Canberra: Supporting information

For the water account period 01 July 2022 - 30 June 2023

  • Total annual rainfall was the third highest on record, contributing to extremely high runoff and storage inflows across the region.
  • End-of-year storage volume remained unchanged, finishing at 101% full by 30 June 2023 - the third consecutive year where end-of-year storages have finished above 100% full.
  • Approximately, 20% of surface water allocations and 19% of groundwater allocations were taken in 2022-23, all for individual users.

Schematic representation of the Canberra region. In 2022–23, runoff was 110% more than average. Storage volumes at 30 June 2023 were 101% full, much higher than the previous year. 90% of the total surface water accessible (55 GL) was taken. 19% of the total groundwater accessible (2 GL) was taken.

For further information on the region's water accounting statements scroll down this page or click on the links below:

 

Water assets

Aerial cityscape, Canberra region (Bureau of Meteorology © Andrew Terracini)

 

  • Total water asset volumes in the region at 30 June 2023 were 328 GL, 87% of which is water held in surface water storages.
  • Around 12% of the water assets are held in rivers, lakes and wetlands, while the remaining 1% of water assets are part of the urban water supply system.

 

Table S1 Accessible storage volume in the Canberra region over the past six water accounting periods ending 30 June
Surface water 2023 2022 2021 2020 2019 2018
Bendora 11,446 11,446 11,446 9,506 5,038 9,094
Corin 69,283 70,787 70,787 30,332 16,827 23,478
Cotter 79,374 76,374 76,374 60,665 65,247 75,939
Googong 119,409 119,409 119,409 55,439 73,116 86,395
Accessible total 279,512 281,016 281,016 155,942 160,225 194,906
Dead storage 5,058 5,058 5,058 5,058 5,058 5,058
Total storage 284,898 286,074 286,074 161,000 165,284 199,964
Total capacity 282,898 282,898 282,898 282,898 282,898 282,898
% full 101.0% 101.0% 101.0% 57.0% 58.0% 71.0%

 

  • Storage volume remained stable at 101.0% from 30 June 2022 to 30 June 2023. This is the third year running that end-of-year storages have been more than 100%.
  • In 2013, the Cotter Dam was enlarged, increasing the region's total storage capacity to better deal with water demand during periods of drought (see 2013 Account).
  • Due to extraordinary rainfall and flooding in March 2012, the Cotter Dam spilled during construction. In July 2016, the newly constructed dam spilled for the first time.

 

Map of Canberra region showing the status of each storage at 30 June 2022. The storages are colour coded into eleven categories of volume as a proportion of capacity. Canberra storages at 30 June 2022 were 100% full, the same as last year.
Figure S1 Percentage-full volume on 30 June 2023 for each storage and total daily storage volume from 2009–2023 (inset)

  • Storage volume remained at, or near, 100% for the 2022-23 year following the region's wettest three-year period on record.
  • None of the storages fell below 95% throughout the entire year, reflecting the continuous rainfall events which occurred over the region during the 2022-23 year.
  • More detailed information on the individual storages within the region is available on the Bureau of Meteorology's Water Storage website.

 

Water liabilities

Lake Burley Griffin, Canberra region (Bureau of Meteorology © Malcolm Watson)

 

  • Water liabilities in the Canberra region refer to the volume of allocation remaining on licence entitlements at the end of the 2022-23 year.

 

Table S2 Opening and closing balance of surface water allocations for individual users in the Canberra region
Description 2023 2022 2021 2020 2019 2018
Opening balance at 01 July 0 0 0 0 0 0
add Allocation 6,869 9,255 9,255 9,253 8,296 7,669
less Allocated diversion 1,341 782 933 2,784 2,890 2,805
less Adjustment and forfeiture 5,528 8,473 8,322 6,469 5,406 4,864
Closing balance at 30 June 0 0 0 0 0 0

 

Table S3 Opening and closing balance of groundwater allocations for individual users in the Canberra region
Description 2023 2022 2021 2020 2019 2018
Opening balance at 01 July 0 0 0 0 0 0
add Allocation 2,341 4,646 4,698 2,448 2,537 2,537
less Allocated extraction 453 319 549 1,064 763 830
less Adjustment and forfeiture 1.888 4,327 4,149 1,384 1,774 1,707
Closing balance at 30 June 0 0 0 0 0 0

 

  • The water supply licences for the region have a water management year that ends on 30 June. The portion of water allocation that has not been abstracted at the end of the water year is either forfeited or is carried over into the next water year.
  • For individual users and the urban licence entitlement the unused portion of the allocation is assumed to be forfeited and the allocation remaining at the end of the year was 0 ML.
  • A more detailed description of water allocations in the Canberra region is given in the Water use section below.

 

Water flows

Scrivener Dam, Canberra region (Bureau of Meteorology © Andrew Terracini)

 

  • Total water inflows into the Canberra urban region was 1,845 GL, 79% more than last year.
  • Surface water inflows contributed 1,656 GL (90%) of total water inflows, with inflow from outside the region accounting for 43% of the total surface water inflows.
  • Groundwater inflows contributed 92 GL (5%) of total water inflows, with recharge from surface water accounting for 96% of the total groundwater inflows.
  • Urban water inflows contributed 97 GL (5%) of total water inflows, with wastewater collected accounting for 50% of the total urban water inflows.
  • Total water outflows from the Canberra urban region was 2,298 GL, 75% less than last year.
  • Surface water outflows contributed 2,203 GL (96%) of total water outflows, with outflow to outside region accounting for 84% of the total surface water outflows.
  • Groundwater outflows contributed 453 ML (<1%) of total water outflows, with allocated extraction to individual users accounting for 100% of the total groundwater outflows.
  • Urban water outflows contributed 95 GL (4%) of total water outflows, with treated wastewater discharge to surface water accounting for 46% of the total urban water outflows.
  • A more detailed breakdown of inflows and outflows is given in the Statement of Changes in Water Assets and Water Liabilities for the Canberra urban region.

 

Water availability

 

Table S4 Annual surface water available in the Canberra region over the past six water accounting periods ending 30 June
Surface water 2023 2022 2021 2020 2019 2018
Water availability 1,172,766 1,155,790 905,767 324,868 353,376 468,564
Water accessible 55,132 55,140 59,069 65,131 61,554 60,164
Water taken 49,604 46,667 50,747 58,662 56,148 55,300
% water accessible taken 90% 85% 86% 90% 91% 92%

 

  • Physical surface water availability is calculated as the sum of storage volumes at the start of the year (see Water assets) and estimated inflows into storages and rivers during the year.
  • Surface water availability in the Canberra region in 2022-23 was the highest on record, reflecting the region's wettest three year period on records began in 1900. As physical water availability is much higher than the region's water needs, water allocations vary little between years.
  • Surface water accessible is calculated as the sum of surface water allocations and other statutory rights, plus carryover at the start of the year.
  • Water taken during the year is influenced by the physical water available. Typically, water taken from surface water resources is lower than water availability and water accessible. Water taken is 6% more than from last year.
  • During the 2022-23 year, surface water accessible for take and water taken from surface water resources was at its third lowest since 2013-14, likely influenced by the region's saturated catchments, meaning there was less demand for consumptive use during the year.

 

Water use

Evening cityscape, Canberra region (Bureau of Meteorology © Andrew Terracini)

 

Consumptive use

 

Table S5 Surface water taken for consumptive use in the Canberra region over the past six water accounting periods ending 30 June
Surface water 2023 2022 2021 2020 2019 2018
Individual users 1,341 782 933 2,784 2,890 2,805
Urban system 47,768 45,390 49,319 55,383 52,961 52,198
Statutory rights 495 495 495 495 297 297
Total 49,604 46,667 50,747 58,662 56,148 55,300

 

Table S6 Groundwater taken for consumptive use in the Canberra region over the past six water accounting periods ending 30 June
Groundwater 2023 2022 2021 2020 2019 2018
Individual users 453 319 549 1,064 763 830
Statutory rights 0 434 434 435 435 435
Total 453 753 983 1,499 1,198 1,265

 

  • Water taken from surface water and groundwater resources for consumptive use was 50,057 ML, 6% more than last year.
  • Total surface water diverted in the region was 49,604 ML, an increase of 6% from the previous year.
  • Around 96% of the total surface water diverted was for the urban system, while the remaining 4% was supplied to individual users under allocated diversions and statutory rights.
  • Total groundwater extracted in the region was 453 ML, a decrease of 40% from the previous year.
  • All groundwater extractions were for individual users, of all which were allocated extractions. There were no extractions made under a statutory right for this reporting year.

 

Allocations and diversions

 

Table S7 Individual users surface water allocations and diversions in the Canberra region over the past six water accounting periods ending 30 June
Surface water 2023 2022 2021 2020 2019 2018
Individual users
Carryover 0 0 0 0 0 0
Allocated announcements 6,869 9,255 9,255 9,253 8,296 7,669
Allocated diversions 1,341 782 933 2,784 2,890 2,805
% used 20% 8% 10% 30% 35% 37%

 

  • Total surface water allocated (not including urban water supply) in the region during 2022-23 was 6,869 ML, all for individual users.
  • Around 20% of the allocated surface water was taken, which was 71% more than the previous year. This could be attributed to the decrease in rainfall and soil moisture during autumn and winter.

 

Table S8 Individual users groundwater allocations and diversions in the Canberra region over the past six water accounting periods ending 30 June
Groundwater 2023 2022 2021 2020 2019 2018
Individual users
Carryover 0 0 0 0 0 0
Allocated announcements 2,341 4,646 4,698 2,448 2,537 2,537
Allocated extractions 453 319 549 1,064 763 830
% used 19% 7% 12% 43% 30% 33%

 

  • Total groundwater allocated in the region during 2022-23 was 2,341 ML, all for private and commercial use.
  • Around 19% of the allocated groundwater was taken, which was slightly more than last year, but less compared to the previous few years.

 

Urban supply system

 

Table S9 Water sources used in Canberra's urban supply system over the past six water accounting periods ending 30 June
Water sources 2023 2022 2021 2020 2019 2018
Surface water 47,768 45,390 49,319 55,383 52,961 52,198
Total urban water supplied 47,768 45,390 49,319 55,383 52,961 52,198

 

  • Total inflow to the urban water supply system was 47,768 ML, approximately 5% more than the previous year.
  • Surface water diversions from the region's storages accounted for 100% of the urban supply.

 

Water restrictions

Irrigation system (istock © Phillip Minnis)

 

  • Icon Water introduced permanent water conservation measures for potable water use in November 2010, which govern how water can be used on gardens and lawns and for pool filling, car washing, and cleaning.
  • For more information, refer to the Bureau of Meteorology's Water Restrictions website.