National Water Account 2021

Urban regions: Overview

  • Average to wet conditions were experienced across most urban regions within southern Australia.
  • Storages in South East Queensland were at their lowest levels in more than 11 years.
  • As at 30 June 2021, storages were full in Canberra and nearly full in Sydney.

 

Climate and Water

Map of southern Australia showing the spatial distribution of relative rainfall in decile categories for 2019–20. Annual rainfall was below average to very much below average across most of southern Australia. Annual rainfall was average to above average over a small area in southeastern Australia, including Melbourne. Key aspects of the rainfall map are described in the text below the figure.
Rainfall across southern Australia during July 2020–June 2021 compared with historical records (1900–2021)

 

  • Average to above-average annual rainfall occurred across much of southern Australia, including most of the urban regions. Sydney and Canberra experienced higher than average rainfall in 2020–21. In contrast, annual rainfall in South East Queensland was below average for sixth consecutive year.
  • Rainfall was mostly average during the 2020–21 financial year with some very wet months that brought the annual rainfall above average.
  • Very heavy rainfall events impacted coastal New South Wales in December 2020 and March 2021.

 

A map showing the location of the 6 urban regions in southern Australia. Line graphs for each of the 6 urban regions show the time series of percentage-full storage volumes between 1 July 2013-30 June 2021. South East Queensland storages at 30 June 2021 were 62% full, more than last year. Sydney storages were 97% full at 30 June 2021, much higher than last year. Canberra storages at 30 June 2021 were 100% full, much higher than last year. Melbourne storages were 75% full at 30 June 2021, higher than last year. Adelaide storages at 30 June 2021 were 48% full, similar to last year. Perth storages at 30 June 2021 were 42% full, similar to last year.
Percentage-full volume during 1 July 2013–30 June 2021 for urban region storages

 

  • Storage volumes in Sydney started to increase following heavy rainfall in early-February 2020. Total storage further increased during 2020-21 to reach a record high. Sydney's largest urban supply dam Warragamba was spilling in March 2021 following heavy rainfall event.
  • Similar to Sydney, Canberra storages remained full for most of 2020–21, with the Cotter dam spilling for months.
  • Storage volumes in South East Queensland, Perth and Adelaide at 30 June 2021 were similar to the previous year.
  • In South East Queensland, storage volumes at 30 June 2020 were at their lowest end-of-year level in more than 11 years, similar to the previous year.
  • In Melbourne, storage volumes increased and reached to the highest levels in last four years.

 

Water sources and supply

Doughnut graph showing total water sourced for urban regions in 2020–21 from different sources. Total water sourced was 2,509 GL. Surface water made up 58% of water sourced, groundwater 25%, desalinated water 12%, and inter-region water 5%. A map showing the location of the 6 urban regions in Australia. Smaller doughnut graphs show the water supplied by source in 2020–21 for each of the 6 urban regions. Surface water made up most of the water sourced in South East Queensland, Sydney, Canberra, Melbourne, and Adelaide. A large part of the surface water supply for Adelaide was from inter-region transfers. Groundwater made up most of the water sourced in Perth.
Total water sourced in the urban regions for 2020–21

 

  • Total water sourced by the urban regions was 2,509 GL.
  • Surface water made up 58% of total water supply and was the predominant source of water in all urban regions except for Perth.
  • In 2020–21, desalinated water made up 12% of total water supply compared to 15% in the previous year. Relatively better conditions during the year, particularly during the latter half of 2020, meant urban utilities opted to reduce their reliance on desalinated water supply to meet urban demand.
  • Groundwater use remained similar to previous year.

 

Doughnut graph showing total water supplied to urban regions in 2020–21 for different users. Total water supplied was 2,509 GL. 73% of water supplied was for the urban system, 24% for individual users, 2% for the irrigation scheme, and less than 1% for inter-region supply. A map showing the location of the 6 urban regions in Australia. Smaller doughnut graphs show the water supplied to users in 2019–20 for each of the 6 urban regions. Most of the water supplied in South East Queensland, Sydney, Canberra, Melbourne, and Adelaide was for the urban system. In Perth, most of the water supplied was to individual users. Water was only supplied to irrigation systems in Adelaide and Perth.
Users of water in the urban regions for 2020–21

 

  • 73% of total water supply in urban regions was used for the urban system.
  • Individual users, including the industrial, commercial and agricultural sectors, accounted for 24% of water supplied.
  • In contrast to other urban regions, more than half of Perth’s water supply was for individual users, primarily for agricultural use.
  • The National Water Account presents the volumes of water supplied to urban systems, irrigation schemes, and individual users for each region. The Bureau's National Performance Report focuses on water supplied to urban systems.

 

Urban water use

Set of stacked vertical bars for six major urban centres in Australia showing the sources of water for the period July 2011–June 2020. Each bar in the stack progressively represents surface water, inter-region inflow, groundwater, and desalinated water. There is a general increasing trend in urban system water supply over the 9-year period for each of the 6 regions. Surface water is the predominant water source in the regions, except for Perth, which is primarily sourced from groundwater and desalinated water. Key aspects of the graph are described in the text below the figure.
Urban system water sources and volumes for years 30 June 2013–30 June 2021

 

  • Total water sourced for the urban systems decreased slightly compared to last year, reflecting wetter conditions and reduced water demand for most of the urban regions.
  • In Sydney, desalinated water use reduced from 13% to 3% following higher rainfall and increased surface water storage volumes.
  • In Melbourne, the contribution of desalinated water to urban supply was a record high 26%. The Melbourne Water Corporation opted to increase its reliance on desalinated water in 2020–21 following the very dry conditions in the previous year.
  • In Perth, low storage inflows following a dry winter in 2020 meant more desalinated water was required to meet urban demand; the region's two desalination plants were run at near capacity, similar to the 3-year period between 2015–2018.
  • In Adelaide, inter-region transfers from the River Murray were 54% of the total water sourced. Inter–region transfers remained the main source of urban supply for the third  consecutive year due to the continued low inflow into the region's storages.