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

11.2 billion litres

10.4 billion litres
Dam storage levels N/A 62.6%
Monthly streamflow into dams N/A 6 billion litres
October rainfall to date 51.5 mm (October average rainfall 1876-2016) 45.6 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 703 million litres per day – below the demand forecast of 761 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)
15/10/2021 667 773
14/10/2021 676 773
13/10/2021 732 773
12/10/2021 686 773
11/10/2021 775 743
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 68.32 billion litres of water – which is 1.11 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 62.6 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 122.8 billion litres of streamflow. The post-1975 average for the May to April period (called the streamflow year) is 178.7 billion litres.

Annual rainfall

Perth has received 763.2 mm of rainfall since 1 January 2021. The average (1876-2016) rainfall for the same period to the end of October is 809 mm.

General water news

October is Mental Health Month, and this week at Water Corporation we’ve been focusing on how we can look after our minds and mental wellbeing on a daily basis.


Today, our CEO Pat Donovan painted one of the trees at our Balcatta office blue, to help spark difficult conversations and encourage people to speak up when battling mental health concerns.


Having a positive workplace culture is a priority for Water Corporation, and since 2017 we have been actively working to minimise risks related to mental health and improve support for people with mental health conditions.


In October 2020, we commenced our Mental Health Champions program in partnership with mental health provider, Blooming Minds. The goal was to recruit and train approximately 100 employees to become Mental Health Champions – individuals who can play an active role in building a positive culture and helping people thrive in the workplace.


As of August 2021, Water Corporation now has 173 Mental Health Champions, representing a wide cross-section of the business, regional areas, and job levels. In 2022, a further 100 employees will be trained as a Mental Health Champions, to continue building and supporting a positive mental health culture for our employees and the wider community.