River Murray operations 8-15 March 2017
17 March 2017
Welcome to our summary report on River Murray operations for the week ending 15 March 2017.
You can find the full weekly report under the River Murray system section of our website.
Rainfall and inflows
Rainfall was recorded across much of the Murray–Darling basin this week with highest totals in the north-eastern basin and central New South Wales. Little or no rain was recorded in much of the southern basin. The highest weekly totals included 130 mm at Coolmunda in Queensland’s Border Rivers catchment. Further north, 126 mm and 124 mm fell in Meandarra and Hannaford respectively. South of the border in New South Wales, 90 mm was recorded at Dubbo and 86 mm at Inverell.
Along the River Murray, conditions have been relatively warm and dry over recent weeks. However, the Bureau of Meteorology is now forecasting rainfall along the Murray upstream of the South Australian border later in the coming week, with totals of 25 mm or more forecast upstream of Echuca.
Stream flows along the upper Murray tributaries have remained relatively stable over the last week. Flows at Hinnomunjie Bridge on the Mitta Mitta River averaged around 180 ML/day. On the upper Murray at Biggara flows averaged around 150 ML/day. The flow at Wangaratta on the Ovens River averaged around 480 ML/day.
Total in storage
Total MDBA storage decreased 170 GL this week, with the active storage now 5,833 GL (68% capacity).
Water availability outlook in 2017-18
During the week, South Australia announced the opening allocation in 2017-18 for their River Murray water access entitlement holders would be 100 percent. NSW also issued a preliminary water availability outlook for 2017-18 for water entitlement holders in the NSW Murray and Lower Darling and the Murrumbidgee. In Victoria, the seasonal determination outlook for 2017-18, issued in mid-February 2017, is available from the Northern Victoria Resource Manager’s website.
- At Dartmouth Reservoir, the storage volume decreased by 8 GL to 2,992 GL (78% capacity). Over the weekend, releases from Dartmouth Reservoir, measured at Colemans, increased to 1,860 ML/day for two days. The aim of this release was to mimic a small natural pulse to boost lower Mitta Mitta River water quality and ecosystem function. Releases from Dartmouth have now returned to just under 300 ML/day.
- The Hume Reservoir storage volume decreased 91 GL this week and is currently 2,115 GL (70% capacity). Releases increased this week and are currently 17,000 ML/day.
- At Lake Mulwala diversions to the Mulwala Canal and Yarrawonga Main Channel have both continued to increase during the week. Mulwala Canal diversions are the highest they have been since mid-January, increasing to 5,800 ML/day on Monday 13 March. Diversions to Yarrawonga Main Channel peaked at 2,380 ML/day on Sunday 12 March. The pool level rose to 124.81 m AHD over the weekend and is currently around 124.75 m AHD. The average downstream release at Yarrawonga Weir for the week was 7,930 ML/day.
- Inflows to the Edward-Wakool system have remained fairly consistent over the past week. Flows through the Edward River and Gulpa Creek off-takes were around 1,550 ML/day and 340 ML/day respectively. Diversions to the Wakool Main Canal at Stevens Weir increased slightly this week and averaged around 1,200 ML/day. Downstream of the weir, the release continues to target 600 ML/day. Further downstream, the flow at Stoney Crossing averaged 600 ML/day.
- On the Goulburn River, the flow at McCoys Bridge is currently 4,000 ML/day. The flow will fall away over the remainder of March to around 1,200 ML/day as the delivery of an environmental pulse concludes. As inflows from the Goulburn River recede, River Murray levels at Echuca and downstream of Torrumbarry Weir are expected to fall away noticeably. More in our media release.
- At Torrumbarry Weir, the downstream flow rate reduced from 6,800 ML/day to 6,000 ML/day. Over the coming week, the release is expected to reduce below 5,000 ML/day. Diversions to National Channel have remained steady at around 3,300 ML/day. However demand is forecast to increase and remain relatively high during the next few weeks if the weather remains dry.
- On the Murrumbidgee River at Balranald, flows have receded to around 600 ML/day and are expected to continue around this rate during March. This is above the normal end of system target for March due to the continuing delivery of water traded to the Murray.
- Downstream at Euston Weir, the pool level was held around full supply level (FSL) for the Robinvale Euston 80 Ski Race. The level is now being re-lowered to around 20cm below FSL to restore a more natural wetting and drying cycle along the river within the influence of the weir pool. The flow rate downstream of Euston has averaged around 5,500 ML/day and is expected to remain fairly steady over the coming week.
- On the Darling River, total storage in the Menindee Lakes fell by 44 GL, to the current volume of 986 GL (57% capacity). The release from Menindee Lakes to the lower Darling River, measured at Weir 32, has averaged around 2,100 ML/day. The release is expected to remain around 2,000 ML/day for the remainder of March if conditions remain dry and demand along the Murray remains high. At the Lake Cawndilla outlet, the release by NSW is currently around 1,250 ML/day. The bulk of this release is environmental water for the Great Darling Anabranch which commenced around one month ago and is expected to continue until late May. Flows have currently progressed around one third of the way along the anabranch and are expected to reach half way by the end of March.
- At the confluence of the Darling and Murray Rivers at Wentworth, the flow continued to recede to 5,500 ML/day. Flows of around 5,500 ML/day are expected during the coming week.
- Downstream at Lock 8, the weir pool level is currently 40cm below FSL. The pool level will increase during the remainder of March to around 30cm below FSL in order to provide a small reconnection flow into the Potterwalkagee Creek system. At Lock 7, the weir pool level is currently around 50cm below FSL. The pool level will increase during the remainder of March to around FSL in order to provide a small reconnection flow into the upper Lindsay Creek system and provide a small flow pulse into the Mullaroo Creek. Early in April, the pool levels at Locks 8 and 7 are expected to be relowered to target around 50 cm below the normal FSL.
- At Lake Victoria, the storage volume decreased by 27 GL to 414 GL (61% capacity) and will continue to fall over the coming week. The flow into South Australia is currently targeting 10,000 ML/day and is expected to increase to around 10,500 ML/day in the coming week. This flow is higher than the normal entitlement due to the delivery of traded environmental water previously released from both Hume and Eildon Reservoirs. Over the next 10-12 days, releases from Lake Victoria will be managed to maintain flows across the border at or above 10,000 ML/day. Downstream at Lock 1, the flow is currently 6,400 ML/day and is expected to continue to rise during the coming week.
- At the Lower Lakes, the 5-day average water level in Lake Alexandrina fell 5 cm to 0.61 m AHD. This drop occurred as a result of continuing barrage releases, which have averaged around 5,200 ML/day over the last few weeks. With higher flows in transit to the Lower Lakes and a relatively high level in Lake Alexandrina for this time of the year, operations have taken advantage of relatively calm conditions to maintain freshening flows into the Coorong.
Please note: MDBA is undertaking website maintenance work from 5.00 pm Thursday 9 March until 9.00 am Monday 20 March. During this period, website access may not be reliable and Live River Data may not be up to date.