Many City Councils offer Greywater application fee rebates.
Please check with your council.
City of Fremantle
The City offers a rebate on the application fee if the system is installed to the satisfaction of our environmental health officers. To apply to install a grey water reuse system, complete the application to install an apparatus for the treatment of sewage together with a fee and submit it to the City of Fremantle for approval. https://www.fremantle.wa.gov.au/residents/health-and-wellbeing/effluent-disposal
City of Joondalup
To encourage the reuse of greywater, the City is currently offering a rebate scheme which will refund the City’s approval fees under the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974, to install and operate a Greywater System. https://www.joondalup.wa.gov.au/kb/resident/grey-water-disposal
City of Stirling
Consider installing a grey water system and using waste water from your shower and laundry to irrigate your garden. To encourage the uptake of grey water systems, the City of Stirling has waived all applications fees.
City of Subiaco
Rebates are available to encourage residents to install greywater reuse systems. Once you have a Permit to use apparatus certificate for the installation of your greywater system, you are eligible to claim the City of Subiaco Greywater Use Incentive Program Rebate form (PDF, 109KB), a rebate of the application fees paid when you lodged your application.