New State Electoral Boundaries for South Australia Finalised

(Post re-written and updated 20 November)

South Australia’s Electoral Districts Boundaries Commission (EDBC) released the final version of the state’s new electoral boundaries on 18 November. The new boundaries will apply for the first time at the next South Australian election in March 2022.

The final boundaries unwound some of the more consequential changes proposed by the draft boundaries. After much opposition, Mount Barker was retained in Kavel, leaving that seat based in the Adelaide Hills, and allowing Schubert to be a Barossa Valley based seat. Flowing from this, the proposed move of Gawler into Schubert was undone, unravelling major changes to Light and resulting in a string of further changes to seats across northern Adelaide.

The final boundaries also unwound a series of suburb swaps between the inner-southern Adelaide seats Badcoe and Elder with political consequences for the margins in both seats.

If you are after more detail on the composition of the new electorates, maps can be found on the EDBC’s website.

In this post I’ll provide some commentary on the approach taken by the EDBC and the political consequences that flow from the changes.

Dealing with Low Enrolment in Country Districts

When the draft boundaries were released, I went into detail on the methodology adopted by the EDBC. (You can find my discussion in this post.)

In short, the Weatherill government’s abolition of fairness as a major criteria for drawing electoral boundaries meant the Commission could no longer justify consistently lower country district enrolments on the ground of it being required to achieve fairness. As discussed in my previous post, equality of enrolment now has a higher priority than other criteria in drawing boundaries, and definitely has higher priority than fairness, which is no longer listed as a criteria and the EDBC is only permitted to consider it under the catch-all provision of “any other matters it thinks relevant”.

In my earlier post I explained how the EDBC had attemtpted to deal with a 9,000 vote under-enrolment in country districts. On the draft boundaries this saw most southern country districts set above quota, brought about by the transfer of Mount Barker from Kavel to Hammond, a consequence of which was then transfer of Gawler from Light into Schubert.

The table below sets out what has happened to country enrolments after the final boundaries undid the Mount Barker and Gawler changes.

Percentage Variation form Quota in Country Districts – 2016 and 2020 SA Redistributions

District 2016 Redistribution 2020 Draft 2020 Final
Chaffey -6.6% +6.7% -3.3%
Flinders -9.9% -5.8% -5.8%
Frome -8.5% +1.9% 0.0%
Giles -6.9% -4.5% -4.5%
Hammond -2.5% +5.6% -2.7%
Kavel -8.4% +3.5% -2.5%
MacKillop -7.0% +1.9% +1.9%
Narungga -3.6% -1.8% -6.6%
Stuart -6.5% +0.1% -4.2%

The 2016 redistribution had set country districts under quota in an effort to achieve fairness. With fairness no longer a major criteria, the 2020 draft boundaries put many country districts over quota. Now the final version of boundaries has undone many of the proposed changes.

Where on the draft boundaries Chaffey, Hammond, Kavel and Stuart had been set above quota, on the final boundaries they have all been set below quota. Narungga is now set further under quota than on the draft boundaries.

In its draft report the EDBC wrote that fixing country under-enrolment created a cascading shift of around 9,000 voters or one third of a quota. Dealing with that resulted in the transfer of 11,800 voters in Mount Barker from Kavel to Hammond, and the transfer of 12,500 voters in Gawler from Light to Schubert.

On my estimates, setting the rural districts back under quota has undone around 7,000 of the 9,000 voter enrolment shift.

Community of interest arguments, plus arguments on future population growth in the Adelaide Hills, have been used to undo the Mount Barker change, which flows thought to unwinding the Gawler transfer. As a consequence, country districts have again been drawn below quota. This was justified in 2016 on the grounds of dealing with fairness. In 2020 it is arguements over community of interest in the Adelaide Hills and Barossa Valley that has undone boundaries initially drawn with greater emphasis on equality of current and future enrolment.

A similar scenario has unfolded with recent draft state boundaries for NSW. The NSW boundary panel must deal with two 10% variation quotas, one current and one set for the time of the next state election. The recent NSW draft boundaries made greater use of this 10% variation than past panels to avoid a major re-arrangement of rural boundaries. Prior to the 2013 NSW redistribution, the future quota variation had been set at 3%, and this had forced more slow-growing rural districts to be drawn above the current enroment quota.

A similar issue arises with Federal redistributions where boundaries must be re-drawn within a 10% current enrolment variation, but also a projected 3.5% variation set for 3.5 years in the future. The narrower future enrolment quota forces low growth electorates to be drawn above the current quota.

For the second redistribution on a row, the Electoral Districts Boundaries Commission has drawn country districts below quota to take account of other redistribution criteria. With SA boundaries re-drawn every four years, the permitted 10% variation from quota permitted under South Australian law can be viewed as either a weak method of enforcing equality of enrolment, or a useful method of avoiding the tyranny of numbers over-ridding all other considerations in the drawing of electoral boundaries.

Summary of the Major Redistribution Changes

While the EDBC publishes estimated margins for new electorate, for technical reasons I prefer to calculate my own. First, the EDBC tweaks estimated margins to take account of future population growth, so despite no change in boundaries, the EDBC estimates the Liberal margin in Adelaide to decline from 1.0% to 0.8%. I also weight the transfer of declaration votes to new boundaries to take account of voting patterns in the areas transferred where the EDBC evenly apportions the declaration vote to new electorates. I also calculate the new boundaries to obtain estimates of first preference vote shares.

So in the rest of this post, including the detailed list of changes to all districts and the new electoral pendulum, I am using my own estimates rather than those published by the EDBC. In most of the districts that will decide the result of the next election, there are only minor differences between the two estimates.

The major political consequences of the draft and final electoral boundaries are as follows.

  • Port Pirie has been transferred from Frome to Stuart. Port Pirie is the base of Independent Geoff Brock, and in the areas transferred to Stuart, he polled 65% of the first preference vote, and 75% after preferences. Brock’s vote in Port Pirie more than counterbalanced the dominant Liberal vote in the rest of Frome, so contesting Frome on its new boundaries is not feasible for Brock. He has said he will follow his electors and contest Stuart at the next election, but Stuart has its own populat MP, Liberal Dan van Holst Pellekaan. Stuart loses solid Liberal voting territory in the south to the new Frome, as well as losing Port Augusta West to the Labor seat of Giles. The Liberal two-party preferred margin in Stuart declines from 23.1% to 11.7% on the new boundaries, but the two-party margin is not relevant. On first preferences, the Liberal vote in the re-drawn Stuart is 44.4%, Labor 15.3% and Brock 34.6%. If Brock follows through with his intention to contest Stuart, it will be a much closer contest than suggested by the two-party preferred margin.
  • The draft boundaries engaged in a radical re-draw of the adjoining inner-southern Adelaide seats of Badcoe and Elder. The scale of the suburb swaps looked like the EDBC engaging in its old game of swapping suburbs to balance the electoral pendulum. This despite fairness no longer being a major criteria for drawing boundaries. On the draft boundaries, Badcoe’s Labor margin declined from 5.5% to 1.4% and Elder’s Liberal margin from 4.4% to just 0.1%. The final boundaries undid a series of the suburb swaps and Badcoe has returned to having a Labor margin of 4.6% and Elder’s margin has been boosted to 2.0%. Labor had announced former federal Boothby candidate Nadia Clancy to run in Elder, but the final version of the boundaries of Elder improve the chances of sitting Liberal MP Carolyn Power. (For outsiders, Power was elected as Carolyn Habib but has since married.)
  • The reversal of the original proposal to transfer Gawler from Light to Schubert has also had political consequences. On the draft boundaries the Labor margin in Light increased from 9.9% to 12.8% while Schubert’s Liberal margin plummeted from 14.3% to 6.3%, endangering the position of sitting Liberal MP Stephan Knoll. Labor quickly endorsed Light MP Tony Piccolo to contest Schubert, hoping his personal popularity in Gawler could wash across the rest of the electorate. The final boundaries reverse the Gawler transfer and Light now has a 8.4% Labor margin and Schubert reverts to a 15.6% Liberal margin. The future of Piccolo’s seat swap and a proposed swap of Federal MP Nick Champion to contest Light are yet to be determined by the Labor Party.
  • Only around half of former voters in Florey remain in the re-drawn electorate, though the major boundary changes have little impact on the safe Labor margin of Florey or surrounding Labor seats. The issue is that Florey was won by long-serving Labor turned Independent MP Frances Bedford in 2018. The new boundaries may have an impact on her decision whether to contest the next election.
  • King, held by Liberal Paula Luethen, had its margin boosted from 0.7% to 1.6% on the draft boundaries, but reverts to just 0.6% on the new boundaries.
  • Newland, held by Liberal Richard Harvey, has its margin cut from 2.0% to 0.1% as it looses its eastern end to Schubert.

My estimate of the new pendulum is set out below, followed by a table that provides old and new margins for all seats as well as brief descriptions of the boundary changes.

In the carefully constructed way that the EDBC has in the past measured fairness, there are 20 seats with an underlying Labor majority and 27 with an underlying Liberal majority. (The actual numbers are Liberal 25, Labor 19 with three Independents, two in underlying Liberal seats, one in a Labor seat.)

A swing of 2.0% will deliver Labor 50.1% of the two-party preferred vote, and if the swing is uniform, will deliver Labor majority government by winning the four Liberal seats on the electoral pendulum under 2.0%.

Of course, the past has shown how uneven the swing can be in South Australia. And the calculus of two-party preferred swing will be undermined if Geoff Brock contests and wins Stuart.

The New Electoral Pendulum

Liberal Seats (27) Labor Seats (20)
Margin Electorate Margin Electorate
LIB 0.1 Newland ALP 0.7 Mawson
LIB 0.6 King ALP 3.1 Wright
LIB 1.0 Adelaide ALP 4.6 Badcoe
LIB 2.0 Elder ALP 5.3 Lee
LIB 6.1 Colton ALP 5.7 Torrens
LIB 6.7 Hartley ALP 6.2 Enfield
LIB 7.4 Waite ALP 8.4 Hurtle Vale
LIB 7.4 Dunstan ALP 8.4 Light
LIB 7.6 Heysen ALP 9.4 Reynell
LIB 8.1 Davenport ALP 11.9 Taylor
LIB 9.3 Morialta ALP 13.3 Florey (IND held)
LIB 9.4 Black ALP 14.2 West Torrens
LIB 10.0 Gibson ALP 14.9 Giles
LIB 11.0 Morphett ALP 16.0 Kaurna
LIB 11.5 Unley ALP 16.7 Cheltenham
LIB 11.7 Stuart ALP 16.8 Port Adelaide
LIB 14.5 Kavel ALP 17.2 Elizabeth
LIB 14.5 Finniss ALP 18.5 Ramsay
LIB 15.6 Schubert ALP 18.6 Playford
LIB 16.9 Hammond ALP 23.3 Croydon
LIB 16.9 Bragg
LIB 17.6 Frome
LIB 18.0 Chaffey
LIB 18.2 Narungga
LIB 18.5 Mount Gambier (IND held)
LIB 25.2 MacKillop
LIB 26.1 Flinders

New Electorates – Old and New Margins with Description of Major Changes

Change in Margin Notes on Changes
Adelaide
Old LIB 1.0 Unchanged
New LIB 1.0
Badcoe
Old ALP 5.5 Gains Plympton Park and the rest of Plympton from Morphett as well as Marleston and Netley fromWest Torrens. Loses Clarence Gardens, Clarence Park and parts of Ascot Park and Edwardstown to Elder.
New ALP 4.6
Black
Old LIB 8.7 Gains South Brighton from Gibson, loses O’Halloran Hill, Darlington and Seacombe Heights to Davenport.
New LIB 9.4
Bragg
Old LIB 17.4 Various suburb swaps with neighbouring Dunstan, Unley and Morialta.
New LIB 16.9
Chaffey
Old LIB 17.3 Gains 1,760 voters in Karoonda East Murray District Council and parts of Mid Murray Council from Hammond.
New LIB 18.0
Cheltenham
Old ALP 15.9 Gains Athol Park from Croydon. Loses Albert Park and Hendon to Lee.
New ALP 16.7
Colton
Old LIB 7.9 Loses Glenelg North to Morphett. Gains part of Grange from Lee.
New LIB 6.1
Croydon
Old ALP 24.4 Gains Kilburn and parts of Prospect from Enfield. Loses Athold Park to Cheltenham, and the rest of Allenby Gardens, Welland and West Hindmarsh to West Torrens.
New ALP 23.3
Davenport
Old LIB 8.8 Loses Cherry Gardens to Heysen and Bellevue Heights to Waite. Gains Darlington, O’Halloran Hill and Seacombe Heights from Black.
New LIB 8.1
Dunstan
Old LIB 6.1 Various suburbs swaps with neighbouring Bragg and Hartley.
New LIB 7.4
Elder
Old LIB 4.4 Gains Clarence Gardens, Clarence Park and parts of Ascot Park and Edwardstown from Badcoe. Loses parts of Liberal voting Hawthorn to Unley, and Clapham and Lower Mitcham to Waite.
New LIB 2.0
Elizabeth
Old ALP 17.7 Loses Elizabeth Vale and parts of Elizabeth South to Ramsay.
New ALP 17.2
Enfield
Old ALP 7.9 Gains Walkley Heights from from Florey and Gepps Cross from Port Adelaide. Loses Kilburn and parts of Prospect to Croydon.
New ALP 6.2
Finniss
Old LIB 14.2 Gains Milang from Hammond.
New LIB 14.5
Flinders
Old LIB 26.3 Gains Cowell, Kimba and a large but thinly populated area in the west of the state from Giles.
New LIB 26.1
Florey
Old ALP 11.0 Major boundary changes with neighbouring safe Labor seats. Florey is currently held by Independent Frances Bedford, her margin against Labor in 2018 6.1%.
New ALP 13.3
Frome
Old LIB 11.1 Radically re-drawn. Port Pirie, Risdon Park and Solomontown have been moved into Stuart as the electorate shifts closer to Adelaide. Frome is currently held by Independent Geoff Brock and he polled 78% of the two-candidate preferred vote in the area transferred to Stuart. Margins shown here are based on two-party preferred results. Brock’s margin versus the Liberal Party in 2018 was 8.2%. It is impossible to calculate a new 2CP margin for either Frome or Stuart.
New LIB 17.6
Gibson
Old LIB 9.3 Gains parts of Somerton Park from Morphett and loses South Brighton to Black.
New LIB 10.0
Giles
Old ALP 15.2 Loses Cowell and Kimba to Flinders, gains Port Augusta West from Stuart.
New ALP 14.9
Hammond
Old LIB 19.5 Areas to the east transferred to Chaffey and MacKillop with Strathalbyn and Woodchester gained from Heysen. The radical re-draw where Mount Barker was moved into the electorate was abandoned in the final version of the boundaries.
New LIB 16.9
Hartley
Old LIB 7.8 Gains Dernancourt from Torrens and Felixstowe and Glynde from Dunstan. Loses parts of Newton and Magill to Morialta.
New LIB 6.7
Heysen
Old LIB 8.5 Loses Strathalbyn and Woodchester to Hammond. Gains Hahndorf from Kavel and Norton Summit, Summertown, Uraidla and Montacute from Morialta.
New LIB 7.6
Hurtle Vale
Old ALP 5.3 Strengthened for Labor by a number of suburb swaps with Kaurna and Reynell.
New ALP 8.4
Kaurna
Old ALP 14.9 Strengthened in boundary changes with neighbouring Hurtle Vale and Reynell.
New ALP 16.0
Kavel
Old LIB 14.8 The radical re-draw of boundaries set out in the draft boundaries was abandoned. Now loses Hahndorf to Heysen and gains Lenswood and Lobethal from Morialta.
New LIB 14.5
King
Old LIB 0.7 Only minor changes.
New LIB 0.8
Lee
Old ALP 3.8 Strengthened for Labor by losing parts of Grange to Colton while gaining Albert Park and Hendon from Cheltenham.
New ALP 5.3
Light
Old ALP 9.9 The major boundary changes flowing from the transfer of Gawler to Schubert were abandoned on the final boundaries. No only minor changes, gaining Gawler Belt from Schubert and losing parts of Munno Para West to Taylor.
New ALP 8.4
MacKillop
Old LIB 25.0 Gains the eastern parts of Hammond.
New LIB 25.2
Mawson
Old ALP 0.3 Main change is gaining part of Maslin Beach from Kaurna.
New ALP 0.7
Morialta
Old LIB 10.7

Loses its eastern end in the Adelaide Hills to Heysen, Kavel and Schubert. Gains parts of Magill and Newton from Hartley.

New LIB 9.3
Morphett
Old LIB 10.5 Gains Glenelg North from Colton. Loses Plympton Park and part of Plympton to Badcoe, and loses part of Somerton Park to Gibson.
New LIB 11.0
Mount Gambier
Old LIB 18.5 Unchanged. Held by Independent Troy Bell whose margin versus the Liberal Party in 2018 was 10.3%.
New LIB 18.5
Narungga
Old LIB 17.4 Gains parts of Clare and Gilbert Vallys Council from Frome, loses Dublin and Mallala to Frome.
New LIB 18.2
Newland
Old LIB 2.0 Gains parts of Modbury and Modbury North from Florey. Loses its eastern end in the Adelaide Hills to Schubert.
New LIB 0.1
Playford
Old ALP 16.3 Gains Salisbury Downs and Parts of Paralowie from Ramsay. Loses Para Hills, Para Hills West, Parafield and parts of Mawson Lakes to Florey.
New ALP 18.6
Port Adelaide
Old ALP 16.8 Loses Gepps Cross to Enfield, gains Bolivar, Globe Derby Park and St Kilda from Taylor.
New ALP 16.8
Ramsay
Old ALP 18.9 Gains Elizabeth Vale and parts of Elizabeth South from Elizabeth. Gains Burton and Direk from Taylor. Gains Brahma Lodge and Salisbury South from Wright.Loses Salisbury Downs and parts of Paralowie to Playford.
New ALP 18.5
Reynell
Old ALP 14.5 Labor margin weakened in suburb swaps that strengthen Labor in Hurtle Vale and Kaurna.
New ALP 9.4
Schubert
Old LIB 14.3 After being radically re-drawn on the draft boundaries, the final version has had less drastic changes. Gains areas around Gumeracha and Mount Torrens from Morialta. Gains aroeas aroun d Houghton and Kersbrook from Newland. Gains Truro from Stuart. Loses areas north of Gawler to Frome.
New LIB 15.6
Stuart
Old LIB 23.1 Loses Port Augusta West to Giles, the southern end of the electorate has been transferred into the re-drawn Frome, but the most significant change is the transfer of Port Pirie, Risdon Park and Solomontown from Frome. This produces a huge cut in the notional Liberal majority. The Port Pirie area voted 78.0% for Independent Geoff Brock at the 2018 election and the area was his electoral base in the old Frome.
New LIB 11.7
Taylor
Old ALP 10.8 Loses Two Wells to Frome and swaps suburbs with Port Adelaide, Ramsay and Light.
New ALP 11.9
Torrens
Old ALP 4.6 Gains Valley View from Florey, loses Dernancourt to Hartley.
New ALP 5.7
Unley
Old LIB 11.3 Loses areas in the north-east to Bragg and shifts south taking Kingswood, Netherby and Urrbrae from Waite.
New LIB 11.5
Waite
Old LIB 7.8 Significant suburbs swaps all round but with little impact on the Liberal margin.
New LIB 7.4
West Torrens
Old ALP 13.2 Gains the balance of Allenby Gardens, Welland and West Hindmarsh from Croydon, loses Marleston and Netley to Badcoe.
New ALP 14.2
Wright
Old ALP 3.5 Gains parts of Modbury North from Florey, loses Brahma Lodge and Salisbury South to Ramsay
New ALP 3.1