Supply options
Stormwater storage and use for irrigation
Stormwater collected from urban runoff or existing stormwater drains is stored in tanks or underground storage cells for irrigation use. Since stormwater is of a seasonal nature, adequate storage is required to store sufficient volumes for irrigation supply during the drier months, which can be an expensive way of managing stormwater. Therefore, managed aquifer recharge can provide an economic means of storing stormwater for indirect use.
Managed aquifer recharge using stormwater (indirect use)
Managed aquifer recharge is the intentional recharge by injecting or infiltrating a water source under controlled conditions into an aquifer.
Subject to satisfying the ecological water requirements of ecosystems that previously received stormwater input, stormwater from urban runoff or drains can be used to recharge local aquifers for environmental benefits or for later abstraction; e.g. for irrigation. Appropriate treatment of the source may be required.
The Department of Water has developed a state-wide policy – Operational policy 1.01 – Managed aquifer recharge in Western Australia – to address environmental and allocation management impacts of managed aquifer recharge.
This policy aligns with the environmental risk assessment approach taken in the Australian Guidelines for Water Recycling: Managing Health and Environmental Risks (Phase 2) Managed Aquifer Recharge (July 2009).
For more information on managed aquifer recharge and a copy of the Department of Water draft policy click here.
Third pipe stormwater schemes
Although stormwater might be used primarily for irrigation purposes, appropriately treated stormwater can be supplied through a third pipe scheme to new residential developments for irrigation of lawns and gardens, and potentially for in-house uses, such as toilet flushing. A major limitation in designing a third pipe stormwater scheme is being able to guarantee that sufficient water will be available for the intended uses.
Further information on these supply options can be found in the Non-drinking water supply section of the toolkit.