River Murray Weekly Report For the week ending Wednesday, 27 January 2021

Trim Ref: D21/2130 Rainfall and inflows Climatic conditions varied over the southern Murray-Darling Basin this week. The week began with heatwave conditions across much of the southern Basin before lower temperatures and widespread moderate rainfall totals were recorded. In the , Falls Creek recorded 64 mm, while in the NSW Snowy Mountains region Cabramurra recorded 38 mm. Over the irrigation districts, Deniliquin in recorded 21 mm, and Rutherglen in recorded 17 mm. In the Murrumbidgee catchment Gundagai recorded 35 mm, and in the Darling catchment Karpa Kora Station, Pooncarie, recorded 50 mm. In South , Peake in the Upper South- East recorded 16 mm while Yunta in the North East recorded 30 mm. Further widespread rainfall and mild conditions are forecast across the southern Basin in the coming days. The Bureau of Meteorology has issued an initial flood watch for the North Central catchments from the to the Broken River.

Map 1: Murray-Darling Basin rainfall for the week ending 27 January 2021. Source: Bureau of Meteorology.

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Modest stream flow responses were observed in the upper Murray tributaries following the widespread rainfall at the end of the week. On the , Rocky Point increased from 300 ML/day to around 750 ML/day, and the at Bandiana peaked at near 600 ML/day. Further specific information about flows at key locations can be found at the MDBA’s River Murray data webpage. Up-to-date river data for sites in the upper Murray can also be found on BoM’s website and in the Basin Daily River Report at the WaterNSW website.

River operations

• Hume dam releases reduced in response to widespread rainfall • Lake Victoria continues to be drawn down to support system demands • Red alert level for blue-green algae for parts of Sunraysia

Water demand The MDBA is actively monitoring shortfall risks. A shortfall occurs when water cannot be delivered to users when and where it is needed. A delivery shortfall occurs when actual water use is higher than it was forecast to be when river water was released from storages, weeks earlier, to meet the forecast needs for irrigation and environmental water. A system shortfall occurs when the combined capacity of the system is unable to supply all downstream requirements over the full season. More information about shortfalls can be found at Water demand (shortfalls) | Murray-Darling Basin Authority (mdba.gov.au). The risk of a delivery shortfall in the River Murray between Wakool Junction and the SA border over the coming week is currently trending towards negligible. Increased (but still low) risk is to be expected, at times, across summer in response to periods of hot weather. The MDBA is continuing to monitor weather conditions and forecast demands and will continue to actively manage the risk of delivery shortfall across the high demand summer-autumn period as conditions evolve. The risk of a system shortfall is being closely monitored in consultation with states. The system is finely balanced and the potential for a system shortfall in late summer and early autumn has been identified within river operations planning scenarios. The MDBA and states will continue to monitor this risk closely over the coming weeks and will take steps to minimise the risk of a shortfall as necessary. If the forecast rainfall eventuates it is expected to assist in reducing the risk of any potential system shortfall. For more information, please see the MDBA’s October update to the 2020-21 River Murray System Annual Operating Outlook. This update refines the scenarios from the July publication using data to the end of October. The Operating Outlook may be updated again later this water year if observed conditions deviate significantly from the scenarios assessed in the report. The MDBA, Basin state governments and their agencies have different roles and responsibilities in managing delivery shortfalls. Read more information on delivery shortfall risks for Victorian water licence holders. Water quality impacts WaterNSW have recently declared a number of red and amber alerts for blue-green algae in the River Murray System. Currently, a red alert is declared for the lower River Murray from Mt Dispersion to Lock 9. Amber alerts are in place at Hume Dam and Yarrawonga Weir. On the River Murray all stations between Picnic Point and Euston Weir are on amber alert. There is also an amber alert at Lock 8. Along the Edward- system amber alerts remain current for Gulpa Creek, Mathoura, Old Morago, at Moulamein on the and at the Wakool- Barham Road station on the Wakool River. It is important that water users regularly keep up to date with algal alerts, notices and health warnings. This information is available through Goulburn-Murray Water and WaterNSW. Monthly snapshot of water in the system River Murray communities can now access a monthly point-in-time snapshot that shows what proportion of water in the river has been provided for the environment compared with water for towns, industries and irrigators. Find out more on Flows in the River Murray system.

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River operations Total active storage reduced over the last week by 106 GL to 4,177 GL (51% capacity). At Dartmouth Reservoir, the storage decreased slightly by 2 GL to 2,395 GL (62% capacity). The release, measured at Colemans, continued to target 350 ML/day and is expected to remain around this rate in the coming weeks. Over the past week the Hume Reservoir storage decreased by 71 GL to 1,642 GL (55% capacity). The Hume release targeted 16,300 ML/day as the week commenced before gradually decreasing to the current rate of around 11,000 ML/day. The release is expected to continue to decrease in the coming days with further forecast rainfall. The release continues to supply consumptive demands and system conveyance, and to slow the rate of decline of Lake Victoria’s storage volume — a typical operational requirement across summer. At Lake Mulwala, the pool level averaged around 124.8 m AHD over the Australia Day period in anticipation of high irrigation demands and very hot weather. In response to widespread rainfall following the public holiday, the pool has since risen marginally and is forecast to reach, and possibly exceed, full supply level (FSL) in the coming days. The exact weir pool level reached will depend on a variety of factors including the location and intensity of rainfall, irrigation demand and losses along the River. Targeting levels above FSL is undertaken when necessary to help manage a “rain rejection” of irrigation orders and assist in reducing or preventing unseasonal flooding of the downstream Barmah-Millewa forest.

In response to recent and forecast rainfall, diversion to Yarrawonga Main Channel reduced from near 1,000 ML/day to the current rate of around 300 ML/day this week. Similarly, diversion to Mulwala Canal reduced from 5,000 ML/day at the start of the week to the current rate near 3,700 ML/day. Of this diversion, just over half is returning to the river system to meet demands downstream of the Barmah Choke.

The release from Yarrawonga Weir is currently targeting 9,500 ML/day but may vary over the coming week in response to the level in Lake Photo 1. from the Horsefall Road Bridge near Mulwala and downstream demands. Dartmouth town. Source: Digby Jacobs, MDBA. Flow through the Edward River Offtake has averaged near 1,600 ML/day, while flow through the Gulpa Creek Offtake has remained near 350 ML/day to help fill wetlands adjacent to the creek. Downstream, flow through the Wakool River, Yallakool Creek and Colligen Creek offtakes has reduced as the pulse of water for the environment targeting silver perch recedes. Flow is currently around 85, 300 and 230 ML/day, respectively. Flows are expected to vary over the coming week depending on rainfall and irrigation demand. All actions associated with water for the environment are tracked and water usage debited from environmental water holder (EWH) accounts.

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Diversion to Wakool Main Canal averaged around 1,100 ML/day until mid-week when it began reducing to the current rate of 700 ML/day. The flow downstream of Stevens Weir peaked at around 2,630 ML/day near the end of the week before reducing slightly to the current rate of 2,530 ML/day. It is expected the flow will remain around this rate over the coming week. On the , the flow measured at McCoys Bridge has remained relatively steady since the start of December as Goulburn Inter Valley Trade (IVT) is delivered to the Murray. This week the flow varied around 1,100 ML/day. An initial Flood Watch for North Central catchments from the Avoca River to the Broken River has been issued and provides more information on possible flows in the Goulburn system over the coming week. In addition to the Goulburn River, the delivery of water from the Goulburn IVT account to the Murray is continuing via the and Broken Creek. Combined, IVT deliveries are expected to total 40 GL in each of January and February. For more information see the Goulburn-Murray Water website. Information regarding opportunities for allocation trade between the Goulburn and Murray Valleys is available at the Victorian water register website. Diversions to National Channel have averaged around 1,350 ML/day this week. The release from Torrumbarry Weir is currently near 6,600 ML/day and is expected to gradually rise again in the coming week. Inflow from the , measured at Balranald, averaged around 1,000 ML/day and is forecast to increase over the coming week. The Murrumbidgee IVT balance is open for trade from the Murray to the Murrumbidgee (85.7 GL) but remains closed for trade from the Murrumbidgee to the Murray. Around 40 GL of Murrumbidgee IVT was delivered in December and MDBA has called a further 45 GL for January which will be extended into February.

Photo 2. Pollack Swamp in the Koondrook-Perricoota Forest. Source: Jean Dind, Forestry Corporation of NSW.

At Euston Weir, the weir pool level remains near FSL. The downstream release is currently 7,800 ML/day and forecast to increase over the coming week. Menindee Lakes storage decreased by 5 GL to 326 GL (19% capacity) over the last week. At Weir 32, the release reached around 420 ML/day following widespread rainfall in the area. The flow is expected to slowly reduce over the coming week. Upstream the flow at Bourke is near 1,000 ML/day thanks to earlier summer rain events further up the Darling catchment. This flow is expected to gradually reduce over the coming week as the peak of the event has passed. Some water restrictions remain current in NSW. Links to drought services and assistance can be accessed via the MDBA drought webpage. At Wentworth Weir, the weir pool level continues to be managed around FSL. The downstream flow decreased from around 6,700 ML/day at the start of the week to the current rate near 5,400 ML/day. Downstream at Lock 9 the weir pool continues to vary near FSL. The Lock 8 and Lock 7 weir pools are 50 cm below FSL as part of the weir pool variability program and are planned to remain at these levels over the coming months.

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Photos 3: Wilcannia Bridge, . Source: Donovan McComb-Gray. This week the storage level at Lake Victoria reduced by 29 GL to 334 GL (49% capacity) as releases continue to supplement Murray flows to meet system demands. The forecast rainfall over the coming 8 days, downstream of the choke, may suppress irrigation demands and slow the rate of storage decline over the coming week. The flow to averaged near 9,200 ML/day this week and will remain near this rate until the end of January at which point the flow is expected to decrease to around 8,350 ML/day for February. The flow includes South Australia’s normal monthly Entitlement flow, small volumes of consumptive trade and water for the environment. In January, environmental water holders are delivering an additional 40 GL of water for the environment to South Australia, delivered at an additional rate of around 1,300 ML/day. The Lower Lakes 5-day average water level is 0.75 m AHD. Barrage releases will continue to be made, when conditions allow, to push fresh water into the Coorong and to support Black Bream spawning over the coming months. For information on barrage releases and South Australia’s Entitlement flow, see the South Australian Department for Environment and Water Weekly River Murray Flow Report.

For media inquiries contact the Media Officer on 02 6279 0141 ANDREW REYNOLDS Executive Director, River Management

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Water in Storage Week ending Wednesday 27 Jan 2021 Full Full Current Change in Total Dead Active MDBA Storages Supply Supply Storage Current Storage Storage for the Storage Storage Level Volume Level Week (m AHD) (GL) (m AHD) (GL) % (GL) (GL) (GL) Dartmouth Reservoir 486.00 3 856 460.45 2 395 62% 71 2 324 -2 Hume Reservoir 192.00 3 005 183.99 1 642 55% 23 1 619 -71 Lake Victoria 27.00 677 23.90 334 49% 100 234 -29 Menindee Lakes 1 731* 326 19% (- -) # 0 -5 Total 9 269 4 697 51% - - 4 177 -106 Total Active MDBA Storage 50% ^

Major State Storages Burrinjuck Reservoir 1 026 727 71% 3 724 -39 Blowering Reservoir 1 631 1 206 74% 24 1 182 -45 Eildon Reservoir 3 334 2 149 64% 100 2 049 -22

* Menindee surcharge capacity – 2050 GL ** All Data is rounded to nearest GL ** # NSW has sole access to water when the storage falls below 480 GL. MDBA regains access to water when the storage next reaches 640 GL. ^ % of total active MDBA storage

Snowy Mountains Scheme Snowy diversions for week ending 26 Jan 2021 Storage Active Storage (GL) Weekly Change (GL) Diversion (GL) This Week From 1 May 2020 Lake Eucumbene - Total 1 226 -53 Snowy-Murray +34 590 Snowy-Murray Component 594 -30 Tooma-Tumut +2 211 Target Storage 1 520 Net Diversion 32 379 Murray 1 Release +39 853 Major Diversions from Murray and Lower Darling (GL) * New South Wales This Week From 1 July 2020 Victoria This Week From 1 July 2020 Murray Irrig. Ltd (Net) 18.1 392 Yarrawonga Main Channel (net) 5.8 115 Wakool Sys Allowance 3.1 65 Torrumbarry System + Nyah (net) 8.8 172 Western Murray Irrigation 1.3 15 Sunraysia Pumped Districts 5.4 72 Licensed Pumps 7.1 157 Licensed pumps - GMW (Nyah+u/s) 0.7 16 Lower Darling 0.1 1 Licensed pumps - LMW 18.4 272 TOTAL 29.7 630 TOTAL 39.1 647 * Figures are derived from actual and estimates where data is unavailable. Please note that not all data may have been available at the time of creating this report. ** All data above is rounded to nearest 100 ML for weekly data and nearest GL for cumulative data

Flow to South Australia (GL) Entitlement this month 217.0 * * Flow to SA will be greater than normal entitlement for Flow this week 64.1 (9 200 ML/day) this month due to environmental flows. Flow so far this month 238.2 Flow last month 388.9

Salinity (EC) (microSiemens/cm at 25o C) Current Average over the last week Average since 1 August 2020 Swan Hill 120 110 100 Euston - - - Red Cliffs 110 110 130 Merbein - 110 140 Burtundy (Darling) 460 450 370 Lock 9 130 130 130 Lake Victoria 130 130 120 Berri 180 170 160 Waikerie 220 210 210 Morgan 220 220 210 Mannum 240 230 230 Murray Bridge 230 230 240 Milang (Lake Alex.) 710 700 770 Poltalloch (Lake Alex.) 530 580 7 220 Meningie (Lake Alb.) 1 610 1 610 1 630 Goolwa Barrages 970 970 1 240

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River Levels and Flows Week ending Wednesday 27 Jan 2021 Minor Flood Average Flow Average Flow Gauge Height Flow Trend Stage this Week last Week (m River Murray (m) local (m) AHD) (ML/day) (ML/day) (ML/day) Khancoban - - - 1 790 F 4 880 2 540 Jingellic 4.0 1.86 208.38 5 970 F 6 170 3 560 Tallandoon ( Mitta Mitta River ) 4.2 1.59 218.48 980 R 650 630 Heywoods 5.5 3.12 156.75 13 030 F 15 350 15 650 Doctors Point 5.5 2.99 151.46 15 040 F 17 100 17 180 Albury 4.3 2.03 149.47 - - - - Corowa 4.6 3.09 129.11 15 360 F 16 020 15 770 Yarrawonga Weir (d/s) 6.4 1.56 116.60 9 550 S 9 550 9 360 Tocumwal 6.4 2.15 105.99 9 640 R 9 490 9 230 Torrumbarry Weir (d/s) 7.3 2.29 80.84 6 600 F 6 510 6 290 Swan Hill 4.5 1.30 64.22 6 630 R 6 570 6 610 Wakool Junction 8.8 3.03 52.15 8 250 R 8 120 8 850 Euston Weir (d/s) 9.1 1.41 43.25 7 520 R 7 950 9 420 Mildura Weir (d/s) - - 6 200 F 7 090 7 370 Wentworth Weir (d/s) 7.3 2.80 27.56 5 440 R 5 890 6 050 Rufus Junction - 3.88 20.81 9 130 S 8 820 8 130 Blanchetown (Lock 1 d/s) - 0.89 - 5 430 R 5 400 4 490

Tributaries Kiewa at Bandiana 2.8 1.08 154.31 580 R 340 350 Ovens at Wangaratta 11.9 7.89 145.57 400 R 330 390 Goulburn at McCoys Bridge 9.0 1.54 92.96 1 070 F 1 140 1 220 Edward at Stevens Weir (d/s) 5.5 2.39 82.16 2 620 F 2 420 1 970 Edward at Liewah - 2.57 57.95 1 950 R 1 900 2 180 Wakool at Stoney Crossing - 1.49 54.98 640 R 570 530 Murrumbidgee at Balranald 5.0 1.47 57.43 1 050 R 1 010 2 130 Barwon at Mungindi 6.1 3.27 - 200 F 380 340 Darling at Bourke 9.0 4.25 - 1 140 F 1 470 1 040 Darling at Burtundy Rocks - 0.75 - 210 F 210 240

Natural Inflow to Hume 1 450 1 840 (i.e. Pre Dartmouth & Snowy Mountains scheme)

Weirs and Locks Pool levels above or below Full Supply Level (FSL) Murray FSL (m AHD) u/s d/s FSL (m AHD) u/s d/s Yarrawonga 124.90 -0.04 - No. 7 22.10 -0.52 -28.25 No. 26 Torrumbarry 86.05 -0.00 - No. 6 Murtho 19.25 +0.03 +0.28 No. 15 Euston 47.60 +0.04 - No. 5 Renmark 16.30 +0.05 +0.28 No. 11 Mildura 34.40 +0.04 +0.12 No. 4 Bookpurnong 13.20 +0.03 +0.88 No. 10 Wentworth 30.80 +0.02 +0.16 No. 3 Overland Corner 9.80 +0.06 +0.29 No. 9 Kulnine 27.40 -0.06 -0.52 No. 2 Waikerie 6.10 +0.04 +0.25 No. 8 Wangumma 24.60 -0.50 -0.49 No. 1 Blanchetown 3.20 +0.04 +0.14

Lower Lakes FSL = 0.75 m AHD Lake Alexandrina average level for the past 5 days (m AHD) 0.75

Barrages Fishways at Barrages Openings Level (m AHD) No. Open Rock Ramp Vertical Slot 1 Vertical Slot 2 Dual Vertical Slots Goolwa 128 openings 0.86 All closed - Open Open - Mundoo 26 openings 0.78 All closed - - - Open Hunters Creek - - - - Open - - Boundary Creek 6 openings - All closed - Open - - Ewe Island 111 gates - All closed - - - Open Tauwitchere 322 gates 0.79 All closed Open Open Open - AHD = Level relative to Australian Height Datum, i.e. height above sea level

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Week ending Wednesday 27 Jan 2021

State Allocations (as at 27 Jan 2021) NSW - Murray Valley Victorian - Murray Valley High security 97% High reliability 96%

General security 46% Low reliability 0%

NSW – Murrumbidgee Valley Victorian - Goulburn Valley High security 100% High reliability 100%

General security 100% Low reliability 0%

NSW - Lower Darling South Australia – Murray Valley

High security 100% High security 100%

General security 30%

NSW : https://www.industry.nsw.gov.au/water/allocations-availability/allocations/summary

VIC : http://nvrm.net.au/seasonal-determinations/current

SA : https://www.environment.sa.gov.au/topics/river-murray/water-allocations-and-announcements

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