A key government document outlining the impact of the $1.6bn plan to raise the Warragamba Dam wall was changed to make the project’s consequences for an area of world heritage-listed environment appear “less definite”.
The robustness of a peer review of an environmental impact statement (EIS) may also have been “compromised” because the agency charged with getting approval for the dam raising, WaterNSW, did not act “in accordance with best practice”.
The Guardian can reveal an independent investigation found the EIS – a key document used to weigh approvals – was changed to make the project’s impacts appear “less definite”.
The revelations come after the New South Wales premier, Dominic Perrottet, this week announced his government would designate the project as critical state significant infrastructure.
In November last year Rachel Musgrave – the former primary assessor for biodiversity surveys and analysis for the EIS – told an upper house inquiry into the project that she quit after being asked to change the document to interpret the impacts of the project as being “indirect” rather than “direct”.
Musgrave was concerned WaterNSW wanted the change in order to limit the potentially billions in environmental offsets the government would need to purchase.
The government subsequently commissioned law firm MinterEllison to conduct a review of the “serious” allegations.
The findings of that investigation reveal WaterNSW “directed” Musgrave’s consultancy firm to change the EIS “on the basis that the upstream impacts of the project on biodiversity would be ‘indirect’ rather than ‘direct’”.
It found that in 2019 there was a “dispute” between WaterNSW and Musgrave over the “certainty” of the project’s impacts and that another ecologist reviewing her work also had “different professional opinions about the certainty of the impact”.
Musgrave quit after her firm eventually sided with WaterNSW, fearing for her professional qualifications if she signed off on the changes.
While the investigation did not agree with Musgrave’s concerns over environmental offsets, it identified more than 100 changes between her draft and the final document.
For example, a line that the project “would” have an impact on the local environment was changed to “may”.
On the impact on the critically endangered regent honeyeater, the EIS was changed from stating the project would “likely” result in the local population being “negatively impacted”, to stating it “may” result in “local fragmentation of breeding habitat”.
A paragraph stating the “removal and degradation of critical breeding habitat may lead to the loss of the local population which would represent a considerable increase in population fragmentation at the entire population scale” was removed entirely.
After Musgrave resigned, the report said, the ecologist with whom she had a “genuine scientific disagreement” replaced her as the accredited assessor for the EIS and the changes to the document reflected his “preferred approach”.
That ecologist previously worked for WaterNSW, on secondment from another firm. The MinterEllison report was critical of WaterNSW for hiring him, saying it was “not in accordance with best practice”.
While it found no evidence of a conflict of interest, it was “liable to expose” WaterNSW and the EIS to criticism because of his previous disagreement with Musgrave on the project’s impacts.
It also found the firm from which the ecologist had been seconded “continued to undertake peer review of the EIS”.
“There is a real risk that the peer review of [the ecologist’s] work by persons who reported to [him] would have been less effective than peer review undertaken by a person who was not employed by [the consultancy firm],” it stated.
WaterNSW said on Thursday some of the concerns raised by Musgrave were found to have “no basis”.
“The independent report states that WaterNSW undertook a rigorous process in developing the EIS, and that key allegations at the hearing were unable to be substantiated,” a spokesperson said.
“The review identified instances of genuine scientific disagreement between industry experts, rather than any attempt to understate the potential environmental impacts of the proposed project.”
They noted the peer review process was initiated by WaterNSW and was “not a formal requirement”.
The government this week said the decision to declare the wall-raising project “critical” would aid the streamlining of approvals, in order to prevent flooding in the Hawkesbury-Nepean valley. Perrottet justified the move by declaring he would put “people before plants”.
The Guardian understands the government will release modelling showing the proposal to raise the dam wall by 14 metres would save more than 8,000 people from flood risk in the next two decades.
The modelling is based on the “potential development” of thousands of homes in the region.
The designation would limit the ability of communities to seek judicial review of any approval, something the independent NSW MP Justin Field said was concerning in light of the investigation’s findings.
“This report raises significant questions about the integrity of the Warragamba Dam assessment process and would almost certainly justify a legal challenge to any approval based on the environmental impact statement,” said Field, who chaired the parliamentary review into the wall raising.
“It’s extraordinary that the government agency proposing the project altered the assessment of the scientist preparing the biodiversity assessment.”
