NSW Premier Dominic Perrottet says it is critical to raise the Warragamba Dam wall.

The New South Wales government has announced it will fast-track plans to raise the wall of Sydney's Warragamba Dam by declaring it critical state infrastructure, with the Premier claiming that raising the dam wall by 14 metres will help “future proof” Western Sydney from major flood events.

“This infrastructure project will save lives and protect property,” Mr Perrottet said.

“If there was a major flooding event in the Hawkesbury-Nepean, by raising the dam wall we would reduce those properties that would be affected from 15,000 to 5,000.

“Currently we would have to evacuate around 90,000 people — that would be reduced to 14,000 people.”

The New South Wales Planning Minister will now have final approval for the project, though the Premier says it will still be subject to a “rigorous” assessment process.

“The minister will ensure, through being the final decision-maker, that it's not caught up in red tape, in court cases, in government bureaucracy,” he said.

“This is about getting this project done, protecting lives and saving properties across our state.”

There have been close to 2,000 submissions to WaterNSW regarding the proposal to raise the dam wall.

WaterNSW has been instructed to respond to the feedback and issues raised in the submissions before it undertakes a comprehensive assessment in accordance with the New South Wales Environmental Planning and Assessment Act.

Some critics argue that raising the dam wall will destroy environmental and Indigenous cultural sites in the Blue Mountains, while others say the project is designed to allow more development in flood prone areas of Western Sydney.