As many as 4,000 homeowners in St. Charles Parish may be eligible for a dramatic reduction in flood insurance rates that would lower their bills by hundreds of dollars a year, according to FEMA and parish officials.

Starting Oct. 1, residents on the parish's east bank may be eligible for something called a "preferred risk policy," which is available only to homeowners who live in areas thought to be at minimal risk for flood damage.

Depending on their individual coverage, those in St. Charles who qualify for such policies could see their rates drop to as low as $400 or $450 a year, down from as much as $2,500 a year, according to Earl Matherne, administrator for the parish's Planning and Zoning Department.

"That is the lowest possible combination of rates and best deductible available in the flood insurance program," Matherne told the St. Charles Parish Council last week.

Those reductions will soon be available to more people in St. Charles because of a change in FEMA policy on how a certain category of land can be insured.

The land in question is known as A99, a temporary designation in a high-risk area that has made "adequate progress" toward becoming more secure from flooding thanks to projects like levee work, according to Earl Armstrong, a FEMA spokesman.

Yet, according to Matherne, the flood insurance rates for people living in A99 zones in St. Charles haven't fairly reflected the protection they've received from the area's improved levees.

In St. Charles, large swaths of land were designated as A99 in 2003, when the East Bank Hurricane Protection Levee was fully funded and halfway complete.

At that point, Matherne said, the A99 designation was supposed to be temporary. It was expected that when FEMA came out with an updated flood map, those areas would mostly be changed to the lower-risk X designation.

That's the best-case scenario on a flood zone map in an area like St. Charles, because it's where FEMA has decided residents have the lowest risk of flooding.

Officials at the time anticipated FEMA would come out with a new flood map by 2005 or 2006, but when Hurricane Katrina hit, that all changed, Matherne said.

Fast-forward to 2016, and the levee is now complete, but St. Charles Parish officials are still working with FEMA to create an accurate flood map that reflects the reduced risk. A preliminary version is anticipated to be ready for review sometime in 2017.

In the meantime, flood insurance rates have continued to rise, and 13 years later, people in A99 zones are paying $800 or often much more a year.

The policy change will make people in the A99 zone eligible for policies previously available only to homeowners in X zones, Matherne said. "These people are getting the break they deserve," he said.

FEMA first announced the change in March in a memo to homeowners saying the National Flood Insurance Program would begin making the change Oct. 1. 

In St. Charles, the policy change will apply mostly to those living between the Bonnet Carre Spillway and the Jefferson Parish line. It's likely to impact homeowners in St. Rose, Destrehan, New Sarpy and parts of Norco, Matherne said.

Just last week, he said, a woman living in St. Rose applied for the reduction and was told she would have to pay just $425 a year starting this fall, down from the $1,768 she was paying for her old flood policy.

Few people in St. Charles seem yet to be aware of the policy change, as many homeowners who got the letter from FEMA didn't understand what it meant, Matherne said.

Parish officials are now working on making sure residents are better informed. Last week, the administration issued a release urging residents to consult their flood insurance agents to see if they were eligible.

“This is big news for our residents on the east bank, as many of them are in an A99 flood zone,” St. Charles Parish President Larry Cochran said in the release. “We encourage them to bring this to their insurance agent to see if they qualify.”

Matherne reiterated that message at the council meeting, adding that he is still trying to clear up whether homeowners will have to wait until their policies are up for renewal to get the lower rates or whether they can convert existing policies immediately.

He also wanted to make sure residents understand two facts about the policy change: that it doesn't reflect a change in the FEMA flood maps, which will likely not be finalized until after 2017, and that it won't apply to everyone living in A99 zones.

For instance, policyholders won't qualify if they have filed multiple flood claims of $1,000 or more each, or if they have had more than three flood claims of any amount, according to FEMA.

Moreover, Matherne said, the change could be temporary for some residents, since it's still unclear how all A99 zones will be classified once the new maps are finalized.

The worst-case scenario, he said, is that up to 30 percent of people could see their rates go back up after the new maps are finalized because their property would be reclassified from A99 to an AE zone, rather than to an X zone. An AE zone is considered to be at a higher risk of flooding, and insurance rates there are tied with the elevation levels of houses.

Despite the caveats, Councilwoman Julia Fisher-Perrier called the discovery "huge," particularly since St. Charles Parish has dealt with "the perfect storm" of insurance hikes, she said.

"We stumbled upon this luckily," she said.

The parish has been further threatened by the Biggert-Waters Flood Insurance Reform Act of 2012, which could mean higher rates as part of reforms in federal flood insurance policy. Those increases haven't been implemented because flood maps haven't been finalized.

"Flood insurance has been one of the top items on our radar for the last couple of years," Fisher-Perrier said. 

In the meantime, Matherne said, St. Charles Parish continues to work on the flood maps with FEMA in hopes that more residents will get a permanent break on their insurance costs.

In the broadest sense, he said, the parish is working on proving what "risk" means when it concerns levees, home elevation levels and potential flooding.

The administration has hired modelers to map the parish's geography and present the information to FEMA, Matherne said.

As it stands now, people who live in AE zones and have homes at 2.5 feet or less above sea level are at risk of big insurance hikes. He thinks that number is too high, by 6 inches or more, he said.

"Ultimately, this is about keeping people safe," Matherne said about his work on the flood maps. "We’re not looking to just arbitrarily lower the numbers so people can pay less. We do want to get it right."

Follow Della Hasselle on Twitter, @dellahasselle.