Cornwallis flood map & planning overlays
A planning-constraint profile of Cornwallis
(Hawkesbury, NSW) - 6.81 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
6.81 km² - this suburb is highly constrained by planning overlays.
Elevation hillshade with street names, clipped to Cornwallis'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 Cornwallis
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
<1% 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
- Defence Airfields ANEF
Observed overflight - sampled 4 Sep to 2 Oct 2026
typical observed square 1 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.
Cornwallis at a glance
How Cornwallis is zoned
Buying in Cornwallis? 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 6.81 km², Cornwallis is highly constrained by planning overlays. About 100% of the suburb sits within a mapped flood overlay, and 22% is flagged bushfire-prone. There are 2 heritage-listed sites on record, and the dominant land-use zone is Rural Landscape. The median lot measures about 100,936 m² across 55 parcels.
Who lives in Cornwallis
Census 2021 figures published by the ABS for the Cornwallis 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 1016, and decile 7 within New South Wales. The national average is 1000.
Population trend, 2001 to 2025
Estimated resident population of Richmond - Clarendon, the wider ABS statistical area containing Cornwallis. There is no annual population series published at suburb level, so this describes the surrounding area rather than Cornwallis itself.
13,660 in 2001 to 16,743 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.
Cornwallis 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 | 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) | Inside a held contour | 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 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 Cornwallis 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 80% of Cornwallis. 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 Cornwallis. 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 Cornwallis lot.
See what's in the $9 report →Cornwallis planning - frequently asked
Is Cornwallis flood-prone?
About 100% of Cornwallis falls within a mapped flood overlay, against the council-wide suburb average of 24%. Published flood models are held over parts of Cornwallis; the free check on the Flood Model Report page says whether one reaches a given address.
Is Cornwallis bushfire-prone?
Around 22% of Cornwallis is mapped as bushfire-prone, compared with a Hawkesbury average of 84%.
Is Cornwallis affected by aircraft noise?
About <1% of Cornwallis 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 Cornwallis under a flight path?
Aircraft were observed below 3,000 ft over about 80% of Cornwallis, and over about 89% at any altitude up to 10,000 ft, in the period sampled (4 Sep 2026 to 2 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 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 Cornwallis?
The dominant planning zone in Cornwallis is Rural Landscape, though the suburb also includes Natural Waterways and Environmental Conservation.
Does Cornwallis have heritage-listed places?
Cornwallis has 2 heritage-listed places on record.
What is the typical lot size in Cornwallis?
Across 55 surveyed parcels in Cornwallis, the median lot size is about 100,936 m².
Is Cornwallis an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Cornwallis scores 1016 and sits in decile 7 of 10 nationally and decile 7 within New South Wales (decile 1 is the most disadvantaged tenth, decile 10 the least).
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| Freemans Reach | 2.0 km | 43% | 50% |
| Windsor | 2.8 km | 90% | 18% |
| Clarendon | 3.1 km | 100% | 29% |
| Pitt Town Bottoms | 3.4 km | 100% | 18% |
| Richmond | 3.8 km | 56% | 64% |
| Mcgraths Hill | 4.3 km | 100% | 59% |
| Mulgrave | 4.6 km | 91% | 54% |
| South Windsor | 4.8 km | 80% | 54% |
| Richmond Lowlands | 5.6 km | 100% | 89% |
| Bligh Park | 5.8 km | 36% | 24% |