Water Availability
The State Water Plan 2007 noted that there is about 1,937 gigalitres of water available in the Perth groundwater basin and 1,610 gigalitres of surface water in the South West. Of this only about 30% is still available for development - the balance is either reserved for the environment or already allocated for use. Many of these resources are a long way from Perth and many are also relatively small and not suitable for development for public water supply.
The Department of Water is updating these regional assessments of surface and groundwater availability as part of the Perth-Peel Regional Water Plan. This will involve estimates of available average annual surface water and groundwater resources forecast to 2030. As part of this work they are considering the impact of reduced rainfall projections.
In addition, the Department of Water is currently finalising a study that provides more information about the potential volume of drainage water that may be available for recycling across the Swan Coastal Plain. Other work being undertaken includes the preparation of maps that will provide more information about the availability of water for garden bores.
The Water Corporation will incorporate the findings of these studies, as they become available.
Water Forever will be developed in the context of understanding the availability of all water resources, including the need to retain water in the environment and share water resources with other sectors.