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

21.6 billion litres

21.4 billion litres
Dam storage levels N/A 50.9%
Monthly streamflow into dams N/A 0 billion litres
May rainfall to date 116.9mm (May average rainfall 1876-2016) 83.6mm
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 671 million litres per day – below the demand forecast of 722 million litres per day.

Daily water use for the last five days

Table showing daily water use for the last 5 days
Date Actual water use (million litres) Forecast water use (million litres)
26/05/2022 TBC 710 
25/05/2022 692  710
24/05/2022 623  710
23/05/2022 638  731
22/05/2022 735  731
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 283.21 billion litres of water – which is 9.96 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 50.9 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 2022, the dams have received 0.0 billion litres of streamflow. The post-1975 average for the May to April period (called the streamflow year) is 177.1 billion litres. 

Sprinkler roster compliance

Since 1 January 2022, we have taken a total of 2,174 actions (warnings + fines) compared with 2,274 actions for the same period in 2021.

Annual rainfall

Perth has received 166.4mm of rainfall since 1 January 2022. The average (1876-2016) rainfall for the same period to the end of May is 202.8mm.

General water news

Five billion litres of water. That’s how much Perth and Peel households can save by switching off their garden irrigation in winter, which is enough to fill Optus Stadium five times.


Next Wednesday (1 June) is the deadline for the Winter Sprinkler Switch-Off, when residents in Perth, Peel, and parts of the South West and Great Southern must turn off their sprinklers from 1 June to 31 August.


Introduced as a permanent water efficiency measure in 2010, the annual switch-off saves around five billion litres of precious drinking water annually, and close to 55 billion litres to date.


Adopting water-saving practices is vital as climate change impacts rainfall levels. Since the 1970s, long-term average rainfall has declined by around a fifth, leading to an 80 per cent reduction in rainfall run-off (streamflow) to metropolitan dams. 


Using sprinklers during the switch-off can result in a $100 fine if witnessed by a Water Corporation inspector, or a written warning if reported by a member of the public.


The switch-off applies to scheme and bore water users, in addition to many licensed groundwater users. Hand watering and some exemptions apply. In areas of the State not subject to the ban, normal watering rosters and the daytime sprinkler ban still apply.


To find out if you are included in the switch-off, please visit here.


For details on how the switch-off applies to bore and licensed water users, please visit here.