Almost 20 towns in southeastern Australia remained under threat Tuesday as rising floodwaters hit communities in Victoria state.

Two men push a flood-damaged sofa out of a house in West End, a suburb of Brisbane, Australia, after floodwaters receded last Friday. Floods are now menacing Victoria state. (Tim Wimborne/Reuters)

The Australian Broadcasting Corporation reported that 3,800 residents in Kerang were asked to leave their homes because water was seeping under the levee. The Red Cross said 18 towns were still at risk of flooding.

Unprecedented water levels have already affected more than 40 towns in Victoria. Local media reported an eight-year-old drowned Monday in the most recent flooding.

At least 30 people have died in Australia's weeks-long flooding crisis, which has already devastated large parts of Queensland state, with water pouring through fields, mines and parts of Brisbane, the country's third-largest city.

People in the town of Warracknabeal, northwest of Melbourne, were being told Tuesday to brace for the worst flood in 200 years. At least 84 homes were at risk.

In nearby Horsham, about 500 homes in the city of 14,000 were surrounded by water after the Wimmera River overflowed its banks Tuesday.

Horsham Mayor Michael Ryan said the flooding was worse than anything the area had seen in the last two centuries.

Emergency officials issued a series of warnings overnight to alert people in the path of the rising water.

"At 5 a.m. they were out on the megaphone just yelling 'evacuate,"' said West Horsham resident Brett Insall, who decided to stay at home instead. "I'm not too worried about it. It's only water."

Stephen Warren of the state emergency service said the water would slowly recede through the day, and the cleanup had already begun.

Victoria state is the latest Australian area to be hit by flooding. (CBC)

"We may even be able to get the [western] highway open late in the day and actually have some access later tonight," Warren told reporters.

An evacuation warning was issued to residents of Kerang, who face isolation for at least three days when the Loddon River peaks. Emergency officials said any resident unable to cope without electricity, water, sewer and telephone connections should leave home.

Response is 'at a critical stage'

"The emergency response is at a critical stage," said Adam Dent, the Red Cross emergency services state manager.

The organization, which is working with Victoria state officials to raise money for flood victims, called on people forced out of their homes to register their names and whereabouts with the Red Cross.

"We know many communities are anxiously waiting as floodwaters rise, and many townships across Victoria have already been impacted by floodwaters," Prime Minister Julia Gillard said. "Our thoughts are with everybody who is dealing with this emerging flood crisis in Victoria."

The prime minister said she was forming a panel of business leaders to help guide the reconstruction effort.

With files from The Associated Press, Australian Broadcasting Corporation, The Canadian Press