How does Gnangara groundwater support our environment?

We use our expertise in the hydrological and ecological sciences to protect environments that depend on our water resources.
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Without groundwater we wouldn’t have the lakes, wetlands, green parks, bushland and trees that make Perth such an enjoyable place to live.

Many people have made significant investments so they can live near and enjoy wetlands and bushland areas. The presence of wetlands adds to home values by about $4 billion across Perth, and native vegetation on the Gnangara Mound is valued at $100 million1.

1. Marsden Jacob Associates 2012, Assessing the value of groundwater, Waterlines report, National Water Commission, Canberra

Gnangara supports our environment in many ways

  • Supports lakes and wetlands
    Our natural lakes and iconic wetlands on the Gnangara Mound depend on groundwater to survive. These include Loch McNess (Wagardu) in Yanchep National Park, Lake Joondalup and Herdsman Lake (Ngurgenboro).
  • Supports vegetation
    Some of the bushland and large trees in our communities and parks tap into groundwater to survive our hot, dry summers.
  • Helps create our sense of place
    Lakes, wetlands, bushland and cave systems that depend on groundwater help support rare species, create our ‘sense of place’, link closely with cultural values and make our communities cooler and more attractive places in which to live.
  • Protects water quality
    Leaving enough water in the ground also helps protect water quality by preventing saltwater from moving into the aquifer from the sea and keeping acid-forming soils saturated and safe from oxidising.

Managing our iconic wetlands and bushland

Ministerial Statement no. 819 sets environmental water provisions in the form of water level criteria at 30 sites across the Gnangara Mound – 14 wetland sites and 16 terrestrial phreatophytic vegetation sites. Phreatophytic vegetation is vegetation that uses groundwater to meet at least part of its water needs.

We monitor water levels, the condition of wetland vegetation, macroinvertebrate richness and water quality at a suite of these sites to check how their health is responding to our management of groundwater use.

The Department of Water and Environmental Regulation reports on compliance with Ministerial conditions and commitments for the Gnangara Mound each year, which is published in annual and triennial reports. View the Ministerial compliance reports.

See updates on compliance with Ministerial conditions and groundwater levels.

Protecting water for the environment through allocation planning

Important wetlands and native bushland will be protected and more resilient from climate change by taking the actions in the Gnangara groundwater allocation plan. See Chapters 2 and 6 of the new plan for more information.

The new plan also includes some proposed revisions to the environmental water provision criteria in Ministerial Statement no. 819, which are currently being assessed by the Environmental Protection Authority under section 46 of the Environmental Protection Act 1986.

We have provided submissions made to us on the proposed changes to Ministerial Statement no. 819 during the public comment period of the Gnangara groundwater allocation plan: draft for public comment to the Environmental Protection Authority to consider as part of its assessment. The Environmental Protection Authority will also assess the department’s response to those submissions.