Is greywater suitable for my garden?

Answering a few key questions can help to determine whether installing a greywater system is feasible. In particular, whether you have an existing home or are building a new home, the size of your house and garden, your budget and whether you have sought professional advice.

Using greywater for irrigation is generally feasible as one of the water-saving strategies adopted for a new home. If you are looking to install a greywater system in an existing home please refer to the information and case studies in the West Australian Greywater Guide for details on how to best proceed.

Greywater suitability 9 point checklist

Is the garden large enough to make a Greywater system worthwhile?

1. A ‘whole of house’ greywater system includes baths, showers, laundry: allow for a minimum garden area of 10m² per person for sandy coastal plain, or minimum 20m² in areas with less permeable soils.

2. Laundry only: allow a minimum 4m² per person in coastal plain or 8m² elsewhere.

3. “Garden areas” means trees, shrubs, garden beds and small lawns but not paving or the verge.

Is Greywater within your budget?

4. Check Department of Health approved systems and cost estimates.

5. All-up, a typical whole-of-house system should be around $5000 including irrigation.

6. Your builder will add a cost for additional pipework

Do you have enough time to plan and implement a greywater system?

7. All greywater systems need to be considered at the design stage for new houses.

8. Pipework separating greywater from other wastewater sources must be designed and laid before the concrete floor slab goes down.

Get some advice

9. An experienced greywater professional can design a system that is practicable, site specific and complies with the “Code of Practice” (Department of Health, 2010).

About The Author


Greywater & Wastewater Industry Group. We are a group of water industry professionals who are active in the design, research, manufacture, installation and servicing of greywater and wastewater treatment systems. GWIG is a non-profit organisation which was formed in late 2010 in order to provide a united voice for a WA industry that is largely unsupported and under-acknowledged for the important work that it does.