Can I drain my pool to the sewer in WA?

The WA rule, quoted

Water Corporation's swimming pool discharge page is short and leaves no room for interpretation.

‘Backwash and drainage from domestic swimming pools and spas are not considered as trade waste and are not permitted to be discharged to sewer.’

Two parts matter. The classification — not trade waste — is what removes the permit pathway that a commercial facility uses. The prohibition then follows: with no trade waste classification, there is no mechanism to accept the discharge.

The quotable version: in Western Australia the sewer is closed to domestic pool water, and it is closed by classification rather than by discretion.

This matters most on the two occasions a domestic pool produces a lot of water: routine backwashing of a sand or DE filter, and a full or partial drain for repair, resurfacing or a water-chemistry problem. Our page on what it costs to empty and refill a pool covers the volumes and the refill cost that follows, and the disposal question is the half of that decision most people leave until the pump is already running.

What Water Corporation says to do instead

This is the part a prohibition page usually omits, and Water Corporation does answer it — by pointing somewhere else.

For disposal options, the page directs: ‘please contact your Local Government Authority’.

That is not a brush-off; it is the correct referral. Disposal to land, to a soakwell, or to stormwater is a local government and environmental matter rather than a water utility one, and the right answer genuinely depends on your soil, your lot, your proximity to a waterway and your local government's policy. Perth's sandy and limestone soils behave very differently from a clay lot, and a discharge that soaks away harmlessly on one block runs to the kerb on another.

We are not publishing a specific approved disposal method for WA, because we could not verify one that applies statewide. Water Corporation refers the question to 139 separate local governments and we have not read all of them. What we can say with confidence is the sequence:

• Ask your local government before you drain, naming the volume and whether the water is salt or chlorinated.
• Ask specifically about salt. Salt-chlorinated water is a different problem from chlorinated water for soil, plants and drains, and the answer may differ.
• Do not default to the stormwater drain. It is the most common assumption and, in other states that publish on it, the one most often expressly prohibited.

The commercial exception, and why it tells you something

Water Corporation does accept aquatic facility discharge, under conditions, and the conditions are instructive.

Commercial aquatic facilities must apply for a Trade Waste Permit prior to connection to sewer, and ‘the level of chlorine is not to exceed Water Corporation's current limit of 10 milligrams per litre’.

That 10mg/L limit is the useful number. It tells you what the utility is actually worried about: the chlorine, not the water. A well-balanced domestic pool sits far below 10mg/L of free chlorine in normal operation, which is why the prohibition on domestic discharge reads as a matter of classification and metering rather than of contamination risk per litre. The commercial pathway exists because a commercial operator can be permitted, monitored and billed. A householder cannot.

It is also worth noting what the permit regime implies about timing: prior to connection. A commercial facility that connects first and applies later is in the same position as a homeowner who installs a barrier before it is approved.

Why South Australia says the opposite, and what to take from that

If you have read Australian pool advice that told you confidently to use the sewer, it was probably written for a state that says so.

South Australia's published position, in EPA-derived council guidance, is close to the reverse of WA's. In areas connected to the sewerage system, backwash water from all swimming pools can be directed to a sewerage drainage point, and new swimming pools should be permanently connected to the sewer at the time of installation or construction, with approval from SA Water. South Australian legislation prohibits the disposal of backwash water into the stormwater system, and pool backwash water is named as a pollutant listed in Part 1 of Schedule 4 of the relevant policy. Failure to comply with the general obligations may result in a $300 fine, with Environment Protection Orders and prosecution also available.

In unsewered SA regions the guidance is to discharge to a grassed, vegetated or garden area, and where a septic system exists, backwash is to bypass the septic tank.

The rule to carry: pool water disposal is set by your water authority and your council, not by the pool industry, and the two neighbouring states can and do publish opposite instructions. Verify locally before you open a valve. Our pages on WA pool barrier rules and what it costs to fill a pool cover the other two WA-specific questions that come up at the same time, and you can get a quote if the drain is the prelude to a renovation.

Common questions

Sources

• Water Corporation — swimming pool discharge regulations
• SA EPA guidance on disposal of swimming pool backwash water, as published by Yorke Peninsula Council

General information only, current at 2026-09-22. Pool rules differ by state and by council, and penalty amounts are updated regularly. Confirm your own obligations with your council or a registered inspector before acting.