Thirlmere zoning & planning overlays
A planning-constraint profile of Thirlmere
(Wollondilly, NSW) - 33.3 km², mapped from live council and
state overlay data. This suburb is highly constrained on the overlays we could measure - no flood mapping covers this suburb, so this is not a suburb-wide verdict.
Profile updated 26 September 2026.
Suburb-wide figures; the free map shows which overlays touch your lot.
Constraint readout
33.3 km² - this suburb is highly constrained on the overlays we could measure - no flood mapping covers this suburb, so this is not a suburb-wide verdict.
Elevation hillshade with street names, clipped to Thirlmere's boundary, with the bushfire and environmental overlays drawn on top. Magenta is where aircraft were observed in the sampled period, brightest below 3,000 ft. No flood layer is drawn because we hold no flood mapping for this area.
Nearby suburbs, nearest first
Aircraft noise and flight paths over Thirlmere
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 26 Sep 2026
typical observed square 1 a day
Night movements: observed, lowest 9,500 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.
Thirlmere at a glance
How Thirlmere is zoned
Buying in Thirlmere? 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 33.3 km², Thirlmere is highly constrained by the planning overlays we hold. We hold no flood mapping covering this suburb, so no flood figure is shown - that is a gap in our data, not an all-clear. Of what is mapped, 88% is flagged bushfire-prone. There are 26 heritage-listed sites on record, and the dominant land-use zone is Primary Production. The median lot measures about 986 m² across 2,254 parcels.
Who lives in Thirlmere
Census 2021 figures published by the ABS for the Thirlmere 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 5 within New South Wales. The national average is 1000.
Age profile
Share of Thirlmere's 4,986 residents in each ABS age band.
Population trend, 2001 to 2025
Estimated resident population of Picton - Tahmoor - Buxton, the wider ABS statistical area containing Thirlmere. There is no annual population series published at suburb level, so this describes the surrounding area rather than Thirlmere itself.
14,113 in 2001 to 22,603 in 2025, up 60%.
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.
Thirlmere data sources and coverage
“Not mapped” means we hold no source layer for this suburb - never an all-clear.
| Dataset | Coverage | Publisher |
|---|---|---|
| Flood mapping | Not 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 |
| Aircraft noise contours (ANEF) | Not held | NSW Government spatial services, NSW ePlanning and published council flood studies, 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 26 September 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 Thirlmere 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 78% of Thirlmere. 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 Thirlmere lot.
See what's in the $9 report →Thirlmere planning - frequently asked
Is Thirlmere flood-prone?
We don't yet hold flood mapping covering Thirlmere, so this page can't say how much of the suburb is flood-affected - that is a gap in our data, not an indication that the suburb is free of flood risk. Wollondilly is the authority to check for flood mapping in this area.
Is Thirlmere bushfire-prone?
Around 88% of Thirlmere is mapped as bushfire-prone, compared with a Wollondilly average of 93%.
Is Thirlmere under a flight path?
Aircraft were observed below 3,000 ft over about 78% of Thirlmere, and over about 98% at any altitude up to 10,000 ft, in the period sampled (4 Sep 2026 to 26 Sep 2026). The lowest measured aircraft was at 1,000 ft, with an average of 3,500 ft. At the busiest point in the suburb about 4 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 Thirlmere?
The dominant planning zone in Thirlmere is Primary Production, though the suburb also includes National Parks and Nature Reserves and Primary Production Small Lots.
Does Thirlmere have heritage-listed places?
Thirlmere has 26 heritage-listed places on record.
What is the typical lot size in Thirlmere?
Across 2,254 surveyed parcels in Thirlmere, the median lot size is about 986 m². There are also 11 registered easements mapped in the suburb.
Does Thirlmere have a train station?
There is no train station inside Thirlmere itself. The suburb is served by 48 bus stops.
What is the population of Thirlmere?
At the 2021 Census Thirlmere had 4,986 usual residents, with a median age of 38 and an average household size of 2.7 people. The wider Picton - Tahmoor - Buxton statistical area, which contains Thirlmere, went from 14,113 people in 2001 to 22,603 in 2025, up 60%.
Is Thirlmere an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Thirlmere scores 984 and sits in decile 5 of 10 nationally and decile 5 within New South Wales (decile 1 is the most disadvantaged tenth, decile 10 the least).
What is the median household income in Thirlmere?
Median household income in Thirlmere was $1,708 a week at the 2021 Census, against $2,250 for the typical suburb in Wollondilly. Median rent was $420 a week and the median mortgage repayment $2,300 a month.
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| Couridjah | 3.4 km | Not mapped | 100% |
| Tahmoor | 3.8 km | Not mapped | 70% |
| Mowbray Park | 5.4 km | Not mapped | 99% |
| Lakesland | 5.5 km | 0% | 100% |
| Picton | 5.7 km | Not mapped | 84% |
| Buxton | 6.3 km | 0% | 93% |
| Maldon | 6.8 km | Not mapped | 85% |
| Bargo | 9.2 km | 0% | 89% |
| Pheasants Nest | 10.1 km | 0% | 97% |
| Razorback | 10.2 km | Not mapped | 99% |