RIVER MURRAY WEEKLY REPORTFOR THE WEEK ENDING WEDNESDAY, 27 APRIL 2023Trim Ref: D16/15689

Rainfall and inflowsA weak trough and frontal system crossed the southern Murray–Darling Basin early in the past week before clearing to a fine weekend. The system brought modest rainfall to southern and eastern areas, although only light rain fell away from the Great Divide. In the north and west of the Basin, conditions remained dry (Map 1). Fine weather continued throughout the Basin during the latter part of the week with warm temperatures once again a feature for many parts of the Basin.

The highest weekly rain totals were recorded in the far south and south-east of the Basin and included falls of around 20 mm over the NSW Snowy Mountains and totals between 10 and 25 mm along Victoria’s central divide and north-east ranges.

Map 1 - Murray-Darling Basin rainfall for the week ending 27 April 2016 (Source: Bureau of Meteorology).

Flows along upper Murray tributaries remain low, with only a small rise observed during the week at gauges on the upper Mitta Mitta, Murray and Ovens Rivers following the rain. Base flows under 200 ML/day have been observed at upstream catchment gauges during recent weeks (Figure 1). However, rain forecast by the Bureau of Meteorology over the south-eastern Basin for the coming weekend brings the potential of catchment wetting and a possible increase in flow rates.

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Figure 1 - Kiewa River at Bandiana on the evening of 26 April 2016 with flows of 170 ML/day. Flows at many key upper catchment gauges have remained below 200 ML/day for most of April. Photo: Adam McLean, MDBA.

River operations

Red alerts for blue-green algae continue along the River Murray and now extend from Hume Reservoir all the way to Lock 9. The alerts apply to the main channel of the river as well as many anabranches and connected lakes and wetlands. Non-toxic blue-green algae has also been detected in South Australian reaches of the Murray. More information is available from NSW DPI, Goulburn Murray Water , SA DEWNR and the MDBA website.

A significant break down may still be several weeks away and will require a change to weather conditions over the Murray valley that are less favourable to algal blooms such as decreased sunshine, increased wind and rainfall.

MDBA total storage decreased by 65 GL this week, with the active storage now 2,258 GL (27% capacity).

At Dartmouth Reservoir, the storage volume decreased 4 GL to 1,667 GL (43% capacity). The release from Dartmouth, measured at Colemans is currently at 600 ML/day. However, the release will be decreased during the coming weekend to the minimum rate of 200 ML/day. See the attached flow advice for more details.

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Blue-green algae alerts extended along the Murray Low flows continue in upper catchments Release from Dartmouth returning to minimum rate Flows into South Australia decreasing for the beginning of May

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At Hume Reservoir, the storage volume decreased by 44 GL to 568 GL (19% capacity) (Figure 2). Storage levels in Hume have continued to decline, however, release requirements are now decreasing significantly as irrigation and flow demands downstream fall away towards the end of the season. This should result in Hume levelling off during the next few weeks at a storage volume just above 500 GL – the lowest seen since May 2010. Releases from Hume have been decreased this week from around 11,000 to 9,000 ML/day. Further reductions are expected during the coming week.

Figure 2 - The pylons of Bethanga Bridge once again exposed above Hume Reservoir with storage volume at 19% capacity.Photo: Adam McLean, MDBA, 26 April 2016.

At Lake Mulwala total diversion to Yarrawonga Main Channel and Mulwala Canal has decreased from around 3,800 to 3,100 ML/day. Orders so far suggest demands will continue decreasing during the coming week. The downstream release from Yarrawonga Weir continues to be gradually decreased as overall system demands downstream continue to decline. The current release is 6,500 ML/day. A release of around 6,000 ML/day is planned by the coming weekend.

On the Edward-Wakool system, inflows from the Murray via the Edward River and Gulpa Creek offtakes have decreased. The total flow through these two offtake regulators is about 1,100 ML/day with similar flow rates expected in the coming days. The flow rate should decrease further as we head into May. Downstream at Stevens Weir the release has averaged close to 600 ML/day. Diversions through the Wakool Main Canal decreased from around 500 to 300 ML/day.

On the Goulburn River, the flow at McCoys Bridge has remained fairly steady at just over 700 ML/day. Small volumes of additional environmental water continue to boost the flow a little above the normal end of system target flow for this time of year.

At Torrumbarry Weir, diversions to National Channel are now being wound back ahead of the upcoming completion of the irrigation season. The current diversion is around 2,500 ML/day and is expected to reduce to around 1,500 ML/day during the coming week. The downstream flow has risen slightly this week from around 4,000 to 4,600 ML/day. Flow rates above 5,000 ML/day are anticipated during the coming week.

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Further downstream, inflows into the Murray from the lower Murrumbidgee River at Balranald have receded slowly to around 350 ML/day. A steady flow is expected during the coming days.

Downstream at Euston Weir, flows are slowly rising, with the current flow at 4,400 ML/day. The weir pool level is currently 47.44 m AHD, which is 16 cm below the full supply level (FSL). A pool level down to 47.40 m AHD, or 20 cm below FSL is currently being targeted. This action is being undertaken as part of the on-going weir pool level variability trial. A further lowering of the pool level is being planned during the first half of May.

On the Darling River system, small flows resulting from rainfall in the northern Basin during January have now effectively ceased at Wilcannia. There is now no flow of any significance at gauges along the Darling and Barwon Rivers all the way upstream to the Queensland border. At the Menindee Lakes, the storage volume remains very low at about 49 GL (3% capacity), which is a 1GL reduction from this time last week.

At the confluence of the Darling and Murray Rivers at Wentworth, the flow in recent days has remained steady at around 3,300 ML/day. The flow is expected to rise slowly during the coming week. The weir pool remains around 10 cm above full supply level to assist water users on the Lower Darling arm of the weir pool.

At Lake Victoria, the storage volume decreased by 16 GL to 217 GL (32% capacity). The flow into South Australia averaged 4,400 ML/day and is expected to decrease a little during the remainder of April with a target of 3,000 ML/day planned for the beginning of May.

At the Lower Lakes, the 5-day average water level in Lake Alexandrina has remained unchanged at 0.58 m AHD. Small releases are continuing through the Tauwitchere barrage and via the fishways, however large swells and high tides forecast over the coming weekend may force the closure of barrage gates to limit the reverse flow of seawater into Lake Alexandrina.

For media inquiries contact the Media Officer on 02 6279 0141

DAVID DREVERMANExecutive Director, River Management

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Water in Storage Week ending Wednesday 27 Apr 2016

MDBA StoragesFull

Supply Level

Full Supply Volume

Current Storage

LevelCurrent Storage Dead

StorageActive

Storage

Change in Total

Storage for the Week

  (m AHD) (GL) (m AHD) (GL) % (GL) (GL) (GL)Dartmouth Reservoir 486.00 3 856 444.00 1 667 43% 71 1 596 -4Hume Reservoir 192.00 3 005 174.32 568 19% 23 545 -44Lake Victoria 27.00 677 22.68 217 32% 100 117 -16Menindee Lakes   1 731*   49 3% (- -) # 0 -1Total   9 269   2 501 27% - - 2 258 -65Total Active MDBA Storage             27% ^                   

Major State StoragesBurrinjuck Reservoir   1 026   335 33% 3 332 -9Blowering Reservoir   1 631   738 45% 24 714 +33Eildon Reservoir   3 334   1 030 31% 100 930 -24

* 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 Apr 2016 Storage Active Storage

(GL)Weekly Change

(GL) Diversion (GL) This Week From 1 May 2015

Lake Eucumbene - Total 1 418 -44 Snowy-Murray +16 714Snowy-Murray Component - n/a Tooma-Tumut +0 168Target Storage 1 340   Net Diversion 16 546      Murray 1 Release +16 912

Major Diversions from Murray and Lower Darling (GL) *New South Wales This Week From 1 July

2015 Victoria This Week From 1 July 2015

Murray Irrig. Ltd (Net) 17.3 447 Yarrawonga Main Channel (net) 5.6 246Wakool Sys Allowance 1.9 81 Torrumbarry System + Nyah (net) 0.1 481Western Murray Irrigation 0.3 20 Sunraysia Pumped Districts 0.9 104Licensed Pumps n/a 194 Licensed pumps - GMW (Nyah+u/s) n/a 41Lower Darling n/a 10 Licensed pumps - LMW n/a 278TOTAL 19.5 752 TOTAL 6.6 1150

* 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)* Flow to SA will be greater than normal entitlement for this month due to the delivery of additional environmental water.

Entitlement this month 135.0 *  Flow this week 31.1 (4 400 ML/day)Flow so far this month 147.9Flow last month 219.0

Salinity (EC) (microSiemens/cm at 25o C)  Current Average over the last week Average since 1 August 2015Swan Hill 60 70 70Euston 90 90 -Red Cliffs 120 120 120Merbein 120 120 120Burtundy (Darling) 1 770 1 750 1 270Lock 9 110 110 120Lake Victoria 170 190 210Berri 210 200 210Waikerie 260 250 270Morgan 220 220 270Mannum 260 250 310Murray Bridge 280 280 330Milang (Lake Alex.) 880 880 810Poltalloch (Lake Alex.) 650 630 680Meningie (Lake Alb.) 2 220 2 250 2 100

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Goolwa Barrages 1 450 1 440 1 230

River Levels and Flows Week ending Wednesday 27 Apr 2016

 

Minor Flood Stage Gauge Height Flow Trend Average Flow

this Week

Average Flow last

WeekRiver Murray (m) local (m) (m AHD) (ML/day)   (ML/day) (ML/day)Khancoban - - - 390 F 1 940 4 250Jingellic 4.0 1.38 207.90 2 130 F 3 110 3 880Tallandoon ( Mitta Mitta River ) 4.2 1.47 218.36 690 S 680 680Heywoods 5.5 2.77 156.40 8 890 F 10 260 11 140Doctors Point 5.5 2.53 151.00 9 210 F 10 770 11 710Albury 4.3 1.56 149.00 - - - -Corowa 4.6 2.31 128.33 9 630 F 10 420 11 320Yarrawonga Weir (d/s) 6.4 1.18 116.22 6 490 F 6 730 7 450Tocumwal 6.4 1.81 105.65 7 070 S 7 320 7 690Torrumbarry Weir (d/s) 7.3 1.60 80.15 4 550 F 4 510 3 960Swan Hill 4.5 0.98 63.90 4 580 R 4 080 3 550Wakool Junction 8.8 2.21 51.33 4 680 S 4 620 4 460Euston Weir (d/s) 9.1 0.99 42.83 4 350 S 4 220 4 580Mildura Weir (d/s)   - - 4 160 F 4 110 5 060Wentworth Weir (d/s) 7.3 2.83 27.59 3 470 R 3 470 4 240Rufus Junction - 2.94 19.87 3 310 F 3 970 4 780Blanchetown (Lock 1 d/s) - 0.49 - 3 290 F 3 570 3 580               Tributaries              Kiewa at Bandiana 2.8 0.72 153.95 170 S 170 160Ovens at Wangaratta 11.9 7.69 145.37 140 S 130 130Goulburn at McCoys Bridge 9.0 1.36 92.78 730 F 800 870Edward at Stevens Weir (d/s) 5.5 0.84 80.62 620 F 590 580Edward at Liewah - 1.08 56.46 540 F 600 710Wakool at Stoney Crossing - 1.36 54.85 300 F 320 320Murrumbidgee at Balranald 5.0 0.67 56.63 340 F 390 380Barwon at Mungindi 6.1 3.14 - 10 S 10 20Darling at Bourke 9.0 3.80 - 0 F 0 0Darling at Burtundy Rocks - 0.53 - 0 F 0 0               Natural Inflow to Hume           650 470

(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/sYarrawonga 124.90 -0.06 - No. 7 Rufus River 22.10 -0.09 +0.63No. 26 Torrumbarry 86.05 -0.08 - No. 6 Murtho 19.25 -0.01 +0.28No. 15 Euston 47.60 -0.16 - No. 5 Renmark 16.30 +0.02 +0.11No. 11 Mildura 34.40 +0.01 +0.09 No. 4 Bookpurnong 13.20 +0.05 +0.41No. 10 Wentworth 30.80 +0.08 +0.19 No. 3 Overland Corner 9.80 +0.01 +0.11No. 9 Kulnine 27.40 +0.08 -0.16 No. 2 Waikerie 6.10 +0.00 +0.03No. 8 Wangumma 24.60 -0.14 -0.07 No. 1 Blanchetown 3.20 -0.10 -0.26

Lower Lakes FSL = 0.75 m AHDLake Alexandrina average level for the past 5 days (m AHD) 0.58

Barrages Fishways at Barrages

  OpeningsLevel (m AHD) No. Open Rock Ramp

Vertical Slot 1 Vertical Slot 2

Dual Vertical Slots

Goolwa 128 openings 0.67 All closed - Open Open -Mundoo 26 openings 0.62 All closed - - - OpenHunters Creek - - - - Open - -Boundary Creek 6 openings - All closed - Open - -Ewe Island 111 gates - All closed - - - OpenTauwitchere 322 gates 0.66 2 Open Open Open -

* Mundoo Barrage Dual vertical slots are currently under construction.AHD = Level relative to Australian Height Datum, i.e. height above sea level

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Week ending Wednesday 27 Apr 2016

State Allocations (as at 27 Apr 2016)NSW - Murray Valley Victorian - Murray Valley

High security 97%General security 23%

High reliability 100%Low reliability 0%

NSW – Murrumbidgee Valley Victorian - Goulburn ValleyHigh security 95%General security 37%

High reliability 90%Low reliability 0%

NSW - Lower Darling South Australia – Murray ValleyHigh security 75%General security 0%

High security 100%

NSW : http://www.water.nsw.gov.au/Water-management/Water-availability/Water-allocations/Water-allocations-summary/water-allocations-summary/default.aspx

VIC : http://www.nvrm.net.au/allocations/current.aspxSA : http://www.environment.sa.gov.au/managing-natural-resources/river-murray

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Flow advice

27 April 2016 Page 7 of 8

Mitta Mitta flow reduces

Landholders and river users, including pumpers, on the Mitta Mitta River are advised to take into account the forecast releases of water from Dartmouth Dam and make any necessary adjustment to their river activities.

Releases will be reduced from 600 megalitres per day (ML/day) to 200 ML/day on Saturday 30 April.

The releases from Dartmouth Dam may vary from those forecast and flows on the Mitta Mitta may increase at any time if there’s rainfall in the catchment downstream of the dam.

Forecast Mitta Mitta flows

Date Releases from

Dartmouth Dam

Colemans Gauge Tallandoon Gauge

Flow(ML/day)

Height(m)

Flow(ML/day)

Height(m)

Friday 29 April Flows steady 580 1.22 640 1.44

Saturday 30 April Flows decreasing 580 1.22 640 1.44

Monday 2 May Flows steady 200 0.86 280 1.19

A further flow advice will be issued when there is a significant change to releases.

Landholders and river users on the Mitta Mitta are advised to regularly check the current flows and forecasts on the MDBA website for more information on releases from Dartmouth Dam: www.mdba.gov.au/river-information/storage-volumes-releases

Live river data for Dartmouth Dam, the Mitta Mitta and other sites on the Murray system can be seen at: http://livedata.mdba.gov.au.

Summary information about the River Murray system is available in the River Murray weekly report at: http://www.mdba.gov.au/river-information/weekly-reports

ENDSFor more information, contact the MDBA Media office at media@mdba.gov.au or 02 6279 0141Follow us on Twitter @MD_Basin_Auth or Facebook @Murray-DarlingBasinAuthority

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