There’s more good news for the Murray system, with another round of welcome rain falling across some of the key catchments that ultimately help supply water to Sunraysia.
After a strong winter helped lift water storages across northern Victoria and the Upper Murray, widespread rain during the opening days of October is providing another useful boost.
Lake Eildon has been one of the standout performers. After sitting at around 43% in June, the massive Goulburn storage had climbed to more than 61% by the beginning of October — a rise of around 18 percentage points in just a few months.
And now more water could be on the way.
Lake Eildon recorded 23.6mm of rain on Friday, taking its total for the first two days of October to 25.4mm.
Other parts of the broader Goulburn catchment have also received good falls during the past week, including 37.2mm at the Acheron River at Taggerty and 34.4mm at Marysville.
The Upper Murray is getting a drink too
It’s a similar story further north-east, with rain falling across the Upper Murray and surrounding catchments that feed the Hume and Dartmouth storage systems.
At Hume Reservoir, 19.2mm was recorded on Friday, while further rain and showers have been forecast across parts of north-east Victoria.
Hume and Dartmouth play a major role in regulating Murray River supplies and supporting communities, irrigators and the environment all the way downstream through Sunraysia.
Rain falling hundreds of kilometres upstream may seem a long way from Mildura, but water captured throughout these upper catchments forms an important part of the Murray system we rely on downstream.
Lake Eppalock catchment also receiving rain
The Campaspe catchment is another area worth watching.
Good rainfall has been recorded through parts of central Victoria, with 41.2mm recorded at Kyneton during the seven days to Friday and more than 30mm at several other locations across the region.
Lake Eppalock captures water from the Campaspe catchment, with the Campaspe River eventually joining the Murray at Echuca.
That makes rainfall and storage conditions around Eppalock another piece of the much larger Murray River picture.
Lake Eildon has climbed from around 43% in June to more than 61% at the beginning of October, while improved water availability has already resulted in higher northern Victorian seasonal water allocations.
Water allocations have also improved
The improvement across the catchments is already showing up in water availability.
Current northern Victorian seasonal determinations have Murray high-reliability water shares at 75% and Goulburn high-reliability water shares at 57%.
The Campaspe system is in an even stronger position, reaching 100% of high-reliability water shares plus 64% of low-reliability water shares.
The next Murray and Goulburn seasonal determination announcement is due on 12 October, which will provide another indication of how the improved conditions are translating into water availability.
Now we wait for the runoff
The interesting part over the next few days will be seeing how much of this latest rainfall makes its way into rivers, creeks and ultimately the major storages.
Rain falling across a catchment doesn’t immediately appear in dam levels. Depending on where it falls, runoff can take several days to work its way through tributaries and into the storages.
With some catchments already carrying moisture from earlier rain, further falls have a better chance of producing useful runoff than the same amount falling onto completely dry country.
That means Hume, Dartmouth, Eildon and Eppalock will all be worth watching over the coming week.
There is no suggestion at this stage that the major storages are suddenly about to spill, and longer-term spring and summer conditions will still have a major say in where storage levels eventually finish.
But after the recovery we’ve seen through winter, another decent drink across the catchments at the beginning of October is certainly welcome.
And for those of us hundreds of kilometres downstream in Sunraysia, what falls in those hills can eventually make quite a difference down here.
