“A number of gauges in the vicinity of Menindee lakes were impacted by significant flooding in the last months of 2022, and the data taken offline as a result,” said a spokesperson for WaterNSW, the agency responsible for providing the flow data.

“The affected gauges needed to be recalibrated on-site to ensure accuracy before returning to service, a process that was delayed by the widespread flooding across the region, which restricted access to some sites.

“The Weir 32 gauge in question was returned to function on March 13.”

Greens MP Cate Faehrmann, who is calling for a royal commission into the management of the Murray-Darling Basin, said the missing information would shed light on the decision to release oxygen-deprived water.

“This data is crucial to be able to determine the timing and volume of the release of the deadly water into the Menindee Weir Pool that led to the fish kills,” said Faehrmann, who visited the site this week.

“The Menindee community deserves answers and action from the government starting with why their river is dying. Nothing short of a forensic examination of what decisions are being made and by whom in WaterNSW and DPE Water is required.”

Menindee residents demanded answers on water pollution and the clean-up of rotting fish at a town meeting on Tuesday.

Officials from WaterNSW, the Department of Planning and Environment, NSW Police, the Environment Protection Authority and the council publicly drank cups of local water at the meeting in an effort to prove it was fit for human consumption.

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