May water use to date

17 billion litres

18 billion litres

Dam storage levels


45 per cent

Weekly streamflow into dams


1 billion litres

May rainfall to date

88.7 mm

(May average rainfall 1994-2017)


116.9 mm

(May average rainfall 1876-2016)

17.8 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 last week was 709,000,000 litres (709 million litres) per day, which was above the forecast of 686,000,000 litres (686 million litres).


Daily water use for the last five days


Actual water use – litres

Forecast – litres
















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


Since 1 July 2018, we have used 264 billion litres of water - this is about four billion litres above what we had forecast. 


Dam level (total for 15 dams)


The dam storage levels have remained stable this week and is sitting at 45 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 1.1 billion litres of streamflow.  The post-1975 average for the May to April period is 187.2 billion litres.


Sprinkler roster compliance


The two-day-a-week sprinkler roster now applies across Perth, so make sure your sprinklers are programmed for your rostered water days and only to come on once, either before 9am or after 6pm.


Our team of inspectors issued 43 warnings and 43 fines this week.  Since 1 January 2019, we have taken a total of 3455 actions (warnings + fines) compared with 3510 actions for the same period in 2018.


Annual rainfall


Perth has received 75.60 mm of rainfall since 1 January 2019.  The cumulative average (1994-2017) rainfall for the January to May period is 176.6 mm.


General water news


With Perth enjoying cooler temperatures as we head into winter, it is the perfect time of year to visit one of the many dams we manage in the Perth Hills area.


Dams to visit include the iconic Mundaring Weir as well as Canning Dam, where you can meander down the walk trail and go past historic features such as the old contour channel. Wungong Dam is also an amazing spot, as it is full of native birds and has stunning views.


We encourage people to enjoy these beautiful sites, but we ask visitors to remember they are near an important drinking water source, so please help keep our important drinking water clean and protect the environment. Click here for more information.

Media Enquiries:

Contact: Media team

Phone: (08) 9420 2555