The Australian Electoral Commission yesterday published the official statistics that will be used for federal redistributions in South Australia, Tasmania and the ACT. This gives us a bit more insight into what is likely to happen in those redistributions.
Electorates must be drawn so each seat is within 10% of average enrolment at the start of the process (in this case, August 2025), but also so that seats are within 3.5% of the average for a projected enrolment three-and-a-half years after the end of the process (in this case, April 2030). That second rule is much stricter, and thus ends up being more important in the drawing of new seats.
In a previous post, I looked at the population patterns based on June enrolment data. But we didn’t have projected data until yesterday afternoon. So for this post I will look at that second set of datapoints.
Not one seat deviates from the first quota by more than 10%. Nine seats deviate from the projected quota by more than 3.5%: Barker, Bass, Bean, Canberra, Clark, Lyons, Makin, Mayo and Spence.
Firstly, South Australia.
The biggest deviations are in the northern suburbs of Adelaide. Spence is projected to be 12% over quota, while the neighbouring seat of Makin is almost 8% under quota. Mayo is also about 8% over, while Barker is almost 4% under quota. Pretty much every other seat is slightly under quota.
It seems most likely that Spence will shrink, and the surplus voters will mostly go into Makin. Mayo will also need to shrink, likely giving some of those surplus voters to Barker.
In Tasmania, the Hobart-area seat of Clark is projected to be 10% under quota. So Clark will need to grow. Franklin is 3.2% over quota, so can absorb some of that growth, but it will be necessary for Clark to expand north into parts of northern Hobart that are currently contained in Lyons. That central seat is almost 10% over the projected quota. Bass is also 4.4% under quota, so will also need to take more voters from Lyons.
Right now Lyons includes outer suburban areas in both the Hobart and Launceston areas, and they will be the first to be cut, making Lyons more of a rural seat. It’s hard to see any scenario that doesn’t make Lyons more favourable for the Liberal Party.
There just aren’t that many different ways to shift populations in these small jurisdictions with a small number of electorates, and that is particularly true of the ACT. The growth in the ACT has been fastest in the south, with the southern electorate of Bean 7.6% over quota. While the northern seat of Fenner is slightly under quota, it’s the central seat of Canberra which is most under. So I expect we’ll see Canberra expand south, probably taking in parts of Woden or Weston Creek. Fenner can be mostly left alone, but it could gain some more of the Belconnen area to produce more equal numbers.