Bureau Home » Water Information » National Water Account » 2018 Account » Perth » Water Accounting Statements » Changes in Water Assets and Water Liabilities

National Water Account 2018


Perth: Statement of Changes in Water Assets and Water Liabilities

  • Water availability in the Perth region increased during 2017–18 for the second year in a row.
  • The change in water available is represented by the change in net water assets.

The Statement of Changes in Water Assets and Water Liabilities is provided in the table below. The statement presents the changes in water assets and water liabilities that occurred during the year, including accrual transactions (e.g. allocations and forfeitures) and actual water flows, both natural and engineered.

 

Expand all Collapse all
 

Select comparative year

 2018 ML2017 ML2016 ML2015 ML2014 ML2013 ML
Water asset increases
Surface water increases1,374,9441,782,956778,502937,2891,154,779602,345
Precipitation55,87737,45316,82421,23825,00917,978
Runoff749,192840,406352,148549,983787,143389,858
Delivery: inter-region00**0**0**0**0
Inter-region inflow132,914444,08369,756–––
Flood return10,67419,919––––
Groundwater discharge*339,369339,166256,534291,896283,158179,752
Discharge: urban supply*84,49699,858**81,104**72,130**56,936**43,378
Riparian release: urban supply*2,4222,071**2,136**2,042**2,533**1,379
 
Groundwater increases1,780,1341,637,7151,236,0221,372,6932,013,9871,266,864
Inter-region inflow45,77545,72447,47545,21852,78848,940
Inter-region coastal inflow000000
Recharge: landscape1,701,6021,567,1011,165,1061,304,5301,937,9321,194,424
Leakage: urban system*24,27023,43121,87321,15521,00520,583
Managed aquifer recharge*8,4871,4591,568**1,790**2,262**2,917
 
Urban water system increases694,320694,157 688,344 639,119 636,209 633,223
Wastewater collected141,185140,439138,858140,771141,024136,938
Supply system delivery: inter-region1,7951,8321,9531,9222,1211,939
Delivery: desalinated water148,904149,872138,645119,457113,06095,770
Claims: surface water*247,950247,950247,950247,950247,950248,117
Claims: groundwater*154,486154,064160,938129,019132,054151,005
 
Irrigation scheme increases107,42097,565100,850113,990113,99094,280
Claims: surface water*107,42097,565**100,850**113,990**113,990**94,280
Total water asset increases3,956,8184,212,3932,803,7183,063,0913,918,9652,596,712
Water liability decreases
Surface water liability decreases200,002189,224192,322172,804183,581158,536
Adjustment and forfeiture: individual users29221504,0455,219272
Adjustment and forfeiture: urban system*162,319156,624146,746128,301142,071158,264
Adjustment and forfeiture: irrigation scheme*37,39132,579**45,526**40,458**36,2910
 
Groundwater liability decreases31,17727,00732,81520,52821,37543,866
Adjustment and forfeiture: individual users8,63912,5418,75513,63714,17232,483
Adjustment and forfeiture: urban system*22,53814,46624,0606,8917,20311,383
 
Total water liability decreases231,179216,231225,137193,332204,956202,402
Water asset decreases
Surface water decreases1,422,0191,560,606225,475427,127589,186234,838
Evaporation57,41748,59128,91246,05233,60028,719
Outflow1,185,6131,221,652196,413380,925555,390205,977
Leakage: landscape150150150150196142
River losses114,471238,759––––
Overbank flow64,36851,454––––
 
Groundwater decreases1,153,5631,090,188925,1491,034,3041,361,5591,033,038
Inter-region outflow19,52319,35021,86323,43930,16427,056
Inter-region coastal outflow290,714261,169**233,290**261,245**352,251306,260
Discharge: landscape422,166389,247332,617378,114622,737447,397
Non-allocated extraction: individual users81,79181,25680,84579,61073,24972,573
Discharge: surface water*339,369339,166256,534291,896283,158179,752
 
Urban water system decreases686,612685,591688,798638,680636,362633,356
Supply system delivery: urban users227,634224,799263,200232,537234,774232,315
Recycled water delivery: urban users4,6988,6229,0958,0358,2030
Discharge: sea118,202119,190123,163125,025124,900120,293
Discharge: landscape4,4655,7346,1455,9625,6735,338
Supply system transfer: inter-region18,56320,88327,92324,79620,79729,010
Other supply system decreases8,5188,4548,78510,01610,0058,407
Leakage: groundwater*24,27023,43121,87321,15521,00520,583
Supply system discharge: reservoirs*84,49699,858**81,104**72,130**56,936**43,378
Supply system discharge: riparian release*2,4222,071**2,136**2,042**2,533**1,379
Managed aquifer recharge*8,4871,4591,568**1,790**2,262**2,917
Claims: surface water*162,319156,624146,746128,301142,071158,264
Claims: groundwater*22,53814,46624,0606,8917,20311,383
 
Irrigation scheme decreases111,68891,956116,183104,987109,29857,167
Delivery54,05943,456**53,456**52,397**56,310**41,808
Leakage: landscape20,23815,921**17,201**12,131**16,697**13,359
Claims: surface water*37,39132,579**45,526**40,458**36,2910
 
Total water asset decreases3,373,8823,428,3412,022,9442,285,7342,778,1531,958,399
Water liability increases
Surface water liability increases393,825384,388387,642400,496395,898376,283
Allocation: individual users38,45538,87338,84238,55633,95833,886
Allocation: urban system*247,950247,950247,950247,950247,950248,117
Allocation: irrigation scheme*107,42097,565**100,850**113,990**113,990**94,280
 
Groundwater liability increases462,646453,098467,609416,772419,316435,525
Allocation: individual users308,160299,034306,671287,753287,262284,520
Allocation: urban system*154,486154,064160,938129,019132,054151,005
 
Total water liability increases856,471837,486855,251817,268815,214811,808
 
Unaccounted-for difference342,004**(8,818)**(381,211)**(280,035)**(224,225)**(186,048)
 
 
Change in net water assets      
Change in net surface water assets95,64629,293 (58,625) (13,603)90,074 (93,493)
Change in net groundwater assets206,942118,977 (90,817) (39,846) 294,274 (263,779)
Change in net urban water assets00 0 0 (119) 0
Change in net irrigation scheme water assets(2,940)5,709 (13,770)7,4723,84837,822 
Total change in net water assets299,648153,979 (163,212) (45,977) 388,077 (319,450)
 

* between-store flows

** different to published volume in historical accounts (see Governance section for more information)