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

15.7 billion litres

16.2 billion litres
Dam storage levels N/A 61.7%
Monthly streamflow into dams N/A 15.5 billion litres
September rainfall to date 81.0mm (September average rainfall 1876-2016) 43.9mm
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 687 million litres per day – above the demand forecast of 677 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)
24/09/2021 705 687
23/09/2021 713 687
22/09/2021 728 687
21/09/2021 695 687
20/09/2021 690 662
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 54.01 billion litres of water – which is 2.15 billion litres above the forecast target for this period.

Dam levels (total for 15 dams)

The dam storage levels are slightly up on last week and are sitting at a combined 61.7 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 112.8 billion litres of streamflow. The post-1975 average for the May to April period (called the streamflow year) is 178.4 billion litres.

Sprinkler roster compliance

Since 1 January 2021, we have taken a total of 4,507 actions (warnings + fines) compared with 4,410 actions for the same period in 2020.

Annual rainfall

Perth has received 699.3mm of rainfall since 1 January 2021. The average (1876-2016) rainfall for the same period to the end of September is 757.5mm.

General water news

Quinns Mindarie Surf Life Saving Club can lay claim to being among Perth’s most waterwise sporting clubs after receiving a $4,800 Water Corporation waterwise retrofit.


The new water-efficient tapware, showerheads, and toilet cisterns are expected to save the club more than 450,000 litres of water each year – equivalent to nearly 12 swimming pools.


The retrofit was delivered following a recent project to upgrade 1.4km of wastewater pipeline along Rochester Drive, Fairport Vista, and Rosslare Promenade in Mindarie.


Read more here.