NSW Murray irrigators are questioning where large inflows over the last few weeks have gone, with a supplementary event still yet to be called.
A supplementary event occurs when rain falls downstream of storages and cannot be captured. During a supplementary event certain water licence holders are able to pump water for a defined time period.
The Murray Darling Basin Authority's executive director of river management Andrew Reynolds wrote in a recent opinion piece that a supplementary, or unregulated flow in reach of the River Murray system is water that is, or is forecast to be, in excess of the minimum flow needed to meet demands along the river and cannot be captured in Lake Victoria.
The Ricegrowers' Association (RGA) have calculated that from October 12 to October 23, on average more than 25 gigalitres per day flowed into the Murray River system below the Hume Dam.
While, further rain this past weekend saw the Murray River at Barham reach a flow rate per day of 13023ML on Tuesday.
RGA said that during the October time period outlined, demand from the Murray's two largest irrigation districts, Murray Irrigation and Goulburn Murray Water, only averaged 4.5GL/day, leaving at least 20GL unaccounted for.
"The RGA understands that some of this 20GL represents environmental water orders, and that some of this water will be used for river operations and by irrigators outside of the Murray's main irrigation schemes," a statement from the group read.
"However, even when taking this into account, we still estimate that the current surplus flow in the system would be at least 10GL/day."
MDBA says supplementary event unlikely in short term
In a statement to The Land on Monday, Mr Reynolds reiterated that a supplementary event remains unlikely in the short term.
"When it comes to river management, our number one priority is capturing and storing as much water as possible, so it can be allocated to entitlement holders and made available for use later," Mr Reynolds said.
"The rainfall from the weekend was patchy, and a supplementary event is unlikely in the short term as all of this water can be used to supply demands or re-regulated in the system."
RGA have also questioned why so much water was being released from Lake Victoria, which is currently 91pc full.
"Since the start of August, the flow across the South Australian border has averaged more than 9GL/day (747GL in total)," their statement read.
"This is more than double the volume that South Australia is entitled to for this time of the year as set out in the Murray-Darling Basin Agreement.
"While much of this flow has been the remnants of the last supplementary event, it is hard to understand why this flow to SA is now being propped up by releases from Lake Victoria.
"All in all, it appears that South Australia is benefiting from substantial flows across the Border at the expense of a supplementary event in our neck of the woods."
In response, Mr Reynolds said there was a large environmental water event underway known as the Southern Spring Flow, which was contributing to the increased volume of water travelling over the border into SA.
Irrigators struggle to put water management puzzle together
RGA chairman Rob Massina said missing out on a supplementary flow was disappointing and they would continue to call on the MDBA to be transparent on exactly where the water was going.
"Putting the puzzle together is difficult for the everyday irrigator who's trying to make business decisions," Mr Massina said.
He said a supplementary flow would be crucial for ricegrowers at this time, with growers still in the rice planting period.
"The outlook of a potential supplementary event had people very enthusiastic about growing rice and people are busy putting extra blocks in," Mr Massina said.