SA redistribution finalised

South Australia’s Electoral Districts Boundaries Commission published the final version of the state redistribution yesterday, to come into effect at the next state election in March 2026.

Compared to the draft redistribution, the EDBC has generally made the changes even more minimalistic, reversing changes in a number of areas. 27 seats had been untouched on the draft. On the final maps, 30 seats will be left unchanged. The draft moved 3.5% of voters to a new seat – that is now just 3.3%.

The changes in the Adelaide area were already minor but the map shows a bunch of seats in Adelaide have been put back as they were.

Changes between Black, Gibson and Morphett have been reversed, while changes between Black, Reynell and Hurtle Vale have been modified. Changes between Croydon and West Torrens have also been reversed. Changes in the northern outskirts of Adelaide have been left alone.

Outside of Adelaide, there have been some more substantial changes. The seat of Frome has been renamed Ngadjuri. The seat has shifted south to be closer to Gawler on the northern outskirts of Adelaide, but no further changes to the boundary have taken place since the draft was published.

The other major change was to the area of central South Australia that runs from Giles north-west to the WA and NT borders. This enormous area is sparsely populated but does include over 5,000 voters. Quite a few of these voters would live in the Anangu Pitjantjatjara Yankunytjatjara, or APY, lands in the north-western corner of the state.

These areas were contained in the Whyalla-based seat of Giles in 2022, but the addition of the second half of Port Augusta meant Giles needed to lose this area. The draft added this area to the seat of Flinders, which covers Port Lincoln and a majority of the SA coastline. But on the final boundaries, it has been added to independent Geoff Brock’s seat of Stuart, which now stretches from New South Wales to Western Australia. Stuart was already undergoing a significant redrawing as it has lost the remainder of Port Augusta. On the draft, 27.9% of Stuart’s electors were new. On the final map, that number is 35.6%.

Just nine seats have undergone changes between the draft and final boundaries, so the changes to margins are subtle. They make no difference to the swings needed for Labor to lose its majority or for the Liberal Party to gain a majority (ignoring any defections or by-election changes).

The biggest change in margin between the draft and the final was Black. The pre-redistribution margin was 2.7%, and it was cut to 1.1% on the draft redistribution, and it has now bounced back to 2.7%. Of course this doesn’t consider the recent Black by-election, which Labor won with a 9.9% margin.

I estimate that the addition of extra areas in Stuart has increased Geoff Brock’s very safe margin from 16.4% to 17.0%, although this is still less than the 17.1% result in 2022.

The Labor margin in Morphett has also reverted back to its election margin of 4.5%, after the draft increased the margin to 5.1%.

That’s it for now – I’ll be looking to find the time to prepare my guide to the 2026 South Australian state election in early 2025.

Margin estimates

Primary vote estimates

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