Extraordinary rainfall continues to hit the Townsville area, with some areas experiencing almost a year's rain over several days and more than 50 homes already damaged.

A further 100 homes in the north Queensland city are threatened by the high-risk release of water from the Ross River dam, which it is hoped will prevent more widespread flooding.

A monsoonal trough has been sitting over the town for a week, and the heavy rain is expected to continue well into next week.

Some areas have had more than a metre of rain – the yearly average is 1.1 metres – in what is being described as a one-in-100-year event.

The Bureau of Meteorology’s Queensland Weather Services Manager Richard Wardle told a press conference today that “the prolonged nature” of the event is unusual.

“Some locations have been getting up to 400mm per day for a number of days,” he said.

State Disaster Co-ordinator Bob Gee says “most people will not have experienced this type of event in their lifetime”.

About 30 rescues have been carried out and at least 50 properties have been impacted either through inundation or property damage. That number is expected to rise.

Insurance Council of Australia spokesman Campbell Fuller told insuranceNEWS.com.au insurers are keeping a close eye on the situation.

“We will continue to monitor it. We are in frequent contact with the emergency services and government agencies in the region.”

North Queensland Insurance Brokers told insuranceNEWS.com.au its Townsville office is closed and client calls diverted to other branches have been coming in thick and fast.

“We expect that there will be widespread claims,” Ingham branch manager Kieran Volpe said.

“It will be a long road ahead. The rain is just continuing. It’s unlike anything I’ve seen before.”