“It will cause great damage to downstream ecosystems and to pastoralists and Indigenous communities,” Professor Pittock, who also lectures at Australian National University, said. “There is no clear business case and there are cheaper alternatives.”
Professor Pittock urged Minister Ley to designate the wall-raising as a so-called controlled action under the Environmental Protection and Biodiversity Conservation (EPBC) act that would prompt a federal public inquiry.
A spokesman for Minister Ley said the environment department had received 25 submissions on the Wyangala wall project, with a referral decision due on June 22.
“All public submissions will be considered in making a decision about whether the referral is a controlled action or not,” he said.
“If the project is found to be a controlled action, it will be assessed under the bilateral agreement between the Commonwealth and NSW governments and, through that process, will require preparation of an Environment Impact Statement and involve further opportunity for public comment, he said.
WaterNSW said the higher wall would increase Wyangala’s storage by 53 per cent, or about 650 billion litres.
A spokeswoman for Water Minister Melinda Pavey said the wall-raising was part of a series of major projects that would be accelerated “to enhance water security during the ongoing drought and to better protect communities from future drought impacts”.
“The NSW government has cut approvals to permit preliminary works [on Wyangala] to commence as soon as this year,” she said. “This is the biggest water infrastructure build in NSW since the 1980s.”
In his submission, Richard Kingsford, a leading ecologist from the University of NSW, said a proposal to build a weir at Gin Gin near Narromine would create a weir pool extending upstream for 30 kilometres.
He said differing scoping studies put the “re-regulating storage” project at between 6 billion and 9.5 billion litres.
“This will kill riparian vegetation such as river red gums because these plants cannot tolerate permanent inundation resulting from this pool,” Professor Kingsford said, adding a range of nationally threatened fish species such the Murray cod and Macquarie perch would also be affected.
Peter Hannam writes on environment issues for The Sydney Morning Herald and The Age.