Raised Warragamba Dam wall risks ‘irreversible harm’ to Aboriginal cultural heritage, NSW report says

The $1.6bn plan to raise the Warragamba Dam wall would cause "irreversible harm" to Aboriginal cultural heritage, a New South Wales government-commissioned report has found.

Suggesting it is open to Unesco to "provide for modifications to the boundaries of World Heritage properties", the report said the controversial project could also lead to hundreds of sites of Aboriginal cultural heritage suffering increased flooding, including the "total loss" of some sites.

Prepared on behalf of the project's proponent, WaterNSW, the report was produced by consultancy firm Niche after an initial assessment was savaged by Indigenous groups and government agencies.

The updated report, obtained by the Guardian, concedes that if the New South Wales government goes ahead with its controversial plan to raise the dam wall there would be "unavoidable" and "irreversible" harm to sites of Aboriginal heritage.

The project, it found, would have a "deleterious effect" on cultural heritage values and cause "additional injury to the wounds of previous dispossession and loss".

"The project will result in cumulative harm to the intangible values of the cultural landscape through extension of previously unmitigated impact on cultural values from the construction of the Warragamba dam and flooding of the Burragorang valley and its tributary valleys," the report stated.

"The further flooding of the Burragorang valley will contribute to irreversible harm to the cultural and spiritual connection that Aboriginal people hold to this part of the country, their heritage and the cultural landscape and will obscure the tangible aspects of the creation stories associated with the Burragorang such as the Gurrangatch and Mirrigan story."