The world noticed early. On 15 June 1987 the Coongie Lakes were listed under the Ramsar Convention as a wetland of international importance, and they are also recognised nationally in the Directory of Important Wetlands in Australia. The protected wetland is vast - the management area is reported at around twenty-one thousand square kilometres - and it overlaps a patchwork of reserves: the Innamincka Regional Reserve, the Strzelecki Regional Reserve and the Malkumba-Coongie Lakes National Park, along with the Coongie Lakes Important Bird Area. Roughly a thousand kilometres north of Adelaide, it remains one of the least disturbed large wetland systems in arid Australia, valued precisely because the river that feeds it has never been dammed or diverted.