When Lake Illawarra's Darryl Goldrick asked NRMA Insurance why his home premium had increased, he was told it would be for this year only.
But that was after he was told it was because his home was at risk of flooding.
Mr Goldrick, who lives in Reddall Parade, has his home and contents under separate policies. Combined, they rose by $1000.
An NRMA policyholder for 40 years, Mr Goldrick said he received his home insurance renewal last month.
"When I opened up the letter and saw the premium I thought 'What the heck's going on here?'," he said.
"I went to look at the previous year's policies and that's when my fears were realised - there was an extraordinary increase."
Mr Goldrick, who has retired after 20 years as manager of the Illawarra office of the Department of Land and Water Conservation, went into the NRMA's Shellharbour office to query the increase.
"The reason given was because of the flood risk," he said.
"I then went into a debate based on my professional background, because I knew there was no new flood data available since Shellharbour council last released it back in 2006."
He said he pointed out that the rise had nothing to do with flooding, adding that the "without flood-cover" premium had risen by a similar proportion.
Frustrated, he left and later rang an NRMA call centre, where he spoke to a "cordial" woman.
"She was the woman who told me that the premium increases were because of all the Queensland floods and the NSW floods," he said.
"I said: 'Is this rise in perpetuity?' She said: 'No, this will only be a once-off situation'."
Mr Goldrick said he doubted the policy premiums would fall next year.
"I'm not that bloody naive.
"I've got no faith in that whatsoever. It'd be like expecting our electricity, gas and water charges to be reduced."
The NRMA was asked to confirm whether the rises experienced by Illawarra residents were as a result of the Queensland and NSW floods.
"While all home premiums have been affected to some extent by increased reinsurance costs due to the spate of natural disasters and major events, the customers identified in the Illawarra Mercury to date have received increases due to our assessment of their properties' risk to stormwater run-off," a spokesman said.