Greywater in Australia: what it is, and why reuse depends on your state
Reusing shower and laundry water on a garden sounds simple. The rules differ by state and territory, and most of the work is licensed plumbing.
Greywater is the used water from your showers, baths, basins and laundry. But not from toilets or the kitchen sink. Reusing it on a garden is allowed in parts of Australia, under conditions that differ by state and territory. Whether you can do it, and how, depends on where you live.
Most of the work involved is licensed. This page explains what greywater is, why it is not the same as sewage, and where the rules sit. It is an independent guide: no products, no prices, no shortcuts.
What counts as greywater?
The usual definition is wastewater from showers, baths, hand basins and the laundry. Toilet water is blackwater, and kitchen sink and dishwasher water is generally treated as too heavily loaded with fats and food waste to count. Some state rules draw that line differently, so check yours.
Greywater is not clean. It carries soap, hair, skin cells and bacteria from washing, and it goes off quickly when stored. That single fact drives most of the rules.
Can you reuse greywater at home?
In many places, yes, but only in the ways your state or territory allows. A common starting point is to divert laundry or bathroom water straight to the garden without storing it. Storing untreated greywater is where most rules get strict, because it turns foul within a day or so.
Some arrangements need an approved system or a permit from the plumbing regulator or the local council. Others are allowed in a simple form. We will not say which applies to you, because we cannot know your state, and a rule quoted from memory ages badly.
What does greywater recycling involve?
There are broadly two routes, and they are very different jobs:
| Route | What it is | Who does the work |
|---|---|---|
| Simple diversion | Laundry or bathroom water sent to the garden without storage | Often needs a licensed plumber to alter the drainage, and may need approval |
| Treatment system | Water collected, treated and reused, sometimes indoors | Licensed plumber, and an approved product and an approval from the regulator |
Both change the plumbing of the house. Cutting into a waste pipe to add a diverter is plumbing work, not a weekend tidy-up.
What should you ask before you start?
- Is it allowed where you live, and which of the two routes above does your state permit?
- Do you need approval or a permit from the regulator or the council before any work?
- Is the product on an approved list, and who certifies the installation?
- What does your soil and garden take? Salt and detergent can harm soil, so ask what products suit reuse.
- Where does it go in a storm or a fault? A good design sends the water to the sewer when the garden cannot take it.
How far can you take this yourself?
Working out which of your drains carry greywater, reading your regulator's page and listing your questions are all yours. None of that needs a licence.
This far, and no further. Altering waste pipes or connecting a system is licensed plumbing work in every Australian state and territory. Do not cut into drainage yourself and do not drain untreated greywater anywhere you have not been told you may. The rules and approvals are set by each state and territory, so contact the plumbing regulator where you live. Our guide to what plumbing you can do yourself explains how to check.
Is it greywater? A quick sort of your household drains
Before you read your state's rules, work out which of your drains carry greywater. This is all desk work and needs no licence.
| Water source | Usually counted as greywater? | Why |
|---|---|---|
| Shower | Yes | Soap, hair and skin cells, but no toilet waste |
| Bath | Yes | Same loads as the shower |
| Hand basin | Yes | Light soap load |
| Laundry | Yes | Detergent is the main thing to plan around, because salt and detergent can harm soil |
| Toilet | No, this is blackwater | Treated as sewage |
| Kitchen sink and dishwasher | Generally no | Too heavily loaded with fats and food waste |
Some state rules draw these lines differently, so check yours. Trace each pipe from the fixture to where it joins the main drain, and write down which ones you would want to divert. Take that list to your plumbing regulator and your installer. Our guide to what plumbing you can do yourself shows where the licence line sits.
Greywater mistakes and what to do instead
Most trouble with greywater comes from a few repeat mistakes. Each has a simple alternative.
| Mistake | Why it goes wrong | Do this instead |
|---|---|---|
| Storing untreated water | It turns foul within a day or so | Send it straight to the garden, or use an approved treatment system |
| Assuming your state allows it | Rules differ by state and territory, and a rule quoted from memory ages badly | Ask your plumbing regulator or council first |
| Cutting into a waste pipe yourself | Altering waste pipes is licensed plumbing work | Book a licensed plumber |
| Adding kitchen water | Fats and food waste overload the system | Keep it on the sewer |
| Ignoring the soil | Salt and detergent can harm soil | Ask which products suit reuse |
| No plan for storms or faults | The garden cannot always take the water | Design it so overflow goes to the sewer |
None of this replaces advice for your address, because approvals depend on where you live.
Frequently asked questions
What is greywater?
It is the used water from showers, baths, hand basins and the laundry. Toilet water is blackwater, and kitchen sink water is generally treated as too heavily loaded with fats and food to count. Some states draw the line a little differently.
Can I reuse greywater on my garden in Australia?
In many places yes, but only in ways your state or territory allows, and some arrangements need approval first. Storing untreated greywater is where rules tighten, because it goes foul quickly. Check with your plumbing regulator.
Do I need a plumber to set up greywater recycling?
Almost certainly. Altering waste pipes or connecting a diversion or treatment system is licensed plumbing work in every state and territory. You can do the research and list your questions yourself.
Is greywater recycling the same as a greywater system?
Recycling is the goal, and a system is the equipment. A simple diversion sends water to the garden without storage. A treatment system collects, treats and reuses it, and usually needs an approved product and approval.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- NSW Fair Trading. Plumbers, drainers and gasfitters — licensing
- Queensland Building and Construction Commission. Licensing and regulation of plumbing work in Queensland
- Australian Building Codes Board. National Construction Code — Volume Three (Plumbing Code of Australia)