Mountain Lagoon flood map & planning overlays
A planning-constraint profile of Mountain Lagoon (Hawkesbury, NSW) - 54.66 km², mapped from live council and state overlay data. This suburb is highly constrained.
Everything below is suburb-wide. Overlays change block to block - see which ones actually touch your lot. The map is free.
Constraint readout
54.66 km² - this suburb is highly constrained by planning overlays.
Elevation hillshade with street names, clipped to Mountain Lagoon's boundary, with the flood, bushfire and environmental overlays drawn on top. It shows where constraints fall; the interactive map shows them on your exact address.
Mountain Lagoon at a glance
How Mountain Lagoon is zoned
Buying in Mountain Lagoon? 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 54.66 km², Mountain Lagoon is highly constrained by planning overlays. Flood mapping covers the suburb and none of it falls within a mapped flood overlay, and 100% is flagged bushfire-prone. The dominant land-use zone is National Parks and Nature Reserves. The median lot measures about 76,538 m² across 60 parcels. These figures are suburb-wide - the overlays that actually apply to a given lot can differ block to block, which is what a property-level check tells you.
Who lives in Mountain Lagoon
Census 2021 figures published by the ABS for the Mountain Lagoon 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 1044, and decile 8 within New South Wales. The national average is 1000.
Age profile
Share of Mountain Lagoon's 78 residents in each ABS age band.
Population trend, 2001 to 2025
Estimated resident population of Bilpin - Colo - St Albans, the wider ABS statistical area containing Mountain Lagoon. There is no annual population series published at suburb level, so this describes the surrounding area rather than Mountain Lagoon itself.
2,518 in 2001 to 2,781 in 2025, up 10%.
Source: Australian Bureau of Statistics. Census of Population and Housing 2021 (General Community Profile) and SEIFA 2021, both published at the Suburbs and Localities level; Regional Population (estimated resident population) at Statistical Area Level 2. Used under CC BY 4.0. Census counts of small populations are randomly adjusted by the ABS to protect confidentiality, so figures for small suburbs are indicative.
Mountain Lagoon data sources and coverage
Every figure below is an aggregate for the suburb boundary. “Not mapped” means LayeredGeo does not hold a source layer covering this suburb; it is never an all-clear for a particular property.
| 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 |
| Demographics | Available | Australian Bureau of Statistics (2021 Census and SEIFA) |
Profile last materially updated 5 August 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 Mountain Lagoon 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 →Mountain Lagoon planning - frequently asked
Where can I see a flood map of Mountain Lagoon?
The schematic on this page is a Mountain Lagoon flood map: the mapped flood overlays drawn over the suburb's terrain and street grid. Flood lines vary block to block, so for a specific property use the free interactive map - search any Mountain Lagoon address and it shows the flood, zoning and bushfire mapping on the exact lot boundary.
Is Mountain Lagoon flood-prone?
Flood mapping covers Mountain Lagoon and none of the suburb falls within a mapped flood overlay (the council-wide suburb average is 1%). Flood overlays vary block to block, so whether a particular lot is affected needs a property-level check.
Is Mountain Lagoon bushfire-prone?
Yes - around 100% of Mountain Lagoon is mapped as bushfire-prone, compared with a Hawkesbury average of 84%. A bushfire-prone designation can trigger additional building requirements, so check the specific address.
What is the zoning in Mountain Lagoon?
The dominant planning zone in Mountain Lagoon is National Parks and Nature Reserves, though the suburb also includes Environmental Living and Environmental Conservation. Zoning sets what you can build and do on a site, and can differ lot by lot.
Does Mountain Lagoon have heritage-listed places?
No heritage-listed places are on record within Mountain Lagoon. Even so, it is worth confirming for an individual property before any works.
What is the typical lot size in Mountain Lagoon?
Across 60 surveyed parcels in Mountain Lagoon, the median lot size is about 76,538 m².
What is the population of Mountain Lagoon?
At the 2021 Census Mountain Lagoon had 78 usual residents, with a median age of 55 and an average household size of 2.3 people. The wider Bilpin - Colo - St Albans statistical area, which contains Mountain Lagoon, went from 2,518 people in 2001 to 2,781 in 2025, up 10%. ABS publishes no annual population series for individual suburbs, so that trend describes the surrounding area rather than Mountain Lagoon alone.
Is Mountain Lagoon an advantaged suburb?
On the ABS SEIFA 2021 index of relative socio-economic advantage and disadvantage (IRSAD), Mountain Lagoon scores 1044 and sits in decile 9 of 10 nationally and decile 8 within New South Wales - decile 1 being the most disadvantaged tenth of Australian suburbs and decile 10 the least. The national average score is 1000. SEIFA summarises income, education, occupation and housing across the whole suburb, so it describes the area, not any particular household in it.
What is the median household income in Mountain Lagoon?
Median household income in Mountain Lagoon was $1,625 a week at the 2021 Census, against $2,160 for the typical suburb in Hawkesbury. Median rent was $360 a week and the median mortgage repayment $2,167 a month. These are 2021 Census figures and have not been indexed to today.
Do I need a planning report for a Mountain Lagoon property?
A Mountain Lagoon planning report pulls every overlay - zoning, flood, bushfire, heritage and environmental - that touches a single lot, on live council and state data. The interactive map preview is free; a full PDF report is $9.
Compare nearby suburbs
| Nearby suburb | Distance | Flood mapped | Bushfire-prone |
|---|---|---|---|
| Wheeny Creek | 6.0 km | 0% | 100% |
| Bilpin | 8.4 km | 0% | 100% |
| Upper Colo | 8.4 km | 0% | 100% |
| Kurrajong Heights | 9.3 km | 0% | 98% |
| Kurrajong | 10.6 km | 0% | 98% |
| Kurrajong Hills | 10.7 km | 0% | 100% |
| Tesselate Hill Blue Mountains |
11.8 km | 0% | 100% |
| The Slopes | 13.2 km | 0% | 100% |
| Central Colo | 13.8 km | 0% | 100% |
| Kurmond | 14.7 km | 0% | 91% |