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May water use to date

6 billion litres

6 billion litres

Dam storage levels


42 per cent

Weekly streamflow into dams


44 billion litres

May rainfall to date

88.7 mm

(May average rainfall 1994-2017)

32.2 mm

Note: 1 billion litres = approx. 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 786 million litres per day, which was above the forecast of 755 million litres.


Daily water use for the last five days


Actual water use (million litres)

Forecast (million litres)
















Note: water use is calculated up to 8am each day for the previous 24 hour period


Since 1 July 2019, we have used 263.1 billion litres of water – which is 6.6 billion litres over the forecast for this period.


Dam level (total for 15 dams)

The dam storage levels have dropped slightly this week and are sitting at a combined 42.3 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 2019 the dams have received 44.1 billion litres of streamflow.  The post-1975 average for the May to April period (called the streamflow year) is 183.9 billion litres.


Sprinkler roster compliance


The two-day a week sprinkler roster now applies. Since 1 January 2020, we have taken a total of 2313 actions (warnings + fines) compared with 3455 actions for the same period in 2019.


Annual rainfall


Perth has received 113.60 mm of rainfall since 1 January 2020. The average (1994-2017) rainfall for the May period is 176.6 mm.


General water news


Water Corporation will soon start stage two of work to replace century old water mains in the heart of Fremantle to help futureproof water supply in the area for decades to come. 


The essential work will start on 19 May and will be carried out in short stages to ensure each individual street will only be impacted for a maximum of six weeks.


Work will start on High Street and will then progress to Essex Street, Essex Lane, Leake and Cantonment Street, Marine Terrace from Cliff to Essex streets, Nairn Street, Norfolk Street and finishing on Marine Terrace from Essex to Suffolk streets.


Since 2016, our Pipes for Perth program has replaced more than 160 kilometres of water mains across Perth.


For more info, visit


Media Enquiries:

Contact: Media Team

Phone: (08) 9420 2555