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Bureau Home » Water Information » National Water Account » 2023 Account » Perth » Water Accounting Statements » Water assets and water liabilities

Perth: Statement of Water Assets and Water Liabilities

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

  • Water availability in the Perth region's storages decreased during 2022–23.
  • Water availability is represented by the net water assets, which are the volume of water assets minus the water liabilities.

Schematic representation of the Perth region. Total water assets at 30 June 2023 was 467 GL. Total water liabilities was 142 GL. Closing net water assets at 30 June 2023 was 324 GL, 10% less than last year.

The Statement of Water Assets and Water Liabilities is provided in the table below.
The statement presents the volume of water assets, and water liabilities at the start and end of the reporting year.

 

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  2023 (ML) 2022 (ML) 2021 (ML) 2020 (ML) 2019 (ML) 2018 (ML)
Water assets
Surface water 439,849 471,625 365,461 360,126 416,977 391,306
Accessible storage 414,904 446,663 339,106 332,479 388,080 364,455
Dead storage 23,098 23,098 23,098 23,098 23,098 23,098
Rivers 1,847 1,864 3,257 4,549 5,799 3,753
 
Groundwater – – – – – –
Aquifers – – – – – –
 
Irrigation scheme 26,864 29,864 31,798 31,831 40,634 38,141
Claims: surface water* 26,864 29,864 31,798 31,831 40,634 38,141
 
Total water assets 466,713 501,489 397,259 391,957 457,611 429,447
Water liabilities
Surface water liability 38,382 39,873 40,320 40,353 49,156 46,663
Surface water allocation remaining: individual users 10,009 10,009 8,522 8,522 8,522 8,522
Surface water allocation remaining: irrigation scheme* 28,373 29,864 31,798 31,831 40,634 38,141
 
Groundwater liability 104,182 102,352 102,376 102,377 102,377 102,377
Groundwater allocation remaining: individual users 104,182 102,352 102,376 102,377 102,377 102,377
 
Total water liabilities 142,564 142,225 142,696 142,730 151,533 149,040
Net water assets
Net surface water assets 401,467 431,752 325,141 319,773 367,821 344,643
Opening net surface water assets 431,752 325,141 319,773 367,821 344,643 249,381
Net change surface water assets (30,285) 106,611 5,368 (48,048) 23,178 95,263
Closing net surface water assets 401,467 431,752 325,141 319,773 367,821 344,643
 
Net groundwater assets (104,182) (102,352) (102,376) (102,377) (102,377) (102,377)
Opening net groundwater assets (102,352) (102,376) (102,377) (102,377) (102,377) (102,376)
Change in net groundwater assets (1,830) 24 1 0 0 (1)
Closing net groundwater assets (104,182) (102,352) (102,376) (102,377) (102,377) (102,377)
 
Net irrigation water assets 26,864 29,864 31,798 31,831 40,634 38,141
Opening net irrigation water assets 29,864 31,798 31,831 40,634 38,141 41,081
Change in net irrigation water assets (3,000) (1,934) (33) (8,803) 2,493 (2,940)
Closing net irrigation water assets 26,864 29,864 31,798 31,831 40,634 38,141
Total closing net water assets 324,149 359,264 254,563 249,227 306,078 280,407
Total change in net water assets (35,115) 104,701 5,336 (56,851) 25,671 92,321

*between-store claims / liabilities

Note: quantification approaches used to derive each item volume are provided in the Methods