Murray River Operations Report 21 January 2015

River Murray Weekly Report

For the week ending Wednesday, 21st January2018

Trim Ref:D15/2088

Rainfall and Inflows

Humid weather and rain contracted to the northern Basin at the beginning of the week, with quite dry conditions persisting until week’s end when a new trough system brought scattered showers to eastern areas. Highest weekly rainfall totals were recorded across the far northern Basin in Queensland and in north-eastern NSW; with lighter rain in the NSW Riverina and north-eastern Victoria. Most of the western Basin remained dry (Map 1).

The highest rain totals in Queensland included 96 mm at Miles, 60 mm at Mungallala, 54 mm at Goondiwindi and 48 mm at Texas. Totals in NSW included 48 mm at Gravesend, 39 mm at Inverell, 34mm at Grong Grong and 33 mm at Ardlethan. In north-eastern Victoria, there was 37 mm at Wodonga and 26 mm at Barnawartha.

Map 1- Murray-Darling Basin rainfall for the week ending 21st January 2015 (Source: Bureau of Meteorology).

Stream flows in the upper tributaries are steadily receding following the previous week’s good rainfall. Upstream of Dartmouth Dam, the Mitta Mitta River at Hinnomunjie Bridge fell from 700 ML/day to 300 ML/day. On the upper Murray, the flow at Biggara fell from 1,200 ML/day to 400 ML/day; whilst on the Ovens River, the flow at Wangaratta peaked at 700 ML/day before receding to 340 ML/day.

River Operations

MDBA total storage decreased by 118 GL this week, with the active storage now 4,963 GL (59% capacity). This is around 1,000 GL less than the long-term average active storage for this time of year (Figure 1).

At Dartmouth Reservoir, the storage decreased by 26 GL to 3,159 GL (82% capacity). The release, measured at Colemans gauge, will be reduced over the coming week from 4,800ML/day to 3,000 ML/day before increasing back to 4,500 ML/day in late January (see attached flow advice).

At HumeReservoir, the storage volume reduced by 64 GL this week with the total storage now at 1,536 GL (51% capacity). The release was increased during the week from 9,400ML/day to 16,000 ML/day in response to rising downstream demand.

Figure1- MDBA active storage: June 2005 to present.

Diversions at the major irrigation offtakes from Lake Mulwala increased this week from 3,000 to 6,500ML/day.In the absence of rain, diversions are expected to remain reasonably high over coming weeks with many rice crops in the region reaching ‘panicle initiation’ stage. Panicle initiation indicates the start of the reproductive phase of rice development, and represents a cue to rice growers to increase water depths across crops (see Figure 2). The pool level in Lake Mulwala is currently 124.77 m AHD and the downstream release from Yarrawonga Weir is steady at 10,100 ML/day.

On the Edward River system, the combined flow through the Edward River and Gulpa Creek offtakes is steady at around 1,900 ML/day. Diversions to Wakool Main Canal gradually rose throughout the week from 500 ML/day to 950 ML/day. The flow downstream of Stevens Weir has averaged around 1,500 ML/day over the past week, but will be increasing over coming days to around 2,100 ML/day as increased flow is passed into the Edward River from the Edward Escape. Flow down Colligen Creek, which comes off Stevens Weir pool, was raised to around 650 ML/day following rainfall last week and is now being gradually lowered back towards 200 ML/day. Environmental water has been provided by NSW Office of Environment and Heritage to enable this gradual recession, which is similar to how the creek would have responded following rain under natural conditions.

Figure2 –Rice crop near Deniliquin earlier in the season (image taken in November).Photo: Alisha Caldwell, MDBA.

On the Goulburn River, the flow at McCoys Bridge is 2,650 ML/day as a combination of environmental and inter-valley transfer (IVT) water is delivered into the Murray. This flow is planned to recede to approximately 1,000 ML/day by late January, then remain steady during the first week of February.

AtTorrumbarry Weir, diversions at National Channel are 2,000 ML/day. The flow downstream of Torrumbarry is 7,600 ML/day and forecast to remain around 7-8,000 ML/day over the coming week.

The flow in the Murrumbidgee River at Balranald rose this week from 1,650 ML/day to 1,900 ML/day following recent rainfall which added to IVT water already en-route to the Murray. The flow at Balranald is expected to gradually reduce over coming weeks towards 180 ML/day, which is the usual end-of-system target for February.

At Euston Weir, the flow is currently at a peak of around 11,000 ML/day due to a pulse of water released from the Goulburn River earlier in the month.

AtMenindeeLakes, the storage volume has decreased 18 GL to 156 GL (9% capacity). Releases at Weir 32 are steady at 150 ML/day, whilstlocal rain on the lower Darling last week has contributed to boosting the flow at Burtundy to160 ML/day.

At Wentworth Weir, the releaseis 9,000 ML/day and forecast to remain above 8,500 ML/day over the coming week.The weir pools at Locks 8 and 9 are gradually being lowered below their full supply levels and more information on the changing weir pool heights is available on the MDBA website.

Due to essential maintenance work, navigation via the Lock 7 lock chamber will be unavailable from Tuesday 27 January for 10 to 12 weeks (see attached media release). The lock chamber will be de-watered during this time and boat users will be unable to pass through the lock.

At Lake Victoria, the storage volume has decreased by 11 GL to 462 GL (68% capacity). The flow to South Australia was increased this week from 7,500 ML/day to around 10,000 ML/day.These increased flows are a result ofadditional environmental water made available to sustain higher barrage outflows into the Coorong.

At the Lower Lakes, the 5-day average water level in Lake Alexandrina increased this week from 0.63 to 0.64 m AHD. Following improvements to the Lower Lakes water level over the past fortnight, barrage releases wereincreased towards the end of this week from 1,000 ML/day to around 2,000 ML/day.

For media inquiries contact the Media Officeron 02 6279 0141

ANDREWREYNOLDS

Acting Executive Director, River Management

Water in Storage Week ending Wednesday 21 Jan 2015

*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 20 Jan 2015

Major Diversions from Murray and Lower Darling (GL) *

* 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**

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

River Levels and Flows Week ending Wednesday 21 Jan 2015

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

Weirs and LocksPool levels above or below Full Supply Level (FSL)

Lower LakesFSL = 0.75 m AHD

Barrages Fishways at Barrages

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

GPO Box 1801 Canberra ACT 2601Telephone: 02 6279 0100Facsimile: 02 6248 8053

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Email: Web: ABN 13679821382

Week ending Wednesday 21 Jan 2015

State Allocations (as at 21 Jan 2015)

Reducing February flows in the Mitta Mitta

Landholders and river users on the Mitta Mitta River are advised that late-January and early-February flows in the river will be lower than previously notified, as a result of recent rainfall.

The amount of water in Hume Reservoir is currently higher than expected due to recent rain in the upper catchments and reduced demand for water downstream. This means less water needs to be released from Dartmouth Reservoir via the Mitta Mitta to top-up Hume Reservoir.

Flows will continue to be variable over the coming weeks, however, and people along the Mitta Mitta River are advised to adjust their river activities as necessary.

The flow at Colemans gauge will be around 3000 megalitres per day (ML/day) during 23 to 26 January, which is 1.9 metres local gauge height. On Tuesday 27 January the flow will begin to increase and will reach 4500 ML/day on Friday 30 January (down from the 7000 ML/day previously advised).

The flow of 4500 ML/day will be maintained until Thursday 5 February, and will be gradually reduced over the following weeks until flows reach 2500 ML/day at the end of February (see graph below).

Throughout the remainder of February, if conditions remain dry, the flow in the Mitta Mitta River at Tallandoon is expected to be slightly greater than at Colemans gauge. However, this could change if flows from Snowy Creek increase due to rain.

Water is continuing to be transferred from Dartmouth to Hume Reservoir to help meet water demands downstream of Hume. On 20 January, the volume stored in Dartmouth Reservoir was 3163 GL (82 per cent capacity) compared with 1545 GL (51 per cent capacity) in Hume Reservoir.

ENDS

For more information, contact the MDBA Media office at or 02 6279 0141

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19 January 2015

TEMPORARY CLOSURE OF LOCK SEVEN

SA Water, on behalf of the Murray Darling Basin Authority, will soon begin planned maintenance at the last of nine River Murray locks scheduled for refurbishment.

Work is expected to begin at Lock Seven at Rufus River in New South Wales on the 27th of January and take up to 12 weeks to complete.

SA Water’s Senior Manager of River Murray Operations, Garry Fyfe, said during this time, boat users will be unable to pass through the lock.

“We’ve organised for the work to start after the summer school holidays so as to have minimal impact on people visiting and using the river.

“The project will involve pumping all of the water out of the lock chamber and inspecting and repairing the underwater components as necessary.

“Refurbishment of the locks is vital to the longevity of the structures and will ensure their continued safe and efficient operation,” Garry said.

“Although people won’t be able to travel the full length of the river during the maintenance period, they will still be able to enjoy using the river either upstream or downstream of Lock Seven.

Local stakeholders have been advised of the closure, including River Murray tourism operators.

The community will be notified when the lock chamber is back in operation or if there are significant changes to the timeline of works.

The grounds and facilities at Lock Seven will also be temporarily closed to the general public during the maintenance.

“We apologise for any inconvenience while the work is being undertaken and appreciate the public’s cooperation during this period,” Garry said.

For more information, people can contact staff at Lock Seven on (03) 5027 8225 or SA Water’s River Murray Operations office at Berri on (08) 8595 2222.

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