River Murray Weekly Report

For the week ending Wednesday, 22 July 2020

Trim Ref: D20/25074

Rainfall and inflows

Conditions were mostly dry across the Murray-Darling Basin this week, with rainfall limited to the southern slopes and ranges (Map 1). The Bureau of Meteorology (BoM) is currently forecasting a small amount of rainfall over the southern Murray-Darling Basin in the coming 8 days.

Map 1 - Murray-Darling Basin rainfall totals for week ending 22 July 2020 (Source: Bureau of Meteorology)

Stream flows in the upper and mid-Murray tributaries receded this week. Specific information about flows at key locations can be found at the MDBA’s River Murray data webpage. Up-to-date river data for sites in the upper Murray can also be found on BoM’s website and in the Murray River Basin Daily River Report at the WaterNSW website

River operations

· Storage in Dartmouth and Hume continues to rise.

· Tributary inflows downstream of Hume extend period of unregulated flow,

· Unregulated flow at the lower Lakes boosts release to the Coorong.

Unregulated flow event

Tributary inflows downstream of Hume Dam have resulted in continued elevated flows through the mid and lower Murray. Lake Victoria is at 93% capacity and the MDBA is actively slowing the rate of fill of the lake in accordance with the requirements of the Lake Victoria Operating Strategy. There is sufficient surplus flow remaining to extend the period of unregulated flow that commenced on 27 June. For more information on the expected duration and the river reaches where unregulated flow currently applies, refer to supplementary announcements from WaterNSW.

River operations and the COVID-19 virus

The MDBA is continuing to work with government partners and stakeholders during this challenging time. In response to the impact of COVID-19, the MDBA has enacted business continuity arrangements to ensure the continued operation of our business functions. River operations have been identified as a priority in this time as running the river is essential to supporting irrigation supply to agricultural industries.

We hope all our community members remain safe at this time. We encourage all river users to evaluate plans against government advice, social distancing and travel, and to support actions to limit the spread of COVID-19.

Water quality impacts

An amber alert for blue-green algae remains current in the River Murray system at Buronga. It is important that water users regularly keep up to date with algal alerts, notices and health warnings. This information is available through Goulburn-Murray Water and WaterNSW.

Operations

Over the past week, MDBA total active storage (Dartmouth, Hume and Lake Victoria) increased by 88 GL to 3,881 GL (46% capacity).

At Dartmouth Reservoir, the storage increased by 12 GL to 2,044 GL (53% capacity). During the week the power station operator (AGL) continued to release entitlement water from Dartmouth for the purposes of electricity generation. The release rate targeted around 1,000 to 1,200 ML/day (measured at Colemans) for much of the week, compared with normal minimum releases for this time of year of 200 ML/day.

At Hume Reservoir, the storage increased by 76 GL to 1,401 GL (47% capacity). This includes around 37 GL released from Snowy Hydro’s Khancoban Pondage into the Murray River upstream of Bringenbrong. Hume storage is expected to rise in the coming weeks as unregulated tributary inflows and releases from Snowy Hydro continue. The release from Hume remains at the minimum flow rate of 600 ML/day as elevated inflows from the Kiewa and Ovens Rivers meet and exceed minimum flow requirements downstream at Yarrawonga.

At Lake Mulwala, the diversion to Mulwala Canal reached around 3,000 ML/day as Murray Irrigation Limited (MIL) continued to refill their irrigation channels and make available supplementary access water to customers. Goulburn-Murray Water also commenced diverting small volumes to the Yarrawonga Main Canal in preparation for refilling their irrigation channels. In response to the increase in diversions and receding tributary inflows, the release downstream of Yarrawonga Weir was gradually reduced from 10,500 ML/day to 7,400 ML/day. The release is expected to continue to reduce over the coming week to below 6,000 ML/day.

Downstream in the Barmah - Millewa Forest, a number of regulators remained open to manage river levels through the Choke within the capacity of the river channel (ie a water level below 2.6 m on the local gauge at Picnic Point). However, with the release downstream of Yarrawonga reducing below 9,000 ML/day over the weekend, the forest regulators will be closed in the coming days (Note: a release of about 9,000 ML/day from Yarrawonga Weir is a proxy for the capacity of the river through the Choke when around 2,000 ML/day is diverted via the Edward-Wakool system, forest regulators are closed and there are low diversions for irrigation in the reach between Yarrawonga and Barmah).

Photo 1: Kiewa River East Branch (Photo Courtesy Hugo Bowman)

On the Edward River, return flows from the Murray via the Millewa Forest increased by around 200 ML/day late in the week. These return flows are expected to continue for another few days before reducing and finally ceasing in around two weeks following the closure of the forest regulators in the coming days. Diversions into the Wakool River, Yallakool and Colligen Creeks remain at levels sufficient to provide entitlement holders with access to unregulated flows. At Stevens Weir, diversions to the Wakool Main Canal were around 1,100 ML/day and the release downstream of the weir averaged 550 ML/day.

On the Goulburn River, the flow measured at McCoys Bridge peaked near 9,000 ML/day early in the week before reducing to the current rate of 4,000 ML/day. Inflows from the Goulburn to the Murray are forecast to remain around 3,000 to 5,000 ML/day over the coming week. Allocation trade from the Goulburn to the Murray system is currently closed. Information regarding opportunities for allocation trade between the Goulburn and Murray Valleys is available at the Victorian water register website.

The level of the Torrumbarry Weir pool continues to vary daily within the target range of 20-30 cm below Full Supply Level (FSL) as part of the weir pool variability program. Varying pool levels helps to reduce the incidence of notching and can help improve bank stability for riverbanks within the influence of the weir pool. Diversions to National Channel from the weir pool were steady at around 420 ML/day to maintain winter baseflows in the Gunbower Creek for the benefit of native fish. Around 200 ML/day of this flow returns to the River Murray downstream of Torrumbarry Weir near Barham Bridge, via Koondrook Spillway The additional loss arising from this watering action is debited against environmental water holders’ entitlements. In response to inflows from the Goulburn River, the downstream release from Torrumbarry Weir peaked during the week at 14,500 ML/day and is forecast to continue to steadily reduce over the coming week.

Inflow from the Murrumbidgee River, measured at Balranald, gradually receded from 2,400 ML/day to 1,400 ML/day. Elevated flows at Balranald have resulted from rain further upstream over the past month. Flows are expected to steadily recede over the remainder of July as the lower reaches of the Murrumbidgee River return to regulated conditions. The Murrumbidgee IVT balance is open for trade from the Murray to the Murrumbidgee (99.9 GL) but remains closed to trade from the Murrumbidgee to the Murray.

At Euston Weir, the weir pool level continues to target around 30 cm below FSL as part of the weir pool variability program. The downstream release remained above 14,000 ML/day this week and is expected to reach around 15,000 ML/day in the coming week.

Photo 2: Upper Murrumbidgee River at Tharwa (Photo courtesy Andy Lowes)

This week the Menindee Lakes storage decreased by 4 GL to 468 GL (27% capacity). The storage level will continue to ease over the coming weeks with no significant inflows currently forecast. The downstream release, measured at Weir 32, averaged around 240 ML/day over the past week. Despite the rainfall and streamflow responses during recent months, in many parts of NSW drought conditions persist with extensive water restrictions still in place. Links to drought services and assistance can be also accessed via the MDBA drought webpage

Photo 3: Lake Pamamaroo (Photo Courtesy Craig Symonds, WaterNSW)

Photo 4: View of Lake Wetherell from the Pamamaroo inlet regulator (Photo Courtesy Craig Symonds, WaterNSW)

At Wentworth Weir, the weir pool level is being managed to target around FSL (30.80 m AHD) but is expected to vary 10 cm above and below this level as part of normal operations. The downstream release averaged around 14,000 ML/day and is expected to remain around this rate over the coming week.

This week, the Lake Victoria storage volume remained steady at 630 GL (93% capacity). The storage level in Lake Victoria will continue to be managed over the coming weeks in accordance with the Lake Victoria Operating Strategy. The strategy aims to fill the storage as late as possible while also holding a steady level for as short a time as possible to minimise erosion and inundation impacts on sensitive foreshore vegetation and cultural heritage material.

The flow to South Australia averaged 12,900 ML/day this week, as unregulated flows continued across the border. Flow to South Australia will remain above normal Entitlement into August as high flows continue to arrive from upstream. For more information on South Australia’s Entitlement flow, see the South Australian Department for Environment and Water’s latest River Murray flow report.

The Lower Lakes 5-day average water level is currently 0.8 m AHD. The arrival of unregulated flows to the Lower Lakes has allowed around 65 GL to be released to the Coorong this week via Tauwitchere, Goolwa, Mundoo and Boundary Creek Barrages. Increased barrage releases will continue to be made when conditions allow to target outcomes in the Coorong. For information on barrage releases see the South Australian Department for Environment and Water Weekly River Murray Flow Report.

For media inquiries contact the Media Officer on 02 6279 0141

ANDREW REYNOLDSExecutive Director, River Management

Water in Storage Week ending Wednesday 22 Jul 2020

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

452.95

2 044

53%

71

1 973

+12

Hume Reservoir

192.00

3 005

182.20

1 401

47%

23

1 378

+76

Lake Victoria

27.00

677

26.61

630

93%

100

530

-0

Menindee Lakes

 

1 731*

 

468

27%

(- -) #

0

-4

Total

 

9 269

 

4 543

49%

- -

3 881

+83

Total Active MDBA Storage

 

 

 

 

 

 

46% ^

 

 

 

 

 

 

 

 

 

 

Major State Storages

Burrinjuck Reservoir

 

1 026

 

453

44%

3

450

-2

Blowering Reservoir

 

1 631

 

1 010

62%

24

986

+32

Eildon Reservoir

 

3 334

 

1 713

51%

100

1 613

+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 21 Jul 2020

Storage

Active Storage (GL)

Weekly Change (GL)

Diversion (GL)

This Week

From 1 May 2020

Lake Eucumbene - Total

916

-8

Snowy-Murray

+23

328

Snowy-Murray Component

382

-17

Tooma-Tumut

+4

77

Target Storage

1 170

 

Net Diversion

19

251

 

 

 

Murray 1 Release

+30

409

Major Diversions from Murray and Lower Darling (GL) *

New South Wales

This Week

From 1 July 2020

Victoria

This Week

From 1 July 2020

Murray Irrig. Ltd (Net)

21.0

42

Yarrawonga Main Channel (net)

0.1

0

Wakool Sys Allowance

4.1

9

Torrumbarry System + Nyah (net)

0

0

Western Murray Irrigation

0.1

0

Sunraysia Pumped Districts

0.5

1

Licensed Pumps

n/a

18

Licensed pumps - GMW (Nyah+u/s)

0

0

Lower Darling

0.0

0

Licensed pumps - LMW

1.7

3

TOTAL

25.2

69

TOTAL

2.3

4

* 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 and environmental flows.

Entitlement this month

108.5 *

 

Flow this week

90.5

(12 900 ML/day)

Flow so far this month

239.9

Flow last month

104.7

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

 

Current

Average over the last week

Average since 1 August 2019

Swan Hill

110

110

80

Euston

-

-

-

Red Cliffs

120

120

60

Merbein

130

120

100

Burtundy (Darling)

330

320

560

Lock 9

110

110

100

Lake Victoria

130

130

120

Berri

140

130

160

Waikerie

170

210

220

Morgan

210

230

230

Mannum

320

310

260

Murray Bridge

300

300

290

Milang (Lake Alex.)

970

960

900

Poltalloch (Lake Alex.)

500

480

780

Meningie (Lake Alb.)

1 670

1 690

1 800

Goolwa Barrages

4 050

3 810

3 150

River Murray Weekly Report

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

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

River Levels and Flows Week ending Wednesday 22 Jul 2020

 

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

-

-

-

6 890

F

4 970

5 300

Jingellic

4.0

2.29

208.81

9 830

R

8 790

10 020

Tallandoon ( Mitta Mitta River )

4.2

1.86

218.75

1 760

F

1 690

2 130

Heywoods

5.5

1.44

155.07

600

S

600

600

Doctors Point

5.5

1.71

150.18

2 280

R

2 490

3 250

Albury

4.3

0.86

148.30

-

-

-

-

Corowa

4.6

0.79

126.81

2 270

F

2 870

3 280

Yarrawonga Weir (d/s)

6.4

1.25

116.29

7 410

R

8 970

9 310

Tocumwal

6.4

1.87

105.71

7 570

F

9 110

9 040

Torrumbarry Weir (d/s)

7.3

3.97

82.51

13 290

F

13 400

10 760

Swan Hill

4.5

2.34

65.26

13 520

R

12 040

10 900

Wakool Junction

8.8

4.12

53.24

13 520

R

12 750

12 700

Euston Weir (d/s)

9.1

2.46

44.30

14 730

R

14 370

14 960

Mildura Weir (d/s)

 

-

-

14 270

F

14 180

15 050

Wentworth Weir (d/s)

7.3

3.35

28.11

13 720

S

13 860

14 920

Rufus Junction

-

4.33

21.26

12 220

R

12 510

11 740

Blanchetown (Lock 1 d/s)

-

1.06

-

13 750

F

14 340

11 020

 

 

 

 

 

 

 

 

Tributaries

 

 

 

 

 

 

 

Kiewa at Bandiana

2.8

1.91

155.14

1 850

R

1 990

2 650

Ovens at Wangaratta

11.9

9.40

147.08

4 720

F

5 560

7 200

Goulburn at McCoys Bridge

9.0

3.09

94.51

4 020

F

6 770

4 990

Edward at Stevens Weir (d/s)

5.5

0.86

80.64

570

F

550

770

Edward at Liewah

-

1.69

57.07

1 020

F

1 230

1 080

Wakool at Stoney Crossing

-

1.45

54.94

550

R

480

290

Murrumbidgee at Balranald

5.0

1.82

57.78

1 400

F

1 910

2 180

Barwon at Mungindi

6.1

3.21

-

140

F

140

200

Darling at Bourke

9.0

4.01

-

90

F

100

50

Darling at Burtundy Rocks

-

0.71

-

160

S

160

170

 

 

 

 

 

 

 

 

Natural Inflow to Hume

 

 

 

 

 

9 710

10 730

(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

-0.18

-

No. 7 Rufus River

22.10

+0.01

+2.01

No. 26 Torrumbarry

86.05

-0.23

-

No. 6 Murtho

19.25

-0.01

+0.50

No. 15 Euston

47.60

-0.26

-

No. 5 Renmark

16.30

+0.04

+0.59

No. 11 Mildura

34.40

+0.01

+0.51

No. 4 Bookpurnong

13.20

+0.16

+1.31

No. 10 Wentworth

30.80

-0.02

+0.71

No. 3 Overland Corner

9.80

+0.05

+0.74

No. 9 Kulnine

27.40

+0.01

-0.02

No. 2 Waikerie

6.10

+0.11

+0.75

No. 8 Wangumma

24.60

-0.60

+0.62

No. 1 Blanchetown

3.20

+0.16

+0.31

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

0.82

4

-

Open

Open

-

Mundoo

26 openings

0.80

2

-

-

-

Open

Hunters Creek

-

-

-

-

Open

-

-

Boundary Creek

6 openings

-

1

-

Open

-

-

Ewe Island

111 gates

-

All closed

-

-

-

Open

Tauwitchere

322 gates

0.84

12

Open

Open

Open

-

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

Week ending Wednesday 22 Jul 2020

State Allocations (as at 22 Jul 2020)

NSW - Murray Valley

Victorian - Murray Valley

High security

97%

General security

2%

High reliability

15%

Low reliability

0%

NSW – Murrumbidgee Valley

Victorian - Goulburn Valley

High security

95%

General security

14%

High reliability

37%

Low reliability

0%

NSW - Lower Darling

South Australia – Murray Valley

High security

100%

General security

30%

High security

77%

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