How to check if a property is in a flood zone

After the 2022 floods in NSW and Queensland, thousands of homeowners discovered their properties were in mapped flood zones. Many had no idea before they bought. Insurance premiums in affected areas doubled or tripled overnight. Some properties became uninsurable.

The information was always public. It was just buried in government planning maps that most buyers never checked.

What is a flood zone?

A flood zone is a geographic area that has been identified by state or local government as having a risk of flooding. The mapping is based on historical flood data, rainfall modelling, and terrain analysis. Councils and state agencies use this data to set planning controls and inform development decisions.

Flood zones are categorised differently in each state, but they generally fall into a few tiers. The most common are the flood planning area (the broader zone affected by a major flood event, often the 1 in 100 year flood level plus a freeboard), and the floodway (the area where water flows fastest and deepest during a flood).

Why it matters

Being in a flood zone affects three things.

First, insurance. Flood coverage is priced based on the property's flood risk. If your property is in a high risk zone, your premium will reflect that. In some cases, flood cover may not be available at all, or the excess may be set so high that it is effectively useless.

Second, resale value. Flood mapping is public information. Future buyers will see the same data. Properties in flood zones tend to sell for less than comparable properties outside flood zones, especially after a major flood event when awareness is high.

Third, building and renovation. If you want to extend or renovate a property in a flood zone, you may need to meet additional council requirements. Floor levels, building materials, and drainage can all be affected. This adds cost and complexity.

How to check

Every state publishes flood mapping data. In NSW, you can request a Section 10.7 planning certificate from the local council, which will disclose whether the property is in a flood planning area. You can also check the NSW Flood Data Portal online.

In Queensland, the state government publishes flood mapping through the QLD Globe tool. In Victoria, Melbourne Water provides flood maps for the greater Melbourne area, and regional councils have their own mapping.

The data is free. It just takes time to navigate the right website for the right council. On housematch, we overlay flood risk data on every listing so you can see it at a glance.

Things people get wrong

"It has never flooded here" is not the same as "it is not in a flood zone." Flood mapping is based on modelling, not just history. A street that has never flooded may still be mapped as flood prone based on terrain, rainfall, and drainage modelling.

The reverse is also true. A property that flooded in 2022 may not be in the officially mapped flood zone. Mapping is updated periodically, but it does not always reflect the most recent events immediately.

Also, flood zones can change. Councils update their flood studies as new data becomes available. A property that is not in a flood zone today may be reclassified in the future. This is why it is worth checking not just the current status, but also whether any flood studies are currently under review.

The bottom line

Check the flood status before you inspect, not after. Get an insurance quote early in the process so you know the real cost. And remember that flood data is public and free. You just need to know where to look.