Australia floods: Thousands forced to evacuate for second time in weeks as 'worst fears realised'

Thousands of Australian residents have been forced to evacuate their homes for the second time in weeks after extraordinary rain burst river banks and lashed the east coast.

Several towns in northern New South Wales, already struggling after record floods over a month ago, took a month's worth of rain in just six hours, officials said.

"Unfortunately overnight, our worst fears have been realised with significant heavy rainfall across already saturated landscapes," New South Wales emergency services minister Stephanie Cooke said during a media briefing.

Streets in the well-known tourist spot Byron Bay, about 465 miles (750km) north of Sydney, were inundated.

Pictures show submerged shop fronts, residents wading through knee-deep water with umbrellas and others carrying people on their backs.

Australia flooding: Half a million told to evacuate or be ready to as torrential rain lashes Sydney

"It's devastating," Annick Nuylle, a Byron Bay store owner told Reuters. "I've put many years and a lot of love and hard work... it's my livelihood and it has been my life for 17 years, so it's very sad."

In the northern New South Wales (NSW) city of Lismore river water breached the levee height of 10.65 metres for the second time in a month, sparking criticism of the area's flood defences.

There was no official warning that the levee had been breached after sirens malfunctioned, local media reported.

The city's levee system was built in 1999 to protect the area from the kind of extreme flooding expected once in a decade, explained Dr Tom Mortlock from Aon and Macquarie University. But the protection only reduces flood risk by 10%, according to Aon's analysis.

The "relatively low standard of flood protection" means Lismore's defence is "significantly less" than the national average, Dr Mortlock added.

Professor Jamie Pittock from the Australian National University said the "repeated flood risk to key parts of towns like Lismore highlights the grave risks of rebuilding in harm's way".

"No amount of house raising or flood resilient materials will adequately reduce flood risks" in some parts, said Prof Pittock.

He called for government help to relocate the most flood prone areas.

The acting NSW premier, Paul Toole, said at a press conference: "No one could have predicted some of the amounts of rainfall that we have seen land," according to local reports.

Dr Nina Ridder from the University of New South Wales said the strong winds and warm ocean caused by the ongoing La Niña weather event meant further heavy rainfall events were likely on the way.

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