Category 3 water damage: sewage, floodwater and water that sat

Category 3 is where a water damage job stops being about drying: the water is contaminated, and the rule becomes remove what it touched, then dry what is left.

Read from primary sources · Editor-reviewed · Current as at 20 September 2026

By the waterdamagequotesau.com editorial team · Published 20 September 2026 · Last reviewed 20 September 2026 · 8 min read

11 primary sources cited on this page. How we check what is on this site

Category 3 is the point at which a water damage job stops being about drying. The water is contaminated, and the working rule changes from “dry what is wet” to “remove what it touched, then dry what is left”. Three quite different events end up here, and each one sits in a different part of a home insurance policy.

Three ways water becomes Category 3

The sources of Category 3 water, what the health guidance says about each, and the words in the regulations. Read 29 September 2026.
Source	What the guidance says	Words in the regulations
Sewage — a blocked or surcharging drain, a toilet overflow with faeces	Blackwater is the wastewater from toilets, urinals or bidets (WA Health)	Escape of liquid from the building’s own pipes, `reg 19(1)(a)(vi)`; check the policy for a separate sewage clause
Floodwater and water from outside	Floodwater is often contaminated by sewage (Queensland)	Flood if it left a river, creek or other listed waterbody, `reg 34(1)`; otherwise storm depends on the wording
Clean or grey water that sat	Greywater is potentially infectious and microbes thrive when it is stored (NSW Health; Better Health)	The original event, and the argument about how long it was left

The last row is the one people do not expect. A category describes contamination, not source, so a clean supply-line leak left for days in a warm house, or a washing machine overflow left in a carpet, can end up scoped as Category 3. Grey water covers the Category 2 step in between, and categories and classes the whole framework.

What Category 3 changes about the job

Almost none of the difference is in the drying equipment. It is in what can be kept:

What the health departments say to throw away after contaminated water. Read 29 September 2026.
Item	Guidance	Source
Floor coverings, furniture, bedding, linen, clothing	Remove all wet items where possible	NSW Health
Mattresses, carpet, leather goods, ceiling insulation	Throw away if wet for more than 2 days and not easily cleaned	Queensland
Carpet and children’s soft toys	Throw away if they cannot be cleaned or disinfected	Better Health (Vic)
Hard surfaces	Leave wet with disinfectant for 10 minutes before rinsing, after sewage	Better Health (Vic)

In practice that means carpet and underlay come out, and restorers remove and dispose of porous building materials the water reached before the structure is cleaned, disinfected and dried. The equipment list grows too: HEPA air filtration, which on QLD Flood Restoration’s published rate card is $80 per unit per day with a 3-day minimum, is the line that marks a contaminated job.

Get contaminated water dealt with today

Four digits, and restoration companies advertising for your postcode call you back. Tell them whether it was sewage or water from outside.

Protection and health

Clothing. NSW Health lists boots, gloves and eye protection for flood clean-up (NSW Health, Household clean-up for after a flood or storm).
Breathing. Queensland recommends an N95/P2 respirator for a lot of mould or for people with allergies; standard dust masks do not protect against spores (Queensland Government, Mould (disasters and emergencies)).
Cuts. The NSW Government’s position is that all wounds other than clean, minor cuts are at risk of tetanus (NSW Government, Staying healthy after a flood).
Gas and power. Better Health says supplies that may be damaged must be confirmed safe by a qualified electrician or plumber before use (Better Health Channel (Vic), After a flood – returning home safely).

Which part of the policy applies

The category decides the scope of works; the source decides the claim.

Insurance Contracts Regulations 2017 (Cth) reg 19(1)(a)(vi) · 2021 compilation, read 20 September 2026

This is the provision that puts burst pipes, split flexible hoses, failed hot water units and overflowing cisterns inside standard cover. It says nothing about how old the pipe was.

Insurance Contracts Regulations 2017 (Cth) reg 34(1) · 2021 compilation, read 20 September 2026

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.

Sewage that backed up from the building’s own drain points at the first; floodwater from a creek or river at the second, which a policy may cover separately or not at all. Stormwater that came across the ground without leaving a waterbody is neither, and whether it is covered as storm depends on the policy’s wording. Photographs of where the water came in are the evidence for which applies. Sewage backup and flood damage restoration take each source in turn.

What Category 3 drying costs

Drying totals with one HEPA unit on the published rate card, excluding GST. Drying only.
How much of the house	Days	Total
Two rooms	5	$2,669
Around half the floor area	7	$6,213

Removal, disposal and reinstatement of what the water soaked are not on any published Australian rate card this site found, so no figure is given for them. They are the larger part of a Category 3 bill.

Common questions

What is Category 3 water?

The most contaminated of the three categories restorers scope against: sewage, floodwater and water from outside the building, and water that has sat long enough to become contaminated. WA's Department of Health defines blackwater as the wastewater from toilets, urinals or bidets, and Queensland's guidance is that floodwater is often contaminated by sewage.

Can I clean up Category 3 water myself?

Health departments publish household clean-up guidance for floods, with boots, gloves, eye protection and disinfection, and Queensland recommends an N95/P2 respirator for large clean-ups. Porous materials that Category 3 water soaked are removed rather than cleaned, which is usually where a restorer is needed.

Is Category 3 water damage covered by insurance?

It depends on the source, not the category. Sewage from the building's own pipes points at the escape of liquid event in reg 19(1)(a)(vi); water that escaped from a river or creek is flood under reg 34(1); stormwater run-off depends on the policy's storm wording.

Can carpet be saved after Category 3 water?

Generally not. Health departments list carpet among the absorbent items to throw away after floodwater: Queensland if wet for more than 2 days, Victoria if it cannot be cleaned or disinfected.

Can Category 1 or 2 water become Category 3?

Yes. Categories describe contamination, and water that sits in a warm building degrades. That is why the time between the event and extraction matters so much.

How much does Category 3 cleanup cost?

Drying alone, on the published rate card with one HEPA unit, is $2,669 for two rooms over five days and $6,213 for around half a house over seven, excluding GST. Removal, disposal and reinstatement are additional and usually larger.

Sources cited on this page

Every figure above was read from the source it is attributed to on 20 September 2026. How we check this.