MURRAY RIVER, LOWER LAKES

The Hon. DAVID WINDERLICH (15:44): This is my first matter of interest, although looking at the empty red seats it looks more like a matter of disinterest.

An honourable member: We're listening.

The Hon. DAVID WINDERLICH: Good. As members know, the government has sought approval to flood the Lower Lakes with sea water. This is an important, almost certainly irreversible decision, and it is vital that the community feels they are receiving an accurate, scientifically rigorous account of why it is necessary. Unfortunately, we do not have this information and the government has been less than open in the way it has presented the evidence we do have.

In fact, the government has propagated and perpetuated three myths that are being used to gain support for the flooding of the Lower Lakes. It has been argued that the lakes were historically sea water and, therefore, they can be flooded with sea water. The facts refute this argument. Sediment cores, middens, and oral and written histories show that most of the time the lakes were predominantly freshwater. Inflows from the river kept the salt water out. At times of low flow, the salt water would move further up the river; that is why Captain Charles Sturt reported brackish water. That is just one report at one point in time. It is like taking an account of the 1956 floods as an indication of the natural level of the river.

There are other accounts around this similar time to Captain Charles Sturt that paint a very different picture. According to Hamilton, one of the overlanders in 1839:

There in the distance was the lake. We were soon tasting the water. It was fresh and it was not salt. It had a vapid sweet taste but it quenched our thirst.

Eminent Adelaide geologist, Victor Gostin, has said that in recent history (that is, for thousands of years) the lakes were freshwater. Over the longer period of geological history, they were saltier but then, over the longer period of history, much of the Murray-Darling Basin was under the sea. You can find seashells and other marine fossils in the Riverland, but that is hardly the reference point for environmental policy today. The saltwater history of the lakes is a convenient myth.

The second myth is that we should not keep these lakes as freshwater because water there will evaporate. Evaporation is part of the water cycle, so it is not necessarily a problem. If we were really concerned about evaporation, we would not permit water to be stored in Lake Menindee where the evaporation rate is 2.5 metres a year and the rainfall is 243.7 millilitres or in the giant cotton dams in Cubbie Station.

If evaporation was the primary concern, we would completely change our management of water from the current system of storing it in shallow evaporation ponds (which is what they are in effect) to a park and pulse system whereby, every time it rains in Queensland, for example, we would let the equivalent amount of water out of Menindee to flow down to the Murray and refill with the water coming down from Queensland. Of course, that would rely on stopping diversions of water by the cotton dams.

The third convenient myth is that of acid sulphate soils. We are told we must flood the lakes otherwise the sulphuric acid in the cracked wetlands will get into the river and lakes and they will acidify. This may be so, but the scientists cannot predict the rate at which this will happen. They have models but they do not yet have sound science based on rigorous testing and random sampling. In the absence of this, the locals have argued that we can deal with the acid sulphate through a process of bioremediation—planting the right plants, mulching and so on—which sounds idealistic except that they have good evidence.

Locals can report participating in a very solemn tour with scientists about the perils of acid soils while a dog walked through a pool of supposed battery acid without immediate harm. They point out that the shores of Lake Alexandrina near Milang, a supposed acid sulphate hot spot, is covered in vegetation. The land appears to be healing itself.

It is interesting to reflect on the similarities between the Lower Lakes and the battle against the bureaucracies of the Upper South-East where there was a similar debate about whether to deal with saline water by draining it or planting salt-resistant plants, which was the preference of most of the locals.

In truth, members, we have absolutely no reason to trust the advice of the bureaucrats and river engineers in this current crisis. Clearly, they see the river as a drain, a channel, and not a living system. There is no clearer example of this than in the use of the phrase 'transmission losses' to describe the progress of water down the river. It is true that when we let water down the river, or if water is allowed to run down the river, some soaks into the ground, some evaporates, and some flows off into tributaries. This process is not transmission loss; it is the process of reviving the river. It is a natural, organic, ecological process.

That may sound like something a city greenie would say, but it is what the locals, farmers and fisherfolk are saying all along the river, and it is supported by the evidence. The strongest case of all to choose natural, low intervention strategies over dams and weirs is that we have been following that road for decades, and look where it has brought us.

Time expired.