River Murray Weekly Report For the week ending Wednesday, 30 September 2020

Trim Ref: D20/41318 Rainfall and inflows Rainfall was widespread across the central and southern Murray-Darling Basin this week (Map 1). Moderate totals were recorded across the southern Basin. In Victoria’s Alpine region, Harris Lane recorded 70 mm and 48 mm fell at Hunters Hill (near Berringama) in the Upper Murray catchment of Victoria. In , Pooncarie on the Lower recorded 14 mm, while on the , near its confluence with the , recorded 15 mm. Lake Victoria, Hume Reservoir and Yarrawonga all recorded 16 mm. The Bureau of Meteorology is currently forecasting widespread light to moderate rainfall across much of the Murray-Darling Basin in the coming 8 days.

Map 1 - Murray-Darling Basin rainfall totals for week ending 30 September 2020 (Source: Bureau of Meteorology) This week’s rainfall produced increased tributary streamflows in the upper Murray, Kiewa and Ovens Rivers. Peechelba, on the Ovens River, peaked at around 4,750 ML/day, and the Kiewa River at Bandiana peaked at around 2,800 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 Murray River Basin Daily River Report at the WaterNSW website.

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System operations Unregulated flow event concludes The extended period of unregulated flows into South Australia which commenced 27 June 2020, concluded this week on 25 September as anticipated in previous advice. The filling of Lake Victoria was managed within the requirements of the Lake Victoria Operating strategy (LVOS) and the need to bring the storage to effective full supply at the conclusion of the unregulated flow period.

River operations

• MDBA active storage continues to rise • Water for the environment supporting Murray Cod outcomes in the Murray • Unregulated system flows conclude at the SA border • Lake Victoria reaches effective full supply level at conclusion of unregulated flow event

River operations and the COVID-19 virus The MDBA is continuing to work with government partners and stakeholders during this challenging time. In response to the impact of COVID-19, the MDBA has enacted business continuity arrangements to ensure the continued operation of our business functions. River operations have been identified as a priority in this time as running the river is essential to supporting irrigation supply to agricultural industries. We hope all our community members remain safe at this time. We encourage all river users to evaluate plans against government advice, physical distancing and travel, and to support actions to limit the spread of COVID-19. Water quality impacts An amber alert for blue-green algae is current in the River Murray system for the Gulpa Creek at and the at Old Morago. 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. As the Bureau of Metrology declared a La Niña this week and continues to forecast wet conditions across south eastern Australia, Murray Darling Basin communities should be aware there is a significant risk of hypoxic blackwater events occurring particularly in New South Wales. After three hot and dry years, floodplains have a high load of leaf litter. La Niña conditions in spring increases the risk of floods, which can wash organic matter into waterways and lead to hypoxic blackwater events. More information is provided in the MDBA and WaterNSW joint media release. Monthly snapshot of water in the system River Murray communities can now access a monthly point-in-time snapshot that shows what water is in the river for the environment compared with water for towns, industries and irrigators. Every day, water enters the river at different points and for different purposes, including irrigation, town water supply, industries and specific environmental benefits. The monthly snapshot shows in simple terms the volume of flow and the extent to which it comprises water for the environment at five locations—in the Murray River at Yarrawonga and the South Australian border, and in the Murrumbidgee, Goulburn and Darling rivers just upstream of their junction with the Murray. Find out more on Flows in the River Murray system. River operations Over the past week, MDBA total active storage increased by 64 GL to 4,688 GL (55% capacity). At Dartmouth Reservoir, the storage increased by 13 GL this week to 2,180 GL (57% capacity). The release, measured at Colemans, continued to target the minimum flow of 200 ML/day.

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At Hume Reservoir the storage level increased by 49 GL to 2,031 GL (68% capacity). Hume releases peaked on Friday at around 5,500 ML/day before easing across the remainder of the week in response to rising tributary inflows from rainfall over the Ovens and Kiewa catchments. In the coming weeks, Hume releases will continue to be influenced by rainfall, irrigation demands and orders for water for the environment. At Lake , the pool level is 124.76 m AHD and within the normal operating range of between 124.6 and 124.9 m AHD. Earlier in the week irrigation diversions reduced with rainfall and cooler weather. Towards the end of the week diversion to increased to near 1,000 ML/day, while diversion to Yarrawonga Main Channel remained at 400 ML/day. The release from Yarrawonga Weir began to incrementally increase on Monday from 7,000 ML/day to 8,700 ML/day on Wednesday following weekend rain and subsequent increased inflow. The release is expected to remain at around 8,500 ML/day over the coming weeks to continue delivering water for the environment. These higher flows are designed to provide water levels that support the Murray Cod nesting season, while also increasing lateral connectivity between the River Murray and the Barmah-Millewa Forest. This greater connectivity has been enabled by the opening of selected regulators in the forest which promotes increased productivity in the river and supports plants and animals in the forest. All actions associated with water for the environment are tracked and water usage debited from environmental water holder accounts. With the gates raised clear of the water at Edward River Offtake, flows continue to respond to changes in the Murray. This week, with releases from Yarrawonga, flow through the offtake averaged around 1,240 ML/day. Flow through the Gulpa River Offtake remained around 250 ML/day across the week. Downstream, diversions to Main Canal remained steady at 200 ML/day for most of week, increasing to 300 ML/day at the end of the week. This week, the release from Stevens Weir averaged around 1,130 ML/day and is anticipated to remain near this rate in the coming week. On the Goulburn River, the flow measured at McCoys Bridge receded from near 2,000 ML/day to the current rate near 1,400 ML/day, where the flow is expected to remain over the coming week. The current inflow into the River Murray is comprised mostly of water for the environment that has been used to slow the flow recessions in parts of the Goulburn system. Information regarding opportunities for allocation trade between the Goulburn and Murray Valleys is available at the Victorian water register website. Diversions to National Channel from the Torrumbarry Weir pool remained steady at around 1,300 ML/day, before increasing to 1,700 ML/day at the close of the week. Demands are expected to remain steady at around this rate in the coming week. A portion of this flow is being used to maintain baseflows in the Gunbower Creek with the aim of providing increased habitat for native fish and other aquatic animals over the spring period. Flow in Gunbower Creek returns to the River Murray via Koondrook Spillway, downstream of Torrumbarry Weir near Barham. This week the release downstream of Torrumbarry Weir decreased from around 6,800 ML/day to near 4,900 ML/day and over the coming week flows are anticipated to marginally increase.

Photos 1&2 – A swollen River in the Murrumbidgee catchment following rain in the area (Photo by Kate Sandles, MDBA)

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Inflow from the Murrumbidgee River, measured at Balranald, remained steady across the week near the September end of system target of 1,330 ML/day. Flows are anticipated to ease over the coming week, falling away to the October end of system target of 1,030 ML/day. Supplementary access for the Murrumbidgee system has now concluded in all reaches. Please see the WaterNSW website for more information. The Murrumbidgee IVT balance is open for trade from the Murray to the Murrumbidgee (101.7 GL) but remains closed for trade from the Murrumbidgee to the Murray. At Euston Weir, the weir pool level is at FSL. This week the downstream release increased from around 9,200 ML/day to just over 10,000 ML/day before decreasing to the current level of around 9,850 ML/day. The flow is expected to decrease gradually in the coming week. Menindee Lakes storage remained steady this week at 470 GL (27% capacity). The downstream release, measured at Weir 32, remains near 410 ML/day, with the modest environmental releases that commenced the previous week moving down the lower Darling River. These flows aim to improve the condition of the lower Darling and help Murray Cod breed this spring. For more information refer to the Commonwealth Environmental Water Office and NSW Department of Planning, Industry and Environment. Following the rainfall and streamflow responses during recent months, water restrictions have been lifted in many locations across NSW. Links to drought services and assistance can be accessed via the MDBA drought webpage. At Wentworth Weir, the weir pool level is being managed to target around FSL. The downstream flow averaged around 8,000 ML/day across the week and is expected to slightly decrease over the coming week. The Lock 9, Lock 8 and Lock 7 weir pools continue to vary near FSL, within their normal operating range.

Photo 3 – Salt Creek Fishway in the south east drains network, South Australia (Photo by Mark de Jong, DEW, SA)

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The storage level at Lake Victoria increased by 2 GL to 671 GL (99% capacity) this week and was deliberately managed to peak at the conclusion of the unregulated flow event. The filling of Lake Victoria over the last few months was managed within the requirements of the Lake Victoria Operating strategy (LVOS).

Given the period of unregulated flow to South Australia ceased 25 September, Lake Victoria is now being used to help meet requirements across the SA border. The flow to South Australia is currently around 7,800 ML/day and will increase further in coming days as in-transit water for the environment is delivered across the border, in addition to the October South Australian monthly entitlement.

Photo 4 – Yellow-eye mullet from the Morella Fishway, South Australia (Photo by Mark de Jong, DEW, SA) The Lower Lakes 5-day average water level is 0.83 m AHD. Unregulated flow into the Lower Lakes over the past months has allowed large volumes to be released to the Coorong to target outcomes in the Coorong and at the Murray Mouth. Increased barrage releases will continue to be made when conditions allow to push fresh water into the Coorong. 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 30 Sep 2020 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 3 856 455.94 2 180 57% 71 2 109 +13 Hume Reservoir 192.00 3 005 186.59 2 031 68% 23 2 008 +49 Lake Victoria 27.00 677 26.95 671 99% 100 571 +2 Menindee Lakes 1 731* 470 27% (- -) # 0 -0 Total 9 269 5 352 58% - - 4 688 +64 Total Active MDBA Storage 56% ^

Major State Storages Burrinjuck Reservoir 1 026 821 80% 3 818 +6 Blowering Reservoir 1 631 1 282 79% 24 1 258 +28 Eildon Reservoir 3 334 1 986 60% 100 1 886 +28 * 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 29 Sep 2020 Storage Active Storage (GL) Weekly Change (GL) Diversion (GL) This Week From 1 May 2020 Lake Eucumbene - Total 1 148 n/a Snowy-Murray +0 420 Snowy-Murray Component 537 n/a Tooma-Tumut +9 138 Target Storage 1 240 Net Diversion -9 282 Murray 1 Release +17 580 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) 7.6 136 Yarrawonga Main Channel (net) 2.7 22 Wakool Sys Allowance 0.9 26 Torrumbarry System + Nyah (net) 5.8 51 Western Murray Irrigation 0.2 2 Sunraysia Pumped Districts 0.9 9 Licensed Pumps 2.4 41 Licensed pumps - GMW (Nyah+u/s) 0.2 2 Lower Darling 0.0 0 Licensed pumps - LMW 4.9 34 TOTAL 11.1 205 TOTAL 14.5 118 * 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 135.0 * * Flow to SA will be greater than normal entitlement for Flow this week 49.9 (7 100 ML/day) this month due to unregulated flows. Flow so far this month 274.0

Flow last month 261.6 Salinity (EC) (microSiemens/cm at 25o C) Current Average over the last week Average since 1 August 2020 Swan Hill 130 110 120 Euston - - - Red Cliffs 160 160 140 Merbein 160 170 180 Burtundy (Darling) 330 330 310 Lock 9 170 150 130 Lake Victoria 130 120 120 Berri 170 170 150 Waikerie 190 190 200 Morgan 190 190 200 Mannum - 240 220 Murray Bridge 240 240 240 Milang (Lake Alex.) 840 830 870 Poltalloch (Lake Alex.) 390 580 480 Meningie (Lake Alb.) 1 720 1 720 1 690 Goolwa Barrages - 1 320 1 510

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River Levels and Flows Week ending Wednesday 30 Sep 2020 Minor Flood Average Flow this Average Flow last Gauge Height Flow Trend Stage Week Week local (m River Murray (m) (m) AHD) (ML/day) (ML/day) (ML/day) - - - 2 250 F 3 640 3 750 4.0 1.97 208.49 6 920 F 8 350 7 460 Tallandoon ( Mitta Mitta River ) 4.2 1.59 218.48 990 F 1 080 950 Heywoods 5.5 1.89 155.52 2 570 S 3 990 4 120 Doctors Point 5.5 2.03 150.50 4 430 R 5 960 5 710 4.3 1.09 148.53 - - - - 4.6 1.36 127.38 4 930 F 6 010 5 830 Yarrawonga Weir (d/s) 6.4 1.44 116.48 8 720 R 7 540 7 250 6.4 1.89 105.73 7 700 R 6 830 6 780 Torrumbarry Weir (d/s) 7.3 1.81 80.36 4 870 F 5 970 7 000 Swan Hill 4.5 1.31 64.23 6 700 F 7 390 6 790 Wakool Junction 8.8 3.07 52.19 8 420 F 8 690 7 970 Euston Weir (d/s) 9.1 1.75 43.59 9 840 F 9 610 9 170 Mildura Weir (d/s) - - 9 170 F 8 780 9 540 Wentworth Weir (d/s) 7.3 3.05 27.81 8 310 S 7 960 9 370 Rufus Junction - 3.52 20.45 6 860 R 6 230 8 360 Blanchetown (Lock 1 d/s) - 0.82 - 6 260 R 6 510 8 370

Tributaries Kiewa at Bandiana 2.8 1.79 155.02 1 640 R 1 880 1 500 Ovens at Wangaratta 11.9 9.21 146.89 4 110 F 3 970 2 690 Goulburn at McCoys Bridge 9.0 1.70 93.12 1 340 F 1 670 2 700 Edward at Stevens Weir (d/s) 5.5 1.42 81.19 1 180 F 1 130 800 Edward at Liewah - 1.35 56.73 740 R 740 1 030 Wakool at Stoney Crossing - 1.41 54.90 460 F 490 530 Murrumbidgee at Balranald 5.0 1.75 57.71 1 320 F 1 320 1 290 Barwon at Mungindi 6.1 3.17 - 110 F 120 140 Darling at Bourke 9.0 4.09 - 440 F 600 830 Darling at Burtundy Rocks - 0.78 - 270 R 190 150

Natural Inflow to Hume 12 340 12 170 (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 -0.09 - No. 7 22.10 +0.11 -28.25 No. 26 Torrumbarry 86.05 -0.00 - No. 6 Murtho 19.25 +0.15 +0.23 No. 15 Euston 47.60 +0.00 - No. 5 Renmark 16.30 +0.14 +0.43 No. 11 Mildura 34.40 +0.05 +0.26 No. 4 Bookpurnong 13.20 +0.28 +0.71 No. 10 Wentworth 30.80 +0.02 +0.41 No. 3 Overland Corner 9.80 +0.00 +0.42 No. 9 Kulnine 27.40 +0.04 +0.17 No. 2 Waikerie 6.10 +0.19 +0.29 No. 8 Wangumma 24.60 +0.07 +0.31 No. 1 Blanchetown 3.20 +0.11 +0.07

Lower Lakes FSL = 0.75 m AHD Lake Alexandrina average level for the past 5 days (m AHD) 0.83

Barrages Fishways at Barrages Openings Level (m AHD) No. Open Rock Ramp Vertical Slot 1 Vertical Slot 2 Dual Vertical Slots Goolwa 128 openings - 3 - Open Open - Mundoo 26 openings - All closed - - - Open Hunters Creek - - - - Open - - Boundary Creek 6 openings - 1 - Open - - Ewe Island 111 gates - All closed - - - Open Tauwitchere 322 gates 0.83 6 Open Closed Open - AHD = Level relative to Australian Height Datum, i.e. height above sea level

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Week ending Wednesday 30 Sep 2020

State Allocations (as at 2 Oct 2020) NSW - Murray Valley Victorian - Murray Valley High security 97% High reliability 40%

General security 17% Low reliability 0%

NSW – Murrumbidgee Valley Victorian - Goulburn Valley High security 95% High reliability 58%

General security 48% 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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