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

33.8 billion litres

34.3 billion litres
Dam storage levels N/A 54.9%
January streamflow into dams N/A 0.3 billion litres
January rainfall to date 9.7mm (January average rainfall 1876-2016) 0mm
Note: 1 billion litres = approximately 400 Olympic swimming pools.
* Data in table is current to 30 January 2023

Water use 

 
Week ending Daily average use
(million litres per day)
Daily average forecast  
(million litres per day)
28/01/2023 1,132 1,091
21/01/2023 1,122 1,094
14/01/2023 1,056 1,092
07/01/2023 1,082 1,046
Note: Average water use is calculated based on 7 days of data, from Sunday 1 January through to Friday 28 January, 2023.

Since 1 July 2022 to date, the Integrated Water Supply Scheme (IWSS)* has supplied 174 billion litres of water - which is 7 billion litres below the forecast target for this period.

*The IWSS supplies Perth, the Goldfield and Agricultural Region and some parts of the South West.

Dam levels (total for 15 dams)

January's* metro dam storage levels are slightly down from December and are sitting at a combined average of 54.9 per cent* of full capacity (or 346 billion litres). This time last year our metro dam storage levels were at 55.8 per cent* of full capacity (or 352 billion litres).

 

*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 2022, the dams have received 93 billion litres of streamflow. The post-1975 average for the May to April period (called the streamflow year) is 175.5 billion litres.   

Annual rainfall

Perth has received 0mm of rainfall since 1 January 2023. The average (1876-2016) rainfall for the same period to the end of January is 9.7mm. 

Temperature

The maximum temperature this month was recorded on 21 January at 39.5°C. The coolest day was recorded on 16 January at a maximum of just 25.1°C.