Irrewarra flood map & planning overlays
Irrewarra sits 5.9% inside aircraft noise contours, 2nd in Colac Otway.
Free map preview, then PDF reports from $9 - about the price of an iced latte on a public holiday.
A planning-constraint profile of Irrewarra
(Colac Otway, VIC) - 82.02 km², mapped from live council and
state overlay data. This suburb is highly constrained.
Profile updated 24 October 2026.
Constraint readout
82.02 km² - this suburb is highly constrained by planning overlays.
Elevation hillshade with street names, clipped to Irrewarra's boundary, with the flood, bushfire and environmental overlays drawn on top. Amber hatching is the published aircraft noise (ANEF) contour. 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 Irrewarra
The ANEF contour is a published planning forecast and observed overflight is what a sampled tracking feed recorded - neither describes any individual property.
Inside an aircraft noise contour
6% 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.
Contours held
- Victorian Airport Environs Overlay
Observed overflight - sampled 4 Sep to 24 Oct 2026
typical observed square 1 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.
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.
Irrewarra at a glance
How Irrewarra is zoned
Selling in Irrewarra? The zoning and planning overlays on this page are the controls a Section 32 vendor statement discloses.
Across its 82.02 km², Irrewarra is highly constrained by planning overlays. About 21% of the suburb sits within a mapped flood overlay, and 96% is flagged bushfire-prone. There are 6 heritage-listed sites on record, and the dominant land-use zone is Farming Zone (FZ). The median lot measures about 60,702 m² across 387 parcels.
Who lives in Irrewarra
Census 2021 figures published by the ABS for the Irrewarra 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 1008, and decile 6 within Victoria. The national average is 1000.
Age profile
Share of Irrewarra's 365 residents in each ABS age band.
Population trend, 2001 to 2025
Estimated resident population of Colac Surrounds, the wider ABS statistical area containing Irrewarra. There is no annual population series published at suburb level, so this describes the surrounding area rather than Irrewarra 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.
Irrewarra 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 | Vicmap Planning and Victorian Government spatial services |
| Bushfire-prone mapping | Mapped | Vicmap Planning and Victorian Government spatial services |
| Zoning | Mapped | Vicmap Planning and Victorian Government spatial services |
| Heritage and environment | Mapped where published | Vicmap Planning and Victorian Government spatial services |
| Aircraft noise contours (ANEF) | Inside a held contour | Vicmap Planning and Victorian Government spatial services, 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 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 Irrewarra 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 85% of Irrewarra. 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 Irrewarra lot.
Irrewarra planning - frequently asked
Is Irrewarra flood-prone?
About 21% of Irrewarra falls within a mapped flood overlay, against the council-wide suburb average of 12%.
Is Irrewarra bushfire-prone?
Around 96% of Irrewarra is mapped as bushfire-prone, compared with a Colac Otway average of 97%.
Is Irrewarra affected by aircraft noise?
About 6% of Irrewarra sits inside a published aircraft noise contour. 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 Irrewarra under a flight path?
Aircraft were observed below 3,000 ft over about 85% of Irrewarra, and over about 91% 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 500 ft, with an average of 2,000 ft. At the busiest point in the suburb about 8 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 Irrewarra?
The dominant planning zone in Irrewarra is Farming Zone (FZ), though the suburb also includes Public Conservation and Resource Zone (PCRZ) and Public Use Zone (PUZ1).
Does Irrewarra have heritage-listed places?
Irrewarra has 6 heritage-listed places on record.
What is the typical lot size in Irrewarra?
Across 387 surveyed parcels in Irrewarra, the median lot size is about 60,702 m². There are also 269 registered easements mapped in the suburb.
What is the population of Irrewarra?
At the 2021 Census Irrewarra had 365 usual residents, with a median age of 47 and an average household size of 2.5 people. The wider Colac Surrounds statistical area, which contains Irrewarra, went from 5,829 people in 2001 to 5,670 in 2025, down 3%.
Is Irrewarra an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Irrewarra scores 1008 and sits in decile 7 of 10 nationally and decile 6 within Victoria (decile 1 is the most disadvantaged tenth, decile 10 the least).
What is the median household income in Irrewarra?
Median household income in Irrewarra was $1,583 a week at the 2021 Census, against $1,443 for the typical suburb in Colac Otway. Median rent was $238 a week and the median mortgage repayment $1,517 a month.
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| Warncoort | 5.7 km | 10% | 99% |
| Ondit | 6.5 km | 26% | 94% |
| Colac East | 8.9 km | 3% | 91% |
| Colac | 9.3 km | 78% | 15% |
| Balintore | 9.9 km | 26% | 100% |
| Beeac | 11.2 km | 36% | 86% |
| Yeo | 11.3 km | 2% | 100% |
| Warrion | 12.0 km | <1% | 100% |
| Coragulac | 12.4 km | <1% | 100% |
| Cororooke | 13.7 km | 2% | 100% |