Ministerial Statement

River Murray Updated Flow Advice

The Hon. J.K. SZAKACS (Cheltenham—Minister for Police, Emergency Services and Correctional Services) (15:05): I seek leave to make a ministerial statement.

Leave granted.

The Hon. J.K. SZAKACS: I rise to advise the house on the current high flows in the South Australian River Murray. Obviously, we have all seen the incredible reports from further up the Murray, with so many upstream communities experiencing flooding, and our thoughts are with those communities. Over recent weeks, when providing updates on those flows expected in South Australia, the government has emphasised that the peak of the River Murray flood is very difficult to predict, particularly while it is passing through the broad flood plain that lies between the Murray and the Edward-Wakool River system. I understand the anxiety that this level of uncertainty can create in communities right across the river.

Predicting flows in the Murray-Darling is a complex task, with contributions from many parties, including the Bureau of Meteorology, the Murray-Darling Basin Authority and the Department for Environment and Water. Adding to this, the Murray-Darling system is a vast mix of rivers, tributaries and flood plains, and estimates are further complicated by continuing variable weather systems and unusually heavy rainfalls across the basin.

Based on the latest data and modelling, the high probability forecast peak has increased and is now estimated to be around 175 gigalitres a day at the SA border. The timing of early December for the arrival of the peak flows remains unchanged. There continues to be a moderate probability of a peak of 200 gigalitres a day and a low probability forecast of 220 gigalitres a day. Both of these predictions remain unchanged from the last update, but communities should continue to consider this information in their flood emergency preparedness.

To provide some context to the house, a flow rate of 200 gigalitres a day would make this the third largest recorded River Murray flood, behind 1931 and 1956. The 1956 flood saw flows of around 340 gigalitres a day. The significant rainfall that was forecast for large areas of the Murray-Darling Basin over the past week did exceed expectations, particularly in the upper reaches of the Murray catchment.

The additional rainfall, coupled with flood management releases from dams upstream, has increased the possibility of flows staying at or near peak levels throughout December, and we are expecting high flows to continue into January. As a guide, flows are not expected to drop back below 150 gigalitres a day until well into January 2023, with flows as high as 100 gigalitres a day expected to continue for an extended period after that. There is also further rainfall in the order of 25 millimetres to 100 millimetres forecast for the upper reaches of the Murray catchment over the coming week, which does have the potential to extend the duration of high flows.

To help support community, business and personal planning for this flood event, the Department for Environment and Water has added a number of new information products to its website at www.environment.sa.gov.au, including:

flood mapping of major river towns at a flow of 200 gigalitres a day;

estimated travel times of flows along the river;

estimated water levels in the River Murray corresponding to various flow rates; and

estimated arrival times and duration of flows.

These will be updated as required following any upgraded forecast. The government will continue to provide relevant updates as new information comes to hand.