How to check flood risk before buying a property

No single Australian source answers whether a property floods. What exists is a set of planning controls and models, made by councils and state agencies, that cover some land and not other land. The useful question is which of them covers this land, and what that one cannot say.

Ask three things of every flood source

Is it a planning control or a model of water? A control, such as a flood planning area, says what rules apply to building. It does not give a depth, a frequency or a flood level for a floor. Does it cover overland flow, the water that runs across the ground when drains are overwhelmed? Many sources do not. And if the land is not in it, is that because the land is clear, or because nobody mapped the area? The third is the case behind what “unmapped” means.

New South Wales

A flood planning area is a control a council makes in its plan, and the council states flood-related development controls on a section 10.7 certificate. In 115 of 128 New South Wales councils, fewer than one address in ten is on land that has any flood planning map at all in the NSW Planning Portal’s layers. Only 9 councils have a map for the land under nine in ten addresses or more, and 4 more for between one and nine in ten (our count, October 2026) © State of New South Wales (Department of Planning, Housing and Infrastructure), CC BY 4.0. Where a council has no flood planning map, our report turns the row to unresolved and says we cannot say whether the land is in a flood planning area, and that the council may hold flood information no map shows. The NSW Flood Data Portal, whose custodian is the State Emergency Service, says public flood queries go to the council. Our flood planning map by council shows where mapping exists.

Victoria

The Land Subject to Inundation Overlay, the Floodway Overlay and the Special Building Overlay are three different controls, explained in Victorian planning overlays. The section 32 statement names the zone and overlays for land under a planning scheme, and none of the overlays gives a flood level. Melbourne Water issues property flood information on request in the Port Phillip and Westernport region, and the regional catchment management authority or the council holds flood information elsewhere. See also the Victorian hazard map.

Queensland

Queensland has no statewide property flood map. FloodCheck Queensland, run by the Department of Resources, searches by address or lot and plan and shows historic floodlines and flood studies. The Queensland Floodplain Assessment Overlay is an interim screening layer, and the state says it does not indicate that an individual land parcel is subject to inundation; for a property, the state points to the local government's maps. Brisbane City Council's FloodWise Property Report gives flood levels and the 2011 and 2022 extents from its Flood Awareness Map, and does not show overland flow. For the other councils, the council is the one to ask.

We sell reports in four Queensland council areas: Brisbane, Gold Coast, Moreton Bay and Noosa. The report shows the flood layers each council publishes, which differ: Brisbane's risk class, its 2011 and 2022 extents and its river and creek planning areas, one flood risk overlay for the Gold Coast, a flood hazard overlay for Moreton Bay, and a flood extent for Noosa. It does not include the state's flood study index.

Tasmania

The Flood-Prone Areas Hazard Code applies to development in a flood-prone area, and works from the overlay map in each council's Local Provisions Schedule. It is a trigger for assessment and not a risk model, and overland flow is often not in it. Ask the council what flood information it holds. See Tasmanian planning codes and the Tasmanian hazard map.

Australian Capital Territory

The ACT publishes a riverine model of a flood with a 1 per cent chance in any year. It covers only the catchments of the flood studies the ACT has modelled. It does not cover overland flow, burst pipes or overflowing lakes and dams. Ask the ACT Government what flood information it holds for the block. See ACT Territory Plan zones.

Insurance

A planning map is not an insurer's flood rating. Our report suggests asking two or three insurers for a quote on the address before signing, and asking the agent whether water has entered the house or crossed the land.

What our report shows, and does not

For each state above the report shows the planning control or model that state publishes, as one or more rows, and says when the land is outside it or when no map covers the area. It does not show water depth, overland flow paths or the likelihood of a flood, and it is not an insurance quote. It does not do the section 10.7 search. Western Australia's free report holds no flood data. The council pages show, council by council, what is held.

Reports from $9.90 including GST, paid once. The price belongs to the jurisdiction the address is in. The check is free: it tells you the exact total for your address, and which registers cover it, before you pay anything.