Mount Bold Reservoir

The Hon. M.C. PARNELL (14:38): I seek leave to make a brief explanation before asking the Minister for Water and the River Murray a question about the Mount Bold Reservoir.

Leave granted.

The Hon. M.C. PARNELL: I have received reports from constituents that this past winter the Mount Bold Reservoir has overflowed. Whilst that would normally be very good news, a sign of good winter rainfall, much of the water in Mount Bold is actually pumped from the River Murray. It is also generally accepted that the lack of flows to the Lower Lakes and Coorong in the River Murray is a cause for a great deal of environmental, economic and social concern. My questions of the minister are:

1. Is it correct that River Murray water has been released or overflowed from Mt Bold Reservoir this last winter?

2. What steps are in place to ensure that River Murray water is not pumped unnecessarily into Adelaide's water storages?

The Hon. I.K. HUNTER (Minister for Sustainability, Environment and Conservation, Minister for Water and the River Murray, Minister for Aboriginal Affairs and Reconciliation) (14:39): I thank the honourable member for his most important question about SA Water's pumping strategies into our reservoirs to supply drinking water to the city of Adelaide and beyond. It is a very difficult and complex area, and one which far surpasses my skills, but I understand that our experts in SA Water look at the environmental conditions that they are presently faced with.

They look at the environment that we have recently endured in the last few months, and they project out, on the basis of Bureau of Meteorology advice, what we are likely to see in coming months, before feeding those figures into their very complicated machines and coming up with a management plan for our reservoir system in terms of when to pump water from the Murray, how much to store in the reservoirs, and having a reasonable idea of what to expect over winter and spring.

Of course, that is always variable, so from time to time those models are not entirely accurate, but they do supply us with a sustained water supply. They normally do not waste water, but if environmental conditions change (if we do get an abnormally wet spring, for example, and there is more rain than was predicted by the Bureau of Meteorology forecast and our environmental modelling) then of course there will be some spillage.

I am not aware how much spillage there has been, or whether indeed there has been any spillage that was not planned for. Over the summer months, the honourable member will be quite aware that we did spill from some catchments into the River Torrens to flush out any algal growth that might have been accumulating over the hotter months and to reset Lake Torrens.

This summer was probably the first in many years where we did not have large algal blooms in Lake Torrens because of that spill down the Torrens and the flushing of the system, and that is to be commended. I think SA Water and the NRM board got that absolutely spot on and completely right.

Going back to the complex modelling that is used by SA Water: as I say, these are always predictions. They do not always get it right exactly, but more often than not they do, and the evidence of that is that we have not run out of water for some time in terms of what we put into the catchments over the winter period, whether it be by pumping or by natural flows down our catchments and being topped up by the Murray from time to time.

The PRESIDENT: The Hon. Ms Lee.

The Hon. R.L. Brokenshire: A good member.

The Hon. I.K. Hunter: Hear, hear!