Check dam volumes and rainfall and find out how declining rainfall is affecting the amount of water (streamflow) flowing into our dams. In this section you can also learn where our water comes from and how our water use is tracking.

Our water overview

Updated: Sunday, 26 June 2022 Learn more about how this data is updated

To 9am

0.00

mm

May total

May average*

32.20

mm

88.70

mm

Current

42.5%

268 GL

Last year

45%

284 GL

Change

5.7%

-16.2 GL

* Average monthly rainfall (for the period 1876 - 2016).
Dam volumes, rainfall and water use data is updated every working day, streamflow is updated weekly.

How declining rainfall impacts our water supply

We need steady, regular rain in order to soak our catchments and get water flowing into our dams. Slowly declining rainfall means Perth's dams receive much less streamflow than in past years. Streamflow is the amount of water entering our dams from our catchments and is measured by changing water storage levels.

The water in our dams is no longer just made up of inflows from rain. Groundwater and desalinated water are stored in these dams during periods of low demand so it is available when it is most needed in the hotter months.

Learn more about how the impact of climate change continues to affect rainfall, the streams that flow into our dams and water use.

How climate change is impacting our water sources

Water sources for our largest scheme, the Integrated Water Supply Scheme (IWSS) which supplies Perth, the Goldfields and Agricultural Region and some parts of the South West have changed dramatically. Water for the IWSS is now comprised of a combination of sources, including desalinated seawater, groundwater, groundwater replenishment and streamflow into dams.

Traditionally, Perth relied heavily on streamflow into our dams as a water source, but declining streamflow has meant dams now play a bigger role as storage reservoirs. The water in our dams is no longer just made up of inflows from rain. Groundwater and desalinated water are stored in these dams during periods of low demand so it is available when it is most needed in the hotter months.

How Perth's water sources have changed

Perth's water sources at a glance

In 2020-21 the breakdown of Perth's water sources (IWSS) consisted of:

Desalination icon
%
Desalination
Groundwater icon
%
Groundwater
Dams icon
%
Dams
Groundwater replenishment icon
%
Groundwater replenishment

 

Latest dams & rainfall news

17 Jun 2022 | Media Release

Perth Weekly Water Update - 17 June 2022

Latest metro water use, dam levels, streamflow and rainfall data.

  • Climate change
  • Dams
  • Water sources
13 Jun 2022 | Media Release

New species of freshwater sponge discovered in Wyndham

A new species of freshwater sponge has been discovered in Wyndham. This is the first time the genus has been reported in Australia.

  • Dams
  • Environment
  • North West