The New South Wales government’s proposal to raise the wall of the Warragamba Dam could result in complete inundation of some cultural sites and is at odds with Australia’s obligations under the world heritage convention, scientific advisers have warned.
In a letter to the federal government, the International Union for the Conservation of Nature (IUCN) – which provides advice to Unesco’s World Heritage Centre – said the project “appears to be inappropriate in relation to the requirements of the world heritage convention”.
In a scathing review of the environmental impact statement (EIS) prepared for the proposal to raise the dam wall by up to 17 metres, the scientists wrote the findings contradicted the document’s conclusion that raising the dam wall “would not result in a material loss or degradation of the outstanding universal value” of the world heritage area.
They noted the project was expected to result in complete inundation of some cultural sites and this loss was “clearly at odds” with the suggestion there would be no material loss or degradation of world heritage values.
Bob Debus, the chair of the Colong Foundation for Wilderness and a former NSW environment minister, said the NSW government was “putting Australia on a collision course with the world heritage committee” that created the risk of an in-danger listing for the Blue Mountains.
“The Unesco advice is saying quite clearly that raising of the Warragamba Dam wall is totally inconsistent with Australia’s obligations under the world heritage convention,” he said.
Stuart Ayres, the minister for western Sydney, said “we don’t support the view presented by the international union”.
The IUCN assessment raises several concerns with the project, including that the government had insufficiently assessed the effects on threatened plants and animals, cultural values, and the recovery of species after the 2019-20 bushfire disaster.
The IUCN said it was unacceptable the government had proposed compensating for damage to world heritage values by providing offsets in other areas.
The scientists further wrote that local communities and traditional owners had not been properly consulted in the development of the EIS “and it also is apparent they have not provided their free, prior and informed consent”.
Ayres said the proposal to raise the wall was to mitigate downstream floods while minimising environmental impacts behind the wall.
“It’s important to recognise that unlike a water storage dam that holds water permanently, the higher wall at Warragamba will only hold water above the current storage level on a temporary basis, a few hours up to 14 days,” he said.
“We are confident that given the temporary and limited areas covered by inundation that environmental impacts can be managed.”
A spokesperson for the federal environment minister, Sussan Ley, said the NSW government was assessing the project on the government’s behalf, under bilateral assessment arrangements.
“The bilateral agreement provides for a robust assessment of matters of national environmental significance including world heritage values,” he said.
“Before making any decision on the proposal, the minister will consider the NSW government’s environmental assessment and all other matters required under national environmental law.”
