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Government of Western Australia Department of Water and Environmental Regulation
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Finding water

Finding new water resources, including Royalties for Regions-funded programs and other drilling programs to explore resources across the state.

Water allocation plans

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Rural water support

Click here to apply for rebates and grants for farmers, pastoralists and rural communities to improve local water supplies and for information about assistance to help farmers access water during dry seasons.

Flood planning and mapping

Information, advice and management of flood plans based on flood behaviour research and floodplain mapping for the state's major rivers.

Water and land use planning

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Meeting demand

Information about how we work with government, water service providers, industry and communities to identify water demand management and supply options that enable sustainable water use.

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Water licensing Water Licensing

Licences and how to apply, licensing policies, forms to download and answers to questions frequently asked by current and prospective licensees.

Water trading Water Trading

Find out who is eligible to trade water entitlements and how applications are assessed. Click here to identify potential trading partners from the Water Register.

Metering and measurement

Metering and measuring the water you take helps you understand your water usage to make the most of your entitlements and reduce your overall costs.

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Current legislation

Current legislation for which the Department of Water assists the Minister for Water. Click here for current WA legislation.

Water reform

We are updating our policy and legislation to deliver water resource management legislation that is flexible, progressive and capable of managing water today and in the future.

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Legislation and policy for Western Australia’s water service providers.

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Planning and managing water to enable growing, liveable water smart towns and cities.

Recycling and efficiency Recycling

Information about wastewater recycling, water efficiencies and the use of fit-for-purpose water. Recycling is encouraged whenever it is socially, economically and environmentally acceptable to make smart use of waste water for the ongoing development of the State.

Bores Domestic Garden Watering

For information on groundwater, garden bores and waterwise gardens please visit our Be Groundwater Wise website. You can find questions and answers about garden bores,

Drinking water Mundaring Weir

Protecting and managing public drinking water source areas including policies relating to public drinking water source areas, water source protection plans, water quality strategies and management and review processes.

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Groundwater Ground Water

Information on the state’s groundwater resources, locations, investigations, aquifer recharge and sustainable management of water resources, including an overview of state groundwater investigations.

Surface water Surface Water

Surface water, like rivers and streams used for public water supply, self-supply, irrigation, recreation and hydropower and rainfall and streamflow monitoring, catchment modelling and flood studies to manage surface water.

Water quality Water Quality

Click here for information about water quality, including public drinking water source areas, salinity, brochures, fact sheets and best management practices for various land uses and activities to help protect water quality and public health.

Waterways Rivers and Estuaries

Rivers and estuaries and their importance including information on monitoring and assessing waterways, protecting, understanding, planning, restoring, and risks and threats.

Estuaries

There are 166 estuaries in Western Australia as established through the National Land and Water Resources Audit (NLWRA) 2000, where an estuary is defined as

Onshore petroleum and water resources 5.6 Shale_and_tight_gas.jpg

Information on the department’s role in relation to the shale and tight gas industry.

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Climate change and waterways

The Western Australian government recognises that climate change is happening now. While our climate is naturally variable, the warming trend and climate changes observed due to enhanced greenhouse effect are predicted to continue into the future and will affect Western Australia's communities, industries and ecosystems as well as present challenges to managing our state's resources. The Indian Ocean Climate Initiative (IOCI), a long-running research partnership between the WA government, the CSIRO and the Bureau of Meteorology, has improved our understanding of climate changes in Western Australia.Farm dam in the Avon catchment

Changes to our climate, including rainfall, temperature, evaporation and extreme weather events, influence the water cycle, which is the primary driver of the hydrology of waterways. The condition and stability of waterways depends not only on their hydrology, but also on a complex and dynamic network of interactions between bacteria, algae, plants and animals with sediments, rocks, surface water flow, groundwater and chemicals. Climate change will affect these components, and the processes and interactions that occur between them, in a range of different ways.

We monitor how changes in the climate affect the hydrology of our waterways and other water resources. Our challenge is to predict how climate change will affect our waterways and their ecosystems in the future, and to take this into account in land planning and in our approach to managing and restoring waterways, in order to maximise their resilience.

Changes in rainfall

Recent decades have a trend of higher-than normal rainfall in northern and central Australia and decreasing rainfall across south western Australia.

Since 1970, rainfall in south-west Western Australia has decreased significantly, with decreases in average rainfall of up to 200 mm/a in some places. Reduced rainfall and fewer very wet years have resulted in lower and less frequent flows in waterways. For more information on changes in flow, see surface water hydrology.

In some areas (such as around Perth), groundwater recharge and water tables have also fallen, affecting the waterways and other ecosystems that depend on groundwater inflow.

As this drying trend continues, south-west waterways are likely to experience altered patterns of flow with perennial streams becoming seasonal and seasonal streams having longer periods without flow. Some wetlands may disappear. Dry river bed - Ellen Brook

Aquatic organisms will be affected by habitat changes. Many cannot disperse or migrate when river pools become disconnected.

For species that breed in autumn, the delay of winter rainfall and cooler temperatures that are cues for breeding, may not allow them sufficient time to complete their lifecycles.

Since 1960, rainfall in areas outside the south west of Western Australia has increased, with the highest increases recorded in the north-east parts of the state.

Many waterways in arid and semi-arid areas experience irregular large floods, with long dry periods between, where they exist as a series of disconnected pools or dry out completely. The aquatic and riparian fauna and flora that persist there are adapted to this extreme variability, so they may be resilient to future changes.

Increasing temperatures

Average temperatures have increased by 0.2-0.8°C across most of the state during the last 40 years; except in some parts of the central Kimberley, where temperature has declined by 0.2°C. Temperatures are predicted to continue to rise with more hot days, and extremely hot days (above 40°C) and less cold nights.

Temperature affects the rate of many of biochemical processes in aquatic ecosystems. Water temperature directly affects the distribution of aquatic organisms and extreme temperatures may exceed the tolerances of those adapted for the previous cooler climates, causing local extinction of vulnerable species.  This situation is exacerbated in areas with extensive land clearing where little riparian vegetation exists to shade riverine pools. Increased temperatures may also disrupt lifecycles and reproduction, for example affecting species that have a sex ratio dependent on temperature (e.g. crocodiles and freshwater turtles).

Higher temperatures will increase evaporation and transpiration rates, reducing surface water availability, drying river pools and seasonal wetlands more quickly and affecting the survival and reproduction of aquatic organisms. For instance, tadpoles may not have time to develop into frogs before habitats dry out again.

Increased bushfires pose a direct threat to riparian and wetland vegetation and habitats, indirectly to water quality, due to ash and erosion after the removal of fringing vegetation.

Sea level rise

Sea level has increased around the coast, but not by a uniform amount. Sea levels recorded at Fremantle indicate a long-term average rise of 1.5 millimetres each year over 1897 to 2004. More recent shorter-term data from the Hillarys monitoring station indicates a greater increase of about nine millimetres each year between 1991 and 2011.Modelling of future climate scenarios predicts a 100mm increase from 1990 to 2030 for the median case.Aerial photo of the Hardy Estuary

As sea levels rise, low-lying coastal freshwater floodplain and wetland ecosystems are at risk as the incidence of inundation events increases and vegetation has less time to recover after more and more regular flooding by seawater.

Estuaries will be affected by increasing marine influence and changing habitat distribution and quality. Increase in saline habitats, altered sand bar dynamics, shoreline erosion and sediment redistribution due to increased tidal influence and wave height, and changes to stratification within the water column. South-west estuaries are more likely to experience reduced flushing of sediments, nutrients and pollutants as they are affected by both sea level rise and reduced river flows.

Planning for climate change and waterways

Waterways, their habitats and fauna in the south-west are the most vulnerable to climate change, due to the steady and long term decrease in rainfall and streamflow and added population pressures, including increasing demand for water and land development.

The Department of Water takes climate change and its influence on trends into account in the way it manages water resources, including:

  • Assessing water resources and modelling water availability
  • Making decisions about the amount of water that can be taken from surface and groundwater resources
  • Advising about water and land planning and inundation risk
  • Advising about management and restoration of waterways, their floodplains and estuaries.

In 2010, the Department partnered with the National Climate Change and Adaptation Research Facility (NCCARF), Murdoch University and then Department of Environment and Conservation to coordinate a symposium called 'Climate change and Western Australian wetlands and waterways'.

One hundred participants from a range of stakeholders met to review our understanding of the impacts of climate change on our aquatic ecosystems, and then identify adaptation responses, knowledge gaps and barriers.

For further information:

The Western Australian government climate change strategy:  Adapting to our changing climate (Department of Parks and Wildlife 2012).

Page last updated - 09 Jun 2022
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The Department of Water and Environmental Regulation was established by the Government of Western Australia on 1 July 2017. It is a result of the amalgamation of the Department of Environment Regulation, Department of Water and the Office of the Environmental Protection Authority. This website/publication may contain references to previous government departments and programs. Please contact the Department of Water and Environmental Regulation to clarify any specific information.

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