National Water Account 2020

Urban regions: Overview

  • Dry conditions were experienced across most urban regions within southern Australia.
  • Storages in South East Queensland were at their lowest levels in more than 10 years.
  • Storage volumes in Sydney increased due to very high rainfall in February 2020.

 

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 2019–June 2020 compared with historical records (1900–2020)

 

  • Below-average annual rainfall occurred across much of southern Australia, including most of the urban regions. Annual rainfall in South East Queensland was below average for the fifth consecutive year.
  • In contrast, Melbourne was one of the few regions in Australia that experienced above-average rainfall.
  • Rainfall was very low during the latter half of 2019 due to a positive phase of the Indian Ocean Dipole, one of the strongest on record, that influenced Australia's climate during this period (see the Bureau's 2019–20 Climate Report for more information).
  • There was some rainfall relief during the early part of 2020, including very heavy rainfall associated with a coastal trough that impacted the east coast in February 2020.

 

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 2020. South East Queensland storages at 30 June 2020 were 60% full, less than last year. Sydney storages were 79% full at 30 June 2020, much higher than last year. Canberra storages at 30 June 2020 were 56% full, similar to last year. Melbourne storages were 66% full at 30 June 2020, higher than last year. Adelaide storages at 30 June 2020 were 50% full, similar to last year. Perth storages at 30 June 2020 were 41% full, less than last year.
Percentage-full volume during 1 July 2013–30 June 2020 for urban region storages

 

  • Storage volumes in Sydney increased following heavy rainfall associated with a coastal trough that crossed the region in early-February 2020. Total storage almost doubled in 10 days between 8–18 February 2020; the first significant rise in storage since June 2016.
  • Despite below-average annual rainfall, storage volumes in Canberra and Adelaide at 30 June 2020 were similar to the same time last year due to higher rainfall in the first half of 2020.
  • In South East Queensland, storage volumes at 30 June 2020 were at their lowest end-of-year level in more than 10 years.
  • In Perth, storage volumes decreased for the first time in four years. This decrease was influenced by low storage inflows following a relatively dry winter in 2019.

 

Water sources and supply

Doughnut graph showing total water sourced for urban regions in 2019–20 from different sources. Total water sourced was 2,633 GL. Surface water made up 57% of water sourced, groundwater 17%, desalinated water 15%, and inter-region water 4%. A map showing the location of the 6 urban regions in Australia. Smaller doughnut graphs show the water supplied by source in 2019–20 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 2019–20

 

  • Total water sourced by the urban regions was 2,633 GL.
  • Surface water made up 57% of total water supply and was the predominant source of water in all urban regions except for Perth.
  • In 2019–20, desalinated water made up 15% of total water supply compared to 5% last year. The very dry conditions during the year, particularly during the latter half of 2019, meant urban utilities opted to reduce pressure on their surface water resources and increase their reliance on desalinated water supply to meet urban demand.

 

Doughnut graph showing total water supplied to urban regions in 2019–20 for different users. Total water supplied was 2,633 GL. 72% of water supplied was for the urban system, 25% for individual users, 3% 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 2019–20

 

  • 72% of total water supply in urban regions was used for the urban system.
  • Individual users, including the industrial, commercial and agricultural sectors, accounted for 25% 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 2012–30 June 2020

 

  • Total water sourced for the urban systems was similar to last year, reflecting similar dry conditions across most of Australia.
  • In Sydney, desalinated water made up 13% of urban supply, the highest contribution since 2010–11. The desalination plant operated at full capacity between December 2019–February 2020 when Level 2 water restrictions were in place.
  • In Melbourne, the contribution of desalinated water to urban supply was the highest it's ever been. The Melbourne Water Corporation opted to increase its reliance on desalinated water in 2019–20 following the very dry conditions in the previous year.
  • In Perth, low storage inflows following a dry winter in 2019 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 the main source of urban supply for the second consecutive year due to the continued low inflows into the region's storages.