Castlecrag zoning & planning overlays
A planning-constraint profile of Castlecrag
(Willoughby, NSW) - 1.47 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
1.47 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 Castlecrag'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 Castlecrag
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 25 Sep 2026
typical observed square 3 a day
Night movements: observed, lowest 1,000 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.
Castlecrag at a glance
How Castlecrag is zoned
Buying in Castlecrag? 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 1.47 km², Castlecrag 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, 44% is flagged bushfire-prone. There are 51 heritage-listed sites on record, and the dominant land-use zone is Environmental Living. The median lot measures about 704 m² across 1,248 parcels.
Who lives in Castlecrag
Census 2021 figures published by the ABS for the Castlecrag 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 1195, and decile 10 within New South Wales. The national average is 1000.
Age profile
Share of Castlecrag's 2,965 residents in each ABS age band.
Population trend, 2001 to 2025
Estimated resident population of Castle Cove - Northbridge, the wider ABS statistical area containing Castlecrag. There is no annual population series published at suburb level, so this describes the surrounding area rather than Castlecrag itself.
12,615 in 2001 to 13,592 in 2025, up 8%.
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.
Castlecrag 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 Castlecrag 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 52% of Castlecrag. The report's Aircraft Overflight page narrows that to the address itself: how many aircraft a day, how low, and at what heights.
Published flood models are held over parts of Castlecrag. The free check tells you whether one reaches an address; where it does, a Flood Model Report is +$9 with the planning report.
Building or pricing a slab? The $119 geotechnical desktop report covers geology, soils, bores and an indicative AS 2870 site class for a Castlecrag lot.
See what's in the $9 report →Castlecrag planning - frequently asked
Is Castlecrag flood-prone?
We don't yet hold flood mapping covering Castlecrag, 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. Willoughby is the authority to check for flood mapping in this area. Published flood models are held over parts of Castlecrag; the free check on the Flood Model Report page says whether one reaches a given address.
Is Castlecrag bushfire-prone?
Around 44% of Castlecrag is mapped as bushfire-prone, compared with a Willoughby average of 26%.
Is Castlecrag under a flight path?
Aircraft were observed below 3,000 ft over about 52% of Castlecrag, and over about 98% at any altitude up to 10,000 ft, in the period sampled (4 Sep 2026 to 25 Sep 2026). The lowest measured aircraft was at 1,000 ft, with an average of 5,000 ft. At the busiest point in the suburb about 13 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 Castlecrag?
The dominant planning zone in Castlecrag is Environmental Living, though the suburb also includes Environmental Conservation and Low Density Residential.
Does Castlecrag have heritage-listed places?
Castlecrag has 51 heritage-listed places on record.
What is the typical lot size in Castlecrag?
Across 1,248 surveyed parcels in Castlecrag, the median lot size is about 704 m². There are also 4 registered easements mapped in the suburb.
Does Castlecrag have a train station?
There is no train station inside Castlecrag itself. The suburb is served by 31 bus stops.
What is the population of Castlecrag?
At the 2021 Census Castlecrag had 2,965 usual residents, with a median age of 47 and an average household size of 3.0 people. The wider Castle Cove - Northbridge statistical area, which contains Castlecrag, went from 12,615 people in 2001 to 13,592 in 2025, up 8%.
Is Castlecrag an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Castlecrag scores 1195 and sits in decile 10 of 10 nationally and decile 10 within New South Wales (decile 1 is the most disadvantaged tenth, decile 10 the least).
What is the median household income in Castlecrag?
Median household income in Castlecrag was $4,675 a week at the 2021 Census, against $3,196 for the typical suburb in Willoughby. Median rent was $1,010 a week and the median mortgage repayment $4,333 a month.
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| Northbridge | 1.2 km | Not mapped | 29% |
| Middle Cove | 1.3 km | Not mapped | 74% |
| Willoughby East | 1.4 km | Not mapped | 0% |
| Middle Harbour Unincorporated - Sydney Harbour Area |
1.6 km | 0% | 29% |
| Castle Cove | 1.8 km | Not mapped | 73% |
| North Willoughby | 1.9 km | Not mapped | 0% |
| Willoughby | 2.0 km | Not mapped | <1% |
| Seaforth Northern Beaches |
2.3 km | 2% | 37% |
| Naremburn | 2.5 km | Not mapped | 6% |
| Cammeray North Sydney |
2.6 km | Not mapped | 10% |