David Leyonhjelm (NSW, Liberal Democratic Party) Share this | Hansard source

The Murray-Darling Basin Plan was negotiated during the millennium drought, in an atmosphere of crisis, based on the perception that drought was the new normal. As a result, it is deeply flawed. Had the plan been developed in a normal year, I am confident it would have been substantially different.

This disallowance motion, if passed, would not improve the plan. It's based on the simplistic notion that all the environment needs is more water—not the right amount of water in the right place at the right time, just more water. In the last parliament I chaired the Senate Select Committee on the Murray-Darling Basin Plan, which inquired into the implementation of the plan. The committee spent a lot of time examining what was right and what was wrong with the plan and how it was being implemented.

Australia is naturally a land of droughts and flooding rains. Droughts are normal, and too much water can be as harmful as not enough. We had plenty of people telling us the plan was great because it would add more water to the environment, and that the amounts of recovered water in the plan were absolutely essential, yet not once did someone tell us that an environmental watering plan was required in a particular area that didn't have one—not once. We had people tell us they'd like water in the Menindee Lakes, and I sympathise with that, but they wanted it for recreational purposes, not the environment. The fact is there is now an abundance of water available for the environment, and if any more water is added to the Murray River it won't have the capacity to carry it within its banks. It's full, and nobody wants to take responsibility for the damage to private property that will occur if there is man-made flooding caused by adding more water to it.

Speaking of the Murray: it's not a natural environment. In nature it ends in an estuary, and so water would naturally come in when the river flow is low and water would go out when flow is high. The mouth might close from time to time, but it would be open much of the time due to natural tidal scouring. Since 1940 the Murray has not been allowed to operate like a normal estuary. There are barrages near its mouth that prevent the sea from coming in when river flows are low. As a consequence, its mouth is now rarely open naturally. During the spring of 2016, for example, there were major floods in the Murrumbidgee, Murray and Goulburn rivers which saw flows to South Australia in excess of 60,000 megalitres per day for over five weeks, peaking at over 94,000 megalitres on 30 November. From 30 November until 18 December, flows across the South Australian border exceeded 65,000 megalitres per day, and yet on 9 January 2017 the South Australian government resumed dredging of the Murray mouth. The five weeks of high flows had failed to clear sandbars at the Murray mouth.

Natural tidal scouring of the Murray mouth is severely restricted by the presence of the barrages, which prevent the entry of sea water into Lake Alexandrina and also by Bird Island, which is located directly in front of the Murray mouth. And Bird Island has only formed since the barrages were erected. It continues to grow in size and impede flow, and it would not be there in a natural environment. And the Murray is the only river in Australia with an artificially fresh estuary. Because of the barrages, the mouth of the Murray cannot even remain open one year in 10, no matter how much water is sent down the Murray.

And yet one of the aims of the plan is to keep the Murray mouth open nine years out of 10. This is not a realistic environmental outcome and should not be an objective of the plan. In fact, what happens to a lot of the water that flows down the Murray and the Darling is that it evaporates in the Lower Lakes. That's Lake Alexandrina and Lake Albert. Between 800 and 900 gigalitres of fresh water evaporates per annum. That is one-third of all the water saved in the plan. If this evaporation were sea water or, more correctly, a mixture of sea and fresh water, a significant amount of fresh water would be available for consumptive or environmental use within the basin. If this water were used for agriculture production, the potential benefit is worth $300 million to $900 million.

As I said earlier, the Murray-Darling Basin Plan is deeply flawed. It gives no consideration to the barrages that prevent the entry of sea water and whether they are still required or there are better options for preventing sea water from mixing with Adelaide's water supply. Amazingly, the plan excludes the Coorong, probably the most neglected environment in South Australia. I'm delighted that Senator Hanson-Young has now decided to agree with me about that. She didn't when I first raised it. And yet, no matter how much water is sent down the rivers, it won't benefit the Coorong. With the Murray mouth nearly always closed, it doesn't get properly flushed by sea water, which it would if the environment was operating naturally. To claim it should be assisted by more fresh water flowing down the Murray, as Senator Hanson-Young has done, is utterly absurd. The Coorong's narrow entrance is seaward of the barrages and operates in an unnatural tidal environment dictated by the barrages.

That said, the Coorong in its natural state would receive a lot of run-off from the surrounding area. However, that's not happening. That's because of the South East Drainage Network, which diverts fresh water to the sea instead of the Coorong. If that water were allowed to flow into the Coorong as it previously did, it would restore the natural environment.

Environmental outcomes in the basin have improved since the end of the drought. However, it's not clear whether the improvement is due to the 2011 and 2016 floods and improved water, the results of the existing Living Murray program initiatives or environmental watering under the plan. This uncertainty is due in part to the failure to set baseline environmental benchmarks and to report against those benchmarks. This is unacceptable, given the expense of the plan to taxpayers. What is clear is that water taken from Queensland, New South Wales and Victorian agriculture has had a devastating impact on rural communities. It is also clear that more water sent to South Australia will have no additional environmental benefits.

The environment can be an emotional subject for some people, but it's high time some facts and reason were applied to the Murray-Darling Basin Plan. South Australian politicians who don't know the difference between the Darling and Murray rivers, who can't explain why the Lower Lakes should remain fresh and who can't explain why the Coorong is dying, are part of the problem; they are not part of the solution.