How do I check if a house is in a flood zone in Australia?

Reviewed 2026-10-24

Search the full address in the state and council flood maps, then check the property documents and any detailed flood report. An unmapped address is not a guarantee against flooding, and an unavailable HouseScan layer is not a clearance.

Identify the kind of flooding

River flooding, overland flow, historical inundation and storm surge describe different mechanisms. A river-flood layer may say little about water running down a street during intense rain. Start with the dataset name, coverage, map date and explanatory notes. A blue area on one map is not necessarily comparable with a blue area on another. If a legend is unclear, keep the question open rather than converting it into a yes or no answer.

Use the street number, suburb, state and, where available, the lot boundary. A suburb search is useful for locating a map but cannot clear a particular dwelling. Check that the marker falls on the intended lot, not the road centre or a neighbouring property. A sloping block can have different exposure at the rear boundary, garage and living floor. Those distinctions matter more than a suburb-wide label.

Find the right state and council entry points

In NSW, begin with the Planning Portal Spatial Viewer and the local council flood information. Victoria uses VicPlan planning overlays alongside local flood information. Queensland has FloodCheck and council products; Brisbane City information covers Brisbane City, not every Queensland council. In the ACT use ACTmapi. In South Australia begin with SAPPA and Planning and Design Code overlays. In Tasmania use theLIST and the relevant council.

In WA, follow official state and council information directly; HouseScan does not republish the restricted flood layers. In the NT, coastal storm-surge mapping must not be presented as a river-flood check. These are starting points rather than promises of complete coverage. A council may have a newer or more detailed study than the state viewer. Save the name and date of the study, not just a screenshot without a legend.

Understand probability and the map boundary

A 1% annual exceedance probability, or AEP, event has a 1% chance of being equalled or exceeded in a given year. It does not happen only once every hundred years. Nor is the mapped extent a boundary beyond which flooding cannot occur. Look for the modelled event, assumptions, terrain information and any separate treatment of drainage or climate scenarios. A short map label cannot convey all those qualifications.

Separate three questions: does an overlay intersect the lot, could water enter the building, and could access become unsafe? A small intersection at the back fence and an intersection through the dwelling should prompt different follow-up questions. Floor levels, flood levels and access need property-specific evidence. A map cannot establish the height of a living room floor or whether the present building matches the records used by the study.

Bring the map back to documents

For NSW purchases, a section 10.7 planning certificate is an important property document, but its actual content must be read. A browser screenshot is not a substitute. Ask the council whether it holds an address-specific report, whether overland flow is included and whether more recent work changes the picture. A conveyancer can help identify missing documents; a flood professional can interpret technical levels and scenarios.

An insurance quote is a separate enquiry. Give the insurer the same full address and read the flood, stormwater, exclusion and excess terms. A quote does not certify a low-risk home, and the premium is not a flood probability. Its value is in exposing practical questions about cover and cost that a planning overlay cannot answer. Keep any conditions with the purchase research rather than remembering only the headline price.

Use inspections to resolve the open questions

At an inspection, note the fall of the land and road, garage entry, drainage paths and retaining walls. Staining or fresh paint alone cannot prove a history of flooding. Equally, a tidy room cannot prove a dry history. Photograph the places that need explanation and ask an inspector what was accessible, what was not, and whether further investigation is needed. Avoid turning a visual clue into an unsupported accusation.

The seller history, council study, planning documents, insurer and physical inspection each answer different questions. If they disagree, record the exact conflict: for example, a state layer shows no intersection while a council report identifies overland flow. Take that conflict to the appropriate professional. The useful outcome is a clearer account of what is known and unknown about this address, with dated evidence that can be checked again.

What to compare

Result	What it establishes	Still to check
Overlay intersects	The queried layer intersects the lot	Depth, floor levels and access
No intersection	No hit in that particular layer	Other mechanisms and unmapped studies
Unavailable or failed	No valid result was obtained	Official or council follow-up

How HouseScan checks it

HouseScan matches the address to available planning and hazard layers. Coverage varies: WA flood layers are not republished, and NT storm surge is not a river-flood model. A failed query is different from no intersection. HouseScan does not simulate water depth or establish whether a building has flooded internally.

Check this address

Include the state outside NSW. Reports show missing coverage explicitly.

Questions to take to the right person

Which flood mechanism and modelled event does this layer cover?
Does the latest council study agree with the property documents?
What happens to the floor and access route in the relevant scenario?
Which documents or inspection questions remain unanswered?

Sources and further checks

Official maps and calculators can change. The map date, contract and property documents matter.