Grantham Farm flood map & planning overlays
A planning-constraint profile of Grantham Farm
(Blacktown, NSW) - 3.61 km², mapped from live council and
state overlay data. This suburb is highly constrained.
Profile updated 26 September 2026.
Suburb-wide figures; the free map shows which overlays touch your lot.
Constraint readout
3.61 km² - this suburb is highly constrained by planning overlays.
Elevation hillshade with street names, clipped to Grantham Farm'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 Grantham Farm
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 0 a day
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.
Grantham Farm at a glance
How Grantham Farm is zoned
Buying in Grantham Farm? 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 3.61 km², Grantham Farm is highly constrained by planning overlays. About 9% of the suburb sits within a mapped flood overlay, and 47% is flagged bushfire-prone. There are 3 heritage-listed sites on record, and the dominant land-use zone is Low Density Residential. The median lot measures about 502 m² across 4,003 parcels.
Who lives in Grantham Farm
Census 2021 figures published by the ABS for the Grantham Farm 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 1111, and decile 10 within New South Wales. The national average is 1000.
Age profile
Share of Grantham Farm's 3,669 residents in each ABS age band.
Population trend, 2001 to 2025
Estimated resident population of Riverstone, the wider ABS statistical area containing Grantham Farm. There is no annual population series published at suburb level, so this describes the surrounding area rather than Grantham Farm itself.
7,294 in 2001 to 20,068 in 2025, up 175%.
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.
Grantham Farm 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) | 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 Grantham Farm 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 64% of Grantham Farm. 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 Grantham Farm. 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 Grantham Farm lot.
See what's in the $9 report →Grantham Farm planning - frequently asked
Is Grantham Farm flood-prone?
About 9% of Grantham Farm falls within a mapped flood overlay, against the council-wide suburb average of 16%. Published flood models are held over parts of Grantham Farm; the free check on the Flood Model Report page says whether one reaches a given address.
Is Grantham Farm bushfire-prone?
Around 47% of Grantham Farm is mapped as bushfire-prone, compared with a Blacktown average of 21%.
Is Grantham Farm under a flight path?
Aircraft were observed below 3,000 ft over about 64% of Grantham Farm, and over about 69% 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 500 ft, with an average of 5,000 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 Grantham Farm?
The dominant planning zone in Grantham Farm is Low Density Residential, though the suburb also includes Infrastructure and Environmental Conservation.
Does Grantham Farm have heritage-listed places?
Grantham Farm has 3 heritage-listed places on record.
What is the typical lot size in Grantham Farm?
Across 4,003 surveyed parcels in Grantham Farm, the median lot size is about 502 m². There are also 11 registered easements mapped in the suburb.
Does Grantham Farm have a train station?
There is no train station inside Grantham Farm itself. The suburb is served by 32 bus stops.
What is the population of Grantham Farm?
At the 2021 Census Grantham Farm had 3,669 usual residents, with a median age of 30 and an average household size of 3.2 people. The wider Riverstone statistical area, which contains Grantham Farm, went from 7,294 people in 2001 to 20,068 in 2025, up 175%.
Is Grantham Farm an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Grantham Farm scores 1111 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 Grantham Farm?
Median household income in Grantham Farm was $2,570 a week at the 2021 Census, against $2,117 for the typical suburb in Blacktown. Median rent was $540 a week and the median mortgage repayment $2,700 a month.
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| Riverstone | 1.4 km | 22% | 11% |
| Box Hill The Hills Shire |
1.9 km | 20% | 18% |
| Richards | 2.2 km | 68% | 73% |
| Vineyard Hawkesbury |
3.1 km | 72% | 88% |
| Rouse Hill | 3.2 km | 4% | 50% |
| Tallawong | 3.3 km | 12% | 29% |
| Schofields | 4.2 km | 35% | 28% |
| Angus | 4.3 km | 49% | 90% |
| Oakville Hawkesbury |
4.4 km | 23% | 95% |
| Nelson The Hills Shire |
4.8 km | 1% | 100% |