Projected Enrolment Data Released for Redistribution of WA Federal Electoral Boundaries

This post has been retained for posterity, but it was written based on incorrect enrolment data produced by the Australian Bureau of Statistics and released by the Australian Electoral Commission.

Corrected projections were released in January 2024 and a new analysis of redistribution prospects based on the corrected data can be found in this post.

Projected enrolment data has been relased for Western Australia that provides a better picture of how the Federal redistribution will unfold in the state.

Western Australia is to gain a seat, increasing its representation from 15 to 16 seats. It restores a 16th seat to the state after a seat was removed in the previous redistribution three years ago.

Redistribution Rules

While seats are allocated to states based on population, redistributions within each state are conducted based on enrolment. All new seats must have an enrolment within 10% of the state average or quota. A second quota also applies based on projected enrolments. All newly drawn districts should have an average projected enrolment within 3.5% of the state quota.

Current enrolment in Western Australia is 1,816,126 setting an enrolment quota for 16 seats at 113,507, around 8,000 electors fewer than for the current 15 seats. All 16 electorates must be drawn with enrolments within 10% of this number. The 15 current electorates are between 2.9% and 9.3% over the quota and must lose voters to squeeze in a new seat.

The second quota is a projected quota for March 2028 of 121,615, again around 8,000 electors fewer than for 15 seats. Redistribution rules require all drawn electorates have a projected enrolment within 3.5% of the state average. All current electorates are over this quota with only Burt and Forrest under the 3.5% permitted variations. All 16 electorates drawn must fit within the 3.5% band around the quota. The projected requires more changes to boundaries than would be caused by current enrolments.

The narrower projected quota has more impact on the redistribution than current enrolment and forces the drawing of boundaries to take account of slow and fast growing areas.

Within the quota restrictions, the Redistribution Commissioners can take account of –

  • community of interests within proposed districts, including economic, social and regional interests
  • means of communication and travel within the proposed district
  • the physical features and area of the proposed district
  • the boundaries of existing districts

Current Divisional Enrolment and Variation

Western Australia is not so much gaining a 16th seat as regaining a seat it lost in the 2020 apportionment. That loss was caused by slower population growth in the wind down of the mining construction boom. In 2023 the two year Covid19 immigration hiatus has altered population relativities. WA has continued to grow thanks to interstate migration, while Victoria and NSW were cut off from the overseas migration tap that usually counteracts both state’s internal population loss to other states.

The table below shows Western Australia’s 15 current divisions, the current holding party and margin as well as projected enrolment for March 2028. The final two columns show the elector variation from the new quota and the percentage or quota variation in the final column.

For the discussion that follows, the electorates have been listed with regional divisions first, then Perth divisions north of the Swan River, then Perth Divisions south of the Swan. The Perth divisions are listed running inland from coastal seats to the eastern edge of Perth.

‘*’ indicates divisions gained by Labor at the 2022 election.

WA Divisions – Variation from 16-seat Quota

Enrolment Variation
Division Margin Projected
Votes Percentage
Regional seats (Total 0.16 quotas over)
Durack LIB 4.3 130,980 +9,365 +7.7
O’Connor LIB 7.0 128,787 +7,172 +5.9
Forrest LIB 4.3 124,708 +3,093 +2.5
Perth North of the Swan Divisions (Total 0.43 quotas over)
Curtin * IND 1.3 130,733 +9,118 +7.5
Moore LIB 0.7 127,144 +5,529 +4.5
Pearce * ALP 9.0 128,436 +6,821 +5.6
Perth * ALP 14.8 132,518 +10,903 +9.0
Cowan ALP 10.8 132,834 +11,219 +9.2
Hasluck * ALP 6.0 130,773 +9,158 +7.5
Perth South of the Swan Divisions (Total 0.32 quotas over)
Fremantle ALP 16.9 129,429 +7,814 +6.4
Brand ALP 16.7 130,547 +8,932 +7.3
Tangney * ALP 2.4 132,721 +11,106 +9.1
Swan * ALP 8.8 131,984 +10,369 +8.5
Burt ALP 15.2 125,827 +4,212 +3.5
Canning LIB 3.6 128,424 +6,809 +5.6

Changes to the Regional Divisions

The map below is dominated by the giant seats of Durack and O’Connor. This makes it hard to see variation in metropolitan divisions so a second map concentrating on Perth is seat out down the page.

The vast electorates of Durack and O'Connor are both over the projected quota. This suggests that the new seat created in WA cannot fit entirely in the Perth metropolitan area. Either the new electorate or one of the existing greater Perth seats will have to extend into rural areas.

Forrest is within the permitted variation from quota and may be left alone by the redistribution, unless the Commissioners choose to deal with the Durack and O'Connor overflow by shifting Forrest east and Canning moves south. As Commissioners prefer to minimise the number of voters changing seats, leaving Forrest alone is the more likely option.

Changes to Perth Divisions

The map below shows the 12 Perth divisions. If you hover/tap any of the divisions you can see their name and their variation from the new 16 seat quota. As the colouring makes clear, all 12 electorates are over quota, 11 of them more than the permitted 3.5%.

It is very unusual for the Swan River to be crossed by electoral boundaries down river from Guilford, with the single exception of North Fremantle. The drawing of boundaries almost always begins at the Swan River's mouth, drawing Curtin and Fremantle before moving inland.

North of the Swan, the Redistribution Commissioners could choose to retain the three current seats along the coast, Curtin, Moore and Pearce. All need to shed voters to the already over quota seats to the east. Before 2022 there were four seats along Perth's northern beaches with Pearce extending out of the metropolitan area, but I think it more likely the current three seats will be retained rather than begin the redistribution with a wholesale re-draw of the coastal seats.

If there are still three coastal seats, they will shed electors to the east into Cowan, Perth and Hasluck, all of which are already well over quota. As the furthest away from the coast, Hasluck will undergo the greatest change. It is currently based the rapidly growing Ellenbrook area in the upper Swan Valley as well as the Perth suburbs in the Darling Range. It may be that the seat currently called Hasluck becomes an entirely Swan Valley based seat.

In total the six seats north of the Swan have enough voters for 6.4 seats. The creep of boundaries towards the ocean will leave enough voters in suburbs in the Darling Range and around Midland-Guilford to be the base for a new seat. There will be even more voters left over if Hasluck extends north out of the metropolian area to take in rural areas to the north east.

If seats need to extend out of the metropolitan area to deal with the Durack and O'Connor surplus, it is most likely to be Hasluck or any new seat based based on the Darling Range in Perth's east. Both would be able to extend into the Avon Valley, how far depending on the quota.

South of the Swan, Fremantle, Brand, Tangney and Swan must all shed voters and all are likely to creep north or west towards Fremantle. There is a high probability that Canning will contract towards Mandurah in the south, leaving parts of south-east Perth around Armadale to be merged with the surplus north of the Swan. This would probably produce major changes to the boundaries of Burt.

If the new eastern Perth seat is too elongated north-south to accommodate a sensible community of interest, it may be others seats will need to adopt a new alignment.

There are many ways that the boundaries can be drawn, but the key point to make about the redistribution in Perth is that the seats close to the Indian Ocean are likely to see the least change, with the rolling transfer of enrolments creating greater change further inland and leaving room for a new seat in Perth's east.

On another note, the drawing of boundaries and the naming of seats is not always done together. It may be that the new seat is drawn an the area between Perth, Cowan and Hasluck, but the existing name Hasluck remains with a seat further east and based on the Darling Range.

3 thoughts on “Projected Enrolment Data Released for Redistribution of WA Federal Electoral Boundaries”

  1. How likely is it that they may take the easy road and restore Stirling to the electoral map?

    COOMENT: It’s not the easy way. It means running four seats inland from the northern beaches and creates more change than creating a new seat further ind=land.

  2. Since there is already a 16 seat model from the last time WA had 16 seats has any work been done to assess how that meets the new quotas?

    Could save the Commissioners some work!

    COMMENT: They can’t do that. The old Pearce was so over quota it cannot be drawn as it used to be. The previous 16 seat boundaries were drawn when Ellenbrook was in its infancy so those boundaries can’t be a starting point.

  3. If I remember correctly in the last Redistribution WA had only just marginally fallen under the quota and was rounded down to 15, in hindsight it’s not even surprising that WA regained population share to climb back up to 16 even without the Pandemic. I take it there are no mechanisms to moderate quota allocation swings in case it’s likely they shift again soon, and that the redistribution HAS to happen as soon as a new quota is determined?
    With an absolute determination I can imagine Qld, Vic, and maybe WA potentially getting redistributions up and down regularly over the next decade.

    COMMENT: The formula is set out in Section 24 of the Constitution. The High Court has ruled that the determination on the number of seats occurs one year after the House first sits. The Parliament has legislated on what is meant by the most recent statistics of the Commonwealth. The redistribution has to be complete in time for the next election. There is no opportunity to review the apportionment.

    Twice the parliament has reviewed the formula allocating seats to territories after an apportionment has been made, but parliament has the power to deal with Territory representation. It does not have the same power over state representation.

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