River Murray weekly report

For the week ending Wednesday, 1 February2018

Trim Ref:D17/5605

Rainfall and inflows

A ridge of high pressure maintained hot and dry conditions across the southern Basin for much of the week before a weak cold front provided respite from high temperatures. In the north of the Basin conditions remained very hot, with a low pressure trough delivering patchy falls in Queensland and parts of New South Wales (see Map 1). In Queensland, 64 mm was recorded on the Maranoa River at Springfield, while the heaviest falls in NSW were in the Northern Tablelands where 62 mm fell at Glenn Innes. Negligible rainfall was recorded in Victoria and South Australia.

Map 1 - Murray-Darling Basin rainfall week ending 1 February 2017 (Source: Bureau of Meteorology)

This week’s hot and dry conditions reduced stream flows in the upper Murray tributaries. For example, on the Mitta Mitta River, the flow at Hinnomunjie Bridge fell from 550 ML/day to 380 ML/day while Biggara, on the upper Murray, receded from around 430 ML/day to near 290 ML/day. On the Ovens River at Wangaratta, the flow continued to recede, falling from 1,300 ML/day to 850 ML/day.

Forecast rainfall

The eight day forecast for the southern basin shows a widespread rain event throughout Victoria, South Australia and along much of the Murray, with falls in excess of 25 mm. Temperatures along the Murray system are forecast to vary between the high 20s and high 30s over the next week.

January 2017 Summary

Across the Basin as a whole, rainfall was near average in January 2017 (see Map 2). The Bureau of Meteorology (BoM) reports that overall the Basin recorded area-averaged rainfall for January of 38.3mm, which is close to the long-term median for January. Of particular note, monthly rainfall was again above-average in South Australia, following on from above average rain in December 2016 and a wet spring in 2016.Rainfall in the upper Murray catchments was generally near average or above average in January 2017.

Map 2 - Murray-Darling Basin rainfall deciles for January 2017 (Source: Bureau of Meteorology)

River Murray System inflows during January (excluding Snowy Scheme, Darling River and managed environmental flows) totalled around 260 GL, which is slightly above the month’s long-term average around 250 GL (see graph on page 8).

Temperatures were well aboveaverage across the Basin in January 2017 (Map 3). Areas of southern Queensland stretching down into northern New South Wales and south along the New South Wales ranges experienced “Highest on Record” mean January temperatures. Temperatures in much of Queensland and New South Wales have regularly exceeded 40 degrees Celsius and often exceeded 45 degrees Celsius. These hot and mostly dry conditions have contributed to very high evaporation rates from the Menindee Lakes (Table 1).

Map 3 - Mean temperature deciles for January 2017 (Source: Bureau of Meteorology)

Estimated evaporation losses from MDBA storages for January 2017 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 this calculated evaporation. Hot conditions contributed to increased evaporation in January.

Table 1: Monthly evaporation figures for MDBA storages

Storage / *Approximate (net) evaporative loss in January 2017 (GL) / Average storage volume in January 2017 (GL) / Percentage net evaporative loss in January 2017
Dartmouth / 5.2 / 3015.5 / 0.2
Hume / 30.5 / 2661.2 / 1.1
Lake Victoria / 15.8 / 557.3 / 2.8
Menindee Lakes / 109.1 / 1422.0 / 7.7

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

River operations

System Operations

Summer demands and losses along the Murray system have been lower than planned for, meaning that more water has been arriving at Lake Victoria than expected. This allows for deliveries in February, including from tributary inter valley trade (IVT) and from Menindee lakes to be reduced. Updates will be provided in coming weeks as flow rates across the system are adjusted in response to the observed and forecast weather and demands. For example, if the forecast rainfall eventuates, demands along the Murray are expected to decrease allowing for possible further reductions in deliveries to Lake Victoria.

River Operations

MDBA total storage decreased by 137 GL, with the active storage currently 6,686 GL (78% capacity).

Dartmouth Reservoir’s storage volume increased 2 GL this week to 3,024 GL (78% capacity). The release, measured at Colemans gauge, remained at 290 ML/day.

TheHume Reservoirstorage volume fell by 69 GL this week to 2,539 GL (84% capacity), with the release averaging around 12,750 ML/day. Downstream of Hume, the Kiewa River has provided an average of around 900 ML/day to the Murray.

Higher than anticipated diversions fromLake Mulwalaresulted in the pool level falling to 124.72 m AHD early in the week before rising again over the Australia Day weekend. Diversions to Yarrawonga Main Canal and Mulwala Canal have averaged 1,450 ML/day and 3,370 ML/day respectively over the past week. The release from Yarrawonga Weir has remained steady near 8,000 ML/day and would be lower without deliveries of environmental water. Currently, 1,000 ML/day of environmental water is being released for large bodied native fish and continued bird breeding in the Barmah-Millewa forest and sites further downstream. The target flow around 8,000 ML/day will continue in February.

These releases are lower than experienced over the last few years at this time of year due to downstream demands being supplemented by water from the Goulburn, Campaspe and Murrumbidgee Rivers and Menindee Lakes. This allows more water to be conserved in the major storages of Hume and Dartmouth than would otherwise have been the case.

On the Edward River system, the flow through the Edward offtake has continued to average close to 1,600 ML/day. The Gulpa Creek offtake has been reduced to 450 ML/day and is expected to lower to around 400 ML/day later in the week. Downstream at Stevens Weir the flow has fluctuated around 600ML/day and is expected to continue around this rate over the coming week.

Flows in the Broken Creek at Rice’s Weir have averaged 300 ML/day. The Goulburn River at McCoys Bridgehas gently receded to 1,350 ML/day and is expected to gradually fall to around 1,200 ML/day this coming week. The flow is expected to remain around 1,200 ML/day over the next few weeks – well above the minimum flow target of 350 ML/day, as inter valley trade (IVT) water is delivered to the Murray.In January approximately 38,200 ML of IVT was delivered from the Broken, Goulburn and Campaspe systems to the Murray to help meet downstream demands in the Murray system.If conditions remain dry, IVT deliveries can be expected to persist over the next few months to continue to help meet downstream demands.Planning is underway to combine environmental water with IVT deliveries to deliver a flow pulse in early March aimed at providing outcomes for both native fish and for water supply to the Murray. Further information will be available in coming weeks.

At Torrumbarry Weir, diversions to National Channel have remained close to 2,200 ML/day with a portion of this water provided to support Murray Cod in Gunbower Creek. Downstream of Torrumbarry Weir the flow has reduced from 5,300 ML/day to around 4,650 ML/day and is expected to gradually fall to around 4,300 ML/day over the coming week.

On the lower Murrumbidgee River, deliveries of IVT to the Murray have resulted in the flow at Balranald increasing from 650 ML/day to near 2,000 ML/day this week. IVT deliveries are to persist throughout February. Further information on IVT in the Murrumbidgee system is available from WaterNSW.

AtEuston, the flow has fluctuated around 6,000 ML/day and is expected to remain around this rate for the coming week. The lock at Euston remains closed due to repair works being undertaken on one of the upstream lock gates.Damage to the lock gate is more extensive than originally thought and repairs will likely take until mid-February to complete. In the coming weeks the Euston weir pool may be lowered below the Full Supply Level (FSL) as part of weir pool variability but will be returned to near FSL during important recreational times. Downstream of Euston the final volumes of water are returning to the Murray (Photo 1) from the Hattah Lakes following last year’s natural flooding which built upon earlier environmental watering.

Photo 1 – Return flows from Hattah Lakes returning to the Murray via Messengers Creek regulator. Source: Heather Peachey, MDBA.

On the Darling River, total storage at Menindee Lakes fell by 50 GL to a storage volume of 1,301 GL (75% capacity).Additional Dilution Flows to South Australia will cease once the total volume drops below 1,300 GL. Therelease at Weir 32 has targeted 5,000 ML/day this week and is to be gradually lowered to 4,000 ML/day over the coming days. For more information on Menindee operations see the attached media release.

At Wentworth, the flow has declined to around 7,200 ML/dayand may slowly rise over the coming days. The weir pool at Lock 9 was lowered by 100 mm on Wednesday 25 January to investigate a structural issue at Carrs No.2 regulator. The weir pool will remain lowered while the issue is being investigated. Updates will be provided as information comes to hand. Lock 8 weir pool continues to be lowered to target 50 cm below FSL. It is currently 23 cm below FSL. The lowering of Lock 7 weir pool by up to 50 cm is also underway and is currently around 44 cm below FSL. Weir pool variability helps to restore a more natural wetting and drying cycle to riverbanks within the weir pool. More information on possible weir pool levels in the coming weeks is available on the MDBA website.

The storage volume at Lake Victoria fell 20 GL to 496 GL (73% capacity) with the releases from Lake Victoria averaging near 2,600 ML/day. The flow to South Australiaaveraged 10,500 ML/day this week and is expected to be gradually reduced throughout the remainder of February. This flow is largely made up of South Australian entitlement and additional dilution flow,with a smaller proportion of environmental water being delivered to South Australia.

Recent high flows to South Australia helped to improve connectivity between the Coorong and the ocean however they did not scour as much sand at the Murray Mouth as the longer period of high flows in 2010-11. Now that the high flows have passed through the river system, releases over the barrages are being reduced and dredging has again resumed to ensure the Murray Mouth remains open – with only one dredge required at this stage. More information on the Murray Mouth and dredging conditions can also be found in South Australia’s River Murray Weekly Flow Report.

For media inquiries contact the Media Officer on 02 6279 0141

ANDREW REYNOLDS

Acting / Executive Director, River Management

Water in Storage Week ending Wednesday 01 Feb 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 / 472.35 / 3 024 / 78% / 71 / 2 953 / +2
Hume Reservoir / 192.00 / 3 005 / 189.57 / 2 539 / 84% / 23 / 2 516 / -69
Lake Victoria / 27.00 / 677 / 25.44 / 496 / 73% / 100 / 396 / -20
Menindee Lakes / 1 731* / 1 301 / 74% / (480 #) / 821 / -50
Total / 9 269 / 7 360 / 80% / - - / 6 686 / -137
Total Active MDBA Storage / 78% ^
Major State Storages
Burrinjuck Reservoir / 1 026 / 820 / 80% / 3 / 817 / -46
Blowering Reservoir / 1 631 / 1 364 / 84% / 24 / 1 340 / -44
Eildon Reservoir / 3 334 / 2 524 / 76% / 100 / 2 424 / -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 31 Jan 2017

Storage / Active Storage (GL) / Weekly Change (GL) / Diversion (GL) / This Week / From 1 May 2016
Lake Eucumbene - Total / 1 915 / -10 / Snowy-Murray / +10 / 916
Snowy-Murray Component / 867 / -9 / Tooma-Tumut / +1 / 321
Target Storage / 1 460 / Net Diversion / 9 / 595
Murray 1 Release / +8 / 1 313

Major Diversions from Murray and Lower Darling (GL) *

New South Wales / This Week / From 1 July 2016 / Victoria / This Week / From 1 July 2016
Murray Irrig. Ltd (Net) / 40.6 / 533 / Yarrawonga Main Channel (net) / 9.9 / 115
Wakool Sys Allowance / 2.4 / 6 / Torrumbarry System + Nyah (net) / 12.2 / 232
Western Murray Irrigation / 1.2 / 14 / Sunraysia Pumped Districts / 4.7 / 61
Licensed Pumps / 9.8 / 123 / Licensed pumps - GMW (Nyah+u/s) / 1 / 14
Lower Darling / 0.1 / 3 / Licensed pumps - LMW / 11.3 / 218
TOTAL / 54.1 / 679 / TOTAL / 39.1 / 640

* 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 unregulated flows. / Entitlement this month / 194.0 *
Flow this week / 73.7 / (10 500 ML/day)
Flow so far this month / 10.0
Flow last month / 458.7

Salinity (EC) (microSiemens/cm at 25o C)

Current / Average over the last week / Average since 1 August 2016
Swan Hill / 100 / 100 / 130
Euston / - / - / -
Red Cliffs / 190 / 180 / 170
Merbein / 180 / 180 / 170
Burtundy (Darling) / 420 / 430 / 630
Lock 9 / 310 / 270 / 180
Lake Victoria / 210 / 210 / 190
Berri / 330 / 320 / 220
Waikerie / 400 / 390 / 270
Morgan / 420 / 400 / 270
Mannum / 420 / 430 / 290
Murray Bridge / 380 / 410 / 280
Milang (Lake Alex.) / 380 / 370 / 520
Poltalloch (Lake Alex.) / 470 / 450 / 330
Meningie (Lake Alb.) / 1 760 / 1 680 / 1 760
Goolwa Barrages / 460 / 430 / 1 140

River Levels and Flows Week ending Wednesday 01 Feb 2017

Minor Flood Stage / Gauge / Height / Flow / Trend / Average Flow this Week / Average Flow last Week
River Murray / (m) / local (m) / (m AHD) / (ML/day) / (ML/day) / (ML/day)
Khancoban / - / - / - / 940 / F / 2 460 / 2 330
Jingellic / 4.0 / 1.37 / 207.89 / 2 050 / F / 3 260 / 3 930
Tallandoon ( Mitta Mitta River ) / 4.2 / 1.45 / 218.34 / 680 / F / 710 / 1 340
Heywoods / 5.5 / 2.93 / 156.56 / 12 700 / R / 12 850 / 10 250
Doctors Point / 5.5 / 2.93 / 151.40 / 14 160 / F / 14 420 / 12 330
Albury / 4.3 / 1.91 / 149.35 / - / - / - / -
Corowa / 4.6 / 2.85 / 128.87 / 13 200 / R / 13 900 / 11 780
Yarrawonga Weir (d/s) / 6.4 / 1.37 / 116.41 / 7 990 / F / 7 970 / 8 070
Tocumwal / 6.4 / 2.11 / 105.95 / 7 390 / R / 8 540 / 9 420
Torrumbarry Weir (d/s) / 7.3 / 1.63 / 80.18 / 4 650 / F / 4 940 / 5 500
Swan Hill / 4.5 / 1.03 / 63.95 / 4 910 / S / 5 110 / 6 030
Wakool Junction / 8.8 / 2.57 / 51.69 / 6 180 / S / 6 450 / 9 580
Euston Weir (d/s) / 9.1 / 1.31 / 43.15 / 6 360 / R / 6 050 / 7 110
Mildura Weir (d/s) / - / - / 5 010 / F / 5 800 / 7 520
Wentworth Weir (d/s) / 7.3 / 2.90 / 27.66 / 7 230 / R / 7 910 / 9 740
Rufus Junction / - / 3.96 / 20.89 / 9 540 / F / 9 980 / 12 430
Blanchetown (Lock 1 d/s) / - / 0.89 / - / 6 800 / F / 9 250 / 12 510
Tributaries
Kiewa at Bandiana / 2.8 / 1.19 / 154.42 / 800 / F / 880 / 1 350
Ovens at Wangaratta / 11.9 / 8.09 / 145.77 / 850 / F / 970 / 1 480
Goulburn at McCoys Bridge / 9.0 / 1.73 / 93.15 / 1 360 / F / 1 480 / 1 580
Edward at Stevens Weir (d/s) / 5.5 / 0.81 / 80.58 / 580 / S / 700 / 730
Edward at Liewah / - / 1.51 / 56.89 / 860 / F / 890 / 730
Wakool at Stoney Crossing / - / 1.53 / 55.02 / 670 / S / 670 / 720
Murrumbidgee at Balranald / 5.0 / 2.27 / 58.23 / 1 960 / R / 1 710 / 450
Barwon at Mungindi / 6.1 / 3.42 / - / 560 / R / 370 / 70
Darling at Bourke / 9.0 / 4.04 / - / 160 / S / 240 / 420
Darling at Burtundy Rocks / - / 2.72 / - / 4 140 / S / 4 220 / 4 300
Natural Inflow to Hume / 2 860 / 5 090

(i.e. Pre Dartmouth & Snowy Mountains scheme)

Weirs and LocksPool 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 / -0.11 / - / No. 7 Rufus River / 22.10 / -0.44 / +1.63
No. 26 Torrumbarry / 86.05 / +0.00 / - / No. 6 Murtho / 19.25 / -0.03 / +0.30
No. 15 Euston / 47.60 / +0.04 / - / No. 5 Renmark / 16.30 / +0.01 / +0.35
No. 11 Mildura / 34.40 / +0.02 / +0.05 / No. 4 Bookpurnong / 13.20 / +0.03 / +1.08
No. 10 Wentworth / 30.80 / +0.03 / +0.26 / No. 3 Overland Corner / 9.80 / -0.01 / +0.38
No. 9 Kulnine / 27.40 / -0.11 / -0.15 / No. 2 Waikerie / 6.10 / +0.01 / +0.27
No. 8 Wangumma / 24.60 / -0.23 / -0.11 / No. 1 Blanchetown / 3.20 / -0.09 / +0.14

Lower LakesFSL = 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 / 0.84 / 3 / - / Open / Open / -
Mundoo / 26 openings / 0.77 / 1 / - / - / - / Open
Hunters Creek / - / - / - / - / Open / - / -
Boundary Creek / 6 openings / - / 1 / - / Open / - / -
Ewe Island / 111 gates / - / All closed / - / - / - / Closed
Tauwitchere / 322 gates / 0.80 / 17 / Open / Open / Open / -

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

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Page 1 of 11

Week ending Wednesday 01 Feb 2017

State Allocations (as at 01 Feb 2017)

NSW - Murray Valley / Victorian - Murray Valley
High security / 100%
General security / 100%
/ High reliability / 100%
Low reliability / 0%
NSW – MurrumbidgeeValley / Victorian- GoulburnValley
High security / 100%
General security / 100%
/ High reliability / 100%
Low reliability / 0%
NSW - Lower Darling / South Australia – MurrayValley
High security / 100%
General security / 100%
/ High security / 100%
NSW : /
VIC : /
SA : /

WaterNSW manages the Menindee Lakes system to supply licensed customers including Essential Water and lower Darling landholders, as well as ensuring water security for the region. The MDBA calls on water to be released from the lakes as required to contribute to the River Murray System on behalf of Basin governments.

The Menindee lakes system is currently holding approximately 1,347 gigalitres (GL), or 76% of its total capacity. Since 4 January 2017, the total water stored in the lakes has reduced by 160GL, of which 98GL was released to meet downstream demands.

Releases have continued to target 5000ML/d at Weir 32 for the past week. In response to lower than expected demands across the Murray system the MDBA has directed releases to be progressively reduced to 4000 ML/day over four days, commencing Thursday 2 February.

With the Menindee Lakes storage volume expected to reduce below 1,300GL within the next week the target flow to South Australia will reduce by 3,000 ML/d. The MDBA will direct how releases across all Murray System storages, including Menindee lakes, are to be adjusted to most efficiently meet demands and maximise water availability for entitlement holders.

Lake Pamamaroo 332GL (123%) remains surcharged, while Lake Wetherell holds 176GL (91%), Lake Menindee holds 380GL (58%) and Lake Cawndilla holds about 458GL (70%).

WaterNSW is continuing to source the majority of the release from Lake Menindee, with a smaller amount from Lake Wetherell. This is because the Lake Menindee outlet is currently capacity constrained, and water from Lake Wetherell is required to meet the flow target at Weir 32.

Releases from Lake Wetherell have provided two outcomes: reduced loss to evaporation and protected the health of the floodplain ecosystem that was inundated by the storage being surcharged. WaterNSW has also taken the opportunity to transfer water from Lake Wetherell to Lake Pamamaroo to reduce the lakes’ total surface area.

WaterNSW is currently assessing the timing for switching releases from the Lake Wetherell outlet to the Lake Pamamaroo outlet, taking in to consideration both long term water availability, and minimisation of evaporation losses.

WaterNSW is continuing to work with the MDBA to plan releases and minimise impacts to long term water availability for Broken Hill town water supply and lower Darling customers, whilst meeting legislative and operational requirements of the Murray – Lower Darling River system.

WaterNSW is also collaborating with NSW DPI Water, the MDBA and OEH on the potential delivery of water to the Darling Anabranch. Primarily flows to the Darling Anabranch are being considered for environmental outcomes, in particular, maximising recent fish breeding outcomes within the Menindee Lakes system. Assessment of potential resource implications are continuing, with a decision on releases to the Darling Anabranch expected within weeks.