Greenhouse policies International agreements Individual action Teachers guide 1995. Introduction Inland waters refers to all the water on or under the land-rivers, lakes, wetlands and groundwater basins. As Australia is such a dry continent, the state of its inland waters is very important. The volume of inland waters is largely determined by the quantity of rainfall and the rate of evaporation. Rainfall that is not absorbed by soil or evaporated is called run-off.
Rivers carry run-off eventually to the sea.
Australia has few permanent lakes on the mainland. The Murray-Darling is Australia's main river system, but its volume of flow is low by world standards. It is claimed that the volume of water carried by the Murray in a year is discharged by the Amazon in just a day and a half. When in flood, the Fitzroy River in the Kimberley region of Western Australia can discharge as much as the Amazon in a day. But for most of the year it carries little water.