St Marys flood map & planning overlays
A planning-constraint profile of St Marys (Penrith, NSW) - 10.62 km², mapped from live council and state overlay data. This suburb is moderately constrained.
Everything below is suburb-wide. Overlays change block to block - see which ones actually touch your lot. The map is free.
Constraint readout
10.62 km² - this suburb is moderately constrained by planning overlays.
Elevation hillshade with street names, clipped to St Marys's boundary, with the flood, bushfire and environmental overlays drawn on top. It shows where constraints fall; the interactive map shows them on your exact address.
St Marys at a glance
How St Marys is zoned
Buying in St Marys? The zoning, flood and bushfire lines on the section 10.7 certificate attached to the contract are mapped controls - see our s10.7 certificate guide.
Across its 10.62 km², St Marys is moderately constrained by planning overlays. Flood mapping covers the suburb and none of it falls within a mapped flood overlay, and 26% is flagged bushfire-prone. There are 36 heritage-listed sites on record, and the dominant land-use zone is General Industrial. The median lot measures about 667 m² across 3,800 parcels. These figures are suburb-wide - the overlays that actually apply to a given lot can differ block to block, which is what a property-level check tells you.
Who lives in St Marys
Census 2021 figures published by the ABS for the St Marys suburb boundary itself, not a wider region.
Socio-economic standing
ABS SEIFA 2021 ranks every Australian suburb. Decile 1 is the most disadvantaged tenth of the country, decile 10 the least.
Score 906, and decile 2 within New South Wales. The national average is 1000.
Age profile
Share of St Marys's 13,256 residents in each ABS age band.
Population trend, 2001 to 2025
Estimated resident population of St Marys - North St Marys, the wider ABS statistical area containing St Marys. There is no annual population series published at suburb level, so this describes the surrounding area rather than St Marys itself.
13,398 in 2001 to 18,757 in 2025, up 40%.
Source: Australian Bureau of Statistics. Census of Population and Housing 2021 (General Community Profile) and SEIFA 2021, both published at the Suburbs and Localities level; Regional Population (estimated resident population) at Statistical Area Level 2. Used under CC BY 4.0. Census counts of small populations are randomly adjusted by the ABS to protect confidentiality, so figures for small suburbs are indicative.
St Marys data sources and coverage
Every figure below is an aggregate for the suburb boundary. “Not mapped” means LayeredGeo does not hold a source layer covering this suburb; it is never an all-clear for a particular property.
| Dataset | Coverage | Publisher |
|---|---|---|
| Flood mapping | Mapped | NSW Government spatial services, NSW ePlanning and published council flood studies |
| Bushfire-prone mapping | Mapped | NSW Government spatial services, NSW ePlanning and published council flood studies |
| Zoning | Mapped | NSW Government spatial services, NSW ePlanning and published council flood studies |
| Heritage and environment | Mapped where published | NSW Government spatial services, NSW ePlanning and published council flood studies |
| Demographics | Available | Australian Bureau of Statistics (2021 Census and SEIFA) |
Profile last materially updated 5 August 2026. See the methodology and full source list. Source data changes over time and critical decisions should be checked with the responsible authority.
Check a specific St Marys address
See exactly which overlays touch a single property - the interactive map is free. Need it on paper? A full planning PDF is just $9.
See what's in the $9 report →St Marys planning - frequently asked
Where can I see a flood map of St Marys?
The schematic on this page is a St Marys flood map: the mapped flood overlays drawn over the suburb's terrain and street grid. Flood lines vary block to block, so for a specific property use the free interactive map - search any St Marys address and it shows the flood, zoning and bushfire mapping on the exact lot boundary.
Is St Marys flood-prone?
Flood mapping covers St Marys and none of the suburb falls within a mapped flood overlay (the council-wide suburb average is 0%). Flood overlays vary block to block, so whether a particular lot is affected needs a property-level check.
Is St Marys bushfire-prone?
Yes - around 26% of St Marys is mapped as bushfire-prone, compared with a Penrith average of 42%. A bushfire-prone designation can trigger additional building requirements, so check the specific address.
What is the zoning in St Marys?
The dominant planning zone in St Marys is General Industrial, though the suburb also includes Medium Density Residential and Low Density Residential. Zoning sets what you can build and do on a site, and can differ lot by lot.
Does St Marys have heritage-listed places?
St Marys has 36 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.
What is the typical lot size in St Marys?
Across 3,800 surveyed parcels in St Marys, the median lot size is about 667 m². There are also 4 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.
Does St Marys have a train station?
Yes - St Marys has 1 train station: St Marys Station. It is also served by 173 bus stops.
What is the population of St Marys?
At the 2021 Census St Marys had 13,256 usual residents, with a median age of 34 and an average household size of 2.5 people. The wider St Marys - North St Marys statistical area, which contains St Marys, went from 13,398 people in 2001 to 18,757 in 2025, up 40%. ABS publishes no annual population series for individual suburbs, so that trend describes the surrounding area rather than St Marys alone.
Is St Marys an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), St Marys scores 906 and sits in decile 2 of 10 nationally and decile 2 within New South Wales - 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.
What is the median household income in St Marys?
Median household income in St Marys was $1,437 a week at the 2021 Census, against $2,067 for the typical suburb in Penrith. Median rent was $365 a week and the median mortgage repayment $1,847 a month. These are 2021 Census figures and have not been indexed to today.
Do I need a planning report for a St Marys property?
A St Marys planning report pulls every overlay - zoning, flood, bushfire, heritage and environmental - that touches a single lot, on live council and state data. The interactive map preview is free; a full PDF report is $9.
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| North St Marys | 1.3 km | 0% | 38% |
| Werrington County | 2.0 km | 0% | 42% |
| Werrington | 2.0 km | 0% | 25% |
| Tregear Blacktown |
2.1 km | 0% | 21% |
| Ropes Crossing Blacktown |
2.5 km | 0% | 78% |
| Lethbridge Park Blacktown |
3.0 km | 0% | 1% |
| Whalan Blacktown |
3.1 km | 0% | 7% |
| Oxley Park | 3.2 km | 0% | 23% |
| Claremont Meadows | 3.2 km | 0% | 33% |
| Emerton Blacktown |
3.5 km | 0% | 0% |