We saw some heavy rain over the upper catchments in July. As a result, July inflows to the River Murray system (excluding Darling River and Snowy inflows) were about 1,900 GL in total. This is above the long-term average of around 1,200 GL and, like June, is the month’s highest system inflow since 1995. Read more in the full Weekly Report, which also has updated flow advice for the Lower Darling River.
MDBA active storage increased by 27 GL this week to 8,183 GL (95% of capacity). At Dartmouth Reservoir the storage went up by 14 GL to 3,510 GL (91% capacity). Inflows averaged around 2,900 ML/day. The release from Dartmouth continued above minimums, with a flow of around 1,000 ML/day (measured at Colemans) throughout the week due to entitlement releases by AGL Hydro for electricity generation.
At Hume Reservoir, total storage is now 2,944 GL (98% capacity), 29 GL more than last week. Inflow eased slightly this week, averaging around 15,900 ML/day. Releases averaged 11,700 ML/day during the week but will be increased over the coming weekend to near channel capacity (25,000 ML/day at Doctors Point). This will increase airspace in Hume storage ahead of a rain event that is currently forecast to occur mid to late next week. Information on upper State shares within each storage can be found via the MDBA water accounting page.
At Yarrawonga Weir, diversions at both Mulwala Canal and Yarrawonga Main Channel have increased to a combined total of around 3,000 ML/day. The level of Lake Mulwala is currently 124.70 m AHD. The release downstream of the Weir decreased from 29,500 to 17,500 ML/day as inflows receded but will increase again over the coming week due to higher releases from Hume.
Downstream at the Barmah-Millewa forest, water levels have peaked and are now slowly receding. On the Edward River, the flow measured at Deniliquin is currently 13,000 ML/day after peaking at 18,500 ML/day on 1 August. At Stevens Weir the flow has receded from a peak of 12,100 ML/day to around 9,000 ML/day and the gates are still clear of the water. Diversions through the Wakool River and Yallakool and Colligen Creek offtakes have also fallen away with a current total diversion close to 3,500 ML/day compared with the peak rate of around 6,100 ML/day. Downstream on the Wakool River, the flow at Kyalite has increased to 13,400 ML/day and is expected to continue rising to a peak expected in around a week’s time.
On the Goulburn River the flow at McCoys Bridge peaked on 4 August at around 17,500 ML/day and is now falling. Releases from Eildon Reservoir have been reduced and water is being diverted to Waranga Basin. Without further rain, the flow at McCoys Bridge is expected to reduce to around 6,000 ML/day by the end of the coming week. At Torrumbarry Weir, the flow reached a broad peak late in the week of around 35,500 ML/day. The flow is now starting to recede and the weir gates, which are still clear of the water, will be reinstated later in the coming week.
On the Murrumbidgee River, the flow at Balranald continues to creep up and is currently 10,700 ML/day. Inflows from the Murrumbidgee River will continue flowing strongly while upstream demands remain low and inflows are being passed through the main headwater storages at Burrinjuck and Blowering Dams. At Euston Weir the flow in the River Murray is now 38,000 ML/day with flows above 40,000 ML/day expected during the middle of August.
Total storage at Menindee Lakes is 1,971 GL (114% capacity), a decrease of just 2 GL from last week. Inflows increased during the week and will continue to do so for around two weeks. In response, releases from Menindee Lakes have increased to 4,000 ML/day (measured at Weir 32). The flow to the Great Darling Anabranch has also been increased, with a flow of around 2,000 ML/day being released via the Cawndilla Outlet (see attached media release issued by NSW Office of Water). Downstream on the lower Darling, the flow at Burtundy eased to a low of around 1,400 ML/day but has since increased to 1,900 ML/day and is expected to continue rising over the next few weeks.
At Lake Victoria, the volume decreased by 13 GL this week and is now at 432 GL (64% capacity). The storage level will continue to fall for a few more days before rising again, when higher flows arrive from upstream. The current flow to South Australia is 38,800 ML/day and is expected to remain at about this level over the coming weeks unless there is significant rainfall.
At the Lower Lakes, the 5-day average level at Lake Alexandrina has decreased to 0.75 m AHD. The level is expected to decrease further over the next two weeks to assist in drawing higher salinity water from Lake Albert.
Plots showing short term forecast flows and levels for selected key sites are updated each week and are available on the MDBA river flows page.