Is Mosman denser than we think? A look into Mosman’s population density

Aug 7, 2018 Planning News

Mosman Council’s Urban Planning team have been busy crunching numbers to better understand the population density of Mosman.

Population density is a common measurement used by planners and geographers to understand how and where populations are distributed. It is used by urban planners to analyse the demand for services, utilities, infrastructure and housing in an area.

As many who are familiar with Mosman may know there are large parcels of land under the care of National Parks and Wildlife Services, the Department of Defence, Sydney Harbour Foreshore Trust and Taronga Zoo. As Mosman is a relatively small Local Government Area (LGA), this land accounts for a considerable 23% of land in Mosman.

Traditionally this land is included in calculations for population density and results in lower figure for Mosman than would otherwise be the case.

By removing this land from population density we can gain insights as to the actual population density of Mosman and how it compares with surrounding areas.


The total area of Mosman and the Usual Resident Population as of 2016 was sourced from ABS Census data available on Profile ID’s website and was used to determine the population density of Mosman.

From there ABS mesh block data (the smallest statistical area the ABS collects data for) was used to gather population and spatial statistics on Department of Defence Land, Sydney Harbour Foreshore Trust, National Parks and Taronga Zoo. This collated data was then subtracted from the original data to determine the adjusted LGA area (6.69 Sq. Km), the adjusted LGA population (28,271) and to subsequently calculate the adjusted population density (4226 people per Sq. Km).

The below map indicates the mesh blocks selected for this exercise:

Selected mesh blocks highlighted in yellow


Area Total Area

(Sq. Km)

Total Population Density (Population per Sq. Km)
Mosman LGA including other land 8.65 28475 3292
Mosman LGA excluding other land 6.69 28271 4226

 The population density excluding Department of Defence Land, Sydney Harbour Foreshore Trust, National Parks and Taronga Zoo was significantly higher at 4226 people per Sq. Km. This represents a 28% increase in density compared to the standard population density calculation for Mosman of 3292 people per Sq. Km.

A table outlining how both populations densities sit with nearby LGAs is below. It is important to note that the other LGAs have not been adjusted and may include other land such as National Parks or Sydney Harbour Foreshore Trust land, however, for the purposes of this exercise the table below illustrates how significant the difference for Mosman is.

Council Area Population Density (People per Sq. Km)
North Sydney Council area 6450
Mosman Council area adjusted 4226
Lane Cove Council area 3438
Willoughby City 3322
Mosman Council area 3292
Manly Council area 2919
City of Ryde 2878
Hunters Hill Municipality 2412
Ku-ring-gai Council area 1367
Warringah Council area 1010
Pittwater Council area 669
Hornsby Shire 310