The Coliban River, an inland perennial river of the north–central catchment, part of the Murray-Darling basin, is located in the lower Riverina bioregion and Central Highlands region of the Australian state of Victoria. The headwaters of the Coliban River rise on the northern slopes of the Great Dividing Range and descend to flow north into the Campaspe River with the impounded Lake Eppalock.

The Murray–Darling Basin is a large geographical area in the interior of southeastern Australia, encompassing the drainage basin of the tributaries of the Murray River, Australia's longest river, and the Darling River, a right tributary of the Murray and Australia's third-longest river. The Basin, which includes six of Australia's seven longest rivers and covers around one-seventh of the Australian landmass, is one of the country's most significant agricultural areas providing one-third of Australia's food supply. Located west of the Great Dividing Range, it drains southwest into the Great Australian Bight and spans most of the states of New South Wales and Victoria, the Australian Capital Territory, and parts of the states of Queensland and South Australia.