Here is the info on the last week of River Murray operations. If you’d like to see the full report with images, graphs and data on flow and salinity, it’s on the MDBA website.
MDBA active storage decreased by 78 GL during the week to 7,440 GL (87% capacity). At Dartmouth Reservoir, the total storage increased by 13 GL to 2,889 GL, which is 75% capacity. The release remained steady at the normal minimum of 200 ML/day.
Storage in Hume Reservoir continued to fall away, decreasing by 68 GL to 2,737 GL (91% capacity). The release increased from 13,000 ML/d to 19,000 ML/d by the end of the week
At Lake Mulwala, the pool level is currently 124.75 m AHD. Diversions to the Yarrawonga Main Canal were steady at an average of around 1,400 ML/day. Diversions to Mulwala Canal increased over the week from 2,100 ML/day to around 4,500 ML/day. The release from Yarrawonga Weir is currently 13,500 ML/day. The flow will be rising to around 15,500 ML/d over the next few days and is expected to stay at this level for five days before gradually receding back to 11,000 ML/day again. This release is being targeted to supply environmental entitlements that are maintaining over-bank flows to the Barmah-Millewa forest and to stimulate fish breeding.
The release of environmental water to the Goulburn River continued this week. The flow at McCoys Bridge was around 5,600 ML/day for most of the week and is expected to stay at this rate for the coming week.
Flow to the Edward River via the Edward Offtake remained steady at 1,660 ML/day. At Gulpa Offtake the gates are out of the water and flow fell away over the week (from 875 ML/day to 765 ML/day) in response to the falling level in the River Murray at Picnic Point. Inflow of around 1,500 ML over three days from the Edward Escape supplemented the flow in the Edward River to help raise the level in the Stevens Weir pool. An environmental release of up to 800 ML/day to the Colligen Creek system commenced this week with the aim of stimulating fish breeding.
At Torrumbarry Weir, diversion to National Channel increased from 1,500 ML/day to 2,100 ML/day. Flow downstream of the weir was around 11,000 ML/day for most of the week and is expected to remain around this rate for the coming week. Further downstream, the inflow from the Murrumbidgee River increased to 3,600 ML/day and is forecast to rise to around 4,500 ML/day over the next few days before falling away again. Flow at Euston was steady at around 9,100 ML/day for most of the week, but is now rising (currently 9,700 ML/day) and will continue to rise over the coming week to around 15,000 ML/day.
At Menindee Lakes, the total storage decreased by 10 GL and remains surcharged at 1,834 GL (106% capacity). The release, measured at Weir 32 is currently 670 ML/day and will rise to around 750 ML/d over the coming week. On Wednesday 30 November, releases will be further increased to supplement the flow in the River Murray. This will see releases from Menindee Lakes rise to 5,500 ML/day in the coming weeks (see flow advice attached).
The storage in Lake Victoria decreased by 13 GL to 654 GL (97% capacity). Net daily release from the storage increased over the week to around 1,500 ML/day to supplement flow in the River Murray to meet downstream requirements to South Australia. The flow to South Australia averaged 8,900 ML/day over the week.
The average level in the Lower Lakes is currently 0.72 m AHD. Reduced inflows have contributed to releases through the barrages falling away to around 800 ML/day and resulted in the Lower Lakes falling below the full supply level of 0.75 m AHD. In order to continue to flush the Coorong and Murray mouth, a flow of around 4,000 ML/day will be targeted through the barrages, which will result in the Lake levels falling away by around 5-10 centimetres over the coming week.