The Murray Darling Basin Authority says despite unprecedented heatwave conditions in December and January, it’s been able to supply all consumptive water demands along the Murray River.
MDBA River Management executive director Andrew Reynolds said Murray River inflows for January totaled about 100 Gigalitres, well below the month’s long-term median of 193 GL.
“In comparison with historical records since 1891, around eight per cent of January monthly totals have been lower than the inflows observed in 2019,” Mr Reynolds said.
The Bureau of Meteorology reported January 2019 was an exceptionally warm month.
Australian temperatures in January 2019 were the warmest on record in terms of mean, maximum and minimum temperatures.
Persistent stable and sunny conditions brought sustained and unprecedented heatwaves throughout the Murray-Darling Basin.
For the week ending February 6, moderate rainfall was observed in the south-east of the Murray-Darling Basin and further into central New South Wales
The highest rainfalls totals for the week included 82millimetres at Rocky Valley, 42 mm at Lake Dartmouth in Victoria and Gungahlin, in the ACT, recorded 40 mm.
Across the Basin as a whole, the BoM reported an area-average rainfall for the Murray-Darling Basin in January of 16.2mm.
“This is 71pc below the long-term average and makes January 2019 the 11th driest January in 120 years of historical records,” Mr Reynolds said.
“Over the coming week, there is a low risk of a shortfall (based on current demands, weather forecasts and operations) while flows remain sufficiently high along the Murray.”
The MDBA active storage volume decreased by 86GL this week to 3,705 GL (44pc capacity)
This is approximately 2,000GL below the long term average for the start of February.
The Dartmouth Reservoir storage volume decreased by 31 GL to 2,559 GL (66pc capacity).
The release from Dartmouth reservoir, measured at Colemans, averaged near 5,000 megalitres/day.
Throughout February, the flow is expected to cycle between the current flow and 3,800 ML/day to assist in reducing erosion impacts caused by sustained high river flows.
The rate and timing of transfers to Hume for the coming months will depend on climatic conditions, storage inflows and demands over the coming months.
Water stored in Dartmouth Reservoir is generally maintained as the system’s drought reserve and is called upon in dry seasons when the downstream storages have insufficient water to meet demands.
At Hume Reservoir, the storage volume continued to decline, reducing by 25 GL to 960 GL (32pc capacity).