St Agnes flood map & planning overlays
A planning-constraint profile of St Agnes
(City of Tea Tree Gully, SA) - 2.6 km², mapped from live council and
state overlay data. This suburb is moderately constrained.
Profile updated 3 October 2026.
Suburb-wide figures; the free map shows which overlays touch your lot.
Constraint readout
2.6 km² - this suburb is moderately constrained by planning overlays.
Elevation hillshade with street names, clipped to St Agnes's boundary, with the flood, bushfire and environmental overlays drawn on top. Magenta is where aircraft were observed in the sampled period, brightest below 3,000 ft.
Nearby suburbs, nearest first
Aircraft noise and flight paths over St Agnes
Two different things, kept apart on purpose. The ANEF contour is the planning instrument - a forecast published per airport that planning schemes use to control noise-sensitive development. Observed overflight is what a sampled aircraft-tracking feed actually recorded over the suburb - where aircraft flew, how low and how often.
Observed overflight - sampled 4 Sep to 3 Oct 2026
typical observed square 14 a day
Night movements: observed, lowest 3,000 ft - night is sampled as often as day, but night traffic is light, so this is a floor and no rate can be put on it.
Traffic is sampled rather than watched continuously, so every figure is a floor: aircraft not captured between samples are not represented. Rates are per 500 m square - the busiest square in the suburb, not a count of flights over the suburb - and a square is only rated where enough traffic was seen to measure it. Altitudes are above mean sea level. Flight paths change with runway use, weather, season and airspace design. This is a record of observed traffic; it is not a noise contour and not a planning control.
St Agnes at a glance
How St Agnes is zoned
Selling in St Agnes? The zone and overlays on this page are the Planning and Design Code controls a Form 1 vendor's statement has to disclose.
Across its 2.6 km², St Agnes is moderately constrained by planning overlays. About 25% of the suburb sits within a mapped flood overlay. There is 1 heritage-listed site on record, and the dominant land-use zone is General Neighbourhood. The median lot measures about 664 m² across 2,035 parcels.
Who lives in St Agnes
Census 2021 figures published by the ABS for the St Agnes 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 984, and decile 6 within South Australia. The national average is 1000.
Age profile
Share of St Agnes's 4,233 residents in each ABS age band.
Population trend, 2001 to 2025
Estimated resident population of St Agnes - Ridgehaven, the wider ABS statistical area containing St Agnes. There is no annual population series published at suburb level, so this describes the surrounding area rather than St Agnes itself.
12,678 in 2001 to 13,531 in 2025, up 7%.
Source: ABS Census 2021 and SEIFA 2021 (Suburbs and Localities), Regional Population (SA2), CC BY 4.0. Small counts are randomly adjusted by the ABS.
St Agnes data sources and coverage
“Not mapped” means we hold no source layer for this suburb - never an all-clear.
| Dataset | Coverage | Publisher |
|---|---|---|
| Flood mapping | Mapped | the South Australian Planning and Design Code and Location SA spatial data |
| Bushfire-prone mapping | Mapped | the South Australian Planning and Design Code and Location SA spatial data |
| Zoning | Mapped | the South Australian Planning and Design Code and Location SA spatial data |
| Heritage and environment | Mapped where published | the South Australian Planning and Design Code and Location SA spatial data |
| Aircraft noise contours (ANEF) | Not held | the South Australian Planning and Design Code and Location SA spatial data, Defence |
| Observed flight paths | Observed | adsb.lol, under the Open Database License |
| Demographics | Available | Australian Bureau of Statistics (2021 Census and SEIFA) |
Profile last materially updated 3 October 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 Agnes 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.
Aircraft have been seen below 3,000 ft over about 30% of St Agnes. The report's Aircraft Overflight page narrows that to the address itself: how many aircraft a day, how low, and at what heights.
Building or pricing a slab? The $119 geotechnical desktop report covers geology, soils, bores and an indicative AS 2870 site class for a St Agnes lot.
See what's in the $9 report →St Agnes planning - frequently asked
Is St Agnes flood-prone?
About 25% of St Agnes falls within a mapped flood overlay, against the council-wide suburb average of 16%.
Is St Agnes bushfire-prone?
Bushfire mapping covers St Agnes and little to none of it is mapped as bushfire-prone (the City of Tea Tree Gully average is 36%).
Is St Agnes under a flight path?
Aircraft were observed below 3,000 ft over about 30% of St Agnes, and over about 88% at any altitude up to 10,000 ft, in the period sampled (4 Sep 2026 to 3 Oct 2026). The lowest measured aircraft was at 1,500 ft, with an average of 3,500 ft. At the busiest point in the suburb about 77 aircraft a day were recorded passing over one 500 m square. Traffic is sampled rather than watched continuously and flight paths change with runway use, weather and season; the ANEF contour is the planning instrument.
What is the zoning in St Agnes?
The dominant planning zone in St Agnes is General Neighbourhood, though the suburb also includes Employment and Housing Diversity Neighbourhood.
Does St Agnes have heritage-listed places?
St Agnes has 1 heritage-listed place on record.
What is the typical lot size in St Agnes?
Across 2,035 surveyed parcels in St Agnes, the median lot size is about 664 m².
Does St Agnes have a train station?
There is no train station inside St Agnes itself. The suburb is served by 28 bus stops.
What is the population of St Agnes?
At the 2021 Census St Agnes had 4,233 usual residents, with a median age of 44 and an average household size of 2.4 people. The wider St Agnes - Ridgehaven statistical area, which contains St Agnes, went from 12,678 people in 2001 to 13,531 in 2025, up 7%.
Is St Agnes an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), St Agnes scores 984 and sits in decile 5 of 10 nationally and decile 6 within South Australia (decile 1 is the most disadvantaged tenth, decile 10 the least).
What is the median household income in St Agnes?
Median household income in St Agnes was $1,557 a week at the 2021 Census, against $1,703 for the typical suburb in City of Tea Tree Gully. Median rent was $340 a week and the median mortgage repayment $1,500 a month.
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| Ridgehaven | 1.1 km | 14% | 0% |
| Redwood Park | 2.0 km | 13% | 0% |
| Vista | 2.0 km | 14% | 99% |
| Modbury | 2.1 km | 25% | 0% |
| Hope Valley | 2.2 km | 11% | 4% |
| Tea Tree Gully | 2.4 km | 11% | 82% |
| Highbury | 2.6 km | 17% | 66% |
| Modbury North | 2.7 km | 13% | 0% |
| Banksia Park | 2.7 km | 15% | 57% |
| Modbury Heights | 3.0 km | 10% | 0% |