Lachlan River Operations 2019- 20 River Operations Stakeholder Consultation Committee (ROSCCo) 25 Feb 2020
Recent Rainfall : 1 – 23 Feb20 WaterNSW 2
Recent Rainfall 10-2-20 24hrs 9-2-20 24hrs WaterNSW
Recent rain hydrographs WaterNSW
Recent rain hydrographs WaterNSW
Recent rain hydrographs HYPLOT V133 Output 25/02/2020 WaterNSW 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 March 2020 4.2% 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 56 27 76 59 55 55 Cargelligo Weir Wallamundry/Wallaroi/Nerrathong 14 14 13 12 12 6 system 12 7 7 6 6 3 Replenishment flows into Booberoi Ck Flows to Lake Cargelligo through 5 3 3 3 3 emergency works for TWS & BLR 15 4 2 0 2 2 Losses in regulated Willandra Ck system 40 42 47 40 39 20 Losses LC Weir to Booligal 13 15 15 14 13 6 Target Flows required below Booligal Replenishment Flows into Willandra 9 5 0 0 0 0 Creek Replenishment Flows into Merrowie 9 0 0 0 0 0 Creek Replenishment Flows into 7 0 0 0 0 0 Merrimajeel/Muggabh Creek 5 0 0 0 0 0 Operational Surplus WaterNSW 180 118 163 135 130 95 Total
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 Combined Cumulative Inflows in GL 250 200 150 100 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 10,954 7,942 7,894 10,954 - - - 3,000 DOMESTIC AND STOCK DOMESTIC AND STOCK 176 173 173 176 - - - 3 [DOMESTIC] DOMESTIC AND STOCK 1,599 1,429 1,429 1,599 - - - 168 [STOCK] 15,545 9,563 8,935 15,545 - - - 5,982 LOCAL WATER UTILITY REGULATED RIVER 17,911 0 0 6,960 - - - 6,960 (CONVEYANCE) REGULATED RIVER 469,309 51,630 12,839 - 83,441 12,831 21,768 22,848 (Irrigation GS) REGULATED RIVER 123,492 42,108 8,041 - 71,609 11,007 32,221 8,286 (Environment GS) REGULATED RIVER 24,952 12,664 11,794 21,709 - 21,764 11,825 18,973 (Irrigation HS) REGULATED RIVER 2,728 589 589 2,373 - 22,026 1,862 21,949 (Environment HS) 666,667 126,098 51,693 59,317 155,023 67,628 67,676 88,169 Grand Total
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 1,753 697 8 151 Wyangla Dam To Cowra (Gs412002) 4,374 1,808 - 5,731 Cowra (Gs412002) To Nanami (Gs412057) 1,808 2,864 350 3,406 Nanami (Gs412057) To Cottons Weir Available 1,820 785 - 153 Cottons Weir To Jemalong Weir 200 1,764 435 3,134 Jemalong Weir Offtake water in High - - - - Carrawabbity Creek - 224 220 424 Jemalong Weir To Island Creek security - - - - Island Creek To Condobolin 1 11 11 50 Wallamundry Creek accounts - - - - Wallaroi Creek - - - - Bumbuggan Creek 871 498 - 333 Goobang Creek 1,406 278 - - 31 Jan 2020 Condobolin Weir To Booberoi Weir 1,933 480 - 21,516 Booberoi Weir To Lake Cargelligo Weir 38 21 - - Sheet Of Water 28 4 - - Channel Curlew 859 478 - 5 Lake Cargelligo Storage 130 247 128 386 Lake Cargelligo Weir To Lake Brewster Weir 27 - - - Lake Brewster Weir To Willandra Weir - 1 127 1,632 Willandra Creek Offtake to Tocabil - - - - Tocabil to Royston - - - - Royston to Willandra National Park 3,551 692 24 937 Willandra Weir To Gonowlia 1,018 146 - 7 Gonowlia Weir To Hillston Weir 2,645 431 - 1,140 Will/Hillston Unnamed Watercourse 1,772 672 - 880 Hillston To Whealbah Bridge WaterNSW 795 322 - 220 Booligal Weir To Corrong (Gs412045) 2,652 - - (blank) 27,680 12,423 1,302 40,104 Grand Total
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 Cumulative Inflows in GL 500 252 GL Deficit in 400 inflows 300 200 100 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
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