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St Kilda Mangroves Destruction

27 May 2021

The Hon. R.A. SIMMS: I rise to speak briefly in support of this motion, but particularly in condemnation of the way the two ministers, the Minister for Energy and Mining and the Minister for Environment and Water, have handled this matter. I say 'handled the matter', but really they have bungled the matter. It is utterly reprehensible that it took so long for them to act, and the lack of transparency from both departments has been simply appalling.

It has now been a year since there were first signs that something was very wrong down at the mangroves, but it has been even longer since the ponds started to be filled by Buckland Dry Creek. I remind all members here that Buckland Dry Creek were not allowed to move water or brine where these ponds are under the holding pattern that has been in place. This was the care and maintenance plan put in place after the ponds were initially closed back in 2013 and drained, against advice, in 2014—although I note as well that there are separate issues with the holding pattern and whether or not that was even working.

Despite this, despite the holding pattern, there was early evidence of the ponds being filled on 6 December 2019. What follows is a damning time line in terms of the government's management of this issue. The first two ponds south of St Kilda, PA5 and PA7, had shallow brine right across them by 21 December 2019. The brine in those first two ponds continued to deepen until 15 January 2020. The gate to PA8 was opened and brine started to fill that pond, reducing the levels in PA6 and PA7, notably.

By 27 January 2019, which was the next available date for the satellite imagery, the gate to PA9 had been opened and that pond had started to fill, reducing the brine levels in the first three ponds. On 6 May 2020, the satellite imagery shows considerably deeper brine right across the ponds—a clear ramping up of the pumping, which must have occurred in the few days before. By 15 July 2020, the orange patter visible in the false colour in the normalised vegetation index was apparent, signifying a loss of chlorophyll, which is a hallmark of the areas where mangroves and samphires had begun to die. By 30 July 2020, the mangrove dieback area was quite clear on the satellite imagery.

Yet, despite this, despite this evidence very early on in the piece, the government did not get involved until September. In fact, it was not until late September that DEM, DEW, the EPA, the Coast Protection Board and Buckland Dry Creek visited the mangroves and noted that they were sick. At that point as well you could see and hear the brine trickling out of the banks, and you could even see where the acidified brine had reached the surface. This is a damning time line, so it is mind-boggling really to hear from both departments that they were not aware of this issue until September. What is going on here?

It is frankly bizarre that it took until earlier this year—and we do not know the exact date—for a formal investigation committee to be established to look into the impacts of the leaking brine. Worse still, we are told that we might not even have a report until next year. Talk about being asleep at the wheel! None of this has come out of nowhere. We have had clear and consistent warnings as far back as 2012 that this could happen, some of those from the government and the government's commissioned reports.

When the salt fields were first set to be closed, a report prepared for the Adelaide and Mount Lofty Ranges NRM Board outlined the risks of the pond closure, including the discharge of hypersaline brine and its impact on the environment. We have then actually seen a formal complaint—not just one complaint but several complaints—lodged under the Environment Protection and Biodiversity Conservation Act in 2015, once again raising concerns around the risk of acid sulphates and brine leaking into the mangroves.

These complaints also related to concerns that while there was a holding pattern in place, it was not a long-term solution and was originally intended to end in 2014. By then the owners of the site—Ridley, at that time—were supposed to have a closure plan in place. Instead, since then we have seen the holding pattern extending until 2018, and then again until SA Water ran out of water intended for dilution of the brine sometime in 2019.

Then, as if that was not enough, once again a study commissioned by the department in 2019 noted a major issue that hypersaline and sulphide-rich sediments had built up over large areas of the ponds and the salt field, posing a potential environmental hazard and a barrier to the remediation of the site. All of these warnings, all of these concerns, have been ignored.

When we have seen action, the action taken has been inadequate. It has been done in half measures. We have been told that the departments and the EPA have pumped 50 million litres out of the leaking ponds, but what has actually happened is that water has been removed but salt remains. The brine was pumped from one side of the leaking ponds to the other, to a side that is slightly higher up, and that pumping was just to increase the evaporation of these ponds. So of course all the salt has been left behind, so when it rains all of that salt is just going to be washed back into the system.

What is more concerning is that apparently the DEM staff have admitted that they have no data yet to predict the impact of the rain. Instead, they just hope that, based on the annual moisture deficit, there will not be a significant mobilisation of the redissolved salt. This is terrible. What I think the department are hoping for is some sort of miracle, because while the year has been dry so far, the area where the salt fields are actually experiencing negative evaporation—otherwise known as significant rainfall—has been left lacking. So to pin your hopes on a year-long average, rather than on the real-time weather conditions, is simply ridiculous.

Beyond that, I am informed that the Department for Energy and Mining has fully acknowledged to the community that, despite the department's hopes of a second wave of the groundwater, this may move towards the marsh in winter. Let's be clear: they are once again fully cognisant of the possibilities of the risks, but they do not seem to be doing anything at all. This is certainly excessive risk-taking behaviour on behalf of the government. We are seeing far too little action, too little too late, from the state government, and we are seeing one department passing the buck to another, on to the EPA or the federal department, but no-one is prepared to step up and take responsibility, to hold the minister to account, and fix this problem.

When this motion was first introduced, my colleague Tammy Franks raised the fact that the trees in local backyards were suddenly dying and that we were seeing an explosion in mosquito populations, but since then we have seen a devastating impact. This disaster is having a terrible effect on migratory birds. I would commend the work of the St Kilda Mangroves Alliance in raising this issue, and I understand they have now lodged a complaint with the federal environment minister under the Environment Protection and Biodiversity Conservation Act. There is a litany of failures here. It is very clear that the government needs to step up and take some action. More needs to be done sooner rather than later. It has already been too long. I commend the motion.