Cairnlea flood map & planning overlays

The schematic on this page is a Cairnlea flood map: the mapped flood overlays drawn over the suburb's terrain and street grid, covering about 6% of the suburb. Flood lines vary block to block, so for a specific property use the free interactive map - search any Cairnlea address and it shows the flood, zoning and bushfire mapping on the exact lot boundary.

About 6% of Cairnlea falls within a mapped flood overlay, against the council-wide suburb average of 6%. Flood overlays vary block to block, so whether a particular lot is affected needs a property-level check.

Bushfire mapping covers Cairnlea and little to none of it is mapped as bushfire-prone (the Brimbank average is 15%). Always confirm for the exact lot, as mapping can change.

The dominant planning zone in Cairnlea is Neighbourhood Residential Zone (NRZ1), though the suburb also includes Public Conservation and Resource Zone (PCRZ) and Public Park and Recreation Zone (PPRZ). Zoning sets what you can build and do on a site, and can differ lot by lot.

Cairnlea has 2 heritage-listed places on record. Heritage listing affects what you can alter or demolish, so confirm whether a specific property is listed or near a heritage place.

Across 3,314 surveyed parcels in Cairnlea, the median lot size is about 572 m². There are also 1,164 registered easements mapped in the suburb - an easement can restrict where you can build, so always check the title and overlays for the specific lot.

There is no train station inside Cairnlea itself. The suburb is served by 16 bus stops.

At the 2021 Census Cairnlea had 10,038 usual residents, with a median age of 36 and an average household size of 3.4 people. The wider Cairnlea statistical area, which contains Cairnlea, went from 366 people in 2001 to 10,035 in 2025, up 2642%. ABS publishes no annual population series for individual suburbs, so that trend describes the surrounding area rather than Cairnlea alone.

On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Cairnlea scores 968 and sits in decile 4 of 10 nationally and decile 3 within Victoria - decile 1 being the most disadvantaged tenth of Australian suburbs and decile 10 the least. The national average score is 1000. SEIFA summarises income, education, occupation and housing across the whole suburb, so it describes the area, not any particular household in it.

Median household income in Cairnlea was $2,062 a week at the 2021 Census, against $1,486 for the typical suburb in Brimbank. Median rent was $400 a week and the median mortgage repayment $1,883 a month. These are 2021 Census figures and have not been indexed to today.

A Cairnlea planning report pulls every overlay - zoning, flood, bushfire, heritage, environmental and noise - that touches a single lot, on live council and state data. The interactive map preview is free; the full PDF report is $9.