Perth: Key findings

For the water account period 1 July 2020–30 June 2021

  • A relatively dry winter in 2021 resulted in below-average streamflows across the region.
  • End-of-year storage was 42% full, similar to the previous year.
  • Water taken for consumptive water use was 784 GL, almost the same as last year.

Climate and water


Rainfall icon

712 mm

below the average of 794 mm


Streamflow icon

below average

for most of the year


Storage icon

42% full


2% more than last year

Water use

Water sourced

Graph showing breakdown of water sources used in the Perth region. A total of 784 GL of water was used in the region in 2020–21. Groundwater made up about 67% of total water sourced. Desalinated water made up 18%, surface water 15%, and inter-region deliveries less than 1% of the water sourced.

Water supplied

Graph showing breakdown of water users in the Perth region. A total of 784 GL of water was supplied to users in 2020–21. 55% of total water supply was for individual users. 39% was for the urban system and 6% was for the irrigation scheme.

Water status


838 GL

total surface water and groundwater allocations

Water availability

1,286 GL

surface water available in 2020–21


33% less than average



in storage expected during the 2021–22 year