Lachlan River Operations 2019- 20
River Operations Stakeholder Consultation Committee (ROSCCo) 25 Feb 2020 Recent Rainfall : 1 – 23 Feb20
2 WaterNSW Recent Rainfall
10-2-20 24hrs 9-2-20 24hrs
WaterNSW Recent rain hydrographs
WaterNSW Recent rain hydrographs
WaterNSW Recent rain hydrographs
WaterNSW HYPLOT V133 Output 25/02/2020
Period 31 Day 26/01/2020 to 26/02/2020 2020
412077 BELUBULA @ CARCOAR 141.00 Discharge (ML/d) PROV 3000 2500 2000 1500 1000 500 0
412056 BELUBULA THE NEEDLES 141.00 Discharge (ML/d) PROV 12500 10000 7500 5000 2500 0
412195 BELUBULA RV @ LYNDON 141.00 Discharge (ML/d) PROV 10000 8000 6000 4000 2000 0
412033 BELUBULA HELENSHOLME 141.00 Discharge (ML/d) PROV 3000 2500 2000 1500 1000 500 WaterNSW 0 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Recent rain hydrographs
WaterNSW Current Storage Status
• Wyangala: as at 23 Feb 2020 • Storage Volume: 161,937 ML • Storage Percent: 13.2%, increase of 4.8% from 8.4% on 10 Feb • System Inflows since 1July19 – 31 Jan 20: 9,700 ML • System Inflows since 1 Feb 20 – 9 Feb 20: 4,000 ML (2 GL + 2 GL) • System Inflows since 10 Feb 20 – 23 Feb: 69,000 ML (64 GL + 5 GL)
• Lake Cargelligo: • Storage Volume: 24,968 ML (22 Feb 20) • Storage Percent: 61.7% • Projected Volume: 28,550 ML (1 March 20) • Projected Percent: 73% End January 2020 assessment
Assumptions: • Zero inflows • Water savings 15 GL in 2019-20 • 2020-21under IRG 3 Essential Requirements – 130GL • GS under usage – 10 GL • WQA – 1GL • No S&D replenishment • Lake Cargelligo Offline 4.2% March 2020 1.6%
WaterNSW What Does it take to operate Lachlan River - Transmission and Operation Loss
IRG stage 3 IRG stage 4 Millennium Drought Regulated Lachlan River Typical dry drought drought Transmission & Operations Losses year (GL) 2004-05 2006-07 2008-09 operations operations Main regulated river from dam to Lake Cargelligo Weir 56 27 76 59 55 55 Wallamundry/Wallaroi/Nerrathong system 14 14 13 12 12 6 Replenishment flows into Booberoi Ck 12 7 7 6 6 3
Flows to Lake Cargelligo through emergency works for TWS & BLR 5 3 3 3 3 Losses in regulated Willandra Ck system 15 4 2 0 2 2 Losses LC Weir to Booligal 40 42 47 40 39 20 Target Flows required below Booligal 13 15 15 14 13 6
Replenishment Flows into Willandra Creek 9 5 0 0 0 0 Replenishment Flows into Merrowie Creek 9 0 0 0 0 0 Replenishment Flows into Merrimajeel/Muggabh Creek 7 0 0 0 0 0
WaterNSWOperational Surplus 5 0 0 0 0 0 Total 180 118 163 135 130 95 End January 2020 assessment with February inflows
WaterNSW Wyangala Dam Behaviour during Millennium Drought 2003-2010 Wyangala Dam Storage Volume During Millennium Drought 2003 - 2010 450000 45% Wyangala Volume (ML) Wyangala Level (%)
400000 40%
350000 35%
300000 30%
250000 25%
200000 20%
150000 15%
100000 10%
50000 5%
0 0% 01-Jul-03 01-Jul-04 01-Jul-05 01-Jul-06 01-Jul-07 01-Jul-08 01-Jul-09 01-Jul-10
WaterNSW Comparison combined inflows – recent years
Actual Combined Inflows Vs Minimum Combined Inflows starting July 2019 Pre 2004 Combined Inflows for 57% GS access Inflows from 1 July 19 2018-19 Combined Inflows 2017-18 Combined Inflows
350
300
250
200
150
100
Combined Cumulative Inflows in GL in Inflows Cumulative Combined 50
0 Water Availability Sum of Sum of Sum of Sum of Sum of Sum of Allocation Allocation Share Account Available Sum of Carryover Assignments Assignments Sum of 7 Feb 2020 Component Balance Water AWD Vol In In Out Usage
DOMESTIC AND STOCK 10,954 7,942 7,894 10,954 - - - 3,000 DOMESTIC AND STOCK [DOMESTIC] 176 173 173 176 - - - 3 DOMESTIC AND STOCK [STOCK] 1,599 1,429 1,429 1,599 - - - 168
LOCAL WATER UTILITY 15,545 9,563 8,935 15,545 - - - 5,982 REGULATED RIVER (CONVEYANCE) 17,911 0 0 6,960 - - - 6,960 REGULATED RIVER (Irrigation GS) 469,309 51,630 12,839 - 83,441 12,831 21,768 22,848 REGULATED RIVER (Environment GS) 123,492 42,108 8,041 - 71,609 11,007 32,221 8,286 REGULATED RIVER (Irrigation HS) 24,952 12,664 11,794 21,709 - 21,764 11,825 18,973 REGULATED RIVER (Environment HS) 2,728 589 589 2,373 - 22,026 1,862 21,949
Grand Total 666,667 126,098 51,693 59,317 155,023 67,628 67,676 88,169 End of Jan 2020 balances and Likely use from Feb – June 2020
Irrig Irrig Env Env S&D S&D LWU LWU balance Likely balance likely balance likely balance likely use use use use GS 14 8 HS 12 0.5 S&D 9 6 LWU 9 6 Totals 26 21 8.5 3 9 6 9 6 Total 52 balance available for use Total 36 likely use Sum of Sum of Share Sum of Sum of Sum of GS Trade Sum of Sum of River Section Component Available Water Sub-account YTD Usage
Wyangla Dam To Cowra (Gs412002) 1,753 697 8 151
Cowra (Gs412002) To Nanami (Gs412057) 4,374 1,808 - 5,731
Nanami (Gs412057) To Cottons Weir 1,808 2,864 350 3,406
Cottons Weir To Jemalong Weir 1,820 785 - 153
Jemalong Weir Offtake 200 1,764 435 3,134 Available Carrawabbity Creek - - - - water in High Jemalong Weir To Island Creek - 224 220 424 Island Creek To Condobolin - - - - security Wallamundry Creek 1 11 11 50 Wallaroi Creek - - - - accounts Bumbuggan Creek - - - -
Goobang Creek 871 498 - 333
Condobolin Weir To Booberoi Weir 1,406 278 - - Booberoi Weir To Lake Cargelligo Weir 1,933 480 - 21,516 31 Jan 2020 Sheet Of Water 38 21 - -
Channel Curlew 28 4 - -
Lake Cargelligo Storage 859 478 - 5
Lake Cargelligo Weir To Lake Brewster Weir 130 247 128 386
Lake Brewster Weir To Willandra Weir 27 - - -
Willandra Creek Offtake to Tocabil - 1 127 1,632
Tocabil to Royston - - - -
Royston to Willandra National Park - - - -
Willandra Weir To Gonowlia 3,551 692 24 937
Gonowlia Weir To Hillston Weir 1,018 146 - 7
Will/Hillston Unnamed Watercourse 2,645 431 - 1,140
Hillston To Whealbah Bridge 1,772 672 - 880
BooligalWaterNSW Weir To Corrong (Gs412045) 795 322 - 220
(blank) 2,652 - -
Grand Total 27,680 12,423 1,302 40,104
Drought Stages in NSW rivers
Source: https://www.industry.nsw.gov.au/water/allocations-availability/droughts-floods/update/critical-valleys-in-drought
18 Comparison of Drought inflows Wyangala Drought Inflows for 36 Months Starting in August
800 Aug 1979 - Jul 1982 Aug 2001 - Jul 2004 Aug 2007 - Jul 2010 Aug 2017 - Feb 2020 (31 months) Drought of Record Aug 1944 - Jul 1947
700
600
500
252 GL Deficit in 400 inflows
300
CumulativeInflows GL in 200
100
0 0 5 10 15 20 25 30 35 40 No of Months
• Aug 2017 – Jan 2020 (30 months) actual dam inflows = 256 GL • Aug – Jan 30 months pre 2004 DOR inflows = 509 GL (year 1947) • Aug – Jan 30 months millennium DOR inflows = 259 GL (year 2005) Drought Contingency Measures - Current • Reduction to access - remaining GS (57%) and HS (87%) allocations
• Cutdown flows in regulated sections to minimise transmission losses (Willandra Creek)
• Reduced flows in regulated sections to minimise incremental losses (Wallamundry System)
• Reduced End of System Targets
• Booberoi Creek flows assisted by delivery of environmental water
• Booberoi Ck ceased to flow end March 2020
• Conservative use of WQA
• Take Lake Cargelligo offline
• No delivery of S&D Replenishment from Wyangala Drought Contingency Measures – Potential
• Further reduction to access remaining GS after 31 March 20
• After 31 March, normal delivery of remaining HS allocations to Condobolin, but only critical human needs d/s of Condobolin
• Restore flows in regulated Willandra Creek and Booberoi Creek with trib flows
• Reduced flows in Wallamundry System, deliver flows in one of the creeks.
• Control inefficiencies in extraction of BLR
• Above measures and others to be discussed in ROSCCo Supply Source Vs Resource Distribution
End Jan 20 Inflows needed to improve deliverability of carryover Water Allocation Statement 14 Feb 2020
WaterNSW AWDs during millennium drought in %
Year HS LWU S&D GS 2004-05 30 50 30 0 2005-06 100 100 100 19 2006-07 30 80 80 0 2007-08 30 70 50 0 2008-09 30 70 50 0 2009-10 10 50 15 0 HS Share Component
Type of Use Share Component Environment 2,728 Permanent Planting 10,513 Annual crop\Lucerne 7,176 Dairy 749 research 0 Golf & Parks & Gardens 1,098
Mining & Industrial Use 1,125
S&D Water Schemes 200
Nil crops, Trade only 3,387
Sleeper, No trade, no use 444 Discussions and Recommendations • Allocation for next year to meet critical water needs • Should remaining usable GS allocations be made available in 2020-21 • Surplus tribs flow management plan • Trades – should trades move d/s to minimise transmission losses • Delivery of HS for remaining months of this year • Delivery of GS allocations for remaining months of this year • Type of information required in water allocation statements 22 month rainfall deficiency NSW temperatures Soil moisture deficiencies January 2020 Climate Outlook • End of Presentation