The south-west of Western Australia is facing major challenges caused by a drying climate, population growth and reduced groundwater availability, to the extent that it can no longer rely on traditional water supplies to meet the community's demands for water.
We encourage the use of alternative water sources, such as recycled wastewater and stormwater, where it is socially acceptable, economically viable and environmentally sustainable to do so. That way, we can support the ongoing development of the state and meet the growing demand for water.
We also works with developers, local government and industry professionals to improve overall water-use efficiency by promoting water-sensitive urban design principles, ways to save water around the home and introducing measures to protect our groundwater resources.
What is recycled water?
Recycled water is a renewable resource that is not subject to the same water restrictions as drinking water.
Non-drinking water sources include wastewater, greywater, rainwater, stormwater and groundwater which may need further treatment for the intended use. You can read more about these below.
The State water recycling strategy explains how recycled water can be safely used in a range of sectors in Western Australia.
Since this strategy was published in 2008, we have continued to work together with other agencies and the Water Corporation to promote safe water recycling.
What can recycled water be use for?
Recycled water can be used for:
- industrial, commercial and residential uses
- drinking water
- agriculture
- environmental benefits, such as supporting wetlands
- irrigating public parks, playgrounds, sporting grounds and golf courses.
Read more about water recycling:
- Assessing wastewater for recycling using the ‘ecotoxicity toolbox’ approach
- Development of an ‘ecotoxicity toolbox’ to characterise water quality for recycling
- Groundwater community bore
- Domestic garden bores
- Guideline for the approval of non-drinking water systems in Western Australia
- Better Urban Water Management guidelines
Non-drinking water sources
Wastewater
Wastewater is an important alternative water source. It is climate resilient, located closer to potential future demand zones, relatively consistent in quality and available in significant volumes that increase with urban growth.
Wastewater is the used water from households and business that is disposed of through the sewerage network (or into septic tanks in some areas).
Treated wastewater is discharged from a wastewater treatment facility after it has passed through treatment processes to reduce its nutrient and bio-chemical load. If treated wastewater is considered as a non-drinking water source option, further treatment may be required.
In some proclaimed public drinking water source areas, irrigation with treated wastewater is considered an incompatible land use. You can contact us at info@dwer.wa.gov.au for additional information.
Recycling wastewater is part of the managed water cycle and accounted for in developing urban water strategies and management plans.
Read more about wastewater recycling:
- Managed aquifer recharge in Western Australia
- Water Corporation - Wastewater
- Department of Health - Recycled water in WA
- Department of Health - Wastewater
- Guidelines for the non-potable uses of recycled water in Western Australia
- Code of Practice for the Design, Manufacture, Installation and Operation of Aerobic Treatment Units (ATUs)
- Economic Regulation Authority
Greywater
Greywater is used household water sourced from baths, showers, bathroom basins and laundries, but excludes water from the toilet ('blackwater').
Greywater reuse systems can vary in complexity and can be categorised into two main areas: untreated (bucketing and greywater diversion) and treated (greywater treatment systems). The majority of greywater reuse is at the household level.
Find out more about greywater:
- Department of Health
- Greywater
- Code of Practice for the Reuse of Greywater in Western Australia
- Guidelines for the Non-potable Use of Recycled Water in Western Australia
- Australian guidelines for water recycling
- Greywater and Wastewater Industry Group
Rainwater
Rainwater is water harvested directly from roof runoff from domestic or commercial buildings and captured in rainwater tanks. Rainfall is variable in Perth, so to optimise the full potential of rainwater as a water source, the rainwater system should be plumbed into the building for non-drinking purposes, such as in laundries and toilets.
On average, a roof area of 100 m2 (approximately 50 per cent of an average house in Perth) can collect about 50,000 litres of water a year when plumbed for internal and external use. With an appropriately sized rainwater tank, this could supply up to 20 per cent of a household's water needs.
Before installing a rainwater tank, approvals from your local council may be required.
Read more about rainwater:
- Draft Alternate Water Supply Guidelines – Stormwater and Rainwater
- Rainwater storage and reuse systems
- Water Corporation - Waterwise
- Australian guidelines for water recycling
- The cost effectiveness of residential rainwater tanks in Perth
Stormwater harvesting
Stormwater is urban surface water runoff from rain events. In areas such as the sandy soils of the Swan coastal plain, rainfall and resultant stormwater naturally recharges the superficial aquifer.
Stormwater drainage systems are often former natural waterways and the harvesting of stormwater can impact on ecosystems and water bodies that are dependent on that water.
Proponents need to consider these requirements of the catchment in determining the volume of water that can be collected for large-scale harvesting systems and the impacts on the local water balance.
Governance around ownership, operation and management of a community-scale stormwater system should also be considered.
Find out more about stormwater harvesting:
- Draft Alternate Water Supply Guidelines – Stormwater and Rainwater
- Australian Guidelines for Urban Stormwater Management
- Managed aquifer recharge in Western Australia
Non-drinking water systems
A non-drinking water system provides water that can be of lower quality than drinking water but is still suitable for many uses such as irrigating parks, public and private gardens, and in homes for bathrooms and laundries.
We support the use of non-drinking water systems, as long as they meet water quality standards for protecting public health and the environment.
Read more about non-drinking water systems:
