Reusing and recycling alternative water supplies is a key part of reducing the pressure on our water resources and the environment. Helping us adapt to climate change and population growth. When considering alternative water supplies, you should choose the most appropriate water source, taking into account end use, risk, resource and energy requirements.
Further information is available on the following alternative water supplies and the framework for their use:
It is better to reduce water use and avoid generating wastewater in the first place, than to have to identify alternative water supplies and reuse options.
The water conservation hierarchy
You should look into reusing low-risk water sources, such as rainwater or stormwater, before recycling higher risk source water, such as greywater and sewage.
Inherent risk for alternative water sources
The following figure illustrates how inherent risk and energy consumption rise as the choice of alternative water source moves from rainwater to stormwater, then greywater and finally sewage.
It is also important to consider when and how much water is needed and available, and whether you need any approvals.
Using rainwater is an easy and effective way to conserve our water supplies and reduce the amount of mains water you use. Some simple guides have been produced on how to collect and safely manage rainwater:
Greywater (all non-toilet household wastewater) can be a good water resource during times of drought and water restrictions, but its reuse can carry health and environmental risks.
See more information on household greywater reuse, and for larger commercial greywater recycling systems refer to greywater treatment systems.
Recycling wastewater can ease the pressure on our water resources and avoid the need to discharge wastewater to the environment. Recycling wastewater can provide water that, with some management controls, is suitable for a wide range of uses including irrigation and toilet flushing. See more on wastewater recycling.
Reusing and recycling industrial water can ease the pressure on our water resources and avoid the need to discharge to the sewer and/or environment. With appropriate management, which may include treatment, industrial water can be used for a wide range of purposes including industrial uses (e.g. cooling or material washing) or non-industrial uses (e.g. irrigation or toilet flushing). To reuse industrial water in a safe and sustainable way you should identify, assess and appropriately manage the risks. More on industrial water reuse (publication IWRG632).
Managed aquifer recharge (MAR)
In urban areas where there's not enough surface water storage, aquifers can provide a way to store excess water when it becomes available until the time it is needed.
Intentionally injecting or depositing water into an aquifer, and then extracting the water for use at a later date is known as managed aquifer recharge (MAR). There has been an increasing interest in using MAR as a mechanism to store and later supply an alternative water source for various uses. For example, stormwater could be injected into an aquifer and then later reused for watering parks and gardens in drier seasons.
For more information on MAR, refer to Guidelines for managed aquifer recharge: health and environmental risk management (publication 1290) which should be read in conjunction with the Australian guidelines for water recycling: health and environmental risk management (phase 2): managed aquifer recharge (Environment Protection and Heritage Council).
Framework for alternative urban water supplies
The Victorian Government has developed a regulatory framework and guidance to support use of alternative water supplies. For more information refer to the final project report, Review of the regulatory framework for alternative urban water supplies (publication DSE0901).