House of Assembly: Tuesday, September 14, 2010

Contents

LOWER LAKES

Mr WILLIAMS (MacKillop—Deputy Leader of the Opposition) (15:17): My question is to the Minister for Water. If the government has been monitoring the Lower Lakes and the bund at Narrung and you have a plan, as claimed by the minister on radio last week, why is it that the government is now having to build the bund higher before it can be removed? At what additional cost to the taxpayer will this occur, and how will siltation of the narrows be prevented during removal of the bund?

The Hon. P. CAICA (Colton—Minister for Environment and Conservation, Minister for the River Murray, Minister for Water) (15:17): What we have had over a significant period of time is a plan to manage the river system that South Australia is responsible for in the best way we possibly can to mitigate against what has been the most unprecedented drought in anyone's living memory and, in addition, in a cautious approach, to make sure through risk management that we made what were sometimes difficult decisions that needed to be made so that the river system was able to live to fight another day. In regard to the specific or multipronged questions provided by the deputy leader, yes, we have had a plan. We have had a plan for a significant period of time. For some people—

Mr Williams interjecting:

The Hon. P. CAICA: The only thing that is not working, Mitch, is you. What we have attempted to do—and I know it is terminology that some people might say is a bit cute—through what is in essence a real-time management, is work through different scenarios about what might be and then, when situations occur, that we can react accordingly with the situation as it exists at that point in time.

There was no doubt, and everyone knows that the bund is a temporary structure. It was always meant to be a temporary structure. We always knew that as water rose—and that is something I think that we all welcome here, not only in this house but throughout South Australia—that that would then have an impact on the structural integrity. We were aware of that.

Of course, one of the things that we certainly did not want to do was remove a structure until such time as we had a fair indication of what the circumstances and the future circumstances would be. We have received information—and I made a fairly detailed ministerial statement earlier—from the Murray-Darling Basin Authority.

That information is still, to a very great extent, speculative at this time. What the real circumstances might be is not confirmed, but what is confirmed is that we will have a significant amount of water down there. That will obviously have a positive impact on the water levels below Lock 1 and through to Lake Alexandrina. By partially removing that bund we would look at the equalisation of the two lakes by the end of October.

However, in regard to the specifics of the deputy leader's question, we hold safety foremost and paramount. What we needed to do was ensure that, when working on the top of that bund, there was enough structural integrity there so that equipment did not fall over. We know that and, quite simply, that was the right and appropriate thing to do.

That work commenced over the weekend. It will continue and we expect that by later this week, or by the weekend, that 100 metre removal of the bund will ensure that, for the first time in four years, water will flow from Lake Alexandrina through to Lake Albert.

We also know that for too many years the Murray-Darling Basin system has been treated as a compartmentalised system, depending on where you sit within that particular system. What we do know is that it is a connected system, and this is part of the first processes of reconnecting that area that we are responsible for. We are certainly very hopeful that with the water coming down, we will see for the first time significant water flowing over the barrages and finding its way to the Murray Mouth.

I hope this is not construed as being a tautology, but there are going to be significant unregulated flows, as we know, but we are hopeful that we are going to be able to regulate those unregulated flows in such a way that we are able to use that—

The Hon. P.F. Conlon: Oxymoron.

The Hon. P. CAICA: Oxymoron is it, Patrick, thank you. We are hopeful that we will actually be able to regulate that water in such a way that we can use it most effectively to the best benefit of the section of the system over which we are responsible and, in doing so, make sure that, through the regulation of that flow, we are able to ensure that further damage is not caused to those other areas that are suffering structural integrity, and the deputy leader is aware of those, whether they be the banks or our levee banks. So, it is about managing it as best we can and managing it under real-time circumstances, and that is what we will continue to do.

Members interjecting:

The Hon. P. CAICA: Well, what we will be able to do in regard to the siltation is to remove the significant proportion of that. We know that some of that material will find its way into the lake and we will need to, again, manage that as best we can to minimise that amount of siltation, but also do it in such a way that, as best as we can, we can recover it. That is the commitment we have made to the local community down there as well.