Whilst Australia shows less topographical relief than any other continent, it is nonetheless full of watersheds and river systems. In the arid zone, the surface of these rivers only flow with water after periodic rainfall. The vegetation of rivers varies along their lengths, from the rocky higher tributaries where there are shrubs like Eremophila (native fuschia), tea tree (Melaleuca) and perennial grasses; the rivers often will pass through spectacular gorges. At this stage the rivers are lined with River Red Gums (Eucalyptus camaldulensis) and Coolibahs (Eucalyptus microtheca). The branches of River Red Gums are apt to fall without warning, especially but by no means exclusively during still hot summer days. Do not camp underneath these trees.

The rivers of the arid zone will eventually end up like the Finke, disappearing into the sands of the Simpson Desert, or terminating in clayey floodout areas like the Diamantina, where the predominant plants will be lignum (Muehlenbeckia) or Chenopod shrubs.

The topography of the arid zone is invariably flat, causing the rivers often to braid, or flow out into a myriad of channels, such as channel country in Western Queensland. Many rivers, especially in rangelands are subject to flash flood events. Caution should be exercised whenever camping in river beds. Often rainfall which occurs in the upper catchment will not be apparent downstream and you can be caught unawares.