CAPITAL CITIES

The Capital Cities represent each of the eight state and territory capitals and are currently defined by a single Statistical Division (SD) in each state. The Capital City SD has two main uses. First, to provide a stable definition of each of the cities for data such as the Consumer Price Index that is only collected for Capital Cities. Second, to define the Capital City/Rest of State split used in the presentation of population survey data other than labour force.

To facilitate the comparison of labour force data with this other data capital cities will be defined from aggregations of SA4s. Given that SA4s are primarily designed to represent labour markets this implies the capital city definition will be a broad socio-economic definition, rather than a tight reflection of the built up area of the capital city and its likely medium term expansion.

This has the added advantage of providing a greater degree of consistency to the definitions of the capital cities. The current capital city SD boundaries vary considerably in the manner in which they bound each states capital city. For example, the Sydney SD is a broad socioeconomic definition of Sydney that contains its labour market and extends well beyond the built up edge of the city. In contrast the current Adelaide SD barely contains the 2006 Adelaide Urban Centre and Locality (UCL) boundary and will likely be crossed by the UCL by 2011.

It is important to understand that these SA4 derived definitions of capital cities are designed to provide a stable and consistent boundary that reflects the socioeconomic extent of the city over the next twenty years. It is not a definition of the built up area of each capital city, this is provided by the UCL boundaries. From 2011 the UCLs will be aggregations of Statistical Area 1 boundaries updated after each Census. In addition to these two definitions of capital cities, from 2011, the ABS will also define Significant Urban Areas (SUAs). SUAs will be built from aggregations of Statistical Area 2 (SA2) boundaries and provide a similar definition to the current SDs.

To define the edge of the capital cities, in addition to the current labour market, it will be necessary to consider likely future directions in urban planning to ensure consistent and stable capital city boundaries over the next 20 years. Consequently, the ABS has reviewed the boundaries of the current capital cites on the basis that:

1. Capital cities will be defined using whole SA4s to provide a consistent, stable, socioeconomic definition of each city.
2. Capital city SA4 design will take into account any likely changes in urban development and the transport network over the next 20 years.

The impact of this on the definition of each capital city compared with the current (SD) definition varies throughout Australia. Below is a brief description of the impact of the changes on the definition of each capital city.


Sydney

The Capital City definition of Sydney remains essentially unchanged from the current Sydney SD, apart from several small differences around National Parks in the south and west. These do not involve any population.


Melbourne

The Capital City definition of Melbourne has been extended from the current SD particularly in the north and west. In the northwest, Census travel to work data showed significant commuter interaction outside the current Melbourne SD boundary. Using this data to inform the design, the boundary has been extended as far as the towns of Bachus Marsh, Macedon, Lancefield, Wallan and Kinglake. To the south and east, the boundary remains unchanged with the exception of a small area east of Warburton.


Brisbane

The Brisbane Capital City definition has been extended from the current SD primarily in the south and west. In the south west the boundary extends to the NSW border to include Beaudesert and Boonah. While the southernmost parts of this area are quite rural in character, its low population means it cannot be contained in a separate SA4. Given that around one third of the workforce is currently employed in Brisbane, this area has been included in the Brisbane Capital City.

The boundary between the Gold Coast and Brisbane has been adjusted south from the Logan River to the Pimpama River, as the travel to work data shows the area between these two rivers to have significantly stronger links with Brisbane than the Gold Coast.

In the north west, the new Capital City definition extends out to include Laidley, Esk and Kilcoy where Census data shows a large proportion of commuter interaction with Brisbane and Ipswich.


Adelaide

The Capital City definition of Adelaide has extended from the current SD to the north and significantly to the east. To the east the Capital City definition has extended to include a larger area of the Adelaide Hills; towns such as Mt Barker and Lobethal are now included because of the significant commuting interaction with Adelaide. In the north the new boundary has been extended out to contain Gawler as well as Roseworthy and Two Wells, both of which have been identified as possible future growth areas in the Greater Adelaide 30 year plan.


Perth

The Perth Capital City definition has been extended from the current SD in the south to include Mandurah and Pinjarra. Travel to work analysis shows these areas have strong labour market links with the south west of Perth. The remainder of the Perth Capital City definition remains unchanged from the current SD.


Hobart

The Capital City definition for Hobart remains unchanged from the current SD, apart from a small adjustment on the outskirts of Sorrell to the north east of Hobart. This change involves only a very small population and results from differences between the SA2 design and Statistical Local Areas. Travel to work data suggests that the labour market of Hobart extends outside this definition of Hobart and this is reflected in the adjacent SA4. This extended definition of the Hobart labour market was considered impractical for Capital City purposes and consequently the existing SD definition was retained, this contains the vast majority of the population of the Hobart labour market.


Darwin

The Darwin Capital City definition remains unchanged from the current SD. Travel to work data shows that the existing boundary accurately reflects the Darwin labour market.


Canberra

The Capital City definition of Canberra now extends to include the entire ACT. While this involves a large change in area from the current SD the difference in population is minimal. The non-urban component of the ACT has too small a population to be included in a separate SA4 and consequently the SA4 defining Canberra must include the entire ACT.