In Australia, it is important to distinguish between perennial (permanently flowing) and nonperennial (seasonally flowing) rivers and water.
The Australian continent is divided into drainage divisions, which are subdivided into water regions and then into river basins.
Use initial capitals for formal names:
Indian Ocean Division South Australian Gulf Lachlan Catchment
but not for generic or plural uses:
Australia’s drainage divisions lower and upper catchments
Reminder. Initial capitals are used only for formal names. Informal and collective (plural) references to the same item do not need capitals.
