Gnangara groundwater areas allocation plan
New plan is underway
Gnangara groundwater – Perth’s largest, most accessible, lowest cost source of fresh water – has become out of balance through less rainfall and continued groundwater use.
The Department of Water is setting new allocation limits and a water allocation plan to make sure we have a productive and sustainable groundwater supply and healthy environment under a drying climate.
To develop the next Gnangara plan, we are working with water users to find ways to adjust and to bring our Gnangara groundwater system back into balance by 2030.
The plan is due for public comment in late 2018.
The current Gnangara groundwater areas allocation plan was released in 2009. Since then we have regularly evaluated our management against the plan’s objectives and released two evaluation statements:
- Gnangara groundwater areas allocation plan: evaluation statement 2009–2011
- Gnangara groundwater areas allocation plan: evaluation statement 2011–2014.
If you would like to receive updates on the next Gnangara groundwater allocation plan, please register your interest by emailing email@example.com
Water allocation planning in Gnangara
The Gnangara groundwater system is Perth's largest source of good quality, fresh water, and is a shared resource.
Gnangara groundwater supplies almost half of Perth's water supplies. This includes water for Perth’s integrated water supply scheme and water taken by farmers, local governments, schools, industry, and households from their own bores.
It also supports nationally significant groundwater-dependent ecosystems, such as wetlands and Banksia woodlands. These groundwater-dependent ecosystems support biodiversity, help create our 'sense of place' and make our city an attractive place to live.
The 2009 Gnangara groundwater areas allocation plan provided the first strategies to manage sustainable groundwater abstraction and first steps to returning the over-allocated system to balance, after 40 years of declining rainfall and recharge to groundwater. It is a strong first step in adjusting our groundwater management in the context of drier climate and has resulted in the following:
- Significantly reduced abstraction for public water supply.
- Increased compliance and enforcement activities.
- Increased protection of groundwater-dependent ecosystems, by moving abstraction to lower risk areas, including the deeper confined aquifers.
To make sure we have a productive and sustainable groundwater supply and healthy environment under a drying climate, the Department of Water is working with groundwater users to find ways to adapt and reduce use, and will update the Gnangara groundwater allocation plan ready for public comment in late 2018.
The Gnangara groundwater areas cover about 2200 km2 in the northern part of Perth.
The area covers the groundwater resources of the Yanchep, Gnangara, Wanneroo, Swan, Mirrabooka, Gwelup and Perth groundwater areas and includes a portion of the Gingin groundwater area.
The Gnangara groundwater areas consist of three main aquifers – the unconfined Superficial aquifer (commonly known as the Gnangara Mound), the deep, partly confined Leederville aquifer and the deep, mostly confined Yarragadee aquifer. Minor aquifers include the Mirrabooka and Fractured Rock.
Gnangara groundwater areas and plan area