We rely on independent mapmakers to draw electoral boundaries at each redistribution. There is an extensive process of public consultation, and there are rules about how seats can be drawn, but ultimately the mapmakers have quite a lot of discretion about how they apply guidelines, and where they draw the lines.
This post is looking at how boundaries are drawn federally. I have noticed some evidence of the federal mapmakers choosing boundaries that minimised the number of voters moved between electorates during the 2022-25 round of redistributions, which has sometimes produced quite strange boundaries. I think it raises some questions about how they apply the criteria, and why.
First I should clarify who I mean when I talk about “mapmakers”. For federal redistributions in Australia, there are six people who play a role in actually deciding the boundaries. The Redistribution Committee draws up the draft boundaries. This committee involves two senior AEC officials and two state public servants: the Commissioner, the Australian Electoral Officer for that state, and the state’s Auditor-General and Surveyor-General. For the final boundaries, the decision is made by the Augmented Electoral Commission, which consists of the first four members as well as the two remaining members of the Electoral Commission: the chair, who is a retired judge, and the Australian Statistician. That’s a long list of experienced and senior public servants from a variety of organisations.
The 2022-25 redistribution cycle was the biggest redistribution cycle since the first modern redistribution process in 1984. Redistributions are usually much more significant when a state or territory has a change to their seat entitlement. I call these “major redistributions”. In 2023, three states had a change in their entitlement, and those three states made up 100 out of 150 seats in the 2025 House. There was also a minor redistribution in the Northern Territory.
The last round of redistributions took a very long time. This next chart compares how long each stage of major redistributions have taken in the last twenty years – and also compares it to the 1984 redistribution.
The 2023-24 redistributions were some of the longest processes on record. It’s worth noting that there was a problem with the population projections for Victoria and Western Australia being incorrect, and requiring more time to use fresh projection data.
So there was pressure on the mapmakers to draw boundaries for over two thirds of Australia, with the schedule blowing out. That is worth noting for what we talk about next.
Prior to the last election, I calculated data on the number of voters moved from each old seat to each new seat at every federal redistribution since 1994. When I did this, I noticed that the proportion of voters moved in the last cycle was quite low compared to past major redistributions.
There have been ten cycles with a major redistribution since 1994 (there were no major redistributions in 2013). Of those ten, the proportion of voters moved ranged from 11.5% in 2022-25, up to 21.2% in 2016-19. The average was 16.2%, and no other redistribution involved less than 13% of voters moving.
This then reminded me of a number of examples of strange boundaries drawn during the 2022-25 cycle that seem to be best explained as a method to minimise voter movements.
The most blatant example is Kingsford Smith.
New South Wales was losing one seat, so most seats were under quota. This was particularly try in the peninsula covering the eastern suburbs, inner city and inner west of Sydney. The four seats of Grayndler, Kingsford Smith, Sydney and Wentworth were collectively projected to have just 3.52 quotas of population by 2028.
There was an obvious path forward – Kingsford Smith and Wentworth could both expand into Sydney, but this would push Sydney a long way into Grayndler, and also significantly shift Grayndler.
Instead, Kingsford Smith jumped across Sydney Airport to take in the bayside suburbs of the former Rockdale council area. Despite these areas being in the same local government area as existing parts of Kingsford Smith (thanks to a very controversial council merger), their connection is very weak. Unless you plan to traverse the tarmac of Sydney Airport or boat across Botany Bay, you would need to leave the electorate for quite some time to move from the old parts of Kingsford Smith to the new parts.
The advantage of this boundary-drawing is it substantially reduces the pressure in terms of the amount of population shifted through the inner west. Wentworth can actually take in parts of Kingsford Smith, rather than Kingsford Smith taking in voters from Sydney or Wentworth. Sydney still moves substantially west, but much less than it would have without Kingsford Smith’s southern push.
I actually made an objection to the NSW redistribution focused on this area. I don’t normally make my own submissions, but the Kingsford Smith change was outrageous enough that I decided to jump in. You can read it here. You can see how much more Sydney and Grayndler would have needed to shift to accomodate that Kingsford Smith change.
You could also argue that the changes to Hughes, where it shifted into the Campbelltown area, is another example of a strange boundary motivated by minimising further changes.
It’s worth noting that the mapmakers left the seat of Fowler almost entirely unchanged, despite the seat sitting in the middle of Western Sydney without particularly strong borders, surrounded by seats that required significant redrawing. It takes quite an effort to not change that seat.
Further north, some others have suggested that McMahon’s strange borders are another example – if Fowler and Reid weren’t preserved intact (seemingly because they were not under-quota), it would have been possible to draw McMahon as a far more rational seat. Instead, the seat pushed north into Blacktown, to the point that the suburb of Blacktown is divided between three seats.
Looking to Melbourne, there are some strange boundaries that seem to revolve around a strategy of abolishing the most under-quota seat (Higgins) and changing some neighbouring seats as little as possible.
There are two egregious examples in this area.
Firstly, shifting Melbourne south is understandably, but where does it go? It would have made far more sense for Melbourne to take in Southbank and other areas in the north-western corner of Macnamara. But taking in South Yarra (an area with weak connections to the rest of the seat) allowed Macnamara to be left almost entirely untouched despite having a seat abolished right next door.
The Kooyong changes are also strange. Kooyong and Toorak may be demographically similar to Hawthorn and Kew, but they are quite a distinct area. But it would have involved more voters moving to create a more natural set of boundaries.
So what is going on here? I don’t have all the answers, but I think questions should be asked of the AEC.
Is this a resourcing issue? There is a cost in time, effort and money in reorganising the electoral roll following a redistribution, and it is likely greater when more voters are moved. It is also necessary to communicate with voters when this happens.
I don’t see a particularly strong amount of political pressure from politicians to minimise voter movements – some MPs may prefer minimal change, but others would prefer greater changes.
It does appear that voter movements are reduced when the scale of the redistribution cycle is greater.
There is not a very strong correlation, but the redistributions that have seen greater voter movements, such as 1996, 2004, 2016 and 2019, have been when a smaller part of the country is being redrawn.
I am concerned that there may have been a shift in priorities – the two most recent cycles have seen the most conservative mapmaking in at least thirty years.
The Joint Standing Committee on Electoral Matters is currently taking submissions into their inquiry into the conduct of the 2025 federal election. I will be raising this issue, and I suggest questions should be asked of the AEC. Are there resourcing constraints forcing the drawing of less logical boundaries? Or is it a time constraint, worsened by the ABS projection problems seen in the last cycle.
Right now it looks like the 2025-28 cycle will be a relatively modest one for redistributions, but this issue will arise again in the future. And if the parliament is expanded, it’s important that the mapmakers have the capacity to draw the best boundaries, and not just play it safe.
I asked the AEC media team for comment on this issue but they declined to comment.
I will be raising it, too.
Both the WA and Vic Redistributions were not performed, I believe, in the spirit of the Commonwealth Electoral Act.
In both cases, the projected enrolment numbers were amended after the window for submissions and objections closed, meaning there was no opportunity for anyone or any party to make new submissions based on the revised projections prior to the draft boundaries being published.
I will also show the folly of using “projected” enrolments as any sort of guide for basing new boundaries.
The whole process is flawed.
I also take issue with your statement that the body conducting reviews is independent.
All of them are on the public purse, and therefore likely to support the side of politics more likely to retain or increase their departments. The political left.
Definitely agree with you, Ben. There’s always been the case of some egregious boundaries in almost every redistribution: Franklin split between Huon Valley and Clarence, the divisions along the Queensland coast splitting every major centre, the old Hume including Camden and Goulburn but splitting out Bowral and Mittagong. But it seemed they just didn’t even try to make divisions coherent the last time. Both NSW and Victoria had changes that should be considered wholly unacceptable, but as you say, the careful, careful minimal approach seems to drive the decisions now. Even going back to Queensland in 2018, they left most divisions alone, exacerbating the erosion along the coast. They seem to boast in the reports that “only 12% of electors move electorates” like it’s an achievement.
If the issue is one of resourcing or time management, it is imperative to address it, as the absence of sufficient public servants to update the rolls results in a reduction in democratic representation.
I’m going to take issue with the last line, most public servants do not care who is in government, but what they care about, is whether that government is doing a good job. I do not understand why the right cannot understand that.
This was most noticeable at the last Queensland federal redistribution. Dickson and Blair taking small pieces of the City of Brisbane can only be understood as a means of keeping elector movements as small as possible. Under previous arrangements, straddling of the LGA boundary in the north and west was confined to Petrie and Oxley respectively.
@jeff regardless there is a legislated process that needs o be followed anyone who wanted to submit a proposal based on the actual numbers coud have done so like i did as a comment on suggestions or any of the other oppurtunites for public repsonse opposition etc
@david i intend to reverse that at the next redistribution
The real problem with recent redistributions has been the AEC trying to match boundaries to a growing population, while maintaining the same number of seats. We saw this in the last Victorian redistribution, when Victoria gave up a seat a seat, and the AEC has the same problem in NSW, were despite Sydney’s growing population.
I must disagree.
“Old” Kingsford-Smith and “new” Kingsford-Smith are continuous. You merely drive along General Holmes Drive and under the 4 lane each way airport tunnel to Brighton. My impression based on 50 years of driving along these roads day in and day out, is the connection is strong and becoming stronger with many people from the western end of Kingsford-Smith eating out & swimming at Brighton hospitality area & picnicking at Ramsgate. If I were to criticise the Kingsford-Smith redistribution it was that:
1 it did not push west perhaps to corner of Cooks river & the main Southern railway line rather than south beyond Brighton to Ramsgate. Perhaps there are too many voters in Wolli Creek? &
2 did not shed the old Phillip parts on its north who are oriented towards what is now Wentworth.
Surely the seat under pressure here is Barton – not Sydney?
Incidentally Grayndler has previously been further west when Frank Stewart briefly & then Leo McCleay held it in the 1970 -90s. In 1977 its movement west caused Tony Whitlam’s doomed flight to St George?
I agree with you about Hughes. The MP should get a light helicopter allowance having to travel from Bundeena to Casula to look after the electorate.
Pencil
The AEC does not make the decision about the number of seats – they have to work with what they have. Jeff is correct in saying that the projections were flawed in Victoria and WA. Some of the NSW projections were odd – Robertson was forecast to grow a lot despite being under quota. Looking at current enrolment, that growth has not manifested itself and it will be well under quota when the next redistribution rolls around. The projection guidelines make it very hard to draw boundaries in high growth areas especially where there are adjoining high growth seats – in making submissions I got seriously stuck in Northern and South Eastern Melbourne and South West Sydney. As for Jeff’s conspiracy theory ….. we might let that one go through to the keeper ….
Pencil sydney population was in the negative territory it had one more seat then it was entitled too
@Redistrbuted, I am aware the AEC doesn’t make decisions about the number of seats, as that’s up to the government, and as Jeff said, there were issues with the population projections used in the last redistribution.
@John, Thanks.
@Pencil, there is a real issue with projections in growth areas. There have been several instances, around the Werriwa/Macarthur region in NSW last time, and Holt/Bruce/Latrobe in Victoria before that, where you can find a division that’s under current quota, but over in projected numbers. It makes changes in those areas very tight and usually results in the suboptimal balancing act, like parts of Ingleburn going into Hughes.
Unfortunately, we can only rely on the projections they provide, which often turn out to be completely wrong anyway so I treat it as a single static number from that point in time. I don’t even try to balance growth areas so they slow because who even knows what the results in 7 years end up.
I think the reality is that if you have a fairly well defined seat with little population pressure for change, it really does make a very strong bias in favour of status quo.
McEwen is one I always think of – you almost always end up with imperfect boundaries and disconnected bits and pieces that don’t really fit well. Would it be better to make a bigger change in order to get a clearer and better defined McEwen, instead of just tinkering at the edges? Yes it would…..but the geography and population pattern of Victoria means that almost every seat surrounding McEwen is fairly coherent and sensible (Mallee, Nicholls, Indi, Casey, Jagajaga, Scullin, Calwell, Ballarat and Bendigo). Is it really worth pulling apart the coherence of 9-10 other seats just to make McEwen ‘better’? Or do you just move the boundary around Woodend or Diamond Creek a bit – and accept McEwen is a bit of a mess – to keep everything else intact?
Similar with McMahon – although they did end up splitting Blacktown, they kept the other major centres relatively together. Again, is it worth splitting Penrith or Parramatta just to avoid awkward boundaries through Blacktown?
Having made many submissions myself, I know that there will always be a couple of seats where it becomes “Do I (a) make major changes that improves these boundaries but requires redrawing 5 other seats that don’t need it , or (b) accept a less-than-perfect status quo here to prevent changes elsewhere”. Almost always you end up with some sort of ‘sacrifice’ having to be made somewhere.
Fair points Mark about being a compromise when doing redistributions. The commissioners have done a good job of removing the number of hybrid urban-rural seats (examples like Pearce, Hume and ex-Wakefield, now Spence) by shifting them towards the metropolitan area.
I do believe having smaller district sizes helps in meeting community of interest needs, this is especially true with state electoral boundaries which are far more compact.
Another point not made here is that trying to minimise the proportion of voters moved in one redistribution merely leads to bigger changes being needed in the next. What happens at the next NSW redistribution when Wentworth and Kingsford Smith both need to expand again? Or the next VIC redistribution when Melbourne and Macnamara both need to expand again? Having the courage/capacity to make the significant changes required for a long-term solution minimises future disruptions. The short-termism is gobsmacking.
@Blast2095
What will happen at the next redistributions? They’ll just make it worse. (I’m half-joking.)
Blast/Nicholas, I would agree more with Mark Mulcair’s comment in that there has to be compromise when drawing boundaries. Even though some seats may look ‘bad’ and not reflect on true community of interest, one has to ask how much else has to change to make it look neater. The Hughes ‘tail’ or panhandle extending into Campbelltown council allowed Hume to be consolidated as a purely urban seat and shed its rural parts.
I do agree that the Kingsford Smith change to make it a seat entirely east of the airport was one that had little or insignificant flow on impacts, pretty much like the 2015 redistribution objections to extending Barton too far north which made a mess of other inner west seats (mostly Reid).
@Jeff Waddell. Let me record my emphatic disagreement with the contention that the redistribution commissioners are biased towards either side of politics. I have been closely involved in redistribution submissions in WA for 25 years and can only speak from experience.
Prior to 1984 I am less sure that such a high standard of impartiality applied. In 1973 in WA there was a questionable, convoluted boundary between Swan and the new seat of Tangney that might have advantaged the ALP in 1974. However both seats were lost in 1975.
Agree Jeremy, most boundaries drawn at the federal and state levels are politically neutral and generally do not provide an advantage to either side. The only perceived ‘bias’ that may come from redistributions is the transfer of power from rural to urban areas, with rural seats abolished and urban seats created in their favour.
But this is due to population shifts overall, with more people moving into the capital cities. Nothing to do with the commissioners wanting to punish the Nationals in any way. In fact, even though urban seats are created you often end up with others shifting towards the conservative side.
There are slso legacy issues regarding boundaries. Eden-monaro is a case in point. At federation and into the 1940s – there was a strong community of interest between the Far South Coast and the Monaro Tableland. Besides shipping, it wss far easier to catch a train to Cooma and then drive down Brown Mountain than go by road down what is now the Princes Highway. This combining of coast and tableland is still existant and basically because the electorate name demands it. If it didn’t exist we would probably have an electorate running up the coast from Eden to about Nowra, and an inland southern tablelands electorate running from Delegate northwards. A geographic based federation era electorate name is driving the boundaries. The commissioners could follow the Corangamite, Werriwa and what happened at one stage Parramatta and take either Eden or Monaro out of the electorate of E-M.
> Another point not made here is that trying to minimise the proportion of voters moved in one redistribution merely leads to bigger changes being needed in the next. What happens at the next NSW redistribution when Wentworth and Kingsford Smith both need to expand again? Or the next VIC redistribution when Melbourne and Macnamara both need to expand again? Having the courage/capacity to make the significant changes required for a long-term solution minimises future disruptions. The short-termism is gobsmacking.
I disagree. I think this goes too far the other way. Whilst there’s no need for committees to show too much fealty to past arrangements, there’s also no need to try to anticipate future arrangements. That can be dealt with at future redistributions.