Warragamba Dam wall-raising assessment open to legal challenge, leaked documents say

The federal government has intervened in a NSW government plan to raise the Warragamba Dam wall, questioning the evidence used to claim the proposal would have no significant environmental impacts on the Blue Mountains World Heritage Area.

According to leaked documents, federal officials took issue with a draft environmental impact statement claiming important ecosystems would not be negatively impacted — a claim they said had “no supporting evidence”.

The Commonwealth experts also criticised the NSW analysis for not including the effects of the 2019-2020 bushfires, which could have made plants and animals impacted by the dam project more vulnerable or more important.

The documents have come to light just weeks ahead of the expected release of the world heritage assessment for the dam, part of the broader environmental impact statement which the ABC understands was earmarked for publication as early as July 13.

That world heritage assessment is an analysis of the impacts the project will have on the Blue Mountains World Heritage Area, and is required by the federal government and UNESCO.

“Twenty years ago, with complete bipartisan support, the government of the Commonwealth of Australia nominated the Blue Mountains to be inscribed on the list of World Heritage by UNESCO,” Bob Debus, who was the NSW environment minister at the time, said.

He is now the chair of the Colong Foundation for Wilderness, which is fighting against the dam project.

“There’s no point in having world heritage declarations unless you take those declarations, and the responsibilities that flow from them, extremely seriously,” Mr Debus said.

Flooding the bush to save the suburbs

The NSW government is planning to raise the height of Warragamba Dam by between 14 and 17 metres to decrease the impacts of floods on Western Sydney.

If that happened, some floodwater could be held behind the dam wall during future flood events, inundating parts of the Blue Mountains World Heritage Area, instead of flowing towards Sydney.

That would cause parts of the area, home to many unique and endangered plants and animals such as the regent honeyeater, to be flooded for up to two weeks.

To proceed with the plans, WaterNSW needs environmental approval from both the NSW government and the federal government.

Part of the approval process for the project includes an assessment of how it would impact on the world heritage values, known as “outstanding universal values”.

The ABC has seen comments and feedback made in June from Commonwealth officials, as well as NSW legal advisers, on a draft created in May.

Assertions with no evidence

The Commonwealth officials complained the document contained assertions “with no supporting evidence” that some areas would not be impacted.

In one section, the Commonwealth officials noted an assertion that some habitat would not be “permanently” lost and they asked: “Based on what evidence?”

In another section, the Commonwealth officials said:

“The basis for suggesting [the] project would not have [a] material effect on [outstanding universal values] component is not sound — Please provide research/evidence on which this claim is based.”

The primary objective of the document is to assess the effects of the project on the site’s outstanding universal values, as those are the basis for the site’s inscription as a world heritage area.

The latest leaked comments came after the ABC revealed earlier this year that WaterNSW fought with the independent ecologist originally writing the environmental assessment, pushing her to weaken her findings.

That ecologist eventually quit and was replaced by someone who, until that very week, was working for WaterNSW on the dam-raising project.

“The record of the relevant agencies of the New South Wales government [gives] one no confidence at all that there’s going to be adequate work done on this assessment,” Mr Debus said.

NSW Minister for Western Sydney Stuart Ayres told the ABC: “I reject any suggestion that the assessment of the environmental impacts of raising the dam wall is not thorough and robust.”

“While the Government has a preferred position to raise the dam wall for flood mitigation only, a final decision to raise the wall will only be made after all environmental, cultural, financial and planning assessments are complete.”

Ignoring worst bushfires in modern history

The Commonwealth officials also complained that the document did not analyse the impacts of last year’s bushfires.

“The section does not include the combined potential impact of bushfires + proposal … is the conclusion that the impacts of the project compound the impacts of the bushfires on any species or communities?” the officials asked.

“Have the bushfires caused any species and communities in the study area to be more susceptible to the impacts from the project?”

That mirrored a request made by the United Nations Educational, Scientific and Cultural Organization (UNESCO), which determines what properties maintain world heritage status.

In a draft decision, UNESCO requested that Australia “thoroughly assess whether raising the wall could exacerbate bushfire impacts”, and asked for that analysis to be submitted to the UN body prior to any final decisions being made.

Bushfire ecologist Rachel Nolan from the University of Western Sydney told the ABC the effects of bushfires were complex and not obvious without proper analysis.

“It’s really important that we have good assessments and good examination of areas that might be affected by later developments,” Dr Nolan said.

Areas around waterways are often less severely burned than the rest of the landscape.

And those less severely burned areas can become crucial refugia for animals across the region.

The flooding of the area caused by the potential dam wall raising could further damage areas burned in the fires, or destroy habitat that was unburned and therefore provided crucial refuge to some of the billions of animals in the fire’s path.

“It’s really important that we identify those areas that can survive,” Dr Nolan said.

“As we have a changing climate and changing fire regimes, they’ll become even more important than they were before.”

In a government inquiry last year, Water NSW did not indicate it was planning to assess bushfire impacts.

David Harper, head of major projects at Water NSW, was asked how the bushfires had changed the analysis. He told the inquiry: “The guidelines do not stipulate that you need to do any more if you have already undertaken the survey prior to the bushfire.”

A spokesman for federal Environment Minister Sussan Ley declined to comment on the issue, referring the ABC to the NSW government.

“When NSW completes its assessment process, the Commonwealth will have a statutory period of 30 days to review matters of national environmental significance,” the spokesman said.

Legal advice to erase uncertainty

The ABC has also seen comments from legal advisors in the NSW government, who recommend the removal of any claims which can’t be scientifically verified.

“The section notes that there is a lack of scientific information on the inundation tolerance of some Blue Mountains plant and vegetation communities including the Forest Red Gum-Yellow Box Woodland PCT,” those comments say.

The legal advisors noted this may provide grounds for a party to argue the project be halted under the “precautionary principle”, whereby the government would need to prove “that serious or irreversible harm is not likely as a result of the project”.

They say: “This is a risk given the lack of current relevant information but we see no obvious way to overcome this risk if there are uncertainties in the current state of knowledge.”

The legal experts advise WaterNSW to “consider whether the assessment of inundation impacts actually unnecessarily highlights the uncertainties”.

Mr Debus said he was shocked to see those comments.

“It’s appropriate for lawyers to point out legal shortcomings in the document, but by heavens, it’s in no way appropriate for lawyers to be suggesting ways in which those shortcomings might be covered up, if that’s what they’re doing,” he said.

Minister Ayres told the ABC: “The Environmental Impact Statement will be released for public consultation in the middle of this year.”

“This will allow communities to consider the environmental impacts behind the raised wall against the benefits of flood mitigation for downstream communities.”