165 gigalitres per day now predicted for SA

AT least 165GL a day is expected to flow down the river in SA from early December, increasing the likelihood of flooding in low-lying areas of the Riverland.

Just two days after predicting 150GL, the State Government has this afternoon again revised up predicted River Murray flows, with new data showing the flow is expected to be around the 1975 flood levels.

The latest forecast shows there is now a moderate probability of 200 GL a day peak flow and a lesser probability of 220GL a day.

“These new flow predictions raise the risk of flooding in low-lying areas and we are urging people to prepare as best they can,” said Water Minister Susan Close.

“The uncertainties in flow forecasting mean people need to prepare for at least the worst-case scenario so we get through this event without any risk to life and reduced impact on property.

“As we have said from the beginning of this event, forecasting the flood peak is exceptionally difficult until the flood peak enters the main channel of the river.

“While these levels of uncertainty are expected to reduce over the coming weeks, the forecast will still be subject to regular refinement.”

Dr Close said the main flood peak was currently passing through the broad floodplain which lies between the Murray and the Edward and Wakool River system, a complex part of the river system that has made forecasting levels difficult.

Also of concern is that significant rainfall in the order of 25-100mm is forecast for large areas of the Murray-Darling Basin over the coming week, potentially influencing future flow projections.

While the peak flow is still expected to arrive at the South Australian border in early December, flows of around 150GL/day are now expected to cross the border in late November and not drop back below this level before the second week of January.

Beyond that, the flow rate is expected to remain above 100GL/day throughout the remainder of January and likely beyond.

The Government also continues to closely monitor for potential blackwater events in South Australia, where reduced dissolved oxygen levels have been recorded. This risk increases with rising temperature.

SASES Chief Officer Chris Beattie said the SES would continue to work with DEW around the increased flows and ensuring the timely advice to communities.