[3][1] In 1970, the Labor-led South Australian government, headed by Don Dunstan, was concerned that Adelaide would become overpopulated following rapid population growth caused by high rates of both birth and immigration in the two decades prior.

[8] In total, population growth was in excess of 3% per annum and the government estimated Adelaide would reach 1.5 million by the end of the century.

[9] Further, the authorities believed that the growing population would, sooner or later, become a threat to the social and environmental quality of urban life, which at the time was relatively high.

[11][12] The government estimated that 1.3 million was the optimal population for Adelaide, which meant that Monarto would have to accommodate about 200,000 people by the end of the century.

thought that the project was motivated by political interest and that the state government only wanted to improve its electoral prospects in nearby Murray Bridge.

[8] Additionally, geographer Professor Peter Scott was sceptical about the idea of a new city, pointing out that population growth was less than had been projected.

This attitude would come to affect planning over the area, as the commission wanted to find a balance between the natural features of the site, its built-form and infrastructure.

On a broad citywide scale, key landscape features would form the basis of park lands articulating built-up areas.

After years of planning and conflicts about compensation of farmland that had been compulsorily acquired, the project reached a turning point when new studies showed that the population growth was excessive.

[citation needed] At the 2011 Census, residents of Monarto are mostly employed in sheep, beef cattle and grain farming (6.8%), school education (4.7%), road freight transport (3.4%), public order and safety services (3.0%) and hospitals (3.0%).

[26] At the 2016 Census, residents of Monarto are split between landscape construction services (11.4%), meat processing (9.1%), hospitals (9.1%) and dairy cattle farming (6.8%) with another 6.8% employed in oil and gas extraction.

[27] A 24-hour freight-only airport at Monarto was proposed by the Liberal party while in opposition in 2017 as part of a broader policy to create a freight bypass of Adelaide from Murray Bridge to the Barossa Valley via Truro.

[28] The party was elected to government in March 2018 and the planning for the new airport and associated freight network was put to tender early July 2018.