United Nations scientists have stoked fears that the Blue Mountains could lose its world heritage status because of a dam-raising scheme. 

The International Union for the Conservation of Nature (IUCN) has written to the federal government to warn that the NSW Government’s plan to raise the Warragamba dam wall “appears to be inappropriate in relation to the requirements of the World Heritage Convention”.

The NSW Government wants to raise Warragamba Dam by at least 14 metres to catch more flood waters, in an attempt to reduce the impact of floods on Western Sydney.

The plan would see thousands of hectares of the Blue Mountains World Heritage Area inundated instead. This would risk the habitats of several endangered and critically endangered species in the area. 

Australia is a signatory to the World Heritage Convention, and federal environment law prevents the federal environment minister from approving projects that are inconsistent with the Convention.

If the project is approved, the IUCN's advice could lead to some embarrassing consequences for Australia.

“The ultimate outcome of that could be a listing of [the Blue Mountains] on the list of World Heritage in Danger or, eventually, a potential delisting of the site,” says Tracey Ireland, a professor of cultural heritage at the University of Canberra.

The IUCN's review said the environmental impact statement (EIS) for the dam-raising is self-contradictory, non-compliant with the requirements of an EIS. 

If the IUCN's advice is taken up by UNESCO's World Heritage Committee, which is made up of representatives from 21 countries, Australia may be formally asked to scrap the plans. 

WaterNSW is waiting for responses to the draft EIS for the plan, before it can seek final determination from the NSW Department of Planning, Industry and Environment.

The project will then be passed on to the federal environment minister for approval under federal environment law. It is at this stage that experts say Australia may breach the terms of  the World Heritage Convention.