What “flood” legally means in an Australian insurance policy
Seven water bodies, one regulation, and a note that stops a product disclosure statement redefining the word. If the water in your house never came out of one of those seven, it is not a flood — and a flood exclusion is the wrong reason to decline it.
This is the single most useful page on this site, and it is short, because the law is short.
Insurance Contracts Regulations 2017 (Cth) reg 34(1) · 2021 compilation, read 20 September 2026
“flood means the covering of normally dry land by water that has escaped or been released from the normal confines of any of the following…”
Paragraphs (a) to (d) each add the words “whether or not it has been altered or modified”, so a concrete-lined channel is still a creek.
The seven things:
- a lake — whether or not it has been altered or modified
- a river — whether or not it has been altered or modified
- a creek — whether or not it has been altered or modified
- another natural watercourse — whether or not it has been altered or modified
- a reservoir
- a canal
- a dam
That is the complete list. There is nothing else in it.
The part that makes it matter
Insurance Contracts Regulations 2017 (Cth) reg 34(1), note; Insurance Contracts Act 1984 (Cth) s 37B(3) · 2021 compilation, read 20 September 2026
The note to reg 34 says the meaning in subsection (1) applies in the prescribed contract “even if the meaning of the word provided by the prescribed contract (or by a notice or other document or information given by the insurer in relation to the prescribed contract) is different”.
A definition that a contract can override is a suggestion. This one cannot be overridden. For a prescribed contract, reg 34 applies the statutory meaning even where the policy provides a different one — and the note goes further than the policy document, reaching any notice, document or information the insurer gave you about the contract.
So the sentence people reach for — “but my PDS defines flood as…” — is usually the wrong sentence. For most householders the PDS definition is decorative. What governs is the regulation.
What is not a flood
Work through the list and the omissions do the work:
| Where the water came from | Flood under reg 34(1)? |
|---|---|
| Rain falling directly on and into the building | No |
| Surface run-off across the ground, including from a neighbour’s land | No |
| A street stormwater drain that could not cope and surcharged | No |
| A blocked sump or a failed pump in your own yard | No |
| Groundwater rising through a slab | No |
| The sea, high water or a tsunami | No — named separately at reg 19(1)(a)(xiv) |
| A river, creek or natural watercourse breaking its banks | Yes |
| A lake rising over its normal confines | Yes |
| A reservoir, canal or dam releasing or escaping | Yes |
| A channelised or concrete-lined creek | Yes — “altered or modified” |
Why this cuts both ways. If the water came out of a creek, calling it storm damage will not help you and the assessor will work it out. If it did not, an insurer relying on a flood exclusion is relying on a definition that does not reach your water, and that is a point worth putting in writing before you do anything else.
Get the drying moving either way
The definition argument can take weeks. Water in a subfloor cannot.
“Whether or not it has been altered or modified”
Four of the seven paragraphs carry those words, and they were drafted to close a specific argument. Australian cities are full of creeks that have been straightened, lined, culverted, piped and renamed as drains. Without those words, an insurer could argue that once a creek is concrete it is a drain, and a drain is not on the list.
With them, a channelised urban creek is still a creek. If the water in your house came out of something that used to be a watercourse and now looks like infrastructure, find out what the council calls it and what it was. The answer is frequently in a flood study the council has published.
Who this applies to, and who it does not
Reg 34 works through reg 33, which lists the prescribed contracts. Householders who bought a home building, home contents or combined policy direct or through a comparison site are inside it. Strata title residences are inside it, at reg 33(1)(d). Small business is inside it, at reg 33(1)(e) and (f).
Insurance Contracts Regulations 2017 (Cth) reg 35(1) · 2021 compilation, read 20 September 2026
The regulation’s own note says 190 hours is the equivalent of five employees each working a 38-hour week.
And then the carve-out:
Insurance Contracts Regulations 2017 (Cth) reg 33(2) · 2021 compilation, read 20 September 2026
If a broker arranged your policy as your agent, the prescribed-contract rules do not apply and the policy’s own definition governs. Brokered commercial property policies frequently define flood more broadly than reg 34 — sometimes to the insured’s advantage, sometimes not. Ask your broker which definition is in your wording before you argue from this page.
The business trap in reg 34(2)
Reg 34(2) is aimed at insurers, not at you, but it tells you something useful. Where an insurer wants to use the word “flood” in a business policy with a meaning other than the statutory one, it must take reasonable steps to ensure the contract is not a prescribed contract — that is, that the business is not a small business as reg 35 defines it. The regulation’s own note adds that the insurer is likely to rely on information the insured provided, and that giving false or misleading information is a serious matter.
The practical reading: if your business is near the reg 35 line, the answers you gave at underwriting about turnover and staff hours may decide which definition of flood applies to your claim.
Get flood and water damage quotes
Restoration companies advertising for your postcode. Whether it was legally a flood or not, the drying is the same work.
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Here is what happens after you submit:
- Your answers go to restoration companies that advertise for your postcode.
- No more than three of them may contact you, using the details you gave.
- You decide who, if anyone, you use. You are committed to nothing, and this does not lodge, alter or affect an insurance claim.
We are not a restoration company and we do not attend, assess or repair anything.
Common questions
What is the standard definition of flood in Australia?
Reg 34(1) of the Insurance Contracts Regulations 2017 (Cth): the covering of normally dry land by water that has escaped or been released from the normal confines of a lake, a river, a creek, another natural watercourse, a reservoir, a canal or a dam. The first four each carry the words “whether or not it has been altered or modified”.
Can my policy define flood differently?
Not for a prescribed contract. The note to reg 34 and s 37B(3) of the Insurance Contracts Act apply the statutory meaning even where the contract, or a notice or document the insurer gave you about it, says something else.
Is stormwater run-off a flood?
Not under reg 34(1). Run-off across the ground has not escaped from a lake, river, creek, natural watercourse, reservoir, canal or dam. If an insurer declines a run-off claim on a flood exclusion, the definition it is relying on is the statutory one, and the statutory one does not reach it.
Is a concrete-lined drain a creek?
It can be. Paragraphs (a) to (d) each add “whether or not it has been altered or modified”, which was drafted precisely to stop the argument that channelising a creek stops it being a creek.
Does the flood definition apply to my business?
Only if it is a small business as reg 35 defines it: turnover under $1,000,000 in the last completed financial year and no more than 190 employee hours a week. Above that, the policy's own definition governs.
Sources cited on this page
- Insurance Contracts Regulations 2017 (Cth)
- Insurance Contracts Regulations 2017 (Cth) reg 34(1)
- Insurance Contracts Regulations 2017 (Cth) reg 34(1), note; Insurance Contracts Act 1984 (Cth) s 37B(3)
- Insurance Contracts Regulations 2017 (Cth) reg 35(1)
Every figure above was read from the source it is attributed to on 20 September 2026. How we check this.