The modelling,seen by theHerald,will be contained in the NSW government’s full response to the independent flood inquiry,which will likely be released within weeks.
Premier Dominic Perrottet said raising the Warragamba Dam wall by 14 metres was the “single biggest piece of work” the government could undertake to address flooding in western Sydney.
“Our primary focus is on saving lives,saving properties and the future-proofing of western Sydney,” he said.
The state government has renewed its push to raise the dam wall following a year of destructive flooding across the Hawkesbury-Nepean and northern NSW. The Perrottet government recently wrote to the Commonwealth government seeking a 50-50 funding arrangement for the $1 billion-plus project.
The modelling suggests in the event of a “one in 100 chance per year” flood in 2041,1,700 people would not be able to evacuate under “committed development” with the dam wall at its current size. That increases to 8,600 people under “potential development”,which includes development that has been announced,but still requires rezoning of land to proceed.
NSW minister David Elliottlast year said raising the Warragamba Dam wall could pave the way for the release of more land for development in Sydney’s north-west. Elliott’s comments were at odds with former Western Sydney Minister Stuart Ayres who said raising the wall would not allow development to take place in flood-prone areas.