Perth metro weekly water update – 17 May 2019





May water use to date

12 billion litres

13 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)

11.4 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 762,000,000 litres (762 million litres) per day, which was above the forecast of 709,000,000 litres (709 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 259 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 0.7 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 60 warnings and 28 fines this week.  Since 1 January 2019, we have taken a total of 3369 actions (warnings + fines) compared with 3510 actions for the same period in 2018.


Annual rainfall


Perth has received 69.2 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


We are now in the final weeks of the two-day-a-week sprinkler roster, a permanent water efficiency measure the Perth community has been successfully following for nearly two decades.


Fines and warnings for breaching the roster were down from last week, which is great news, with only 28 fines and 60 warnings across the metropolitan area.


Now we are getting some rain and cooler temperatures, remember to turn your sprinklers off altogether when it has rained, or rain is forecast.


……….and the big Winter Sprinkler Switch-Off is just around the corner!

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