River Murray weekly report
For the week ending Wednesday, 20 December 2017
Trim Ref: D17/59127
The Murray-Darling Basin Authority and staff at the storages, weirs and barrages of the River
Murray System wish all our readers a safe and happy festive season.
Rainfall and inflows
It was a hot and mostly dry week across the Murray-Darling Basin, although patchy thunderstorms brought rain to parts of eastern NSW. Later in the week, a trough system brought cooler temperatures and patchy rain and thunderstorms through southern areas, including along the mid-Murray.
The highest weekly rainfall totals were recorded over parts of the NSW Northern Tablelands and Victoria’s eastern ranges (Map 1). Notable rainfall totals in NSW included 46 mm at Deepwater, 29mm at Nundle and 21 mm at Burrinjuck Dam. Totals in Victoria included 35 mm at Mt Hotham and 29 mm at Mt Buller.
Map 1 - Murray-Darling Basin rainfall map week ending 20 December 2017 (Source: Bureau of Meteorology).
Stream flows along upper Murray system tributaries continued to recede this week, but are yet to return to the levels observed prior to the significant rain event in the first week of December. Only minimal flow responses were observed from rain late in the past week. On the upper Mitta Mitta River, the flow at Hinnomunjie Bridge decreased from 1,100 to 700 ML/day. On the upper Murray, the flow at Biggara reduced from 1,000 to 700 ML/day. Downstream on the Ovens River, the flow at Wangaratta started the week at 3,400 ML/day and is now flowing at 2,150 ML/day.
River operations
MDBA total active storage decreased by 64 GL to 6,159 GL (73% active storage).
The storage volume at Dartmouth Reservoir increased by 7 GL to 3,428 GL (89% capacity). The release from Dartmouth Reservoir, measured at Colemans, was increased above the minimum flow rate of 200ML/day to 300 ML/day last Thursday to help meet downstream demands along the Mitta Mitta River over summer. A brief increase in the release to around 3,000 ML/day is planned for early January for the benefit of water quality in the Mitta Mitta River downstream of Dartmouth Dam.
At Hume Reservoir, the storage volume decreased by 61 GL to 2,261 GL (75% capacity). The release has averaged close to 14,000 ML/day and is expected to be reduced towards 11,000 ML/day in the coming days. Downstream of the Kiewa River junction, flow rates near Albury have averaged around 15,800 ML/day, which is fairly typical of regulated summer conditions (Photo 1).
Photo 1. ‘Googar’ - a larger than life wooden goanna sculpture by Wiradjuri artist Darren Wighton. Part of the Yindyamarra Sculpture Walk, along the banks of the Murray near Albury. (Photo courtesy: Hugo Bowman MDBA)
Downstream at Lake Mulwala, the pool level is currently at 124.82 m AHD. A pool level within the normal summer operating range of 124.7 to 124.9 m AHD will be targeted over the Christmas period. Irrigation diversions continued to increase on the New South Wales side with diversion into Mulwala Canal increasing from 2,800 ML/day to 4,200ML/day. On the Victorian side, diversion to Yarrawonga Main Channel has reduced from around 1,700 ML/day to 900 ML/day.
Releases from Yarrawonga Weir were around 11,000 ML/day for most of the week and are now targeting 10,500 ML/day. The release is to be lowered back within the channel capacity of the Barmah choke (approximately 10,000 ML/day) by Christmas Day (assuming conditions remain dry). The regulators to the Barmah-Millewa forest have been gradually closed over the last week with the remaining regulators to be closed in the coming week as the releases from Yarrawonga Weir reduce.
Flow into the Gulpa Creek has remained near 500 ML/day for most of this week but has now temporarily increased to 600 ML/day and will remain near this rate over the coming days. Flow through the Edward Offtake has increased from around 1,400 ML/day to near 1,600ML/day and will temporarily increase further to 2,000 ML/day for a few day’s to manage the height in the Murray at Picnic Point. Return flows from the Millewa forest into the Edward River continue to recede, with the flow at Toonalook reducing from 4,100 ML/day to 3,000 ML/day. The hot and dry conditions contributed to Wakool Main Canal diversion more than doubling this week to an average of just over 1,000 ML/day. Further downstream along the Edward River, the release from Stevens Weir has continued to gradually decrease and is currently near 1,500 ML/day. Over the coming week the flow may gradually recede further. Given these flows are now well below channel capacity, the Werai Forest regulators have now been closed.
Inflow to the Murray from the Goulburn River, measured at McCoys Bridge, continues to fall after peaking two weeks ago following heavy rainfall. The flow is now back to 1,450 ML/day and is expected to continue to gradually fall towards 850 ML/day over the coming weeks. Inflows from the Campaspe River have been steady around 100 ML/day.
National Channel diversion from Torrumbarry Weir pool was increased to 2,600 ML/day earlier in the week but has now been reduced to 2,000 ML/day in anticipation of reduced irrigation demand in the Torrumbarry Irrigation District over the next fortnight. This week the release from Torrumbarry Weir has fallen from over 19,000 ML/day to near 9,300 ML/day as inflows from the Goulburn slowed. Without further rain, the flow is forecast to ease further over the next fortnight.
Inflows from the Murrumbidgee River, measured at Balranald, peaked near 3,300 ML/day during the week. This higher flow was a result of inflows and reduced irrigation demand following the widespread rainfall event over a fortnight ago. The flow at Balranald is expected to fall towards 400ML/day in the coming week.
This week’s thunderstorm activity over the mid-Murray has augmented the higher flows that resulted from heavy rainfall in early December. As a result, a small, short-lived unregulated flow event has been called from the Murrumbidgee Junction downstream to the South Australian border. For more information water users in this reach should refer to their local water authority.
At Euston, the weir pool level has been increased to around 20 cm above the FSL to capture additional flow in the river and maximise water availability. The release downstream peaked around 20,400 ML/day and will recede into the New Year. Downstream, return flows from Hattah Lakes continue to enter the Murray via the Messengers and Oateys regulators to Chalka Creek (south and north respectively). These flows provide connectivity between the lakes and the River Murray, and also provide valuable food and nutrients to the Murray. Total return flows from Hattah have averaged around 700ML/day this week.
At Menindee Lakes, the weekly storage volume reduced by 17 GL to 466 GL (27% capacity). The combined storage of the lakes dropped below 480 GL by Saturday 16 December, meaning that water will no longer be released to meet River Murray demands until the combined volume again exceeds 640GL. A red alert warning (high alert) for blue-green algae is current for Lake Wetherell and Lake Menindee. The release from Weir 32 is being gradually reduced by WaterNSW to around 200 ML/day.
Back on the Murray, the flow at Wentworth has increased to around 18,600 ML/day and is likely to peak around Sunday or Monday.
Operations at Lock 9, 8 and 7 continue to target weir pool levels around the Full Supply Level (FSL).
The Lake Victoria storage volume increased by 7 GL to 664 GL (98% capacity). The higher river flows in transit following rainfall over a fortnight ago mean Lake Victoria will be filled in the coming days. The flow to South Australia reduced from 17,000 ML/day to 12,000 ML/day before increasing to 13,800 ML/day. In the coming days the flow will increase further before receding into the New Year.
At the Lower Lakes, the 5-day average water level in Lake Alexandrina has decreased slightly to 0.83mAHD, but remains above the normal full supply level of 0.75 m AHD. Releases through the barrages have increased and continue to be managed to provide salinity gradients in the Coorong to support black bream breeding. Actual flows fluctuate with downstream tidal levels, but estimated rates have exceeded 10,000ML/day at times. All barrage fishways remain open.
There will be no Weekly Report issued for the week ending Wednesday, 27th December 2017. The next report will be available from Friday, 5th January 2018.
Flow and salinity forecasts will be updated and available on the MDBA website on Wednesday, 3rd January 2018.
For media inquiries contact the Media Officer on 02 6279 0141
ANDREW REYNOLDS
Executive Director, River Management
Water in Storage Week ending Wednesday 20 Dec 2017
MDBA Storages / Full Supply Level / Full Supply Volume / Current Storage Level / Current / Storage / Dead Storage / Active Storage / Change in Total Storage for the Week(m AHD) / (GL) / (m AHD) / (GL) / % / (GL) / (GL) / (GL)
Dartmouth Reservoir / 486.00 / 3 856 / 479.25 / 3 428 / 89% / 71 / 3 357 / +7
Hume Reservoir / 192.00 / 3 005 / 187.99 / 2 261 / 75% / 23 / 2 238 / -61
Lake Victoria / 27.00 / 677 / 26.90 / 664 / 98% / 100 / 564 / +7
Menindee Lakes / 1 731* / 466 / 27% / (- -) # / 0 / -17
Total / 9 269 / 6 819 / 74% / - - / 6 159 / -64
Total Active MDBA Storage / 73% ^
Major State Storages
Burrinjuck Reservoir / 1 026 / 710 / 69% / 3 / 707 / -12
Blowering Reservoir / 1 631 / 890 / 55% / 24 / 866 / -41
Eildon Reservoir / 3 334 / 2 515 / 75% / 100 / 2 415 / -10
* 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 19 Dec 2017
Storage / Active Storage (GL) / Weekly Change (GL) / Diversion (GL) / This Week / From 1 May 2017Lake Eucumbene - Total / 1 790 / n/a / Snowy-Murray / +14 / 548
Snowy-Murray Component / 770 / n/a / Tooma-Tumut / +4 / 177
Target Storage / 1 510 / Net Diversion / 10 / 371
Murray 1 Release / +19 / 758
Major Diversions from Murray and Lower Darling (GL) *
New South Wales / This Week / From 1 July 2017 / Victoria / This Week / From 1 July 2017Murray Irrig. Ltd (Net) / 34.2 / 392 / Yarrawonga Main Channel (net) / 9.1 / 128
Wakool Sys Allowance / 0.0 / 16 / Torrumbarry System + Nyah (net) / 15.9 / 207
Western Murray Irrigation / 1.2 / 9 / Sunraysia Pumped Districts / 5.1 / 47
Licensed Pumps / 5.6 / 95 / Licensed pumps - GMW (Nyah+u/s) / 1 / 17
Lower Darling / 5.6 / 41 / Licensed pumps - LMW / 4.6 / 142
TOTAL / 46.6 / 553 / TOTAL / 35.7 / 541
* 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 environmental and unregulated flows / Entitlement this month / 217.0 *
Flow this week / 90.8 / (13 000 ML/day)
Flow so far this month / 293.5
Flow last month / 294.3
Salinity (EC) (microSiemens/cm at 25o C)
Current / Average over the last week / Average since 1 August 2017Swan Hill / 140 / 130 / 110
Euston / - / - / -
Red Cliffs / 160 / 130 / 160
Merbein / 110 / 120 / 150
Burtundy (Darling) / 610 / 600 / 690
Lock 9 / 160 / 150 / 170
Lake Victoria / 210 / 210 / 230
Berri / 210 / 210 / 290
Waikerie / 210 / 230 / 350
Morgan / 240 / 250 / 370
Mannum / 330 / 340 / 420
Murray Bridge / 370 / 360 / 470
Milang (Lake Alex.) / 720 / 700 / 630
Poltalloch (Lake Alex.) / 600 / 640 / 590
Meningie (Lake Alb.) / 1 580 / 1 550 / 1 530
Goolwa Barrages / 840 / 830 / 1 240
River Levels and Flows Week ending Wednesday 20 Dec 2017
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 / - / - / - / 910 / F / 3 590 / 1 010
Jingellic / 4.0 / 1.54 / 208.06 / 3 310 / F / 5 130 / 4 320
Tallandoon ( Mitta Mitta River ) / 4.2 / 1.59 / 218.48 / 1 000 / S / 1 030 / 1 270
Heywoods / 5.5 / 2.92 / 156.55 / 14 000 / S / 14 100 / 6 660
Doctors Point / 5.5 / 3.04 / 151.51 / 15 680 / R / 15 760 / 9 920
Albury / 4.3 / 2.04 / 149.48 / - / - / - / -
Corowa / 4.6 / 3.11 / 129.13 / 14 940 / F / 14 750 / 8 330
Yarrawonga Weir (d/s) / 6.4 / 1.90 / 116.94 / 11 480 / R / 11 190 / 13 060
Tocumwal / 6.4 / 2.50 / 106.34 / 11 260 / R / 11 460 / 13 460
Torrumbarry Weir (d/s) / 7.3 / 3.01 / 81.55 / 9 260 / F / 11 720 / 21 520
Swan Hill / 4.5 / 2.10 / 65.02 / 11 950 / F / 16 110 / 16 670
Wakool Junction / 8.8 / 5.11 / 54.23 / 17 980 / F / 19 380 / 17 140
Euston Weir (d/s) / 9.1 / 3.28 / 45.12 / 20 370 / R / 18 660 / 15 470
Mildura Weir (d/s) / - / - / 18 260 / F / 16 680 / 15 770
Wentworth Weir (d/s) / 7.3 / 3.70 / 28.46 / 18 570 / R / 16 960 / 17 390
Rufus Junction / - / 4.43 / 21.36 / 12 970 / R / 12 150 / 16 140
Blanchetown (Lock 1 d/s) / - / 1.07 / - / 9 820 / F / 11 670 / 14 930
Tributaries
Kiewa at Bandiana / 2.8 / 1.59 / 154.82 / 1 320 / R / 1 440 / 2 180
Ovens at Wangaratta / 11.9 / 8.66 / 146.34 / 2 150 / R / 2 480 / 5 020
Goulburn at McCoys Bridge / 9.0 / 1.78 / 93.20 / 1 450 / F / 1 980 / 9 850
Edward at Stevens Weir (d/s) / 5.5 / 1.69 / 81.46 / 1 510 / F / 1 970 / 2 980
Edward at Liewah / - / 2.85 / 58.23 / 2 300 / R / 2 120 / 2 140
Wakool at Stoney Crossing / - / 1.91 / 55.40 / 1 980 / F / 2 160 / 1 760
Murrumbidgee at Balranald / 5.0 / 2.81 / 58.77 / 2 660 / F / 2 720 / 1 150
Barwon at Mungindi / 6.1 / 3.14 / - / 30 / S / 50 / 110
Darling at Bourke / 9.0 / 4.11 / - / 370 / R / 390 / 360
Darling at Burtundy Rocks / - / 0.85 / - / 490 / R / 490 / 550
Natural Inflow to Hume / 5 320 / 9 550
(i.e. Pre Dartmouth & Snowy Mountains scheme)