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

River Murray Weekly Report For the week ending Wednesday, 1 May 2019

Trim Ref: D19/23469

April summary The Bureau of Meteorology (BoM) reports that April 2019 was the equal 7th warmest April on record for Australia as a whole. Across the Murray-Darling Basin, most of South Australia, Victoria and New South Wales experienced above average minimum and maximum temperatures with many locations recording values in the highest 10% of historical records (Map 1 & 2). In the Queensland section of the Basin, minimum temperatures were above average, although maximum temperatures ranged from above average to below average.

Map 1 & 2 – Maximum and minimum temperature deciles for April 2019 (Source: Bureau of Meteorology)

The BoM reports an area-average rainfall for the Murray-Darling Basin in April of 20.4 mm which is 47% below the April long-term average for the Basin. Despite this, rainfall deciles were mixed across the Basin (Map 3). Areas of southern Queensland and western New South Wales received above average rainfall, largely produced by a cold front and low pressure trough in the second half of April. Conversely, almost all of South Australia, Victoria and the remainder of New South Wales experienced well below average rainfall. Of particular note, the majority of the Great Dividing Range, extending from Queensland down into the New South Wales and Victorian Murray catchments, had very much below average rainfall. This has resulted in another month of low inflows to the River Murray System.

River Murray system inflows for April 2019 totalled approximately 68 GL which is well below the long-term median inflow for April of 169 GL. This is within the lowest 3% of records for April. For the twelve months ending April, inflows to the River Murray System are near 2,730 GL which is in the lowest 7% of records (median for May to April near 7,440 GL). While inflows have been low, inflows over the last 12 months are around three times the historical minimum inflows experienced over the same period in 2006-07.

River Murray Weekly Report

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

Map 3 – Murray-Darling Basin rainfall deciles for April 2019 (Source: Bureau of Meteorology)

Weekly rainfall and inflows Rainfall early this week produced modest totals over the upper Warrego catchment of Queensland, including 32 mm at Derbyshire Downs (Map 4). Conditions across most of the Murray-Darling Basin remained dry for the remainder of the week until a low pressure trough, in association with an approaching cold front and complex low pressure system, delivered between 5 and 25 mm over an area stretching from north-west New South Wales down to the Victorian ranges. Over the coming days the cold front and complex low is forecast (Map 5) to bring significant rainfall to areas of New South Wales and Victoria.

For the week ending 1 May, streamflow in upper Murray tributaries either eased or remained steady at baseflow levels. On the upper Mitta Mitta River at Hinnomunjie Bridge, the flow decreased from around 200 ML/day to 150 ML/day. The flow on the upper Murray, at Biggara, reduced marginally from near 210 ML/day to around 190 ML/day. The Kiewa River, at Bandiana, remained steady around 220 ML/day this week, while the Ovens River at Wangaratta eased from 350 ML/day to 280 ML/day.

Streamflow increases are expected in the coming days if forecast rainfall eventuates.

River Murray Weekly Report

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

Map 4 – Murray-Darling Basin rainfall deciles for the week ending 1 May 2019. (Source: Bureau of Meteorology)

Map 5 – Total forecast rainfall for the four days from 1 May to 4 May 2019. (Source: Bureau of Meteorology)

River Murray Weekly Report

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

River operations

System operations The past 12 months have seen very low inflows to the River Murray system. Transfers from Dartmouth to Hume Reservoir and from Hume to Lake Victoria were required to ensure all system demands could be met over a very hot and dry summer and autumn period. Along with these transfers, the Lake Victoria storage was used to help meet system demands. As a result Lake Victoria is at the fifth lowest level in the past 50 years. Deliberately targeting a low storage level maximises the opportunity for any inflows over autumn and winter to be captured in Lake Victoria – conserving volumes held in upstream storages.

As temperatures continue to ease and the irrigation season draws to a close, system transfers have been reduced. Transfers from Dartmouth to Hume Reservoir ceased in March and both releases from Yarrawonga and IVT delivery from the Goulburn system have both lessened. Over the coming week there is a low risk of a shortfall (based on current demands, weather forecasts and operations).

River operations The MDBA active storage volume decreased by 50 GL this week to 2,820 GL (33% capacity). This is approximately 1,970 GL below the long term average for this time of year (Figure 1).

Figure 1 – MDBA active storage for the period June 2000 to present

At Dartmouth Reservoir, the storage volume decreased by 4 GL to 2,441 GL (63% capacity). The release from Dartmouth, measured at Colemans, will reduce from the current release near 400 ML/day to 300 ML/day in the coming days.

• Welcome rainfall forecast over coming days • Yarrawonga release reduced • The delivery of IVT from the Goulburn continues • Upcoming weir pool level changes at Locks 15, 8 and 7

River Murray Weekly Report

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

At Hume Reservoir, the storage volume continued to decline, reducing by 41 GL to 405 GL (13% capacity). The release from Hume has been reduced throughout the week from 8,200 ML/day to the current release of 3,600 ML/day as system demands ease and significant rainfall is forecast. The release may reduce further in the coming days.

Photo 1 & 2 – Top: The River Murray upstream of Hume Dam at Jingellic. Bottom: Hume Reservoir. Photo courtesy Michelle Hampton

Downstream at Lake Mulwala the level is currently at 124.8 m AHD which is within the normal operating range (124.6 to 124.9 m AHD). Irrigation diversions have decreased over the past few days in anticipation of the forecast rainfall. The diversion to Yarrawonga Main Channel reduced from 600 ML/day to 100 ML/day, with the current diversion being returned to the Murray via Broken Creek. On the New South Wales side, Mulwala Canal has fallen from near 1,400 ML/day to 900 ML/day. Diversion into Mulwala Canal is expected to cease for this irrigation season on 8 May.

River Murray Weekly Report

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

The release from Yarrawonga Weir was gradually reduced this week from 8,200 ML/day to 6,100 ML/day and is likely to lower below 5,000 ML/day in the coming weeks. These reductions are in response to reduced downstream system demands, which is typical for this time of year.

Flows at the Edward River and Gulpa Creek offtakes have remained fairly steady near 1,500 ML/day and 330 ML/day respectively. In the coming week, as River Murray levels downstream of Yarrawonga fall, it is expected that flow into the Edward and Gulpa offtakes will begin to decrease. Once this occurs, the offtake gates can be raised clear of the water, improving fish passage and allowing the flow in the Edward and Gulpa to fluctuate in-line with the Murray. The flow downstream of Stevens Weir averaged 1,300 ML/day this week and is forecast to remain near this rate over the coming week.

Inflow to the Murray from the Goulburn River, measured at McCoys Bridge, remained steady near 950 ML/day and, without substantial rainfall, is expected to remain around this rate during May. The majority of this flow is Goulburn Valley Inter Valley Trade (IVT) water that is being delivered to help meet demands on the River Murray as a result of trade from the Goulburn to the Murray valley. Information regarding current opportunities for allocation trade between the Goulburn and Murray valleys is available at the Victorian water register website.

National Channel diversions reduced this week from 1,900 ML/day to around 1,300 ML/day and are forecast to remain near this rate over the coming week.

The release downstream of Torrumbarry Weir is currently near 5,000 ML/day and expected to ease over the coming fortnight as the reduced Yarrawonga release passes downstream. Lock 26 at Torrumbarry remains closed while urgent repairs are made to damaged inlet valves.

This week, inflows from the Murrumbidgee River, measured at Balranald, averaged around 220 ML/day and are expected to approach 300 ML/day this week. The Murrumbidgee IVT balance is currently only 8.7 GL, preventing the MDBA from calling water from the Murrumbidgee to help meet Murray system demands.

At Euston, the weir pool is currently targeting around Full Supply Level (FSL) and during May will be gradually lowered to 30 cm below FSL. The downstream release increased from 5,700 ML/day to 6,400 ML/day and may increase slightly in the coming days.

In the northern Basin, flows resulting from a significant rainfall event in late March have continued to move steadily downstream along various tributaries. Follow-up rainfall has helped some Warrego flow reach the Darling River, with the first gauge downstream of the Warrego-Darling junction at Louth rising to near 300 ML/day this week. The flows continue to provide significant environmental benefit, recharging parched waterholes, wetlands and landscapes. Without further significant rainfall it is unlikely that flows will progress as far as the Menindee Lakes.

A red level warning (high alert) for blue-green algae remains at a number of sites along the Darling River including Menindee Lakes. A summary of alert levels in New South Wales is available on the WaterNSW website. Current environmental conditions in the Darling River system are well suited to algal growth due to warm water temperatures and low or no flow conditions. More information regarding the water quality conditions of the lakes and the lower Darling is available at the WaterNSW website. Information on factors that affect fish is available from NSW Department of Primary Industries website. Information on drought impacts across the Murray-Darling Basin including on fish and system operations is available on the MDBA website.

The Menindee Lakes storage volume is 17 GL (1% capacity). WaterNSW continues to manage the Menindee Lakes in accordance with the Lower Darling Annual Operations Plan. As part of drought contingency measures within this plan, WaterNSW has installed four temporary block banks across the lower Darling upstream of Pooncarie at Court Nareen and Karoola, below Pooncarie near Jamesville and below Burtundy near Ashvale. Water held in these pools will assist in maintaining supply to domestic, stock and permanent plantings along the lower Darling. The release from Weir 32 ceased on 12th of February. WaterNSW has advised that releases at Weir 32 are only planned to recommence when significant inflows are received into the Menindee lakes. Despite localised rainfall this week inflows are currently zero and no significant inflows are expected. Water restrictions remain in place across much of New South Wales as a result of the extensive and on-going drought conditions.

River Murray Weekly Report

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

At Wentworth Weir, operations continue to target a pool level of around 10 cm above the full supply level to assist pumpers in the upper reaches of the Darling River arm of the weir pool whilst there is no inflow from the Darling River. The downstream release increased from 4,500 ML/day to 5,500 ML/day this week.

The Lock 9 weir pool is currently varying between FSL and 10 cm below FSL. As part of the weir pool variability program Lock 8 and 7 water levels are currently lowered. At Lock 8, the weir pool has targeted 100 cm below FSL and will increase to around 80 cm below FSL during May. The Lock 7 weir pool is around 80 cm below FSL and will increase to around 10 cm below FSL this month.

At Lake Victoria the storage decreased by 5 GL to 168 GL (25% capacity). The flow to South Australia is currently near 4,600 ML/day and is expected to lower to around 3,200 ML/day during this week and remain at this rate for the next fortnight. The current flow consists of entitlement flow, traded water and environmental water.

The 5-day average water level in the Lower Lakes remained steady at 0.52 m AHD. Environmental water delivered to South Australia has helped to slow the rate of fall at the Lower Lakes and prolong small barrage releases to support mudflat habitat for migratory birds and improve salinity levels in the Coorong. All fishways remain open. For more information see the South Australian Department for Environment and Water’s latest River Murray flow report.

For media inquiries contact the Media Officer on 02 6279 0141

ANDREW REYNOLDS Executive Director, River Management

River Murray Weekly Report

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

Water in Storage Week ending Wednesday 01 May 2019

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 3 856 461.38 2 441 63% 71 2 370 -4 Hume Reservoir 192.00 3 005 172.25 405 13% 23 382 -41 Lake Victoria 27.00 677 22.13 168 25% 100 68 -5 Menindee Lakes 1 731* 17 1% (- -) # 0 -0 Total 9 269 3 031 33% - - 2 820 -50 Total Active MDBA Storage 33% ^ Major State Storages

Burrinjuck Reservoir 1 026 308 30% 3 305 +0 Blowering Reservoir 1 631 429 26% 24 405 -4 Eildon Reservoir 3 334 1 196 36% 100 1 096 -21

* 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 30 Apr 2019 Storage Active Storage (GL) Weekly Change (GL) Diversion (GL) This Week From 1 May 2019 Lake Eucumbene - Total 788 -1 Snowy-Murray +5 - Snowy-Murray Component 331 -8 Tooma-Tumut +3 - Target Storage 1 290 Net Diversion 2 - Murray 1 Release +5 -

Major Diversions from Murray and Lower Darling (GL) * New South Wales This Week From 1 July 2018 Victoria This Week From 1 July 2018 Murray Irrig. Ltd (Net) 7.4 374 Yarrawonga Main Channel (net) 2.7 210 Wakool Sys Allowance 2.1 55 Torrumbarry System + Nyah (net) 0.1 494 Western Murray Irrigation 0.2 25 Sunraysia Pumped Districts 1.2 118 Licensed Pumps 1.7 179 Licensed pumps - GMW (Nyah+u/s) 1 36 Lower Darling 0.0 7 Licensed pumps - LMW 4.6 394 TOTAL 11.4 640 TOTAL 9.6 1252

* 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 flows.

Entitlement this month 93.0 * Flow this week 34.4 (4 900 ML/day) Flow so far this month 4.6 Flow last month 190.6

Salinity (EC) (microSiemens/cm at 25o C) Current Average over the last week Average since 1 August 2018 Swan Hill 310 330 80 Euston 90 80 - Red Cliffs 100 110 110 Merbein 110 110 100 Burtundy (Darling) - - 870 Lock 9 110 110 110 Lake Victoria 170 160 160 Berri 170 160 180 Waikerie 210 210 240 Morgan 220 220 250 Mannum 220 220 300 Murray Bridge 250 250 330 Milang (Lake Alex.) 1 040 1 040 930 Poltalloch (Lake Alex.) 460 600 760 Meningie (Lake Alb.) 1 890 1 890 1 590 Goolwa Barrages 4 300 4 780 3 100

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

River Levels and Flows Week ending Wednesday 01 May 2019

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 - - - 2 610 F 1 030 1 500 Jingellic 4.0 1.43 207.95 2 640 R 1 370 1 050 Tallandoon ( Mitta Mitta River ) 4.2 1.41 218.30 510 F 510 520 Heywoods 5.5 2.17 155.80 4 170 F 6 700 10 010 Doctors Point 5.5 2.01 150.48 5 570 F 8 290 11 070 Albury 4.3 1.10 148.54 - - - - Corowa 4.6 1.78 127.80 6 740 F 7 940 10 410 Yarrawonga Weir (d/s) 6.4 1.09 116.13 6 080 F 7 010 8 290 Tocumwal 6.4 1.76 105.60 6 600 F 7 230 8 070 Torrumbarry Weir (d/s) 7.3 1.86 80.41 5 040 F 5 390 5 290 Swan Hill 4.5 1.21 64.13 6 020 R 5 810 5 300 Wakool Junction 8.8 2.77 51.89 6 780 R 6 670 6 050 Euston Weir (d/s) 9.1 1.31 43.15 6 430 R 6 180 5 340 Mildura Weir (d/s) - - 5 940 F 5 470 5 210 Wentworth Weir (d/s) 7.3 2.81 27.57 5 510 R 4 790 4 710 Rufus Junction - 3.14 20.07 4 410 R 4 700 4 930 Blanchetown (Lock 1 d/s) - 0.45 - 3 770 R 3 830 3 920 Tributaries Kiewa at Bandiana 2.8 0.78 154.01 230 R 230 220 Ovens at Wangaratta 11.9 7.83 145.51 290 R 300 250 Goulburn at McCoys Bridge 9.0 1.49 92.91 950 F 960 910 Edward at Stevens Weir (d/s) 5.5 1.64 81.42 1 470 F 1 290 1 230 Edward at Liewah - 1.97 57.35 1 260 R 1 200 1 140 Wakool at Stoney Crossing - 1.38 54.87 390 R 370 380 Murrumbidgee at Balranald 5.0 0.48 56.44 210 R 220 200 Barwon at Mungindi 6.1 3.11 - 0 F 20 30 Darling at Bourke 9.0 2.03 - 0 F 0 0 Darling at Burtundy Rocks - 0.52 - 0 F 0 0 Natural Inflow to Hume 370 970

(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 -0.09 - No. 7 Rufus River 22.10 -0.77 +0.83 No. 26 Torrumbarry 86.05 +0.00 - No. 6 Murtho 19.25 +0.00 +0.00 No. 15 Euston 47.60 +0.02 - No. 5 Renmark 16.30 +0.01 +0.13 No. 11 Mildura 34.40 +0.05 +0.19 No. 4 Bookpurnong 13.20 +0.04 +0.54 No. 10 Wentworth 30.80 +0.12 +0.17 No. 3 Overland Corner 9.80 +0.02 +0.18 No. 9 Kulnine 27.40 -0.05 -0.85 No. 2 Waikerie 6.10 +0.05 +0.11 No. 8 Wangumma 24.60 -0.92 -0.53 No. 1 Blanchetown 3.20 +0.02 -0.30

Lower Lakes FSL = 0.75 m AHD Lake Alexandrina average level for the past 5 days (m AHD) 0.52

Barrages Fishways at Barrages Openings Level (m AHD) No. Open Rock Ramp Vertical Slot 1 Vertical Slot 2 Dual Vertical Slots Goolwa 128 openings 0.55 1 - Open Open - Mundoo 26 openings 0.60 All closed - - - Open Hunters Creek - - - - Open - - Boundary Creek 6 openings - 1 - Open - - Ewe Island 111 gates - All closed - - - Open Tauwitchere 322 gates 0.54 10 Open Open 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 01 May 2019

State Allocations (as at 01 May 2019)

NSW - Murray Valley Victorian - Murray Valley High security 97% General security 0%

High reliability 100% Low reliability 0%

NSW – Murrumbidgee Valley

Victorian - Goulburn Valley High security 95% General security 7%

High reliability 100% Low reliability 0%

NSW - Lower Darling

South Australia – Murray Valley High security 100% General security 0%

High security 100%

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