Frenchs Forest flood map & planning overlays

A planning-constraint profile of Frenchs Forest (Northern Beaches, NSW) - 8.4 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.

Planning schematicFrenchs Forest

Constraint readout

8.4 km² - this suburb is highly constrained by planning overlays.

Flood overlay <1%

below council avg (12%) · #45 of 52 mapped council suburbs

Modelled flood depth held over parts of Frenchs Forest

Bushfire-prone 49%

≈ council avg (47%) · #26 of 56 mapped council suburbs

Environmental12%

below council avg (26%) · #28 of 56 in council

Heritage sites 12 Aircraft seen below 3,000 ft 60% Mostly Low Density Residential Bushfire 26th most affected of 56 →

Elevation hillshade with street names, clipped to Frenchs Forest'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 Frenchs Forest

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 2 Oct 2026

Under observed aircraft

100%

of the suburb, at or below 10,000 ft

Below 3,000 ft

60%

of the suburb's area

Lowest measured

500 ft

averaging 5,000 ft

Busiest square

~50 a day

1 a day below 3,000 ft · ±14%
typical observed square 2 a day

Night movements: observed, lowest 2,000 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.

Frenchs Forest at a glance

Parcels 4,644 Median lot 709 m² Mapped easements 42 Bus stops 194 Landslide overlay 88%

How Frenchs Forest is zoned

Low Density Residential 52%

Public Recreation 15%

National Parks and Nature Reserves 8%

Enterprise 7%

Infrastructure 6%

Environmental Conservation 4%

Buying in Frenchs Forest? 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 8.4 km², Frenchs Forest is highly constrained by planning overlays. Flood mapping covers the suburb and none of it falls within a mapped flood overlay, and 49% is flagged bushfire-prone. There are 12 heritage-listed sites on record, and the dominant land-use zone is Low Density Residential. The median lot measures about 709 m² across 4,644 parcels.

Who lives in Frenchs Forest

Census 2021 figures published by the ABS for the Frenchs Forest suburb boundary itself, not a wider region.

Population

14,267

usual residents, 2021

Median age

years

Median household income

$3,109

per week, Northern Beaches suburb typical $2,778

Median rent

$800

per week, Northern Beaches suburb typical $700

Median mortgage

$3,467

per month

Household size

3.2

people, average

Socio-economic standing

ABS SEIFA 2021 ranks every Australian suburb. Decile 1 is the most disadvantaged tenth of the country, decile 10 the least.

Advantage and disadvantage (IRSAD) Decile 10

most disadvantagedleast disadvantaged

Score 1144, and decile 10 within New South Wales. The national average is 1000.

Relative disadvantage (IRSD) Decile 10

most disadvantagedleast disadvantaged

Age profile

Share of Frenchs Forest's 14,267 residents in each ABS age band.

0-4 5.7%

5-14 16.5%

15-19 7.7%

20-24 5.4%

25-34 7.3%

35-44 13.5%

45-54 16.9%

55-64 11.2%

65-74 7.8%

75-84 6.1%

85+ 1.8%

Population trend, 2001 to 2025

Estimated resident population of Frenchs Forest - Oxford Falls, the wider ABS statistical area containing Frenchs Forest. There is no annual population series published at suburb level, so this describes the surrounding area rather than Frenchs Forest itself.

16,455 in 2001 to 17,765 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.

Frenchs Forest 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 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 Frenchs Forest 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 60% of Frenchs Forest. 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 Frenchs Forest. 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 Frenchs Forest lot.

See what's in the $9 report →

Frenchs Forest planning - frequently asked

Is Frenchs Forest flood-prone?

Flood mapping covers Frenchs Forest and less than 1% of the suburb falls within a mapped flood overlay (the council-wide suburb average is 12%). Published flood models are held over parts of Frenchs Forest; the free check on the Flood Model Report page says whether one reaches a given address.

Is Frenchs Forest bushfire-prone?

Around 49% of Frenchs Forest is mapped as bushfire-prone, compared with a Northern Beaches average of 47%.

Is Frenchs Forest under a flight path?

Aircraft were observed below 3,000 ft over about 60% of Frenchs Forest, and over about 100% 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 5,000 ft. At the busiest point in the suburb about 50 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 Frenchs Forest?

The dominant planning zone in Frenchs Forest is Low Density Residential, though the suburb also includes Public Recreation and National Parks and Nature Reserves.

Does Frenchs Forest have heritage-listed places?

Frenchs Forest has 12 heritage-listed places on record.

What is the typical lot size in Frenchs Forest?

Across 4,644 surveyed parcels in Frenchs Forest, the median lot size is about 709 m². There are also 42 registered easements mapped in the suburb.

Does Frenchs Forest have a train station?

There is no train station inside Frenchs Forest itself. The suburb is served by 194 bus stops.

What is the population of Frenchs Forest?

At the 2021 Census Frenchs Forest had 14,267 usual residents, with a median age of 40 and an average household size of 3.2 people. The wider Frenchs Forest - Oxford Falls statistical area, which contains Frenchs Forest, went from 16,455 people in 2001 to 17,765 in 2025, up 8%.

Is Frenchs Forest an advantaged suburb?

On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Frenchs Forest scores 1144 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 Frenchs Forest?

Median household income in Frenchs Forest was $3,109 a week at the 2021 Census, against $2,778 for the typical suburb in Northern Beaches. Median rent was $800 a week and the median mortgage repayment $3,467 a month.

Compare nearby suburbs

Nearby suburb	Distance	Flood mapped	Bushfire-prone
Forestville	2.1 km	Not mapped	52%
Beacon Hill	2.4 km	3%	49%
Oxford Falls	2.4 km	4%	97%
Allambie Heights	2.5 km	8%	76%
Killarney Heights	2.9 km	0%	76%
Brookvale	3.6 km	39%	18%
Cromer	3.8 km	14%	55%
Narraweena	3.8 km	10%	8%
Belrose	4.0 km	5%	80%
Roseville Chase Ku-Ring-Gai	4.0 km	6%	48%

See all Northern Beaches suburb profiles →