Water information

The City’s recreational water monitoring program is a proactive approach to protecting human health. Sites across the City are regularly monitored to determine suitability for recreational activities. This is to protect against issues such as sewage spills, algal blooms and other health related incidents.

If you have concerns involving recreational water quality please complete a Service Request Form.

Download a service request form

All waste water systems must be approved by the City prior to installation and use.

There are two main types of effluent disposal systems, a conventional system and a nutrient retentive system. The location of your property will determine which system is required and it is recommended that you speak to Health Services prior to deciding which system to purchase.

Conventional system

A conventional septic system incorporates two septic tanks and either two leach drains or four soak wells and is suitable for most location within the City of Mandurah.

Nutrient Retentive System

Properties that are located within 100m of the Peel Harvey Estuary or other environmentally sensitive areas will require a nutrient retentive system.

How do I choose the right system for my property?

Once you have decided which type of system is required, then you will need to check to ensure that the design of the system is approved by the Department of Health prior to completing and lodging your application with the City.

Get more information from Department of Health

Greywater is the household wastewater from the laundry and bathroom (excluding the toilet and kitchen). To find out more about greywater and how to use it refer to the Department of Health for information on approved greywater uses.


  • Contact the City to check you are in a greywater approved area
  • Choose which approved greywater system you like and discuss with a licensed plumber

Our guidelines on maintenance of greywater systems will help you keep your system safe and 

You can also get more information on greywater from the Department of Health website.

Download an application to construct or install a greywater system

You will need approval prior to installing a effluent disposal system or greywater system. 

Application to install and permit to use process:

  • Complete an application to construct or install an apparatus for the treatment of sewage and pay fees. Two copies of site plans (1:100 to scale) and plumbing layouts must be attached
  • Once assessed a Health Officer will book an inspection to ensure system installation will comply
  • Once approved you will receive a permit to install (the plumber must comply with all conditions on the permit)

Following installation, you will need to contact the City and request a final inspection and receive a permit to use prior to operating the system.

Construct/Install Sewage Treatment Apparatus Application

Once a property has been connected to sewer, the septic tank and leach drain/soakwell systems may require decommissioning.

When do I need to decommission a septic system?

Under the Health Regulations 1974 (treatment of sewage and disposal of effluent and liquid waste), decommissioning is required when:

  • The property is sold
  • The use of the property changes e.g. from residence to a child care centre
  • Building extensions may encroach on minimum setback requirements for the system

How do I decommission a septic system?

  • Pump out the contents of the tanks (by an approved contractor)
  • Remove and backfill with sand
  • If the system can’t be removed – break the bottom of the tanks and backfill with sand
  • Notify the City in writing, including certification from the liquid waste contractor of decommissioning

Note: Non-decommissioned septic tanks must not be paved or built over without City approval.

Notification of Septic Decommissioning Form

The City provides and maintains all stormwater drainage infrastructure including the construction of open and piped drainage systems which transport water to sumps, bubble-up structures and swales.

We also carry out regular maintenance, clearing out blocked drains and improving and replacing drainage infrastructure.