Hundreds of people remained isolated and rail lines were still down on Tuesday after heavy rain struck across the state over the weekend, leaving as many as 30 homes uninhabitable.
Councils along the flood-affected Hawkesbury have reignited calls for the wall on Warragamba Dam to be raised, a plan promised by the former coalition government but abandoned under the incoming Labor administration.
Sydney's largest reservoir has spilled a total volume of water equivalent to half of Sydney Harbour since it reached 100 per cent capacity on Saturday, according to Water NSW.
The Warragamba Dam spill rate has now reduced to 19 Gigalitres (GL)/day, and continues to decrease. Other Sydney dams spilling as at 11am Monday are Tallowa, Nepean and Woronora dams and the Blue Mountains storages, except Upper and Middle Cascades. Follow — WaterNSW (@WaterNSW) @BOM & @NSWSES.April 8, 2024
Premier Chris Minns said rebuilding the dam wall would take eight to 10 years, come at an enormous cost and would not stop flash-flooding in western and northwestern Sydney.
"Forty-five per cent of floodwaters in the Hawkesbury, Richmond catchment don't come over the top of Warragamba Dam, so we could be in a situation where we raise Warragamba, we spend $2 billion and those communities are still inundated by flooding," he told reporters on Tuesday.
But Mr Minns said the government would look at all potential changes, including dropping the maximum allowable water level at Warragamba, as long as Sydney's drinking water supply could be supplemented.
"So that's not going to give us an immediate relief, it's going to take a bit of time," he said.
The premier reiterated the government's commitment to spend $200 million on improving evacuation infrastructure, emergency levees and road evacuation routes.
Hawkesbury mayor Sarah McMahon said more needed to be done to ensure her community was not left devastated by more flooding.
"Nobody has seen a 'plan' and won't see a 'plan' for at least another year, and who knows how many more floods will have hit us before we have this 'plan'," she said on Monday.
Disaster assistance has been made available for affected residents and councils across the state.
The NSW SES advises you may now RETURN WITH CAUTION to the following area(s):— NSW SES (@NSWSES) - Properties in the Gronos Point area including properties along Gronos Farm Road and Manns Road.ADVICEFINAL UPDATEFind out more: https://t.co/FSanij9ixV#NSWSES #HawkesburyRiver pic.twitter.com/1aQu89PslDApril 9, 2024
About 800 residents have returned to their homes northwest of Sydney and along the Hawkesbury River after evacuation orders were lifted, although the NSW State Emergency Service is advising people to avoid the area.
Flood levels at the Hawkesbury and Nepean rivers were significantly reduced by Tuesday morning.
The Hawkesbury River reached its peak of 10.52m - about seven metres above average - at 9pm on Saturday.
More water is also expected to be discharged from Warragamba Dam over the coming days.
Parts of the south coast rail line remain out of operation with significant damage to tracks.
Essential supplies have been airlifted to the Blue Mountains after heavy rain blocked access. (HANDOUT/NSW RURAL FIRE SERVICE)
Bulldozers are also set to cut a temporary evacuation road in the Blue Mountains' Megalong Valley after a land slip shut off the only access road, isolating 150 residents and 200 tourists.
Blue Mountains mayor Mark Greenhill said cutting the road through rock would take three days and would be contingent on careful geotechnical advice, which was set to be issued on Tuesday.
Food, fuel and essential supplies are being dropped into the valley via helicopter while all visitors to the area have been successfully evacuated.
