River Murray Weekly Report For the week ending Wednesday, 9 September 2020

Trim Ref: D20/37452

Rainfall and inflows Although some September forecasts showed potential for worthwhile precipitation across Victoria and Southern NSW, conditions have actually remained fairly dry for a second week across much of the Murray- Darling Basin (Map 1). In New South Wales, received 7.4 mm while Bowning received 13 mm across the week. In Victoria, Mildura received 2.2 mm and Bendigo received a total of 1.8 mm across the week. The Bureau of Meteorology is currently forecasting modest rainfall over the southern and eastern areas of the Murray-Darling Basin in the coming 8 days.

Map 1 - Murray-Darling Basin rainfall totals for week ending 9 September 2020 (Source: Bureau of Meteorology) Stream flows in the upper Murray tributaries continued to mostly recede this week. 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.

Subscribe to the River Murray Weekly Report River Data website Water in Storages River Murray Weekly Report

System operations Unregulated flow event Since heavy rainfall in late April soaked catchments and boosted tributary inflows from the Ovens, Kiewa and Goulburn Rivers, catchments have remained responsive to rainfall. Healthy tributary inflows have continued during May, June, July and August. Theses tributary inflows have resulted in the effective filling of Lake Victoria and an extended period of unregulated flows into South Australia since 27 June. Across the past two weeks, drier conditions have prevailed and without further rainfall, the current period of unregulated flow is expected to conclude by mid-September. As such, the re-filling of Lake Victoria has now re- commenced and access to unregulated flows has ceased along river reaches upstream of Barham. For more information on the expected duration and the specific river reaches where unregulated flow currently applies, please refer to your local water authority. River operations

• MDBA active storage continues to rise • is now beginning to release water as both irrigation demands and environmental orders commence • Lock 11 at Mildura closed to boat traffic for maintenance on 15, 16 and 17 of September 2020

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 remains current in the River Murray system upstream of Euston Weir. 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. River operations Over the past week, MDBA total active storage increased by 72 GL to 4,524 GL (56% capacity). The Menindee Lakes storage volume remains below 640 GL and so there is no water currently available to meet Murray system requirements. Therefore, the total active storage available to the Murray does not include water held in the Menindee Lakes. At Dartmouth Reservoir, the storage increased by 15 GL this week to 2,140 GL (55% capacity). The release, measured at Colemans, continued to target the minimum flow of 200 ML/day.

Subscribe to the River Murray Weekly Report River Data website Water in Storages River Murray Weekly Report

Photo 1: Mitta Mitta River near Katie Peters reserve (photo courtesy Michael Broughton)

Photo 2: A sunny day along the river (photo courtesy Kate Sandles, MDBA)

Subscribe to the River Murray Weekly Report River Data website Water in Storages River Murray Weekly Report

At Hume Reservoir the storage level increased by 50 GL to 1,927 GL (64% capacity). Hume releases have responded this week to increasing irrigation demands and environmental orders. Accordingly, across the week Hume release has increased from the minimum requirement of 600 ML/day to 5,000 ML/day. In the coming weeks, Hume releases will continue to be influenced by rainfall, irrigation demands and environmental orders. It is anticipated that if conditions remain dry then Hume releases will continue to rise. 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. Across the week irrigation diversions have been increasing. Mulwala Canal increased its diversion from 500 ML/day to near 1,500 ML/day and is anticipated to further increase into next week. Yarrawonga Main Channel increased its diversion from 200 ML/day to near 700 ML/day and is anticipated to similarly increase into next week.

The release from Yarrawonga Weir averaged 5,800 ML/day across the week and is currently at 6,000 ML/day. Earlier in the week, water for the environment began to be delivered from Hume Dam. From Saturday 12 September these releases will reach Yarrawonga weir, where environmental water holders are targeting an in- channel flow downstream of Yarrawonga Weir. This water for the environment seeks to support the Murray cod nesting season by supplementing in-channel river flows and targeting a more stable flow rate. In association with the above action, some regulators in Barmah-Millewa Forest are open. Accordingly, this water for the environment will also increase the level of connectivity between the Murray River and the Barmah-Millewa Forest creeks and low-level floodplain to support plants and animals in the forest and promote increased productivity in the river. All actions in association with water for the environment are being monitored and water usage debited from environmental water holder accounts. On the Edward River, flows are close to 900 ML/day while on the Gulpa River flows are near to 200 ML/day. These flows are expected to increase slightly over the coming weeks. At Stevens Weir, diversions to the Main Canal remained around 100 ML/day and the release downstream of the weir averaged 1,100 ML/day. On the Goulburn River, the flow measured at McCoys Bridge decreased from 7,000 to 2,700 ML/day across the week and is expected to continue to slowly recede without significant rainfall. 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 have similarly risen from 1,000 to 1,700 ML/day and are likely to further increase without significant local rainfall to dampen demand. 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.

Inflow from the Murrumbidgee River, measured at , remains above the end of system target in response to rainfall in the upper Murrumbidgee catchment in August. Whilst the flow upstream on the Murrumbidgee River at Wagga Wagga has averaged 10,000 ML/day during August, diversions during supplementary access have resulted in the flow at Balranald remaining below 2,500 ML/day. With drying conditions across the last few weeks, supplementary access for the Murrumbidgee River has finished in some reaches of the Murrumbidgee, while in other reaches remains open for a short time longer. Please see the WaterNSW website for more information. The Murrumbidgee IVT balance is open for trade from the Murray to the Murrumbidgee (100 GL) but remains closed for trade from the Murrumbidgee to the Murray.

At Euston Weir, the weir pool level is at FSL. The downstream release averaged around 15,500 ML/day and is forecast to steadily recede over the coming week.

At Mildura Weir, Lock 11 will be closed to boat traffic on 15, 16 and 17 of September 2020. This is to allow installation and load testing of the upgraded lock bridge. Please see the media release for more information.

Subscribe to the River Murray Weekly Report River Data website Water in Storages River Murray Weekly Report

Menindee Lakes storage increased by 2 GL to 460 GL (27% capacity). Continuing inflow has arrested the slow decline in storage and is now maintaining the volume relatively steady. The downstream release, measured at Weir 32, averaged 240 ML/day. 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 continued to rise this week and is currently at 14,100 ML/day.

The Lock 9, Lock 8 and Lock 7 weir pools continue to vary near FSL, within their normal operating range.

The storage level at Lake Victoria increased by 5 GL to 651 GL (96% capacity) this week. The storage level in Lake Victoria will continue to be managed over the coming weeks in accordance with the Lake Victoria Operating Strategy. The strategy aims to fill the storage as late as possible while also minimising the length of time the storage is held at a steady level. This is done with the aim of minimising erosion and inundation impacts on sensitive foreshore vegetation and cultural heritage material.

The flow to South Australia reduced over the past week to around 11,200 ML/day as unregulated flows continued across the border. Flow to South Australia will remain above normal Entitlement (4,500 ML/day) into September as unregulated flows continue to arrive from upstream.

The Lower Lakes 5-day average water level was 0.80 m AHD. Continuing unregulated flow into the Lower Lakes has allowed around 48 GL to be released to the Coorong this week targeting 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

Subscribe to the River Murray Weekly Report River Data website Water in Storages River Murray Weekly Report

Water in Storage Week ending Wednesday 09 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 3 856 455.08 2 140 55% 71 2 069 +15 Hume Reservoir 192.00 3 005 185.93 1 927 64% 23 1 904 +50 Lake Victoria 27.00 677 26.79 651 96% 100 551 +5 Menindee Lakes 1 731* 460 27% (- -) # 0 +2 Total 9 269 5 178 56% - - 4 524 +72 Total Active MDBA Storage 54% ^

Major State Storages Burrinjuck Reservoir 1 026 848 83% 3 845 -2 Blowering Reservoir 1 631 1 273 78% 24 1 249 +24 Eildon Reservoir 3 334 1 924 58% 100 1 824 +33 * 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 08 Sep 2020 Storage Active Storage (GL) Weekly Change (GL) Diversion (GL) This Week From 1 May 2020 Lake Eucumbene - Total 1 005 +40 Snowy-Murray +0 419 Snowy-Murray Component 448 +29 Tooma-Tumut +9 111 Target Storage 1 240 Net Diversion -9 308 Murray 1 Release +5 534 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) 5.8 104 Yarrawonga Main Channel (net) 2.4 11 Wakool Sys Allowance 1.2 20 Torrumbarry System + Nyah (net) 0.1 0 Western Murray Irrigation 0.2 1 Sunraysia Pumped Districts 1.6 6 Licensed Pumps n/a 30 Licensed pumps - GMW (Nyah+u/s) 0.4 1 Lower Darling 0.0 0 Licensed pumps - LMW 5.1 19 TOTAL 7.2 155 TOTAL 9.6 37 * 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 70.8 (10 100 ML/day) this month due to unregulated flows. Flow so far this month 88.5

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 140 140 120 Euston - - - Red Cliffs 150 140 140 Merbein 130 130 140 Burtundy (Darling) 320 310 310 Lock 9 140 150 130 Lake Victoria 120 120 120 Berri 140 150 140 Waikerie 190 210 210 Morgan 210 220 210 Mannum 220 220 220 Murray Bridge 210 230 240 Milang (Lake Alex.) 780 770 900 Poltalloch (Lake Alex.) 310 420 450 Meningie (Lake Alb.) 1 730 1 720 1 710 Goolwa Barrages 1 270 1 300 1 650

Subscribe to the River Murray Weekly Report River Data website Water in Storages

River Levels and Flows Week ending Wednesday 09 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) - - - 3 580 R 2 060 1 610 4.0 1.86 208.38 5 970 F 6 430 8 310 Tallandoon ( Mitta Mitta River ) 4.2 1.59 218.48 990 R 1 030 1 160 Heywoods 5.5 2.05 155.68 3 300 R 990 600 Doctors Point 5.5 2.10 150.57 5 080 R 2 520 2 400 4.3 1.14 148.58 - - - - 4.6 0.72 126.74 2 150 R 2 140 2 970 Yarrawonga Weir (d/s) 6.4 1.09 116.13 6 320 F 5 800 6 470 6.4 1.64 105.48 6 090 R 5 140 7 140 Torrumbarry Weir (d/s) 7.3 2.23 80.77 6 350 F 9 880 13 830 Swan Hill 4.5 1.86 64.78 10 470 F 13 540 10 550 Wakool Junction 8.8 4.19 53.31 13 900 F 14 360 10 240 Euston Weir (d/s) 9.1 2.60 44.44 15 730 S 14 470 10 610 Mildura Weir (d/s) - - 14 310 F 12 310 9 620 Wentworth Weir (d/s) 7.3 3.33 28.09 13 960 R 11 630 8 740 Rufus Junction - 4.06 20.99 10 310 S 9 310 8 870 Blanchetown (Lock 1 d/s) - 0.94 - 9 360 R 8 400 8 090

Tributaries Kiewa at Bandiana 2.8 1.75 154.98 1 560 F 1 580 1 940 Ovens at Wangaratta 11.9 8.89 146.57 3 100 F 4 080 6 000 Goulburn at McCoys Bridge 9.0 2.45 93.87 2 770 F 4 420 10 310 Edward at Stevens Weir (d/s) 5.5 1.12 80.89 830 F 1 110 930 Edward at Liewah - 1.66 57.04 980 R 790 840 Wakool at Stoney Crossing - 1.38 54.87 400 F 440 500 Murrumbidgee at Balranald 5.0 2.05 58.01 1 660 F 1 810 1 830 Barwon at Mungindi 6.1 3.29 - 270 F 430 670 Darling at Bourke 9.0 4.28 - 1 400 R 1 220 1 350 Darling at Burtundy Rocks - 0.70 - 150 R 150 160

Natural Inflow to Hume 11 880 14 260 (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 -0.13 - No. 7 Rufus River 22.10 +0.04 +1.75 No. 26 Torrumbarry 86.05 -0.00 - No. 6 Murtho 19.25 +0.14 +0.46 No. 15 Euston 47.60 -0.01 - No. 5 Renmark 16.30 +0.17 +0.58 No. 11 Mildura 34.40 +0.04 +0.56 No. 4 Bookpurnong 13.20 +0.29 +1.05 No. 10 Wentworth 30.80 +0.02 +0.69 No. 3 Overland Corner 9.80 +0.02 +0.56 No. 9 Kulnine 27.40 +0.00 +0.25 No. 2 Waikerie 6.10 +0.16 +0.52 No. 8 Wangumma 24.60 +0.02 +0.44 No. 1 Blanchetown 3.20 +0.15 +0.19

Lower Lakes FSL = 0.75 m AHD Lake Alexandrina average level for the past 5 days (m AHD) 0.80

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 3 - Open Open - Mundoo 26 openings 0.70 All closed - - - Open Hunters Creek - - - - Open - - Boundary Creek 6 openings - 1 - Open - - Ewe Island 111 gates - All closed - - - Open Tauwitchere 322 gates 0.82 8 Open Closed Open - AHD = Level relative to Australian Height Datum, i.e. height above sea level

Subscribe to the River Murray Weekly Report River Data website Water in Storages

Week ending Wednesday 09 Sep 2020

State Allocations (as at 09 Sep 2020) NSW - Murray Valley Victorian - Murray Valley High security 97% High reliability 32%

General security 12% Low reliability 0%

NSW – Murrumbidgee Valley Victorian - Goulburn Valley High security 95% High reliability 47%

General security 44% 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 : http://www.environment.sa.gov.au/managing-natural-resources/river-murray

Subscribe to the River Murray Weekly Report River Data website Water in Storages