Perth
Water resources and systems

Introduction

The following set of notes provides water accounting statements for each of the water stores and systems within the Perth region during the 2013–14 year. Information on all water flows to and from each water store and system are presented in this note, including between-store flows and transfers that are not presented in the consolidated water accounting statements (which are shown in italics).

For more information about the region, please refer to the General description section of the 'Contextual information'. For more information on between-store flows and transfers that occur in the region, please refer to the Supporting information note.

 

Surface water

 

Table 1  Statement of Water Assets and Water Liabilities as at 30 June 2014 for the surface water store
Water assets2014
(ML)		2013
(ML)
Surface water  
Storages204,898159,492
Unregulated river––
Regulated river––
Lakes and wetlands––
Total surface water assets204,898159,492
   
Water liabilities  
Surface water liability  
Surface water allocation remaining: individual users12,58717,709
Surface water allocation remaining: urban water system0119
Surface water allocation remaining: irrigation scheme12,7186,510
Total surface water liabilities25,30524,338
   
Opening net water assets135,154168,970
Change in net water assets44,439(33,816)
Closing net water assets179,593135,154

 
Table 2  Statement of Changes in Water Assets and Water Liabilities for the year ended 30 June 2014 for the surface water store
Water asset increases2014
(ML)		2013
(ML)
Surface water increases  
Precipitation on surface water25,00917,978
Groundwater discharge283,158179,752
Runoff to surface water787,143359,858
Point return from irrigation scheme––
Delivery of water from outside region2,5391,824
Discharge from urban water system59,46944,757
Total surface water increases1,157,318604,169
   
Water liability decreases  
Surface water liability decreases  
Adjustment and forfeiture of surface water allocation: individual users5,219272
Adjustment and forfeiture of surface water allocation: urban water system142,071158,264
Adjustment and forfeiture of surface water allocation: irrigation scheme5,8070
Total surface water liability decreases153,097158,536
   
Water asset decreases  
Surface water decreases  
Evaporation from surface water33,60028,719
River outflow from the region555,390205,977
Groundwater recharge00
Leakage to landscape196142
River and floodplain leakage, evaporation and errors––
Total surface water decreases589,186234,838
   
Water liability increases  
Surface water liability increases  
Surface water allocation announcements: individual users33,95833,886
Surface water allocation announcements: urban water system247,950248,117
Surface water allocation announcements: irrigation scheme46,48128,420
Total surface water liability increases328,389310,423
   
Balancing item—surface water348,401251,260
   
Change in net water assets44,439(33,816)

 

Table 3  Statement of Water Flows for the year ended 30 June 2014 for the surface water store
Water inflows2014
(ML)		2013
(ML)
Surface water inflows  
Precipitation on surface water25,00917,978
Groundwater discharge283,158179,752
Runoff to surface water787,143359,858
Point return from irrigation scheme––
Delivery of water from outside region2,5391,824
Discharge from urban water system59,46944,757
Total surface water inflows1,157,318604,169
   
Water outflows  
Surface water outflows  
Evaporation from surface water33,60028,719
River outflow from the region555,390205,977
Groundwater recharge00
Leakage to landscape196142
River and floodplain leakage, evaporation and errors––
Entitled diversion of allocated surface water to users33,86130,817
Entitled diversion of allocated surface water to urban water system105,99889,853
Entitled diversion of allocated surface water to irrigation scheme34,46621,910
Total surface water outflows763,511377,418
   
Balancing item—surface water348,401250,555
   
Opening water storage159,492184,001
Change in water storage45,406(24,509)
Closing water storage204,898159,492

 

 

Groundwater

 

Table 4  Statement of Water Assets and Water Liabilities as at 30 June 2014 for the groundwater store
Water assets2014
(ML)		2013
(ML)
Groundwater  
Water table aquifer––
Underlying aquifers––
Total groundwater assets––
   
Water liabilities  
Groundwater liability  
Groundwater allocation remaining: individual users116,430124,858
Groundwater allocation remaining: urban water system00
Total groundwater liabilities116,430124,858
   
Opening net water assets(124,858)(147,367)
Change in net water assets8,42822,509
Closing net water assets(116,430)(124,858)

 

Table 5  Statement of Changes in Water Assets and Water Liabilities for the year ended 30 June 2014 for the groundwater store
Water asset increases2014
(ML)		2013
(ML)
Groundwater increases  
Groundwater inflow from outside region52,78848,940
Groundwater inflow from outside region at coast00
Recharge from landscape1,937,9321,194,424
Recharge from surface water00
Leakage from urban water system20,75420,583
Leakage from irrigation scheme––
Managed aquifer recharge from the urban water system6141,203
Discharge from urban water system to groundwater1,6481,714
Total groundwater increases2,013,7361,266,864
   
Water liability decreases  
Groundwater liability decreases  
Adjustment and forfeiture of groundwater allocation: individual users14,17232,483
Adjustment and forfeiture of groundwater allocation: urban water system7,20311,383
Total groundwater liability decreases21,37543,866
   
Water asset decreases  
Groundwater decreases  
Groundwater outflow to outside region30,16427,056
Groundwater outflow to outside region at coast433,999306,260
Discharge to landscape622,737447,397
Discharge to surface water283,158179,752
Entitled extraction of non-allocated groundwater to users73,24972,573
Total groundwater decreases1,443,3071,033,038
   
Water liability increases  
Groundwater liability increases  
Groundwater allocation announcements: individual users287,262284,520
Groundwater allocation announcements: urban water system132,054151,005
Total groundwater liability increases419,316435,525
   
Balancing item—groundwater164,060(180,342)
   
Change in net water assets8,42822,509

 

Table 6  Statement of Water Flows for the year ended 30 June 2014 for the groundwater store
Water inflows2014
(ML)		2013
(ML)
Groundwater inflows  
Groundwater inflow from outside region52,78848,940
Groundwater inflow from outside region at coast00
Recharge from landscape1,937,9321,194,424
Recharge from surface water00
Leakage from urban water system20,75420,583
Leakage from irrigation scheme––
Managed aquifer recharge from the urban water system6141,203
Discharge from urban water system to groundwater1,6481,714
Total groundwater inflows2,013,7361,266,864
   
Water outflows  
Groundwater outflows  
Groundwater outflow to outside region30,16427,056
Groundwater outflow to outside region at coast433,999306,260
Discharge to landscape622,737447,397
Discharge to surface water283,158179,752
Entitled extraction of non-allocated groundwater to users73,24972,573
Entitled extraction of allocated groundwater to users281,518274,546
Entitled extraction of allocated groundwater to urban water system124,851139,622
Total groundwater outflows1,849,6761,447,206
   
Balancing item—groundwater164,060(180,342)
   
Opening water storage––
Change in water storage00
Closing water storage––

 

 

Urban water system

 

Table 7  Statement of Water Assets and Water Liabilities as at 30 June 2014 for the urban water system
Water assets2014
(ML)		2013
(ML)
Urban water system  
Urban water supply system7,0026,759
Wastewater system––
Recycled water system––
Urban claim on surface water0119
Urban claim on groundwater00
Total urban water system assets7,0026,878
   
Opening net water assets6,8787,459
Change in net water assets124(581)
Closing net water assets7,0026,878

 

Table 8  Statement of Changes in Water Assets and Water Liabilities for the year ended 30 June 2014 for the urban water system
Water asset increases2014
(ML)		2013
(ML)
Urban water system increases  
Wastewater collected141,024136,392
Delivery of water from outside region to urban water system2,1211,939
Delivery of desalinated water to urban water system113,06095,770
Increase of urban claim on surface water247,950248,117
Increase of urban claim on groundwater132,054151,005
Total urban water system increases636,209633,223
   
Water asset decreases  
Urban water system decreases  
Evaporation from urban water system–89
Urban water system leakage to groundwater20,75420,583
Delivery to urban water system users242,053232,315
Discharge from urban water system to surface water59,46944,757
Wastewater discharge outside of region124,900120,293
Other wastewater discharge5,6735,338
Managed aquifer recharge6141,203
Discharge from urban water system to groundwater1,6481,714
Transfer of water outside of region20,79729,010
Adjustment and forfeiture of urban claim on surface water142,071158,264
Adjustment and forfeiture of urban claim on groundwater7,20311,383
Other urban water system decreases11,1808,407
Total urban water system decreases636,362633,356
   
Balancing item—urban water system(277)448
   
Change in net water assets124(581)

 

Table 9  Statement of Water Flows for the year ended 30 June 2014 for the urban water system
Water inflows2014
(ML)		2013
(ML)
Urban water system inflows  
Wastewater collected141,024136,392
Delivery of water from outside region to urban water system2,1211,939
Delivery of desalinated water to urban water system113,06095,770
Entitled diversion of allocated surface water to urban water system105,99889,853
Entitled extraction of allocated groundwater to urban water system124,851139,622
Total urban water system inflows487,054463,576
   
Water outflows  
Urban water system outflows  
Evaporation from urban water system–89
Urban water system leakage to groundwater20,75420,583
Delivery to urban water system users242,053232,315
Discharge from urban water system to surface water59,46944,757
Wastewater discharge outside of region124,900120,293
Other wastewater discharge5,6735,338
Managed aquifer recharge6141,203
Discharge from urban water system to groundwater1,6481,714
Transfer of water outside of region20,79729,010
Other urban water system decreases11,1808,407
Total urban water system outflows487,088463,709
   
Balancing item—urban water system(277)448
   
Opening water storage6,7597,340
Change in water storage243(581)
Closing water storage7,0026,759

 

 

Irrigation scheme

 

Table 10  Statement of Water Assets and Water Liabilities as at 30 June 2014 for the irrigation scheme
Water assets2014
(ML)		2013
(ML)
Irrigation scheme  
Irrigation water supply system390390
Irrigation scheme claim on surface water12,7186,510
Total irrigation scheme assets13,1086,900
   
Opening net water assets6,900390
Change in net water assets6,2086,510
Closing net water assets13,1086,900

 

Table 11  Statement of Changes in Water Assets and Water Liabilities for the year ended 30 June 2014 for the irrigation scheme
Water asset increases2014
(ML)		2013
(ML)
Irrigation scheme increases  
Increase of irrigation scheme claim on surface water46,48128,420
Total irrigation scheme increases46,48128,420
   
Water asset decreases  
Irrigation scheme decreases  
Leakage to groundwater––
Delivery to irrigation scheme users33,62222,619
Return of water to surface water––
Adjustment and forfeiture of irrigation scheme claim on surface water5,8070
Total irrigation scheme decreases39,42922,619
   
Balancing item—irrigation scheme844(709)
   
Change in net water assets6,2086,510

 

Table 12  Statement of Water Flows for the year ended 30 June 2014 for the irrigation scheme
Water inflows2014
(ML)		2013
(ML)
Irrigation scheme inflows  
Entitled diversion of allocated surface water to irrigation scheme34,46621,910
Total irrigation scheme inflows34,46621,910
   
Water outflows  
Irrigation scheme outflows  
Leakage to groundwater––
Delivery to irrigation scheme users33,62222,619
Return of water to surface water––
Total irrigation scheme outflows33,62222,619
   
Balancing item—irrigation scheme844(709)
   
Opening water storage390390
Change in water storage00
Closing water storage390390