The flooding crisis deepened in the southern Victoria state, where engorged rivers threatened to breach a levee around the town of Kerang, forcing the evacuation of all 4,000 residents as engineers raced to fortify it.

British Foreign Secretary William Hague toured Brisbane to inspect damage from floods that swamped 30,000 homes last week – the peak of an unprecedented disaster which hit an area larger than France and Germany combined.

“People in Britain were watching this hour by hour, minute by minute, hoping and praying for you,” said Mr Hague at a barbecue with flood victims in the east coast city, Australia’s third-largest.

“It’s hard to imagine the volume of water that came up from the peaceful-looking river over there.”

“There is a major concern about the integrity of the levee bank which protects the town,” said emergency spokesman Lachlan Quick.

“It has held for many, many years but we are facing an unprecedented volume of water,” he told ABC Radio.

Warracknabeal, west of Kerang, was also bracing for a record inundation after experiencing half its annual rainfall in just a week, sending previously parched creeks into full flood.

Floods are expected to persist in Victoria for up to a fortnight, while the grim recovery in Queensland is still in its early stages, with 10 people still missing and warnings that yet more may be found dead in their homes.

Prime Minister Gillard announced a taskforce of corporate leaders, including transport tycoon Lindsay Fox, Deloitte chief Wayne Goss and Woolworths supermarket chief Michael Luscombe, to rally donations from the business community and mobilise support for the mammoth recovery effort.

The group, which also includes Catherine Livingstone, a director of telecoms giant Telstra and Leighton Holdings construction firm chief David Stewart, will seek both cash and in-kind donations from corporate Australia, said Gillard.

“Already, corporate Australia has been tremendously generous,” she said. “But given the scale of this disaster, we need to do more.”

Queensland Premier Anna Bligh said the real pain was just beginning for those living in the Lockyer Valley, west of Brisbane, where residents were returning home after a terrifying “inland tsunami” that killed 20 people.

“This is something that happened in the space of 20-30 minutes. One minute standing in the lounge room, half an hour later literally banging a hole out of the roof and throwing your children up onto it,” said Ms Bligh, who toured the shattered region on Tuesday.

“People are reliving that terror as well as coming to terms with what they could see around them and what had happened to their town,” she added.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.