Canberra House of Representatives seats for South Australia reduced to 10 in 2018 due to population loss

South Australia's federal electoral divisions for the House of Representatives. At left: The metropolitan seats after the 2018 redraw showing Port Adelaide replaced by an extended Hindmarsh. Right: The huge Grey seas was made slightly bigger. Grey and Barker in blue denoted Liberal held, Wakefield in red for Labor, and Mayo in gold for Centre Alliance, also taking in Kangaroo Island.

South Australia lost a federal electoral House of Representatives division – reducing the state’s members from 11 to 10 – in the 2018 redraw of national boundaries to allow for population changes. 

The Port Adelaide seat in the Adelaide metropolitan area was dropped, replaced by the extended Hindmarsh division. In the redraw, the huge seat of Grey, covering 92% of mostly outback South Australia, had about 17,000 voters from the Clare and Gilbert Valley, Adelaide Plains and parts of Light and Wakefield council areas added.

Voting for federal elections (including byelections) was compulsory for eligible citizens over the age of 18. Federal elections were held on variable dates around a three-year terms. Half of the 12 members representing South Australia in the Australian senate in Canberra were elected at the same time as House of Representatives general elections. Senators were elected for six-year terms.

The loss of South Australian federal House of Representatives divisions in 2018 – taking them to the lowest level since 1954 – was based on the state’s population being calculated at 1,716,966, compared with Tasmania having the smallest state population at 519,050 and the territories: Australian Capital Territory (419,256) and Northern Territory (247,512). All other states had bigger populations than South Australia, ranging from New South Wales with 7,797,791 to Western Australia with 2,567,788.

The number of members from states and territories was decided by a population quota decided by the number of the people of the Australian commonwealth divided by twice the number of senators for the states. Working on a population of the six states at 23,729,561, and twice the number of senators for the states being 144, the population quota was about 164,788.

The House of Representatives had a total of 151 members in 2021.