The Basin was once home to a large number of Aboriginal people whose traditional lifestyle and cultures were gradually altered by the arrival of Europeans, while others were outright killed by the settlers.

Although some tribes organised resistance, such as the Maraura, whose territory lay around the Rufus River above Renmark and the Tanganekald near The Coorong, they were eventually either killed, exiled, or succumbed to disease.

The study found [5] that there were: Historical records show that the previous abundances of fish provided a reliable food source.

[7] Today, roughly 24 native freshwater fish and another 15-25 marine and estuarine species are existent in the Basin, a very low biodiversity.

[10] Initial investigations by the New South Wales Environment Protection Authority (EPA) included single water samples at six sites and were criticised as inadequate.

[11] Subsequently it was announced that the New South Wales government will treat the deaths as a "pollution incident", thus giving the EPA greater investigative powers; earlier testing was described as being primarily intended to ensure public safety.

[13] These fish are very mobile, breed rapidly and can survive in very shallow water and through long periods of very low dissolved oxygen content.

Cane toads have entered the upper reaches of the Darling Basin and there are several reports of individuals being found further down the system.

These waters are divided into four types:[17] The two principal rivers of the Basin, the Murray and Darling, bring water from the high ranges of the east and carry it west then south through long flat and dry inland areas,[19] often resulting in alluvial channel wetlands, such as The (Great) Cumbung Swamp, at the terminus of the Lachlan and Murrumbidgee Rivers.

[2] Under the River Murray Waters Agreement, which did not include Queensland though about a quarter of the Basin lays in the state, the commission was an advisory body with no authority for enforcement of provisions.

[32] Conversely, support for the Murray–Darling Basin plan has been received by various groups, including Australian Conservation Foundation,[33] and Environment Victoria.

The Government's interpretation is that the plan must give equal weight to the environmental, social, and economic impacts of proposed cuts to irrigation.

[36] In late October 2010 the Water Minister, Tony Burke, played down the prospect of a High Court challenge to the Murray–Darling Basin plan, as confusion continued over new legal advice released by the Government.

In response to community concerns that MDBA had put environmental issues first over social and economic needs, Burke released new advice on the requirements of the Water Act.

[38] The then MDBA chairman, Mike Taylor, reassured the public meeting that more work is being done to look at how the proposed cuts would affect regional communities.

[39] Taylor resigned as he allegedly believed that the overriding principle should be the environmental outcome which was in conflict with the Gillard Government and following a period of sustained criticism of the Authority and the implementation of the proposed draft Basin plan.

Following much negotiation between the Commonwealth and State governments and numerous submissions from interested stakeholders and the community, the Basin Plan became law in November 2012 and can now be implemented.