Townsville flooding declared 'catastrophe'

Flooding in Queensland's Townsville has been declared a "catastrophe" by the Insurance Council of Australia as a one-in-100 year deluge swamps the region.

The Insurance Council estimates there's been $16.7 million worth of flood damage in Townsville. (AAP)

A massive monsoonal deluge that has flooded Townsville has been declared a catastrophe by the Insurance Council of Australia.

The one-in-100 year big wet has inundated dozens of homes and businesses and with conditions set to worsen thousands of homes could be affected, the ICA said in a statement.

As of 8pm on Saturday, insurers had received about 1900 claims with insurance losses estimated at $16.7 million.

"The ICA has declared a catastrophe to help escalate the insurance industry's response," said ICA CEO Rob Whelan.

The declaration has been made to "help reduce the emotional and financial stress being experienced by families and businesses, and provide them with peace of mind that their insurer is there to help," he said.

The announcement comes as five hundred homes are under threat of flooding overnight, with torrential forecasts hitting up to 20,000 homes, according to police.