ACT redistribution finalised


Along with the Northern Territory, Western Australia and Brisbane City Council, the ACT has also been redrawing its electoral boundaries for the local Legislative Assembly, with the boundaries finalised in July.

In this post I’ll share a map showing the changes to the electoral boundaries, along with my estimates of the vote percentages for the bigger parties in each electorate before and after the redistribution.

I was close to publishing the draft electoral boundaries and finalising my vote estimates back in early June right before I went on parental leave, but while I was away from the site Elections ACT announced that the final map would not feature any changes compared to the draft map, so that work can apply to the final version.

All five electorates were modified, with two seats gaining territory, two losing territory, and the seat of Murrumbidgee gaining and losing territory.

The Belconnen-area electorate of Ginninderra took in some territory from the Gungahlin-area electorate of Yerrabi, but these two seats did not exchange any territory with the remainder of the electorates.

The other three electorates all effectively shifted slightly north. The Tuggeranong-area electorate of Brindabella expanded north to take in half of the suburb of Kambah from Murrumbidgee. Murrumbidgee then shifted north to take in Yarralumla and Deakin from the central electorate of Kurrajong. This brings Murrumbidgee right up to Capital Hill and Lake Burley Griffin.

My redistribution vote estimates are my first test of a new formula I’ve used for distributing special votes in a way which reflects the different voting trends in different parts of an electorate. I might go into more detail about how this works down the track.

Labor received a boost in three out of five electorates, doing particularly well by picking up almost 1.4% in Kurrajong.

The Greens boosted their support in both of their current electorates but experienced little change in Ginninderra, their best prospect for winning another seat.

The Liberals did particularly well in Murrumbidgee, while they were knocked back badly in Kurrajong.


You can download the Google Earth map file for the 2020 boundaries from my maps page, along with every ACT Legislative Assembly map dating back to the first electorates in 1995.

Liked it? Take a second to support the Tally Room on Patreon!


  1. I would definitely be interested in hearing more about your new method for assigning special votes.

    At the Federal level of course there’s the SA1s to polling place correspondences (with “postal” etc treated as a pseudo-booth), so it’s straightforward to say that “out of on-the-day votes, this SA1 had an estimated 300 Lib voters from Booth X, 150 from Booth Y, etc etc”.

    The straightforward thing to do with “at-large booths” is just to treat them like any other, but that may well produce a homogenising effect. Hence, some adjustment desired. I haven’t figured it all out yet 🙂

  2. Greens are now at a real risk of losing their seat in Murrumbidgee to the third Liberal – particularly since they will lose the personal vote of the retiring member

  3. Liberals also at some risk of losing their second seat in Kurrajong – of course that’s all based on 2016 results – all depends on the swings and last time the swings varied between seats – no uniform swings & personal members votes seem to count for something

  4. I think you could practically say that the third seat in Murrumbidgee has been made notionally Liberal. That leaves them needing to pick up the final seat in Yerrabi, which the redistribution has made a little harder. More significant, probably, will be the delivery of the tram and Fitzharris’ retirement.

  5. the fifth seat in Murrumbidgee is a toss up on Ben’s figures – relevant to the outcome will be the quality & public profile of the Green’s candidate, the general political background is there a good for change in the electorate & whether the Liberals have an attack of conservativitis – also lurking in the background is the fact that there is a Federal LNP government that may put the breaks on the time for a change mood –

Comments are closed.