What is a Flood Zone and Why Is It Important to Know if My Property Is in One?

One issue that plagues Australia is the proliferation of floods. As such, knowing if a site is in a flood zone is crucial. It’s not just to secure your property but also for safety reasons.


Australia maintains a long history of natural disasters like storms and floods. 

In fact, natural disasters in the last decade alone have been increasingly damaging. So, local councils have begun requesting over $10 million in contributions from state and federal governments. This is to better prepare for and mitigate these dangers. 

With that in mind, residents and property builders must also do their part. They need to educate themselves about the risks of natural disasters. In particular, they need to have a better awareness of flood zones.


This question is what the article aims to answer. To do that, we’ll talk about how a flood zone is determined and why it’s an important consideration for property owners and developers. 

In turn, you can better understand if your property—whether already existing or still in the planning stage—is in a flood zone. 

How is a Flood Zone Determined?

A flood zone refers to an area susceptible to flooding during severe weather events. And determining them involves considering various factors. 

In Australia, government planning agencies and private entities, like homeowners’ associations, utilise various tools and resources to determine and assess flood zones. Some of the tools they use include:

  • The Climate Risk Map This is an interactive map that shows the proportion of homes in a suburb that are at risk. You can change its settings to see low to high emissions scenarios, areas, and risks.
  • The Climate Risk site – This website lets you create free reports on the property you currently live in or are considering developing. It also provides a Climate Resilience Rating, as well as information on the risks to a property at three critical times—the current year, the end of the standard mortgage term, and the end of nominal property lifetime.
  • The Floodcheck Interactive Map (for Queensland) – This interactive flood check map can be found on the Queensland government website. It examines historical data to demonstrate where floods originated. So, you can use it to find out if your house is in a high-risk area.
  • The Floods Near Me map (for New South Wales) – It’s always a good idea to keep an eye on surrounding rivers, creeks, and catchments during times of severe rainfall. And if your property is in New South Wales, you can do so by going to the Floods Near Me interactive map.
  • Your local city council’s flood awareness map – You can check with your local council if you have a flood awareness map available in your area.

4 Different Types of Flood Zones

In Australia, flood zones are classified into four specific types. And they are based on flood probability and the impact of overland flow. 

Understanding these classifications is crucial for assessing the level of risk associated with a particular area. By figuring out if your property is in a flood zone and in which category, you can identify the measures to implement. This way, you prevent damage to your property and even loss of lives.

So, what are the different types of flood zones?

Type #1. High likelihood

This kind of flooding is regular. It occurs 1 in 20 times, or 5% of the time, each year.

To lessen the impact on your property, you are strongly recommended to make adequate preparations for flooding. Proactiveness is crucial.

Type #2. Medium likelihood

This type of flood zone is considered irregular. In any given year, flooding has a 1 in 100 chance of happening, or 1% likelihood.  

Type #3. Low likelihood

This particular type of flood zone is unusual. It’s because there is a 1 in 500 probability, or 0.2% likelihood, that floods may occur in any given year.  

So, residents don’t necessarily have to prepare for flooding. But they should still consider how floods might affect their property.

Type #4. Very low likelihood

This kind of flood zone is regarded as an extremely unusual or rare occurrence. It’s because there is only a 1 in 2000 chance or 0.05% likelihood of flooding in a year.

Building/Developing Properties in a Flood Zone

Knowing whether a property is located in a flood zone or not is significant for property owners and developers. After all, flooding directly impacts several crucial aspects related to both an existing property and a planned development. These include:

Aspect #1. Risk assessment and mitigation plans

When you know which flood zone your property is part of, you can develop effective mitigation plans. This way, you safeguard it against potential flood damage.

Some of the appropriate measures you can consider are implementing flood-resistant construction techniques, installing flood barriers, and raising the property’s elevation.

Aspect #2. Property value and resale considerations

Properties situated in flood-prone areas often face lower demand and reduced market value. This is because prospective buyers tend to be cautious about such issues.

But you can provide assurance to them by getting flood insurance. But keep in mind that this can add to the cost of ownership. 

Aspect #3. Restrictions on construction and development

Flood zones often come with specific regulations on construction. Local authorities may impose limitations on building height and materials. And they may also require flood-resistant designs and features, depending on the flood zone category.

By becoming aware of these restrictions, you can ensure compliance with local building codes. You then prevent potential legal issues during the development process.

Aspect #4. Implications for property insurance coverage

When your property is located in flood zones, you may be required to get an insurance policy that covers flood-related damage.

The fees associated with this type of insurance vary. Insurance providers assess the flood risk associated with the property when determining coverage and premiums. 

Identify Flood Zones Faster and Easier With Archistar

Safe to say, properties in flood zones are among the hardest to develop and maintain. After all, there are various factors to take into account. Plus, the environmental risk already exists even before the foundation is laid.

Knowing the flood zone your property is in allows you to consider the safety of the structures on your land and those nearby in case of flooding. This way, you can be proactive and make preparations to secure your property and everyone who lives in it.

Archistar can help you with all that. 

With Archistar, you can assess your lot and location for potential risks. Its flood layer feature, in particular, allows you to quickly determine if a potential site is inside a flood zone with just a few clicks. This lets you make informed decisions about the site in a timely manner. You can also use Archistar to create feasibility reports and value assessments, which is particularly useful if you’re still in the planning stages of your property project. 

Try out Archistar for free today to learn all there is to know about a particular site, regardless of the flood zone it is in.