RIVER MURRAY WEEKLY REPORTFOR THE WEEK ENDING WEDNESDAY, 5TH AUGUST 2023Trim Ref: D15/64251

Rainfall and InflowsThere was rainfall across the southern Murray-Darling Basin this week with the passage of cold fronts and a trough system that brought relatively high totals to the south-east ranges over the weekend. The northern Basin remained dry (Map 1).

The highest weekly totals were recorded in the south-east slopes and ranges and in southern South Australia. In NSW, the highest totals fell over the Snowy Mountains with totals between 50 and 100 mm recorded at several sites. Elsewhere, totals above 25 mm were widespread across the Southern Tablelands including 39 mm at Hume Dam and Albury. Totals in Victoria were highest over the Victorian Alps and included 118 mm at Rocky Valley and 80 mm at Mt Buffalo. Other notable totals included 64 mm at Harris Lane and 60 mm at Yackandandah and Mongans Bridge. In South Australia there were totals between 25 and 50 mm around the Lower Lakes and the eastern Mt Lofty Ranges including 33 mm recorded at Mt Barker and 25 mm at Goolwa.

Map 1 – Murray-Darling Basin rainfall week ending 5th August 2015 (Source: Bureau of Meteorology)

Stream flow responses along the upper Murray tributaries were higher than expected following the weekend rain and have added a much needed boost to System inflows. On the Mitta Mitta River, the flow at Hinnomunjie Bridge increased from 1,200 to 2,300 ML/day. On the upper Murray at Biggara, the flow increased to a daily peak of 3,300 ML/day on 3 August, which is the highest so far this winter. There were also significant responses in the Kiewa River catchment, with flows of 4,300 ML/day in the lower Kiewa River at Bandiana taking the river above the minor flood level for a couple of days.

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July 2015 SummaryWeather conditions across the Murray-Darling Basin during July were fairly typical of winter with cold temperatures and the highest rainfall totals over the south-east ranges. Snow returned to the alpine areas, while a particularly cold outbreak mid-month brought snow to large parts of the ranges and tablelands further north, with falls extending into southern Queensland.

Monthly rainfall totals were fairly close to the long-term average for most parts of the Basin, with slightly less than average rain in the west contrasting with above average rain in parts of central NSW and in southern Queensland (Map 1). Across the Basin as a whole, the Bureau of Meteorology has reported area-averaged rain totalling 35.1 mm, which is 12% below the long-term July mean. Both daytime and overnight temperatures were a little below the long-term average for July.

Map 2 - Murray Darling Basin rainfall deciles for July 2015 (Source: Bureau of Meteorology).

River Murray System inflows for July (excluding Snowy Scheme, Darling River and managed environmental inflows) totalled around 420 GL. This figure represents only around a third of the long-term monthly average for July of about 1,250 GL, with the total affected by the dry catchment conditions during June and early July.

Estimated evaporation losses from MDBA storages for July 2015 are reported in Table 1. Evaporation is estimated by multiplying the surface area of the storage by the net evaporation. Net evaporation is derived by subtracting the rainfall recorded at the storage from the calculated evaporation. As a result of rainfall exceeding evaporation during July, net evaporation at both Dartmouth and Hume Reservoirs was negative. Net evaporation at Lake Victoria and the Menindee Lakes also remained low during July with the prevailing cool winter conditions.

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Table 1: Monthly evaporation figures for MDBA storages

Storage*Approximate (net) evaporative

loss in July 2015 (GL)Average storage volume

in July 2015 (GL)Dartmouth -4 2,776Hume -2.5 1,099Lake Victoria 3 457Menindee Lakes 2 97

* Evaporative loss from storage = surface area of the storage x net evaporation. Net evaporation = measured evaporation (using a ‘pan’ instrument) - rainfall.

River Operations

MDBA total storage increased by 43 GL this week. Active storage is now 4,184 GL (50% capacity).

The storage volume in Dartmouth Reservoir decreased by 18 GL to 2,766 GL (72% capacity) and the release averaged 6,800 ML/day. Release rates between 6,000 and 7,000 ML/day are planned for the coming week to provide further bulk transfers of water from Dartmouth to Hume Reservoirs.

Hume Reservoir storage increased by 74 GL this week and is now 1,162 GL (39% capacity). Inflows increased to more than 21,000 ML/day late in the week following the weekend rain. The increase was in part due to heavy local rainfall that triggered flow responses along a number of ungauged creeks that flow into the reservoir (Figure 1). The release from Hume was reduced throughout the week in response to decreasing downstream demand requirements. The current release is 4,100 ML/day and is down from 13,000 ML/day at the beginning of the week.

Figure 1 - A number of creeks upstream of Hume Dam, including Dry Forest Creek, responded significantly following heavy local rain over the weekend. Photo: Alistair McKenzie-McHarg, MDBA.

The level in Lake Mulwala returned to the normal operating target of 124.7 m AHD on 3 August following the winter drawdown. The current level is 124.83 m AHD and levels between 124.8 and 124.9 are expected during the coming days. Diversions at the major irrigation off-takes were maintained between 1,000 and 2,000 ML/day during the week as the irrigation companies continued filling their channel systems. The flow downstream of Yarrawonga Weir has been increased to 16,000 ML/day in response to higher tributary inflows. This flow rate is expected to persist for several

GPO Box 1801 Canberra ACT 2601 Telephone: 02 6279 0100 Facsimile: 02 6248 8053 Email: engagement@mdba.gov.au Web: www.mdba.gov.au ABN 13679821382

Lake Mulwala and Mildura weir pools back to normal levels; Forest regulators opened in the Barmah-Millewa Forest as flows increase; Significant Lower Lakes barrage release to provide flow pulse into the Coorong.

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more days before decreasing, however similar or higher flow rates are possible in the coming weeks depending on future rain, with further rain forecast over the coming week.

Downstream in the Barmah-Millewa Forest, forest flow regulators have been fully opened by forest managers at most sites to help pass the higher flows arriving from upstream. These flows will also benefit the forest wetland environment.

On the Edward-Wakool system, the combined flow through the Edward River and Gulpa Creek offtakes has increased to 2,100 ML/day. Flows are expected to increase a little more in the coming days, although flows through the Edward River offtake will, for the time being, be maintained at no more than 1,600 ML/day. At Stevens Weir, the pool continues to re-fill in preparation for the up-coming irrigation season. The pool level increased from 3.02 to 4.30 m on the local gauge this week. The release downstream of Stevens Weir decreased to 400 ML/day mid-week, however flows are now expected to increase over the coming week with rates above 1,000 ML/day likely in a few days’ time.

On the Goulburn River, the flow averaged 850 ML/day. Slightly higher flows are expected in the coming days. At Torrumbarry Weir, the diversion at National Channel was maintained at 1,200 ML/day. Diversions are expected to increase to 1,500 ML/day this week. Flows downstream of Torrumbarry Weir increased steadily throughout the week with the current flow at 6,800 ML/day and flows in excess of 8,000 ML/day anticipated towards the end of the coming week.

On the Murrumbidgee River, flows at Balranald crept up to around 1,700 ML/day during the week. This is above the minimum target and similar or higher flows are expected in the coming week.

At Euston Weir, the flow peaked at around 9,000 ML/day last week but has now receded to 7,500 ML/day. However, the flow is expected to increase again in the coming days and flows above 9,000 ML/day are likely in around one week’s time. The pool level at Euston remains above FSL, with the current level at 47.81 (21 cm above FSL), as part of the current weir pool variability program that aims to achieve a more natural wetting and drying cycle for the riverine environment.

At Mildura Weir, the weir pool has now almost returned to the normal FSL, with the level now just 4 cm below the FSL of 34.4 m AHD. With the completion of the drawdown and re-fill, standard release operations have now resumed along with a downstream flow more consistent with actual river flows. (See attached media release.) The current downstream flow is now 8,700 ML/day and receding.

On the Darling River system, a steady base flow continues at gauges upstream of Menindee, with flows at Bourke averaging about 500 ML/day in recent weeks. Storage in the Menindee Lakes is currently at 98 GL (6%) and increased by only 1 GL this week, while the release of a small replenishing flow into the lower Darling River continued. The flow at Weir 32 remains at about 200 ML/day. No flow has yet been observed downstream at Pooncarie since the release began and flows from this release are not expected to reach Burtundy.

Storage at Lake Victoria decreased by 14 GL to 450 GL (66 % capacity). The flow into South Australia averaged 7,200 ML/day. A flow rate around 7,000 ML/day is planned for the coming days.

At the Lower Lakes, the five-day average level at Lake Alexandrina is 0.77 m AHD (2 cm above FSL). Releases through the barrages have been restricted in recent days due to reverse flow conditions. However a pulse of significantly higher releases is now planned during the next few days to target a range of environmental benefits and take advantage of the forecast weather and tidal conditions and the current high water levels in Lake Alexandrina. See the attached media release for more details.

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 05 Aug 2015

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 3 856 467.66 2 766 72% 71 2 695 -18Hume Reservoir 192.00 3 005 180.25 1 162 39% 23 1 139 +74Lake Victoria 27.00 677 25.02 450 66% 100 350 -14Menindee Lakes   1 731*   98 6% (- -) # 0 +1Total   9 269   4 476 48% - - 4 184 +43Total Active MDBA Storage             50% ^                   

Major State StoragesBurrinjuck Reservoir   1 026   596 58% 3 593 +39Blowering Reservoir   1 631   666 41% 24 642 +33Eildon Reservoir   3 334   2 254 68% 100 2 154 +332

* Menindee surcharge capacity – 2050 GL ** All Data is rounded to nearest GL ** # NSW takes control of Menindee Lakes when storage falls below 480 GL, and control reverts to MDBA when storage next reaches 640 GL^ % of total active MDBA storage

Snowy Mountains Scheme Snowy diversions for week ending 04 Aug 2015 Storage Active Storage

(GL)Weekly Change

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

Lake Eucumbene - Total 2 107 n/a Snowy-Murray +7 126Snowy-Murray Component 1 065 n/a Tooma-Tumut +9 60Target Storage 1 190   Net Diversion -2 65      Murray 1 Release +15 186

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) 10.4 12 Yarrawonga Main Channel (net) 0.4 1Wakool Sys Allowance -0.2 -1 Torrumbarry System + Nyah (net) 5.6 4Western Murray Irrigation 0.1 -2 Sunraysia Pumped Districts 0.6 1Licensed Pumps 0.5 2 Licensed pumps - GMW (Nyah+u/s) 0 0Lower Darling 0.1 1 Licensed pumps - LMW 1.2 5TOTAL 10.9 12 TOTAL 7.8 11

* Figures derived from estimates and monthly data. 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 124.0 *  Flow this week 50.7 (7 200 ML/day)Flow so far this month 35.8Flow last month 231.8

Salinity (EC) (microSiemens/cm at 25o C)  Current Average over the last week Average since 1 August 2015Swan Hill 70 70 70Euston - - -Red Cliffs 130 170 160Merbein 160 210 200Burtundy (Darling) 900 900 900Lock 9 180 160 160Lake Victoria 180 170 180Berri 260 280 270Waikerie 330 330 330Morgan 300 300 290Mannum 330 330 330Murray Bridge 380 370 370Milang (Lake Alex.) 710 720 710Poltalloch (Lake Alex.) 670 580 570Meningie (Lake Alb.) 1 960 2 040 2 040Goolwa Barrages 1 330 1 270 1 300

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River Levels and Flows Week ending Wednesday 05 Aug 2015

 

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 - - - 5 010 F 3 370 2 200Jingellic 4.0 2.53 209.05 11 700 F 8 200 6 190Tallandoon ( Mitta Mitta River ) 4.2 3.14 220.03 8 080 F 7 690 4 080Heywoods 5.5 2.07 155.70 4 130 F 7 880 11 630Doctors Point 5.5 2.35 150.82 7 240 F 10 440 13 520Albury 4.3 1.39 148.83 - - - -Corowa 4.6 2.54 128.56 11 170 F 12 740 10 560Yarrawonga Weir (d/s) 6.4 2.41 117.45 16 210 R 13 510 6 510Tocumwal 6.4 2.81 106.65 14 600 R 11 830 5 750Torrumbarry Weir (d/s) 7.3 2.25 80.80 6 820 R 5 540 5 050Swan Hill 4.5 1.03 63.95 4 850 R 4 440 5 490Wakool Junction 8.8 2.55 51.67 6 020 R 6 620 7 120Euston Weir (d/s) 9.1 1.51 43.35 7 550 F 8 480 7 960Mildura Weir (d/s)   - - 8 670 F 6 880 8 150Wentworth Weir (d/s) 7.3 3.02 27.78 8 060 R 6 820 7 490Rufus Junction - 3.62 20.55 7 270 R 6 890 5 860Blanchetown (Lock 1 d/s) - 0.85 - 7 410 R 6 320 5 850               Tributaries              Kiewa at Bandiana 2.8 2.56 155.79 3 190 F 2 960 2 100Ovens at Wangaratta 11.9 10.22 147.90 7 870 F 7 090 5 440Goulburn at McCoys Bridge 9.0 1.42 92.84 830 F 850 680Edward at Stevens Weir (d/s) 5.5 0.94 80.71 700 F 630 1 220Edward at Liewah - 2.19 57.57 1 540 F 1 540 1 440Wakool at Stoney Crossing - 1.26 54.75 180 S 190 210Murrumbidgee at Balranald 5.0 1.98 57.94 1 590 F 1 660 1 550Barwon at Mungindi 6.1 3.47 - 690 R 470 280Darling at Bourke 9.0 4.16 - 640 R 490 530Darling at Burtundy Rocks - 0.85 - 0 F 0 0               Natural Inflow to Hume           15 710 13 750

(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 -0.07 - No. 7 Rufus River 22.10 +0.04 +1.30No. 26 Torrumbarry 86.05 +0.00 - No. 6 Murtho 19.25 +0.00 +0.11No. 15 Euston 47.60 +0.21 - No. 5 Renmark 16.30 +0.00 +0.21No. 11 Mildura 34.40 -0.04 +0.29 No. 4 Bookpurnong 13.20 +0.01 +0.91No. 10 Wentworth 30.80 +0.15 +0.38 No. 3 Overland Corner 9.80 +0.06 +0.29No. 9 Kulnine 27.40 +0.08 +0.13 No. 2 Waikerie 6.10 +0.02 +0.27No. 8 Wangumma 24.60 +0.08 +0.13 No. 1 Blanchetown 3.20 -0.05 +0.10

Lower Lakes FSL = 0.75 m AHDLake Alexandrina average level for the past 5 days (m AHD) 0.77

Barrages Fishways at Barrages  Openings Level (m AHD) No. Open Rock Ramp Vertical SlotGoolwa 128 openings 0.66 All closed - OpenMundoo 26 openings 0.66 All closed - -Boundary Creek 6 openings - 0.1 - -Ewe Island 111 gates - All closed - -Tauwitchere 322 gates 0.67 All closed Open Open

AHD = Level relative to Australian Height Datum, i.e. height above sea level

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Week ending Wednesday 05 Aug 2015

State Allocations (as at 05 Aug 2015)NSW - Murray Valley Victorian - Murray Valley

High security 80%General security 0%

High reliability 42%Low reliability 0%

NSW – Murrumbidgee Valley Victorian - Goulburn ValleyHigh security 95%General security 12%

High reliability 50%Low reliability 0%

NSW - Lower Darling South Australia – Murray ValleyHigh security 20%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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NEWS RELEASE 4/08/15

MEDIA CONTACT Jill Freear Senior Media Adviser

Department of Environment, Water and Natural Resources

Phone (08) 8463 7412 Mobile 0428 046 360 Email jill.freear@sa.gov.au

www.environment.sa.gov.au www.nrm.sa.gov.au

Barrage flows to increase significantly this weekFlows through the barrages will increase in coming days to help improve water quality in Lake Albert and the Coorong, and to assist in scouring sand out of the Murray Mouth.

The Department of Environment, Water and natural Resources (DEWNR) Water Resource Operations manager Jarrod Eaton said the operation will involve up to 30 gigalitres on Thursday and Friday, most of which would be released through Mundoo, Ewe Island and Tauwitchere barrages.

“A lower volume will be released through Goolwa barrage because the Goolwa channel is in a comparatively better condition,” Mr Eaton said.

“The operation will increase water levels in the Coorong and flows through the Murray Mouth over the next five days.

“All water users are advised that these flow conditions may present a hazard and people should take care when entering the water and wear appropriate safety equipment.

“Previous operations where barrage releases have been significantly increased have resulted in better water quality and improvements in the condition of the Murray Mouth.

“Monitoring will be carried out during the operation to check the condition of the Mouth and water quality, as the proposed flow on Thursday will be the highest daily flow in more than 12 months.

“The opportunity to adaptively manage lake levels and increase flows through the barrages is the result of local rainfall, and the delivery of South Australia’s full Entitlement Flow and environmental water. “

This operation is being led by DEWNR with support from SA Water and the Murray-Darling Basin Authority.

The action is consistent with DEWNR’s commitment to improve salinity levels in the Lower Lakes and implement actions to achieve Murray-Darling Basin Plan outcomes such as maintaining an open Murray Mouth and exporting salt to the sea.

Page 8 of 9

Lake Mulwala and Mildura weir pool are back to normal operating levels after major works at the weirs over winter.

An ongoing work program will continue to improve the Lake Mulwala foreshore and refurbishment of Mildura’s lock 11 is expected to be finished by mid-September.

MDBA head of river management David Dreverman thanked communities and river users for their understanding and cooperation.

“We had some essential infrastructure maintenance to complete this year and winter has given us a window of opportunity to get it done.

“The works have been a success. Even with an extra check of the trestles at Mildura, we have still managed to return to normal operating height this week as expected.

“With these works done, we are in the best possible place to manage the river well for local industries and communities over the irrigation season,” Mr Dreverman said.

Goulburn–Murray Water did the works on behalf of the MDBA and Mr Dreverman thanked the team for working hard to finish them quickly, safely and to a high standard.

Works at Yarrawonga included routine testing of weir anchors and erosion control on the lake foreshore. The low lake level also helped to control the aquatic weed Egeria densa. GM Water will continue to improve the condition of the foreshore as part of a five year program.

Works at Mildura included repairs to the concrete on the bed of the river and the installation of new trestles. A vibration found in one trestle, turned out to be an easy fix. River users should take note that lock 11 is expected to re-open in mid-September.

To keep up to date on the latest flow forecasts along the River Murray, visit the MDBA website: www.mdba.gov.au/river-data/current-information-forecasts/storage-volumes

Summary information for the week is available in the River Murray weekly report: www.mdba.gov.au/river-data/current-information-forecasts/weekly-report

END

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MEDI