Blue Mountains Conservation Society responds to NSW Premier's Dominic Perrottet dam wall raising plans

That's the response by the Blue Mountains Conservation Society after Premier Dominic Perrottet vowed that NSW will go it alone if the federal government refuses to split the cost of raising the dam wall.

The society issued a statement on October 20 condemning the call to declare the dam wall raising as Critical State Significant Infrastructure in "stark contrast to a decision by former Minister for Planning, Rob Stokes, to resist this move".

Madi Maclean, Blue Mountains Conservation Society president, called it a "desperate move to push through a proposal that will not solve flooding problems in Western Sydney but will open up more floodplain for housing development".

The move means under the NSW Planning and Environment law, the planning approval can't be scrutinised by the community and "minimises any third party right of appeal, preventing community and environmental groups from challenging the project," Ms Maclean added.

The society has long advocated against raising the wall which would inundate 4,700 hectares of the World Heritage-listed Blue Mountains National Park and 65 kilometres of wilderness streams, threatening numerous plants, animals as well as significant Aboriginal heritage.

"It's an incredibly destructive proposal which would not solve the problem of flooding in Western Sydney.

"It's crucial politicians offer alternative solutions that work, rather than something that's obviously dubious in the eyes of experts - otherwise, it's just false hope."

The project was designated as critical state significant infrastructure earlier this month to cut red tape, but NSW is yet to secure a funding commitment from Canberra.

"This is a project that is going to happen. We are raising the Warragamba Dam wall," Mr Perrottet told reporters at a State Emergency Service centre in Sydney on October 18.

"The reason this needs to occur ... is that in a catastrophic event we would have 75,000 people required to be evacuated from western Sydney."

Reports from Water NSW and an environmental impact statement would be completed "as soon as possible".

"You can't put a price on human life and ultimately this is a project that I would expect the commonwealth government to provide 50-50 funding for," he said.

Labor's Water spokeswoman Rose Jackson raised concerns about how the project would go ahead, without it being accounted for in the budget.

"The people of western Sydney and Hawkesbury-Nepean Valley need real answers right now," she told reporters.

"There's no funding for the project, there's no timeline for the project, there's no timeline for the EIS (environmental impact statement)."

The premier's vow to proceed with or without federal funding was "a desperate political act months before the election" exhibiting "political immaturity", she said.

She also questioned the effectiveness of the project, saying about 45 per cent of flood waters in that part of western Sydney came from catchments that were upstream from Warragamba.

She urged Mr Perrottet to call Prime Minister Anthony Albanese to show how "serious" he was about pushing the project.

Last week, the prime minister insisted that Mr Perrottet had not raised the funding directly with him.

"This is all about protecting lives. We need to get on with it," Mr Perrottet said.

with Australian Associated Press