St Johns flood map & planning overlays
A planning-constraint profile of St Johns
(Light Regional Council, SA) - 17.26 km², mapped from live council and
state overlay data. This suburb is highly constrained.
Profile updated 3 October 2026.
Suburb-wide figures; the free map shows which overlays touch your lot.
Constraint readout
17.26 km² - this suburb is highly constrained by planning overlays.
Elevation hillshade with street names, clipped to St Johns'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 Johns
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
Night movements: not established - night is sampled as often as day, but too few night flights have been seen here to conclude either way.
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 Johns at a glance
How St Johns is zoned
Selling in St Johns? 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 17.26 km², St Johns is highly constrained by planning overlays. Flood mapping covers the suburb and none of it falls within a mapped flood overlay, and 100% is flagged bushfire-prone. There are 3 heritage-listed sites on record, and the dominant land-use zone is Rural. The median lot measures about 330,638 m² across 45 parcels.
Who lives in St Johns
Census 2021 figures published by the ABS for the St Johns 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 982, and decile 6 within South Australia. The national average is 1000.
Population trend, 2001 to 2025
Estimated resident population of Light, the wider ABS statistical area containing St Johns. There is no annual population series published at suburb level, so this describes the surrounding area rather than St Johns itself.
7,332 in 2001 to 10,631 in 2025, up 45%.
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 Johns 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 Johns 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 5% of St Johns. 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 Johns lot.
See what's in the $9 report →St Johns planning - frequently asked
Is St Johns flood-prone?
Flood mapping covers St Johns and none of the suburb falls within a mapped flood overlay (the council-wide suburb average is 4%).
Is St Johns bushfire-prone?
Around 100% of St Johns is mapped as bushfire-prone, compared with a Light Regional Council average of 100%.
Is St Johns under a flight path?
Aircraft were observed below 3,000 ft over about 5% of St Johns, and over about 12% 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 2,000 ft, with an average of 6,000 ft. 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 Johns?
The dominant planning zone in St Johns is Rural.
Does St Johns have heritage-listed places?
St Johns has 3 heritage-listed places on record.
What is the typical lot size in St Johns?
Across 45 surveyed parcels in St Johns, the median lot size is about 330,638 m².
Is St Johns an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), St Johns scores 982 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).
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| Moppa | 4.4 km | 0% | 100% |
| Koonunga | 6.3 km | 0% | 100% |
| Kapunda | 6.6 km | 1% | 100% |
| Fords | 7.1 km | 0% | 100% |
| Greenock | 7.1 km | 2% | 100% |
| Ebenezer | 7.9 km | 0% | 100% |
| Nain | 9.2 km | 0% | 100% |
| Bagot Well | 9.5 km | 0% | 100% |
| Nuriootpa The Barossa Council |
10.4 km | 4% | 97% |
| Allendale North | 11.1 km | 0% | 100% |