This article is more than 1 year old

This article is more than 1 year old

The crisis on the Lower Darling, which has seen up to 1 million fish die, is largely due to the decisions by the Murray-Darling Basin Authority on instructions from the New South Wales government, a report by the Australia Institute finds.

It says the reasons for those decisions appear to be about building the case for the new Broken Hill pipeline and the Menindee Lakes project, which will see the lakes shrink and “save” water by reducing evaporation.

“It is clear what has caused the Darling River fish kill – mismanagement and repeated policy failure,” said Maryanne Slattery, senior water researcher with the Australia Institute. “To blame the fish kill on the drought is a cop-out, it is because water releases were made from the lakes when this simply shouldn’t have happened.

“It’s time to stop passing the buck.

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“Drought and high temperatures are a factor, but a key issue is that smaller flow events now rarely reach Menindee,” the institute says after a detailed analysis of flows and releases from the Menindee Lakes system. “Large floods still occur, but smaller flows to regularly replenish the system have largely stopped.”

Since the fish kills, Slattery, a former MDBA employee with expertise in analysing river data, has closely analysed the inflows and outflows from Menindee Lakes and and how the lakes have been managed compared with previous years.

“The lakes were drained in late 2016 and 2017, with a total of 819GL released from Menindee Lakes, almost the equivalent of two Sydney harbours,” she said. “This is not a natural phenomenon, but a management decision.

“Such releases have been made in the past, but in recent times inflows from the northern basin to refill the lakes have declined significantly.”

According to the MDBA’s own reports, 2017-18 was the third-largest cotton crop on record.

“While this year is likely to be much smaller, a substantial amount of irrigation is still occurring,” she said.

Meanwhile there have been decisions to release water from the lakes downstream.

The full capacity of Menindee Lakes is quoted as 1,730GL, although it can hold up to 2,000GL during flood, the institute says.

Under the Murray-Darling basin agreement, the management of Menindee Lakes is shared between MDBA and the NSW government. The MDBA “controls” the lakes until the lake volumes drop to 480GL, then control reverts to NSW.

But the institute says when the the MDBA is in control it is guided by the basin committee made up of state ministers and by the states themselves. The decisions of this body are not public.

The releases were not just about about keeping the river healthy downstream.

The Australia Institute’s analysis showed that a total of 89GL of environmental water – water to keep the river system healthy – was released from Menindee in the 2016-17 year.

“This represents just 11% of the total releases to the Lower Darling,” she said. “Furthermore, no Menindee environmental releases were badged in the delivery to South Australia.”

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Nor were they drained to meet South Australia’s needs, as the NSW minister for primary industries, Niall Blair, has suggested, Slattery said.

“Releases were made from Menindee Lakes in excess of South Australia’s requirements,” she said. “In fact, parts of South Australia were recovering from flooding and months of wet weather at that time.”

Instead, Slattery said, the lakes were drained to “save evaporation”.

“Long-standing practice by the MDBA is to prioritise releases from Menindee Lakes above other storages to minimise evaporation,” she said.

“However, causing an ecological disaster to avoid evaporation can hardly be described as good environmental management, particularly when downstream areas were in flood.”

There is nothing in the laws and regulations guiding the management of the basin that directs its managers to prioritise evaporation efficiency over environmental and community outcomes.

“A possible part of the answer is that the lakes were drained to justify the Menindee Lakes water-saving project, related changes to the basin plan and the related Broken Hill pipeline project,” she said.

“These are opposed locally and have proceeded with minimal transparency around business cases, cultural and environmental impacts. They are easier to justify if the lakes are empty and Broken Hill appears at risk of running out of water.”

The report also tries to answer the question who is to blame.

“The MDBA coordinated the management of the lakes for most of this time and is partly responsible,” Slattery said. “However, claims by the NSW water minister that this crisis was ‘under the control of Canberra’ are false.

“The MDBA coordinates the management of the lakes but does not ‘control’ it. In fact, states can direct the management of the lakes via the Ministerial Council and Basin Officials Committee.”

The Australia Institute report called for a full inquiry, like a royal commission, and much greater transparency on decision making by the MDBA.

“There is very little transparency around exactly why the lakes were drained by the MDBA with the consent of the BOC and state governments,” she said.

Cotton Australia said earlier this month its crop this season would be half of the previous year’s and that it was wrong to blame the industry for the fish kill.

The general manager of Cotton Australia, Michael Murray, said “as an industry, we are growing very tired of being ‘the whipping boy’ for all the problems that are being brought on by this crippling drought”.

The minister has also blamed the extreme conditions for the crisis.

“You can’t dismiss the impact of drought when in the last six months, we have had record low inflows into northern NSW rivers, with many waterways ceasing to flow and the summer heat placing further pressure on the dwindling water supplies,” he said in a statement this week.

• This article was amended on 21 January 2019 to correct the capacity of the Menindee Lakes from 1,730ML to 1,730GL.