Kiwis among those evacuated from horror Townsville flooding

Townsville in Australia's North Queensland has been declared a disaster zone after widespread flooding.

It's been described as a one in 100-year event. Residents have been left waist-deep in water after two years' worth of rainfall fell over the city in just a few days.

In the coming days up to 20,000 homes could be flooded if heavy rain continues to fall, reports ABC.

Three hundred homes have been evacuated, according to local police acting chief Supt Steve Munro, with that number to likely rise to 500 by Sunday morning.

From the air Townsville looks like a swampy mess, with cars barely able to get through. One person used a blow-up mattress to flee the flooding. Others are using surfboards to get around.

Newshub spoke to a Kiwi who was evacuated from their home - Porirua mother-of-four Te Oranga Mihaere among those who have fled to higher ground.

"Several cars that have been parked on the street are now covered up in water up to the windows, I just spoke to somebody who had walked down my street which is one block that way and it was waist-deep in water," she said.

She lives just 150 metres from the river, and more heavy rain forecast for the coming days the threat continues to rise.

The Ross River Dam has more than doubled its maximum capacity. In response, the city's mayor has ordered the high-risk release of dam water.

It's a decision authorities have warned will push more flood waters into homes - including Ms Mihaere's.

"There is still quite a lot our things downstairs that we were not able to move up. We sandbagged up a little bit but if the water is already waist-deep at my house then not enough," she says.