[4][5] The site was officially designated by the federal government on 15 April 2014, after decades of debate on the location of another airport within Greater Sydney.

The Federal Government announced in February 1986 that Badgerys Creek had been chosen as the location for a second major airport for Sydney.

[13] The Federal Government then undertook a series of land acquisitions for the site, primarily during the period 1986 to 1991, and spent approximately A$170 million.

[14] However, following the purchase, the decision was made by the Government that construction of a third runway at Sydney Airport was more appropriate, and all work on the site was halted.

Despite the expansion, concerns remained that Kingsford Smith Airport would run out of capacity by 2030, especially since the introduction of strict night flying restrictions in 1995.

A 3,200-page joined Federal/NSW study released in 2012 concluded that Badgerys Creek was "clearly the best site for a much-needed second airport for Sydney"[16] and recommended that planning should start.

[7][8][10] The site is within the City of Liverpool local government area and consists of approximately 1,700 hectares (4,200 acres) of Commonwealth land that was acquired between 1986 and 1991.

[33] The height started at 1,266 metres (4,154 ft) above ground level over Blaxland, with the southwest path descending over the World Heritage-listed national park, declared wilderness, declared wild rivers, and Warragamba Dam, until reaching 457 metres (1,499 ft), over the township of Warragamba and descending towards the airport over Wallacia, Greendale, Silverdale and Luddenham before landing.

[34] After an extensive community backlash[citation needed] and as a measure to retain her seat of Macquarie, Liberal Louise Markus[35] and the Coalition government announced a scrapping of the Blaxland merge point.

A consistent message portrayed to the public since then is that the flight paths are unknown, will not be released, noise impacts will not be assessed nor community consultation undertaken until after construction of the airport.

In June 2023 the proposed flight paths were released with an interactive online map displaying the predicted noise impacts.

[65] New express bus routes to the airport precinct were announced in March 2018, running from Penrith, Liverpool and Campbelltown.

Eleven months after the purchase, the parcel of land was valued at just $3.1 million, triggering an investigation by the Australian National Audit Office (ANAO).

[66] The ANAO found serious shortcomings in the Commonwealth's acquisition processes, including that:[14] Subsequent to this, the Australian Federal Police announced that they were investigating potential corruption related to the land deal.

Qantas and Jetstar aircraft would be based there within a year of opening, with projected destinations to include Melbourne, Brisbane and Gold Coast.