Ministerial Statement

High Flows in the SA River Murray

The Hon. S.E. CLOSE (Port Adelaide—Deputy Premier, Minister for Industry, Innovation and Science, Minister for Defence and Space Industries, Minister for Climate, Environment and Water) (14:02): I seek leave to make a ministerial statement.

Leave granted.

The Hon. S.E. CLOSE: The distribution of the statement should arrive momentarily, and I apologise for the delay. I rise to advise the house on the current high flows of the South Australian River Murray. First, let me acknowledge the devastating situation that many upstream communities are currently experiencing as a result of flooding in the River Murray system. I believe I speak for all of us when I express my heartfelt concern for their wellbeing as they deal with the damage and losses that flooding of that scale can create.

It is timely to remember that just prior to the current run of successive La Niña events that have filled storages across the basin we were teetering on a return to Millennium Drought style conditions. While we will certainly be confronted with drought conditions again in the future, drought could not be further from people's minds in the Riverland today. As most members would be aware, the continuing high rainfall, full storages and graphic images of flooding upstream in the Murray-Darling Basin have created great speculation in the community about how big this current high-flow event will be. The truth is that we do not know yet.

Flood forecasting for the River Murray is a particularly challenging exercise as water spreads out and fills large areas of flood plains upstream, which can significantly affect the size and timing of the peak. Experience has shown that this occurs differently in each high-flow event. In addition, the complex interaction of inflows arriving from multiple river systems at different times, including the Murray, Murrumbidgee, Goulburn and Darling rivers, also increases the complexity of providing accurate forecasts in advance.

What this means is that you cannot just add the upstream flows in the different rivers and tributaries together and assume that this is what South Australia will be receiving in several weeks' time—it does not work like that. However, what we do know is that the peak in South Australia during this event will be higher than the high-flow events of recent memory, being 94 gigalitres per day in 2011 and 95 gigalitres per day in 2016. Those a little older may remember the peaks of 104 gigalitres per day in 1990 and 112 gigalitres per day in 1993. The advice that has been provided is that these peaks will be exceeded too.

The official projection from the South Australian Department for Environment and Water, following discussions with upstream authorities, is that flow in the River Murray in South Australia is expected to peak at 120 gigalitres per day in early December. However, it is important to note the department views this as a conservative estimate, as it does not account for any of the 50 to 150 millimetres of rain currently forecast by the Bureau of Meteorology to fall across large areas of the basin over the coming week.

A flow forecast of 120 gigalitres per day means that the current flow advice for the River Murray issued by the State Emergency Service will be expanded from only the shack areas to cover the length of the River Murray in South Australia. While we do not know what the peak flow will yet turn out to be, we do know that it will be the highest flow to come across the South Australian border since the run of high flows experienced from the early to mid-1970s that peaked at 182 gigalitres per day in 1974. There is currently no data that indicates a repeat of the 1956 flood, which peaked at 341 gigalitres per day. However, I can assure the house that there will be significant additional communication and action undertaken should the situation begin to change.

To assist response agencies, businesses and river communities with their risk management planning, the Department for Environment and Water will provide additional commentary to supplement the official warnings in its weekly high-flow advice that it already provides. Aligned with these projections, the department will also publish maps of the major towns along the river that show the modelled areas of expected inundation at each of the potential flow rates provided. These are available at www.waterconnect.sa.gov.au, and a link will be added to the Department for Environment and Water website shortly. The department will also work with PIRSA to provide the best advice possible to support primary producers in their risk management and business planning.

In the preparation for the anticipated high flows, the Murray Mallee Zone Emergency Support Team, otherwise known as the ZEST, has been meeting weekly since August. Through the ZEST, various state agencies are working closely together with local government to ensure that the community, business and visitors are well prepared for the high water levels, while also promoting the region as a visitor destination that can still be enjoyed despite restrictions on some activities.

In response to the potential seriousness of this issue, the government has also activated the state emergency centre process to ensure there is a strong and joined up response across the public sector to this matter. The SEC, as it is known, met earlier today to be briefed on this matter and has set up a number of working groups to address the issues we expect will arise. The Premier has announced a six-week campaign to ensure River Murray communities are afforded the best possible protection for floodwaters heading to South Australia.

As part of that immediate work, I can assure those concerned that I have a team of people from my department heading to the Riverland in the next 24 hours to work with councils and other landholders to ensure the levee banks of concern are being reviewed and action taken to ensure the integrity of those flood protection levies. As I indicated earlier, this is a complex and ever-changing matter, and I undertake to keep this house and the broader South Australian community informed as new information comes to hand and to do our best to support our River Murray communities.