Surface water

Surface water plays a very important role in water supply across Western Australia.
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Surface water refers to our streams, rivers, lakes, reservoirs and wetlands.

While the majority of Western Australia's drinking water comes from groundwater, the state's surface water is an important source of drinking water.

A number of rivers and streams throughout Western Australia provide water for public use, as well as being used in irrigation and as a source of recreation and for hydropower.

Surface water monitoring and data

Changes in land use and climate variability can significantly affect surface water resources.

We manage an extensive network of monitoring and reporting activities, including streamflow monitoring and catchment modelling, to determine the quantity and quality of water within a resource.

Our ongoing water monitoring programs and flood studies give us a better understanding of Western Australia's wide range of hydrological conditions.

Free online data

We collect data from more than 300 streamflow gauging stations and 600 rainfall stations throughout Western Australia. Data and reports from these stations are freely available through the Water Information Reporting tool

Current river level advice is available from the Bureau of Meteorology and the Department of Fire and Emergency Services.

Sustainable diversion limits

Sustainable diversion limits are a tool developed to help us make the best water supply decisions in areas where the level of surface water use is low, such as in the south west of Western Australia.

They provide a regional hydrological estimate of the sustainable yield of surface water resources and are used as the hydrological basis in determining surface water extraction volumes.

If you would like to know more about this technique, the following reports provide further detail on the sustainable diversion limit approach.

Surface water hydrology

We have developed detailed surface water hydrology studies for specific areas across Western Australia, using the best hydrological information, to successfully manage and allocate surface water.

The following reports will help you to understand how catchments, geology, land use and climate, influence hydrology throughout the South West region. They will also assist you to understand the methods we use to determine hydrologically available and sustainable volumes of water within a resource.