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

0.2 billion litres

1.3 billion litres
Dam storage levels N/A 43.8%
Monthly streamflow into dams N/A 0 billion litres
July rainfall to date 167.70 mm (July average rainfall 1876-2016) 1.40 mm
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 646 million litres per day – above the demand forecast of 608 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)
02/07/2021 646 607
01/07/2021 N/A N/A
30/06/2021 630 584
29/06/2021 656 584
28/06/2021 610 607
Note, water use is calculated up to 8am each day for the previous 24 hour period.

Since 1 July 2021, we have used 0.65 billion litres of water – which is 0.04 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 43.8 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 2.9 billion litres of streamflow. The post-1975 average for the May to April period (called the streamflow year) is 175.58 billion litres.

Sprinkler roster compliance

Since 1 January 2021, we have taken a total of 3,501 actions (warnings + fines) compared with3,315 actions for the same period in 2020.

Annual rainfall

Perth has received 330.6 mm of rainfall since 1 January 2021. The average (1876-2016) rainfall for the same period to the end of July is 543.6mm.

General water news


Did you know Water Corporation supports the State Government’s response to COVID-19 by undertaking wastewater sampling at its wastewater treatment plants (WWTP) across Perth?


The wastewater testing program is a collaboration between the Department of Health, PathWest, the WA Country Health Service, and of course, Water Corporation!


Weekly testing has been ongoing since November 2020 at six of Perth’s wastewater treatment plants – Subiaco, Woodman Point, Alkimos, Beenyup, Gordon Road and Point Peron – as well as at 10 localities in regional WA.


The wastewater testing program acts as an early warning surveillance initiative to monitor the virus in the community. It’s important to note however that the virus is not ‘alive’ in wastewater, and presents no public health risk.


As a result of this week’s lockdown, the Department of Health asked us to increase sampling from once to thrice weekly at all six WWTP sites. You may have seen on Nine News last night one of our operators taking a wastewater sample at the Alkimos WWTP. If you missed it, check out the footage here.


For more information about COVID-19 wastewater testing in WA, please visit the Department of Health website here.