HORSHAM, Australia (AFP) – Floodwaters feared to have claimed the life of a young boy cut the southern Australian town of Horsham in two Tuesday as Canberra urged big business to dig deep for the disaster's victims.

Prime Minister Julia Gillard turned to corporate Australia for help in what is expected to be the nation's costliest ever natural disaster -- a deluge that has lashed five of its seven states, killing more than 30 people.

"The support pouring in from across Australia for people affected by the (northeastern) Queensland floods has been amazing, but Queensland is going to need much, much more in the coming months," the prime minister said.

Rising waters spilled into the streets of Horsham's town centre as the swollen Wimmera River inched towards its peak, dividing the town of 14,200 and cutting power to thousands of homes in a once-in-200-year event.

"We are expecting to see the peak maximum flood levels today and inundation will come with that," an emergency services spokeswoman said.

"Significant inundation of properties is currently being experienced with water up to a metre deep in some areas."