[PPT] - 2019- 20 River Operations Stakeholder Consultation Committee PowerPoint Presentation

SLIDE 1

Lachlan River Operations 2019- 20

River Operations Stakeholder Consultation Committee (ROSCCo) 25 Feb 2020

SLIDE 2

WaterNSW 2

Recent Rainfall : 1 – 23 Feb20

SLIDE 3

WaterNSW

Recent Rainfall

10-2-20 24hrs 9-2-20 24hrs

SLIDE 4

WaterNSW

Recent rain hydrographs

SLIDE 5

WaterNSW

Recent rain hydrographs

SLIDE 6

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 412056 BELUBULA THE NEEDLES 141.00 Discharge (ML/d) PROV 412195 BELUBULA RV @ LYNDON 141.00 Discharge (ML/d) PROV 412033 BELUBULA HELENSHOLME 141.00 Discharge (ML/d) PROV 500 1000 1500 2000 2500 3000 2500 5000 7500 10000 12500 2000 4000 6000 8000 10000 500 1000 1500 2000 2500 3000 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

SLIDE 7

WaterNSW

Recent rain hydrographs

SLIDE 8

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%

SLIDE 9

WaterNSW

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

End January 2020 assessment

4.2% 1.6%

SLIDE 10

WaterNSW

What Does it take to operate Lachlan River

Transmission and Operation Loss

Regulated Lachlan River Transmission & Operations Losses Typical dry year (GL) Millennium Drought IRG stage 3 drought

perations

IRG stage 4 drought

perations

2004-05 2006-07 2008-09

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 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

Replenishment Flows into Merrowie Creek

9

Replenishment Flows into Merrimajeel/Muggabh Creek

7

Operational Surplus

5

Total

180 118 163 135 130 95

SLIDE 11

WaterNSW

End January 2020 assessment with February inflows

SLIDE 12

WaterNSW

Wyangala Dam Behaviour during Millennium Drought 2003-2010

0% 5% 10% 15% 20% 25% 30% 35% 40% 45%

50000 100000 150000 200000 250000 300000 350000 400000 450000 01-Jul-03 01-Jul-04 01-Jul-05 01-Jul-06 01-Jul-07 01-Jul-08 01-Jul-09 01-Jul-10

Wyangala Dam Storage Volume During Millennium Drought 2003 - 2010

Wyangala Volume (ML) Wyangala Level (%)

SLIDE 13

Comparison combined inflows – recent years

50 100 150 200 250 300 350 Combined Cumulative Inflows in GL

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

SLIDE 14

Water Availability

7 Feb 2020 Sum of Share Component Sum of Account Balance Sum of Available Water Sum of AWD Vol Sum of Carryover In Sum of Allocation Assignments In Sum of Allocation Assignments Out Sum of 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 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

SLIDE 15

End of Jan 2020 balances and Likely use from Feb – June 2020

Irrig balance Irrig Likely use Env balance Env likely use S&D balance S&D likely use LWU balance LWU likely 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 balance available for use 52 Total likely use 36

SLIDE 16

WaterNSW

Available water in High security accounts 31 Jan 2020

River Section Sum of Sum of Share Component Sum of Sum of Available Water Sum of GS Trade Sub-account Sum of Sum of 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

Carrawabbity Creek

Jemalong Weir To Island Creek
224

220 424

Island Creek To Condobolin

Wallamundry Creek

1 11 11 50

Wallaroi Creek

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

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

Booligal Weir To Corrong (Gs412045)

795 322

220

(blank)

2,652

Grand Total

27,680 12,423 1,302 40,104

SLIDE 17

SLIDE 18

Drought Stages in NSW rivers

18

Source: https://www.industry.nsw.gov.au/water/allocations-availability/droughts-floods/update/critical-valleys-in-drought

SLIDE 19

Comparison of Drought inflows

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)

100 200 300 400 500 600 700 800 5 10 15 20 25 30 35 40 Cumulative Inflows in GL No of Months

Wyangala Drought Inflows for 36 Months Starting in August

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

252 GL Deficit in inflows

SLIDE 20

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

SLIDE 21

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

SLIDE 22

Supply Source Vs Resource Distribution

End Jan 20

SLIDE 23

Inflows needed to improve deliverability of carryover

SLIDE 24

WaterNSW

Water Allocation Statement 14 Feb 2020

SLIDE 25

AWDs during millennium drought in %

Year HS LWU S&D GS 2004-05 30 50 30 2005-06 100 100 100 19 2006-07 30 80 80 2007-08 30 70 50 2008-09 30 70 50 2009-10 10 50 15

SLIDE 26

HS Share Component

Type of Use Share Component Environment 2,728 Permanent Planting 10,513 Annual crop\Lucerne 7,176 Dairy 749 research 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

SLIDE 27

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

SLIDE 28

22 month rainfall deficiency

SLIDE 29

NSW temperatures

SLIDE 30

Soil moisture deficiencies

January 2020

SLIDE 31

Climate Outlook

SLIDE 32

End of Presentation