Free · NSW · Checked against government flood data

Is this house in a flood zone? Check any NSW address.

Flood is the one risk a listing will not mention and an inspection cannot see. Type the address and the free report shows the flood layer for that lot, with bushfire, heritage, zoning, noise and recent sales beside it.

What "flood zone" means in NSW

NSW does not have one flood zone. Each council maps its own floodplain and applies development controls to the part of it called the flood planning area: usually the land below the 1% annual exceedance probability (AEP) flood level plus a freeboard, most often 0.5 metres. The 1% AEP flood is the one people call the 1-in-100-year flood. It means a 1% chance in any year, and it can happen two years running.

Beyond the flood planning area is land that can still flood in a rarer event, up to the probable maximum flood. A property can be flood-prone without being inside the flood planning area, which is why the council's full flood study matters more than a yes-or-no label.

Normal river level1% AEP flood (the "1-in-100-year")Flood planning level: 1% AEP + 0.5 m freeboardProbable maximum floodFlood controls applyAbove the planning level
Not to scale. The flood planning area is the land below the flood planning level; land between that and the probable maximum flood can still flood in a rare event. Levels and freeboard are set by each council.
  • Flood planning area1% AEP level plus freeboard. Development controls apply.
  • Probable maximum floodThe largest flood that could plausibly occur. Evacuation planning uses it.
  • 10.7 certificateAttached to every NSW contract. States whether flood controls apply to the land.

Five ways to check an address

  1. Read the Section 10.7 planning certificate. It is attached to the contract for sale and says whether the land is subject to flood related development controls. Ask the agent for the contract before the open home; you are entitled to it.
  2. Open the council flood map or request a flood certificate. Councils are the authority for property-level flood information. Many publish an interactive map; most will issue a flood information certificate for a fee that gives the flood planning level and historic levels for the lot.
  3. Check the NSW SES Flood Data Portal and Local Flood Insights. The portal hosts council flood studies and models; Local Flood Insights summarises flood history and risk by suburb.
  4. Run the free knest report. It shows the flood layer for the address from government datasets, next to bushfire, heritage, zoning, power lines and road or rail noise, and lists recent sales so you can see what flood-affected homes on the street actually sold for.
  5. Get an insurance quote on the exact address. Insurers price flood by address. A premium two or three times the suburb norm, or an exclusion, is the clearest signal there is.

Checked against NSW planning and SES guidance on 8 October 2026. Reading the contract? Here is what a flood-prone tag means for insurance and value.

What flood risk changes when you buy

Insurance
Priced by address under the single legal flood definition used since 2012. Higher risk means a higher premium, and cover can be excluded. Quote before you exchange.
Building
Inside the flood planning area councils set minimum floor levels and can restrict excavation, fences and ground-floor uses. Extensions and knock-down rebuilds need checking first.
Lending
Lenders expect the home to be insurable. If flood cover is refused or priced out, that can affect the loan, so settle the insurance question early.
Value
Buyers discount exposed homes for all of the above. The size of the discount is local: compare sales on the same street rather than the suburb median.

Sydney's main floodplains

Three river systems account for most of Sydney's residential flood exposure. Each suburb below links to its knest suburb page, where every address has its own report.

Aerial view of floodwater spreading across paddocks to the edge of a Sydney suburb
Floodplains flood by design: the Hawkesbury-Nepean, Georges and Cooks river systems carry most of Sydney's residential exposure.

Cooks River

Flash flooding in the inner south-west, where heavy rain runs off hard surfaces faster than the channel can carry it.

Not in one of these? Flash flooding from local creeks and stormwater affects suburbs across Sydney. The address check above covers every NSW property.

Ask about any address

Flood, bushfire, zoning, heritage, noise and what comparable homes sold for, in one free report. Then ask the AI agent what it means for your offer.

Get the free property report
FAQ

NSW flood zone questions, answered.

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

Check the address, not the suburb. The Section 10.7 planning certificate attached to the contract states whether the land is subject to flood related development controls. Your council's flood map or flood study gives the detail, the NSW SES Flood Data Portal publishes many of those studies, and a knest free report shows the flood layer for the address alongside the other risks. Then get an insurance quote on the exact address: the premium is the market's view of the risk.

What is the flood planning area?

The land a council applies flood related development controls to. In NSW it is usually the area below the 1% annual exceedance probability (AEP) flood level plus a freeboard, commonly 0.5 metres. The 1% AEP flood is often called the 1-in-100-year flood, which means a 1% chance in any given year, not once a century.

What does the Section 10.7 certificate say about flooding?

A 10.7(2) certificate must be attached to every NSW residential contract for sale. It states whether the land is within the flood planning area, and in many councils whether it sits between the flood planning area and the probable maximum flood. It does not show the flood depth or history: ask the council for the flood study or a flood information certificate for that.

Is a flood zone the same as flood-prone land?

Not quite. Flood-prone land is any land that can be inundated, up to the probable maximum flood. The flood planning area is the smaller part of it that councils control development on. A property can be flood-prone without being inside the flood planning area, which is why the council's full flood study matters.

Does flood risk affect home insurance?

Yes. Since 2012 Australian home policies use one legal definition of flood, and insurers price it by address. A higher-risk address pays more, and in some cases flood cover is excluded. Get a real quote before you exchange rather than after.

Can you build or renovate on flood-prone land in NSW?

Usually, with controls. Inside the flood planning area councils typically require a minimum floor level set at the flood planning level, and may limit excavation, fencing and ground-floor uses. Check the council's flood controls before assuming an extension or a knock-down rebuild is possible.

Does being in a flood zone lower a property's value?

It can. Buyers price in higher insurance, building limits and the risk itself, and the discount depends on how exposed the property is. Compare recent sales of flood-affected and unaffected homes on the same street; a knest report lists both.

Sources

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