The Wentworth Group of Concerned Scientists say the Murray Darling Basin’s environment and communities are at stake in the upcoming May 8 vote on 37 sustainable diversion limit offset projects in the Southern Basin.
The scientists are a chief critic in the debate which has led to the Greens putting an ultimatum before the Senate, requesting a disallowance motion to overturn the approval already granted for the projects.
The projects are designed to variously improve the flow of water to environmental assets like wetlands, reduce by 605 gigalitres the amount water buybacks required of irrigators and build capacity in the river system to carry higher flow rates without damaging floods. (Here’s a brief explanation of what how the offset projects work)
The Wentworth Group’s Basin Plan spokesman, Associate Professor Jamie Pittock, said a number of big issues are ringing alarm bells.
“We’re concerned that the Senate vote could be a de facto approval to spend $1.3 billion in taxes on these projects,” Mr Pittock said.
“Before they are agreed, they projects should exposed to proper scrutiny to ensure value for money per megalitre, as the MDBA standards requires.”
Last year the Wentworth Group assessed the available information and found all the projects fail the Murray Darling Basin Authority’s own environmental and economic standards.
Mr Pittock cited several examples, starting with NSW which wants to re-engineering Menindee Lakes to save water by reducing evaporation - that means less holding time and faster water cycling.
“It’s been proposed to dry Lake Cawndilla, which is a key nursery for golden perch. The government hasn’t showed how it will address the sustaining the fish population,” Mr Pittock said.
The Basin Plan sets a capacity target of peak flow rates of 50 megalitres a day above Yarrawonga weir, in NSW.
“But the projects located downstream of Yarrawonga are predicated on 30ML/day - “which just doesn't add up,” Mr Pittock said.
Similarly, Victoria has “chickened out”, Mr Pittock said. An initial proposal would have seen peak flows of 40ML/day in the Goulburn River, but that has been downgraded to 20ML/day.
The lower flow regimes won’t provide the push needed for the Basin Plan’s target to flush the Murray Mouth at regular intervals.
“What NSW and Victoria are doing renders that useless and some projects are incredibly expensive,” he said.
“Victoria’s projects are more the double the agreed maximum cost.”
Other projects would see river regulators deployed to direct targeted flows onto key floodplains for environmental benefit.
“Typically on a floodplain build you’d require 3 per cent of the capital costs to maintain projects each year,” Mr Pittock said.
“As yet governments haven’t agreed who pays for the operation and maintenance.”
Another key concern of the Wentworth Group is what it says is lack of capacity building that is being planned to accommodate the increased flow rates the result from water recovery.
That means building bridges, upgrading roads and levee banks as well purchasing easements on private land to prevent third party impacts from overbank flows, that will be deployed by river managers.
Mr Pittock said there had been minimal costing on this work to date, and said politicians “really need to get a handle on this” to protect Basin communities from economic impacts.
The scientists have also argued the projects aim to deliver environment water more efficiently, but are banking on reductions to consumptive use that have yet to be implemented.
A successful disallowance vote could yet scuttle support for the Basin Plan from NSW and Victoria, who argue the disruption it would cause communities is untenable.
Despite his scepticism, Mr Pittock said the $13b Basin Plan can be a force for positive change.
“There’s $5b still unspent. That’s a lot of money to do good things if political leaders have a mind to.
“I hope the government will take the opportunity to tweak elements of the implementation to maximise returns to the community and rural communities.”
The Murray Darling Basin Authority and irrigator groups have argued the offset projects are backed by a safety net, where any environmental shortfalls are required by law to be filled by further buybacks of water entitlements.
The MDBA has also said the Wentworth Group’s assessment of offset projects was based on incomplete data, which cannot be released for commercial in-confidence to protect the Commonwealth from potential sellers jacking up the price in ongoing entitlement buybacks.