Areas / Colac Otway / Irrewillipe

Irrewillipe flood map & planning overlays

Irrewillipe farms 7 ha lots at 100% bushfire, median 48.

Free map preview, then PDF reports from $9 - about the price of an iced latte on a public holiday.

A planning-constraint profile of Irrewillipe (Colac Otway, VIC) - 125.25 km², mapped from live council and state overlay data. This suburb is highly constrained.
Profile updated 24 October 2026.

Elevation hillshade with street names, clipped to Irrewillipe'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 Irrewillipe

The ANEF contour is a published planning forecast and observed overflight is what a sampled tracking feed recorded - neither describes any individual property.

Observed overflight - sampled 4 Sep to 24 Oct 2026

Under observed aircraft
15%
of the suburb, at or below 10,000 ft
Below 3,000 ft
8%
of the suburb's area
Lowest measured
1,500 ft
averaging 3,000 ft
How often
not established
aircraft were seen, but not often enough to put a rate on

Night movements: not established - night is sampled as often as day, but too few night flights have been seen here to conclude either way.

How this is measured

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.

Irrewillipe at a glance

Parcels 316 Median lot 67,760 m² Mapped easements 82

How Irrewillipe is zoned

Farming Zone (FZ) 68%
Public Conservation and Resource Zone (PCRZ) 31%
Transport Zone (TRZ2) 1%
Public Park and Recreation Zone (PPRZ) 0%
Public Use Zone (PUZ6) 0%
Farming Zone (FZ1) 0%

Selling in Irrewillipe? The zoning and planning overlays on this page are the controls a Section 32 vendor statement discloses.

Across its 125.25 km², Irrewillipe is highly constrained by planning overlays. About 5% of the suburb sits within a mapped flood overlay, and 100% is flagged bushfire-prone. There is 1 heritage-listed site on record, and the dominant land-use zone is Farming Zone (FZ). The median lot measures about 67,760 m² across 316 parcels.

Who lives in Irrewillipe

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

Population
100
usual residents, 2021
Median age
48
years
Median household income
$1,536
per week, Colac Otway suburb typical $1,443
Median rent
$229
per week, Colac Otway suburb typical $239
Median mortgage
$1,166
per month
Household size
2.3
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 8
most disadvantagedleast disadvantaged

Score 1028, and decile 8 within Victoria. The national average is 1000.

Relative disadvantage (IRSD) Decile 9
most disadvantagedleast disadvantaged

Age profile

Share of Irrewillipe's 100 residents in each ABS age band.

0-4 4.2%
5-14 10.4%
15-19 0.0%
20-24 13.5%
25-34 8.3%
35-44 12.5%
45-54 17.7%
55-64 16.7%
65-74 13.5%
75-84 3.1%
85+ 0.0%

Population trend, 2001 to 2025

Estimated resident population of Colac Surrounds, the wider ABS statistical area containing Irrewillipe. There is no annual population series published at suburb level, so this describes the surrounding area rather than Irrewillipe itself.

5,829 in 2001 to 5,670 in 2025, down 3%.

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.

Irrewillipe data sources and coverage

“Not mapped” means we hold no source layer for this suburb - never an all-clear.

DatasetCoveragePublisher
Flood mappingMappedVicmap Planning and Victorian Government spatial services
Bushfire-prone mappingMappedVicmap Planning and Victorian Government spatial services
ZoningMappedVicmap Planning and Victorian Government spatial services
Heritage and environmentMapped where publishedVicmap Planning and Victorian Government spatial services
Aircraft noise contours (ANEF)Not heldVicmap Planning and Victorian Government spatial services, Defence
Observed flight pathsObservedadsb.lol, under the Open Database License
DemographicsAvailableAustralian Bureau of Statistics (2021 Census and SEIFA)

Profile last materially updated 24 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 Irrewillipe 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.

See what's in the $9 report →

Aircraft have been seen below 3,000 ft over about 8% of Irrewillipe. 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 the indicative soil reactivity range to expect for a Irrewillipe lot.

Irrewillipe planning - frequently asked

Is Irrewillipe flood-prone?

About 5% of Irrewillipe falls within a mapped flood overlay, against the council-wide suburb average of 12%.

Is Irrewillipe bushfire-prone?

Around 100% of Irrewillipe is mapped as bushfire-prone, compared with a Colac Otway average of 97%.

Is Irrewillipe under a flight path?

Aircraft were observed below 3,000 ft over about 8% of Irrewillipe, and over about 15% at any altitude up to 10,000 ft, in the period sampled (4 Sep 2026 to 24 Oct 2026). The lowest measured aircraft was at 1,500 ft, with an average of 3,000 ft. 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 Irrewillipe?

The dominant planning zone in Irrewillipe is Farming Zone (FZ), though the suburb also includes Public Conservation and Resource Zone (PCRZ) and Transport Zone (TRZ2).

Does Irrewillipe have heritage-listed places?

Irrewillipe has 1 heritage-listed place on record.

What is the typical lot size in Irrewillipe?

Across 316 surveyed parcels in Irrewillipe, the median lot size is about 67,760 m². There are also 82 registered easements mapped in the suburb.

What is the population of Irrewillipe?

At the 2021 Census Irrewillipe had 100 usual residents, with a median age of 48 and an average household size of 2.3 people. The wider Colac Surrounds statistical area, which contains Irrewillipe, went from 5,829 people in 2001 to 5,670 in 2025, down 3%.

Is Irrewillipe an advantaged suburb?

On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Irrewillipe scores 1028 and sits in decile 8 of 10 nationally and decile 8 within Victoria (decile 1 is the most disadvantaged tenth, decile 10 the least).

What is the median household income in Irrewillipe?

Median household income in Irrewillipe was $1,536 a week at the 2021 Census, against $1,443 for the typical suburb in Colac Otway. Median rent was $229 a week and the median mortgage repayment $1,166 a month.

Compare nearby suburbs

Nearby suburbDistanceFlood mappedBushfire-prone
Irrewillipe East 6.8 km <1% 100%
Bungador 7.3 km 13% 100%
Swan Marsh 9.6 km 36% 100%
Pirron Yallock 10.2 km 22% 100%
Barongarook West 11.6 km <1% 100%
Carlisle River 13.5 km 6% 100%
Larpent 13.6 km 11% 100%
Nalangil 14.1 km 25% 98%
Simpson
Corangamite		 14.8 km 2% 100%
Gellibrand 15.6 km 6% 100%

See all Colac Otway suburb profiles →