Underdale flood map & planning overlays
A planning-constraint profile of Underdale
(City of West Torrens, SA) - 1.04 km², mapped from live council and
state overlay data. This suburb is relatively unconstrained.
Profile updated 3 October 2026.
Suburb-wide figures; the free map shows which overlays touch your lot.
Constraint readout
1.04 km² - this suburb is relatively unconstrained by planning overlays.
Elevation hillshade with street names, clipped to Underdale's boundary, with the flood, bushfire and environmental overlays drawn on top. Amber hatching is the published aircraft noise (ANEF) contour. 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 Underdale
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.
Inside an aircraft noise contour
4% of the suburb's land sits inside a published ANEF or airport-environs contour. Contours vary street by street, so whether a particular lot is inside one needs a property-level check.
Highest contour present
Under AS 2021, land between ANEF 20 and 25 is conditionally acceptable for houses, usually with noise attenuation built in. The contour is a forecast, not a measurement at any one house.
Contours held
- SA Planning and Design Code aircraft noise
Observed overflight - sampled 4 Sep to 3 Oct 2026
typical observed square 3 a day
Night movements: observed, lowest 500 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.
Underdale at a glance
How Underdale is zoned
Selling in Underdale? 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 1.04 km², Underdale is relatively unconstrained by planning overlays. About 5% of the suburb sits within a mapped flood overlay. There are 3 heritage-listed sites on record, and the dominant land-use zone is Housing Diversity Neighbourhood. The median lot measures about 445 m² across 1,295 parcels.
Who lives in Underdale
Census 2021 figures published by the ABS for the Underdale 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 1012, and decile 8 within South Australia. The national average is 1000.
Age profile
Share of Underdale's 2,429 residents in each ABS age band.
Population trend, 2001 to 2025
Estimated resident population of Lockleys, the wider ABS statistical area containing Underdale. There is no annual population series published at suburb level, so this describes the surrounding area rather than Underdale itself.
11,556 in 2001 to 14,336 in 2025, up 24%.
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.
Underdale 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) | Inside a held contour | 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 Underdale 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 100% of Underdale. 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 Underdale lot.
See what's in the $9 report →Underdale planning - frequently asked
Is Underdale flood-prone?
About 5% of Underdale falls within a mapped flood overlay, against the council-wide suburb average of 32%.
Is Underdale bushfire-prone?
Bushfire mapping covers Underdale and little to none of it is mapped as bushfire-prone.
Is Underdale affected by aircraft noise?
About 4% of Underdale sits inside a published aircraft noise contour, and the highest contour present is ANEF 20 - under AS 2021, land between ANEF 20 and 25 is conditionally acceptable for houses, usually with noise attenuation in the build. ANEF contours are forecasts published per airport and used to control noise-sensitive development; they are not a measurement at any one house, and a property can sit under a flight path and outside every contour.
Is Underdale under a flight path?
Aircraft were observed below 3,000 ft over about 100% of Underdale, in the period sampled (4 Sep 2026 to 3 Oct 2026). The lowest measured aircraft was at 500 ft, with an average of 2,000 ft. At the busiest point in the suburb about 5 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 Underdale?
The dominant planning zone in Underdale is Housing Diversity Neighbourhood, though the suburb also includes Suburban Neighbourhood and Urban Renewal Neighbourhood.
Does Underdale have heritage-listed places?
Underdale has 3 heritage-listed places on record.
What is the typical lot size in Underdale?
Across 1,295 surveyed parcels in Underdale, the median lot size is about 445 m².
Does Underdale have a train station?
There is no train station inside Underdale itself. The suburb is served by 14 bus stops.
What is the population of Underdale?
At the 2021 Census Underdale had 2,429 usual residents, with a median age of 38 and an average household size of 2.3 people. The wider Lockleys statistical area, which contains Underdale, went from 11,556 people in 2001 to 14,336 in 2025, up 24%.
Is Underdale an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Underdale scores 1012 and sits in decile 7 of 10 nationally and decile 8 within South Australia (decile 1 is the most disadvantaged tenth, decile 10 the least).
What is the median household income in Underdale?
Median household income in Underdale was $1,578 a week at the 2021 Census, against $1,539 for the typical suburb in City of West Torrens. Median rent was $310 a week and the median mortgage repayment $1,786 a month.
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| Flinders Park City of Charles Sturt |
1.0 km | 22% | 0% |
| Torrensville | 1.2 km | 3% | 0% |
| Brooklyn Park | 1.3 km | 29% | 0% |
| Lockleys | 1.5 km | 7% | 0% |
| Cowandilla | 1.7 km | 85% | 0% |
| Allenby Gardens City of Charles Sturt |
2.0 km | 23% | 0% |
| Welland City of Charles Sturt |
2.0 km | 25% | 0% |
| Mile End | 2.1 km | 0% | 0% |
| Kidman Park City of Charles Sturt |
2.1 km | 15% | 0% |
| West Hindmarsh City of Charles Sturt |
2.1 km | 11% | 0% |