Table showing target and actual water use, dam levels, streamflow and rainfall
Target Actual
December water use to date 17.8 billion litres
17.1 billion litres
Dam storage levels N/A 48.9 per cent
Monthly streamflow into dams N/A 0.69 billion litres
December rainfall to date 13.1mm (December average rainfall 1876-2016) 4.4mm
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 963 million litres per day, which was below the forecast of 1,004 million litres.

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)
18/12/2020 978 1,012
17/12/2020 985 1,012
16/12/2020 953 1,012
15/12/2020 904 1,012
14/12/2020 899 993
Note, water use is calculated up to 8am each day for the previous 24 hour period.

Since 1 July 2020, we have used 121.18 billion litres of water – which is 2.85 billion litres below the forecast target for this period.

Dam levels (total for 15 dams)

The dam storage levels have decreased slightly this week and are sitting at a combined 48.9 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 2020 the dams have received 42.9 billion litres of streamflow. The post-1975 average for the May to April period (called the streamflow year) is 176.73 billion litres.

Sprinkler roster compliance

Since 1 January 2020, we have taken a total of 5,630 actions (warnings + fines) compared with 9,240 actions for the same period in 2019.

Annual rainfall

Perth has received 677.8mm of rainfall since 1 January 2020. The average (1994-2019) rainfall for the same period to the end of November is 727.2mm.

General water news

Did you know that showers make up almost 22 per cent of total household water use? One of the most effective ways to reduce consumption is by limiting showers to less than four minutes and installing water-efficient showerheads.


Well, <drum roll>, Perth and Mandurah residents now have the opportunity to exchange their old inefficient showerheads for stylish waterwise alternatives under a new program.


Already available in some regional communities, Water Corporation’s Showerhead Swap program is being extended to metropolitan households, allowing them to replace up to two inefficient fixtures with WELS 4-star rated showerheads for free.


The program could reduce water consumption in an average Perth household by 20,000 litres a year, potentially saving around 92 million litres of precious water in total.


Find out how to apply on the Metro Showerhead Swap page.