Located in the south-east of Australia, the Murray-Darling Basin covers 1 061 469 square kilometres, equivalent to 14% of the country's total area.
East-west, the Basin extends 1250 km, from the most easterly point near
From the source of the Warrego River in the north to the headwaters of the Goulburn River in the south, in latitudinal terms from 24°S to almost 38°S, the distance is some 1365 km .
Figure 1 The Murray-Darling Basin
Boundaries and topography
The Basin is defined by the catchment areas of the Murray and Darling Rivers and their many tributaries.
To the east and south, the Great Dividing Range forms the limit of the Basin, including Australia's highest country, with Mount Kosciuszko rising to 2228 metres.
In the north, west and south-west, the boundaries are much less distinct, particularly in the Wimmera to the south-west and with the Bulloo Basin to the north-west, both areas of internal drainage.
Elsewhere, areas of low to medium altitude mark the Basin's limits, including the Mount Lofty Ranges in the south-west, the Grey and Barrier Ranges in the west, and the Chesterton and Warrego Ranges in the north.
Most of the Basin is extensive plains and low undulating areas, mostly below 200 metres above sea level. Of greatest extent are the vast plains, the Darling Plain in the north, drained by the Darling and its tributaries, and the Riverine Plain in the south, drained by the Murray and Murrumbidgee and their tributaries.
Proportion in each State
The Basin's extends over three-quarters of New South Wales, more than half of Victoria, significant portions of Queensland and South Australia, and includes the whole of the Australian Capital Territory. Well over half of the Basin is in New South Wales and almost a quarter is in Queensland (Table 1).
Table 1 State shares of the Murray-Darling Basin
An important consequence of the extent of the Murray-Darling Basin is the great range of climatic conditions and natural environments, from the rainforests of the cool and humid eastern uplands, the temperate mallee country of the south-east, the sub-tropical areas of the northeast, to the hot, dry semi-arid and arid lands of the far western plains.
Some Basin facts
At the time of European settlement the range of species in the Basin included 85 mammals, 367 birds, 151 reptiles, 24 frogs and 20 freshwater fish.
The Basin has at least 35 endangered birds and 16 endangered mammals with 20 mammals being extinct.
There are 11 introduced species of fish in the Basin.
It is estimated that there are more than 30 000 wetlands in the Basin.
The total area of crops and pastures irrigated in the Basin is 1 472 241 hectares. This is 71.1% of the total area of irrigated crops and pastures in Australia (2 069 344 hectares). Note, these figures are based on 1992 estimates.
Around 70% of all water used for agriculture in Australia is used by irrigation in the Basin (1992).
The Basin is Australia's most important agricultural region, accounting for 41 per cent of the nation's gross value of agricultural production (1992).
Manufacturing industries in the Basin have a turnover of more than $10.75 billion (1992)
More detailed information can be found in the Basin encyclopedia.