In 1975 the Australian government presented a idea to use which source to irrigate the Australian deserts?

In 1938, Dr John Bradfield (1867-1943), a Queenslander and an Australian, and the civil engineer, who designed the Sydney Harbour Bridge and Brisbane's Story Bridge proposed a scheme where the dry outback regions of Queensland would be irrigated from the rivers in tropical Northern Queensland. These large plentiful rivers had vast quantities of water supplemented by an annual monsoon. It was expected to provide irrigation for more than 3,000 square miles (7,800 km2) of agricultural land in Queensland that was considered too arid for agricultural production. It was debated for many years (a revised scheme was developed in the 1970s and tabled in the Queensland Parliament in 1981). Still, a final decision was made in 2022 when the Queensland Government released a report that concluded "There is simply not enough consistently available water to make the proposals work," the report said.

https://www.csiro.au/en/research/natural-environment/water/water-resource-assessment/the-bradfield-scheme-assessment
https://www.abc.net.au/news/2022-12-09/queensland-government-abandons-bradfield-scheme-after-report/101751678