New South Wales Rural Fire Service firefighter Elisabeth Goh monitors a hazard reduction burn in Sydney, Australia, 10 September 2023; Credit: Reuters/Cordelia Hsu/File Photo

SYDNEY (Reuters) - Less than 24 hours since residents in parts of Australia's Victoria state fled bush fires, authorities warned of flooding on Wednesday 4 October 2023 as heavy rain douses flames and swells rivers in the southeastern state.

Flash flooding is expected through Wednesday afternoon in northeastern Victoria, according to the Australian Bureau of Meteorology, as rain drenched parts of the state where as recently as Tuesday 3 October 2023 about 17,000 hectares were ablaze.

First responders overnight rescued a farmer in the area who got trapped after driving through floodwaters, according to chief officer operations Tim Wiebusch at Victoria state emergency service.

Parts of the state had received up to 150 mm of rain, almost eight times the state's average in September, with more expected on Wednesday, he said.

"Fortunately we have seen some rainfall across those two fires," said Wiebusch. "But over these next 24, 48 hours flash flooding, riverine flooding, is really the key risk. We can't emphasise enough, people need to be alert to their conditions."

The rain comes during an unseasonably dry Australian spring, which began in September. Last month was the driest September on record, according to the Bureau of Meteorology, with rainfall 71% below the 1961-1990 average.

Firefights are working to contain bush fires in two parts of Victoria state but authorities said there was no immediate threat to residents.

Across the border in New South Wales state, a 5,200 hectare bush fire was out of control near the town of Bermagui, roughly 300 km southwest of Sydney.

"I just feel anxious and a bit on edge because we don't really know yet what's next," Sheena Boughen, a resident of a nearby town, told state broadcaster ABC.

Prime Minister Anthony Albanese said on a visit to the area that the severity of the fires would likely bring back memories of the catastrophic fire season in the summer of 2019-2020.

"This must be an incredibly traumatic experience," he said. "We're standing here, we can smell, we can see the impact that these fires are having."

State fire authorities said conditions eased overnight although several properties were lost and firefighters were working to contain the blaze.