Remapping of Nantucket's flood zones could mean rate increases

Issuer of flood insurance, the Federal Emergency Management Agency, is remapping the flood plains on Nantucket, which could mean increases in insurance rates for Nantucketers living close to or on the shore.

This revision of FEMA's flood plain maps includes flood zones across Massachusetts and the entire country, going county by county, in a six-year effort to update and digitize flood zone maps dating back to the early 1980s.

Employing the latest computer models and topographical maps of island areas vulnerable to ocean storm flooding at least once in a 100 years, FEMA is able to more accurately identify these areas. But, unfortunately for some island property owners, they may be included in the new flood zone maps where they were not before and be forced to purchased flood insurance costing as much as $2,000 a year to satisfy bank requirements for federally-backed mortgages.

"If they are going to be in an area that will be newly mapped as in the high risk zone, if they are going to be in the one-percent annual chance of flood, if someone isn't currently in the flood zone but will be in the new maps, they would be required to purchase flood insurance," said David Mendelsohn, FEMA's map modernization program coordinator. "There's a federal requirement for those people in the high-risk zone to have flood insurance to help cover that mortgage."

Insurers in the private sector administered by FEMA-issued flood insurance policies cover up to $250,000 for the building and up to $100,000 for its contents. Mendelsohn said that FEMA defines flood conditions as "two or more acres of normally dry land or two or more properties that are inundated by water or mudflow" and classifies properties as within the flood plain if historical data shows that there is a one-percent or greater chance of flooding during any given year.

FEMA sent a draft copy of the new maps for Nantucket to the Conservation Commission in late June and regional representatives planned to hold an information session on the island on Dec. 9, but ironically, stormy conditions prevented them from getting out to the island. The meeting will be rescheduled in early January.

As FEMA's flood map revisions are relatively new, island insurance agents had little to say about potential impacts on policyholders. Although he is aware of the forthcoming changes, Jim Congdon of Congdon & Coleman Insurance said he does not yet know who will be affected on Nantucket. He added that FEMA's last revisions had minimal effect on Nantucketers living in the flood zones.

However, with the new maps available to the public right now, Mendelsohn is urging property owners to look at them to determine if there is any change to their properties' status in or out of the flood plain. If there is and it looks like their FEMA insurance might increase when Nantucket's new maps become effective in 2011, there is the opportunity for significant discounts on extra insurance that they can get by buying it within the National Flood Insurance Program before the maps become law, essentially grandfathering their policies.

Mendelsohn said that what could potentially impact Nantucketers located in the current flood plain, or those who may find themselves within the newly designated additions to it, is where their properties are in relation to frontal dunes or hurricane barriers, such as the Jersey barriers along Codfish Park Road. If the town cannot certify for FEMA that these barriers are effective in controlling the ocean, FEMA would then place a certain amount of the land immediately behind frontal dunes and hurricane barriers into the flood plain.

Property owners who disagree with their placement within the newly revised flood zone can appeal the new map based on technical grounds because that is what it is based on, said Mendelsohn.

The map itself could be finalized by this summer.

"Our timeline on this after we have our meeting is we would probably wait about 30 days to get comments from the town and then schedule a 90-day comment/appeal period," he said. I