Welcome to Friday and your regularly scheduled River Murray Operations update!
For the full River Murray Weekly Report – including images, graphs and data on flow and salinity – head to the MDBA website.
MDBA active storage decreased by 63 GL during the week to 6,548 GL (76% capacity). At Dartmouth Reservoir, the total storage decreased by 3 GL to 2,956 GL (77% capacity). The release to the Mitta Mitta River, measured at Colemans, was around 300 ML/day during the week, although as of
25 January, a higher pulse release had commenced that is expected to temporarily increase the flow to around 2,700 ML/day followed by a smaller peak of around 1,300 ML/day in two days time. This double pulse is to assist in maintaining water quality in the Mitta Mitta River and follows similar short flow pulses released earlier in January and in December 2011.
At Hume Reservoir the storage volume fell by 91 GL to 2,157 GL (72% capacity). The flow past Doctors Point averaged around 16,500 ML/day during the week.
At Yarrawonga weir, the pool level is currently at 124.79 m AHD, which is within the operating target of 124.7–124.8 m AHD. Demand at the irrigation offtakes eased slightly again this week, totalling around 60 GL compared with 65 GL last week. The release downstream of Yarrawonga was maintained at around 8,300 ML/day throughout the week, although the release is expected to decrease slightly over the coming week.
At the Barmah-Millewa forest, the environmental watering operation that started in the spring of 2011 has entered its final stages. Only small volumes of additional water are now entering the forest – targeting specific wetlands via an elevated flow through the Gulpa Offtake. This flow will be decreased further towards 450 ML/day in the coming weeks, enabling the critical drying phase to continue.
Over 400 GL of environmental water consisting of Living Murray and NSW and Victorian environmental water entitlements has been used for this watering event, which has produced benefits not only at Barmah-Millewa Forest, but also to many other areas including the Coorong in South Australia by providing a higher flow along the River Murray System.
Downstream on the Edward River at Stevens Weir, the pool is currently 5.19 m on the local gauge and the flow downstream is at 1,100 ML/day. The flow is expected to recede further in the coming week and may fall below 1,000 M/day.
On the Goulburn River, the flow at McCoys Bridge is currently 1,550 ML/day, but is expected to drop back towards 1,100 ML/day over the coming week. At Torrumbarry Weir, the pool level remains at 86.05 m. The flow downstream of the weir is currently 5,700 ML/day and is expected to decrease towards 5,000 ML/day during the next week; while diversions through the National Channel remain at around 2,000 ML/day.
In the Gunbower Forest, environmental water has been used to support the breeding cycle of about 50–60 pairs of great egrets (see below). Great egrets are a threatened species listed in Australia’s Environmental Protection and Biodiversity Conservation Act. In November 2011, the egrets were observed to be preparing nests, with some sitting on eggs, while other bird species were well progressed into the breeding cycle with large chicks in nests. Delivery of environmental water commenced in late December and this additional water has ensured that the egret chicks will be able to fledge by mid-February.
Downstream at Euston Weir, the flow is currently 5,800 ML/day, while at Mildura the flow is 5,200 ML/day and is expected to increase slightly in the coming days.
At Menindee Lakes, the storage volume increased by 36 GL during the week and is now at 1,561 GL (90% capacity). The release, as measured at Weir 32, decreased from 18,000 to 15,000 ML/day during the week, and the NSW Office of Water advises that a release of 15,000 ML/day will be maintained for at least the next week to manage the storage level during the period of high inflows and until the impact of further rainfall forecast for the northern Basin in the coming week is understood. The lakes are expected to move back into the surcharge level during the middle of February.
On the lower Darling, the flow at Burtundy increased steadily during the week to 14,000 ML/day, and is now expected to peak within the next week at between 14,000 and 15,000 ML/day. For further information on the flood operations at Menindee Lakes, please see the NSW Office of Water website.
At Lake Victoria, the storage level is currently 25.91 m AHD (548 GL, 81% capacity), and the flow into South Australia is currently 15,400 ML/day. At the Lower Lakes, the five day average level is currently 0.65 m AHD and the release through the barrages during the week has averaged approximately 7,000 ML/day. Slightly lower releases are expected during the coming week.