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

23.6 billion litres

22.4 billion litres
Dam storage levels N/A 62.8%
Monthly streamflow into dams N/A 5.47 billion litres
November rainfall to date 22.40mm (November average rainfall 1876-2016) 48.00mm
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 907 million litres per day – below the demand forecast of 940 million litres per day.

Daily water use for the last 5 days

Table showing daily water use for the last 5 days
Date Actual water use (million litres) Forecast water use (million litres)
26/11/2021 993 951
25/11/2021 930 951
24/11/2021 898 951
23/11/2021 819 951
22/11/2021 921 924
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 101.67 billion litres of water – which is 1.98 billion litres below 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 62.8 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 138.1 billion litres of streamflow. The post-1975 average for the May to April period (called the streamflow year) is 178.2 billion litres.

Sprinkler roster compliance

Since 1 January 2021, we have taken a total of 4,987 actions (warnings + fines) compared with 5,192 actions for the same period in 2020.

Annual rainfall

Perth has received 888.4mm of rainfall since 1 January 2021. The average (1876-2016) rainfall for the same period to the end of November is 831.4mm.

General water news

A little-known dam in the Great Southern is basking in the spotlight after being added to WA’s Register of Heritage Places.


AA (Agricultural Area) Dam No.190 James, or simply James Dam for short, is an old Water Corporation dam constructed in 1914 to help provide an adequate water supply to the eastern Wheatbelt.


While not much of a looker, the square dam pioneered new technologies for more efficient water collection. This included an innovative 'roaded catchment', which uses corrugated ridges and furrows to collect and channel rainwater into the dam.


Although not currently operational, inclusion in the State Register will ensure the protection of James Dam’s heritage values for future generations.


James Dam, we salute you!


Read more here.