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Table showing target and actual water use, dam levels, streamflow and rainfall
Target Actual
March water use to date

9.7 billion litres

10.4 billion litres
Dam storage levels N/A 52.9%
Monthly streamflow into dams N/A 0 billion litres
March rainfall to date 19.5mm (March average rainfall 1876-2016) 1.8mm
Note: 1 billion litres = approximately 400 Olympic swimming pools. Please note the figures in this table are rounded (except for rainfall) to the nearest whole number.

Water use 

Average water use over the past week was 1,080 million litres per day – above the demand forecast of 969 million litres per day.

Daily water use for the last five days

Table showing daily water use for the last 5 days
Date Actual water use (million litres) Forecast water use (million litres)
11/03/2022 1,180 960
10/03/2022 1,087 960
09/03/2022 1,142 960
08/03/2022 1,034 960
07/03/2022 1,047 980
Note: water use is calculated up to 8am each day for the previous 24 hour period.

Since 1 July 2021 to date, we have used 218.87 billion litres of water – which is 8.38 billion litres above the forecast target for this period.

Dam levels (total for 15 dams)

The dam storage levels are slightly down on last week and are sitting at a combined 52.9 per cent* of full capacity.

*Please note some dams are filled from different sources - dam levels include the transfer of groundwater and desalinated seawater from treatment plants as well as streamflow (that comes from rainfall). As we use many different sources of water, dams are no longer an accurate indicator of the health of Perth's overall water supply situation.

Streamflow (total for 15 dams)

From 1 May 2021, the dams have received 138.7 billion litres of streamflow. The post-1975 average for the May to April period (called the streamflow year) is 177.5 billion litres.

Sprinkler roster compliance

Since 1 January 2022, we have taken a total of 1,470 actions (warnings + fines) compared with 1,200 actions for the same period in 2021.

Annual rainfall

Perth has received 3.4mm of rainfall since 1 January 2022. The average (1876-2016) rainfall for the same period to the end of January is 41.7mm.

General water news

After Perth’s hottest summer on record, including 13 days above 40C, heatwaves are likely to only become more frequent and intense due to climate change.


Our warming and drying climate is also dramatically and irreversibly affecting where we get our water from. We can no longer rely on the rain to meet our water needs and are increasingly dependent on manufactured water – desalinated seawater – which now comprises almost half (45%) of Perth’s drinking water.


WA is the only state in Australia to have two desalination plants and, in the near future, we’ll need a third – either south of the river near Kwinana or in the northern suburb of Alkimos.


Learn more about the seawater desalination process and our existing plants here.