Duncan flood map & planning overlays
A planning-constraint profile of Duncan
(Kangaroo Island Council, SA) - 173.53 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
173.53 km² - this suburb is highly constrained by planning overlays.
Elevation hillshade with street names, clipped to Duncan'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 Duncan
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.
Duncan at a glance
How Duncan is zoned
Selling in Duncan? 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 173.53 km², Duncan 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. The dominant land-use zone is Rural. The median lot measures about 1,470,701 m² across 73 parcels.
Who lives in Duncan
Census 2021 figures published by the ABS for the Duncan 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 997, and decile 7 within South Australia. The national average is 1000.
Age profile
Share of Duncan's 67 residents in each ABS age band.
Population trend, 2001 to 2025
Estimated resident population of Kangaroo Island, the wider ABS statistical area containing Duncan. There is no annual population series published at suburb level, so this describes the surrounding area rather than Duncan itself.
4,227 in 2001 to 5,212 in 2025, up 23%.
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.
Duncan 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 Duncan 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 1% of Duncan. 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 Duncan lot.
See what's in the $9 report →Duncan planning - frequently asked
Is Duncan flood-prone?
Flood mapping covers Duncan and none of the suburb falls within a mapped flood overlay (the council-wide suburb average is 7%).
Is Duncan bushfire-prone?
Around 100% of Duncan is mapped as bushfire-prone, compared with a Kangaroo Island Council average of 96%.
Is Duncan under a flight path?
Aircraft were observed below 3,000 ft over about 1% of Duncan, in the period sampled (4 Sep 2026 to 3 Oct 2026). The lowest measured aircraft was at 1,000 ft, with an average of 2,000 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 Duncan?
The dominant planning zone in Duncan is Rural.
Does Duncan have heritage-listed places?
No heritage-listed places are on record within Duncan.
What is the typical lot size in Duncan?
Across 73 surveyed parcels in Duncan, the median lot size is about 1,470,701 m².
What is the population of Duncan?
At the 2021 Census Duncan had 67 usual residents, with a median age of 32 and an average household size of 2.5 people. The wider Kangaroo Island statistical area, which contains Duncan, went from 4,227 people in 2001 to 5,212 in 2025, up 23%.
Is Duncan an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Duncan scores 997 and sits in decile 6 of 10 nationally and decile 7 within South Australia (decile 1 is the most disadvantaged tenth, decile 10 the least).
What is the median household income in Duncan?
Median household income in Duncan was $1,875 a week at the 2021 Census, against $1,249 for the typical suburb in Kangaroo Island Council. Median rent was $158 a week and the median mortgage repayment $550 a month.
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| Middle River | 7.1 km | 0% | 100% |
| Stokes Bay | 10.8 km | 0% | 100% |
| Parndana | 12.6 km | 0% | 100% |
| Newland | 13.8 km | 0% | 100% |
| Western River | 16.2 km | 0% | 100% |
| Gosse | 16.5 km | 0% | 100% |
| Cassini | 17.6 km | 0% | 100% |
| Seddon | 18.3 km | 0% | 100% |
| Vivonne Bay | 26.1 km | 0% | 100% |
| Kohinoor | 26.2 km | 0% | 100% |