San Lorenzo and Cherryland homeowners are shocked that they soon will be paying as much as $1,500 a year for flood insurance they didn't realize they needed.

The insurance — required for the duration of homeowners' mortgages — is the result of a new Federal Emergency Management Agency map that puts them in a 100-year flood zone.

San Lorenzo homeowner Frank Burke, who is among those crying foul, said that in addition to the big insurance payment, he expects his property value to fall now that his home is in the FEMA-designated flood zone.

Last month, residents in the flood zone — which runs through Cherryland and San Lorenzo along the south side of the San Lorenzo Creek — began receiving letters from their mortgage companies informing them that they are required to purchase flood insurance. The letters stated that if insurance is not purchased within 45 days, the banks will purchase it for them at rates of around $1,500 a year.

Burke, who lives on Via Barrett, was shocked and upset when he received his letter from Bank of America.

"To me it's a scam, no matter how you look at it," he said.

He also disagrees with the flood map itself, pointing out other areas that are not in the flood zone, but that he believes are more likely to flood.

FEMA, which has been revising its flood maps as part of a nationwide project, remapped the San Lorenzo area because data from two U.S. Geological Survey gauge

Saleh said that when FEMA issued a preliminary map in 2007, letters were mailed out that November to 2,482 property owners in San Lorenzo and Cherryland, informing them that FEMA had determined that their parcels were in a 100-year flood zone.

Two public meetings were held in April 2008 informing residents that they were required to purchase flood insurance.

"During the public meetings, there was some demand from the public to look deeper at the maps," Saleh said.

The public works department re-examined the maps and 455 parcels were removed, Saleh said.

On July 9, letters went out warning those in the flood zone to purchase insurance before the FEMA flood map became effective on Aug. 3. Those who purchased before the Aug. 3 deadline got lower rates, under $400, that are "grandfathered in" although the flood maps have been revised. Homeowners that missed the deadline will have to pay full rates now that they are officially in a flood zone, Saleh explained.

"Not too many people followed our recommendation, unfortunately," Saleh said. "All we could do is let them know, and these letters are costly."

Burke, for his part, said he never saw the letter and neither did his neighbor.

County Supervisor Alice Lai-Bitker's chief of staff, Sean Wilson, said the supervisor's office has been getting calls from residents upset over the high cost of the required insurance.

"It's really an unfortunate situation, and we want answers," Wilson said. "I think (FEMA) needs to take a close look at this and see how it's impacting our community. It's not the best economic environment to be hitting people with more penalties."

FEMA representative Kathleen Schaefer will be addressing public concerns regarding the maps and insurance at 6:30 p.m. Wednesday during the county's unincorporated services meeting at the San Lorenzo Village Homes Association, 377 Paseo Grande.

Schaefer could not be reached for comment.

Jason Sweeney covers San Lorenzo. Reach him at 510-293-2469.