What's our goal for Gnangara groundwater?

Our goal is to rebalance the Gnangara groundwater system by 2032 to secure our lowest-cost and most accessible water source for Perth and to support a healthy environment.
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Swans at the shore of Lake Joondalup

Learn about the Gnangara groundwater allocation plan below.

What do I need to know?

The Gnangara groundwater allocation plan is part of the State Government’s response to climate change.

The plan sets out how Gnangara groundwater use will be reduced over the next 10 years:

  • Taking less groundwater will rebalance the groundwater system to better match less rainfall in a drier climate, ensuring healthier wetlands and vegetation and a secure water supply for Perth in the long term.
  • The plan includes reductions shared across all groundwater users:
    • A 27 per cent reduction (30 gigalitres per year) in 2028 to groundwater licensed to the Water Corporation for Perth’s Integrated Water Supply Scheme (drinking water).
    • A 10 per cent reduction for most groundwater licensees from 2028, to give people time to adjust to the changes.
    • Alignment of the sprinkler roster for garden bores and scheme users from September 2022 so that all households across Perth and Mandurah now have a two-days-per-week sprinkler roster between 1 September and 31 May each year, regardless of the water source.
  • More information on reductions for different water users is in the Summary and Chapters 4 and 5 of the plan. Water used to irrigate school and hospital grounds and water used to irrigate plants or trees for commercial purposes by established nurseries and tree farms will be exceptions to reductions.
  • Support packages are available to some water users to help them adjust to less groundwater use.

The plan sets groundwater level objectives to protect important groundwater-dependent ecosystems, such as wetlands and bushland areas, and outlines how we will continue to monitor water levels, water quality and ecological health against these objectives to ensure the delivery of real outcomes.

Supporting documents for the plan are also available:

The statement of response summarises our responses to public comments and submissions received on the Gnangara groundwater allocation plan: draft for public comment, and how we used these to modify and finalise the plan.

Why a new plan for the Gnangara groundwater system is needed

  • Climate change has seen Perth’s long-term average annual rainfall decline by about 15 per cent since 1975. Less rainfall means less water recharging our groundwater aquifers.
  • We have been taking out more groundwater than has been recharged by rainfall – tipping the system out of balance. The more the system is out of balance, the bigger the impact on Perth’s wetlands, bushland, wildlife, and water quality and accessibility.
  • Taking less groundwater will help ensure the Gnangara groundwater system is managed sustainably and that it remains a natural, low-cost water source for Perth for the long term.
  • Important wetlands and native bushland will be protected and more resilient to climate change by taking the actions in the plan.

How was the plan developed?

We developed the plan considering:

  • social, economic and environmental issues identified from research and over 150 meetings, workshops and presentations with stakeholders to date
  • extensive modelling and analysis, showing the level of reductions are necessary to measurably improve groundwater levels in critical areas and protect important environmental and water resource values
  • issues raised in stakeholder and submissions received on the draft plan during the public comment period.

What support is there for water users to adjust to less groundwater use?

The State Government is supporting water users to adjust to using less water:

Better water outcomes are more achievable if we work together. There are great examples of this across different industries.