October saw nearly triple the month’s long term average inflows in the River Murray system, after heavy rain in the catchments.
Inflows totalled 4100 GL, which was close to triple the month’s long term average of about 4100GL, according to the Murray Darling Basin Authority (MDBA).
“This total has been exceeded in only three per cent of years in the historic record and is the highest October inflows to the Murray system since 1975,” the MDBA’s executive director David Dreverman said.
MDBA total storage increased by 178 GL this week, with the active storage now at 6,615 GL (77 per cent capacity).
Following the wettest September on record, rainfall across the basin returned closer to the long term average.
The Bureau of Meteorology (BoM) reported the Basin recorded averaged rainfall for the month of 39 mm.
But rainfall in the upper Murray catchments, above Dartmouth and Hume Reservoirs, still remained above average, with a pocket in the Snowy Mountains recording the highest rainfall on record.
“Combined with heavy rainfall in late September on already wet catchments, the resultant flows led to major flooding across northern Victoria and inland and southern New South Wales throughout October,” Mr Dreverman said.
“Inflows to Dartmouth Reservoir have boosted the storage volume there by 36 GL to 2,890 GL (75% capacity),” Mr Dreverman said.
“Releases remain at the minimum of 200 ML/day at Colemans gauge. At Hume Reservoir, the storage has remained steady at about 2,970 GL (99%).”
“At Yarrawonga Weir, the release continues to be gradually reduced and is now 29,000 ML/day,” Mr Dreverman said.
“The pool level at Yarrawonga Weir is currently 124.74 m AHD, and is expected to be raised to about 124.85 m AHD in the coming week.”
Diversions to the major irrigation offtakes had increased over the past week.
Currently around 1,700 ML/day was flowing into Yarrawonga Main Channel and 3,900 ML/day into Mulwala Canal, with a portion of this flow being environmental water to be escaped into the Edward River near Deniliquin.
“The addition of this oxygenated water into the Edward River is aimed at providing refuge flows to minimise fish deaths caused by hypoxic blackwater,” Mr Dreverman said.
“Flows are gradually receding at the Edward River and Gulpa Creek offtakes, with the combined flow now around 3,800 ML/day.”
The Murray at Barmah continued to gradually recede, as water drained out of Barmah and Millewa forests back into the River Murray.
Inflows from the Goulburn River had receded to 3,600 ML/day and from the Campaspe River to around 300 ML/day.
