New flood maps bring good, bad news

New digital mapping technology and congressional funding have allowed the Federal Emergency Management Agency to undertake a substantial update and revision of area flood hazard zones that could now extend to include homes that were not previously part of the flood plain.

Those homeowners would now be required to carry flood insurance, which in some cases could more than double their current rates, according to conservation agents from several communities north and northwest of Boston. Some residents already living in flood zones may now be mapped into a lower- or higher-risk area, which also can change their insurance premiums. For a fortunate few, the new mapping revisions may conclude that homes that were previously deemed to fall within the flood zone now don’t.

“We participated with FEMA in supplying them some of our GIS data in order to make the maps as accurate as possible,’’ said Roland T. Adams, geographic information system coordinator in Beverly. “The maps are based on more accurate topographical data, and there are a number of people in the city of Beverly that were in a flood zone, that when the new maps come out, will not be, and some that historically have not been will be.’’

FEMA is updating flood zone maps in the state by county. So far, only Suffolk and Bristol counties have officially implemented new digital flood insurance rate maps, according to FEMA Region 1 spokeswoman Annie Donovan. The new maps are estimated to be effective in Middlesex County by next summer, and in Essex County by summer 2011.

Most local cities and towns are operating with flood zone maps from the 1970s and 1980s, Donovan said. Digitizing these maps will not only help to accurately calculate flood insurance premium rates, but will allow residents to access them online.

Currently there are several communities in the area involved in 90-day public comment periods on FEMA’s proposed changes, including Newburyport, Newbury, and Salisbury, which held a joint public meeting last Thursday along with a FEMA representative, said Mary Reilly, Newburyport’s conservation administrator.

“The last real update was in ’85, so we’re in need of an update,’’ Reilly said. “In Newburyport, [the revisions] have definitely affected Plum Island the most in terms of putting people who weren’t in high hazard zones within various ratings of high velocity zones.’’

In Beverly, the flood zone maps being used go back to 1986, Adams said.

“If you look at the ’86 maps, there are a lot of people who were in the flood zone who are coming out, and some coming in,’’ Adams said. “For our city, there are a lot more coming out than going in. It’s good news for some people.’’

The 90-day public comment period started on Sept. 18 in Beverly. After a poorly attended public meeting, Adams said, the city is reaching out to affected residents by way of letters, as well as uploading the new flood zone maps to the city website, where residents will be able to plug in their addresses to determine whether they’re in the zone or not.

But that is as far as communities can go. It is up to residents to educate themselves to lock in lower insurance rates before communities officially approve the new maps, Donovan said. FEMA’s National Flood Insurance Program has a grandfathering provision that allows owners of properties that were not in the flood zone, or those that are slated to go from a low-risk to a higher-risk zone, to purchase flood insurance at current rates. When the new maps are approved and flood insurance rates increase, those who purchased under the old rates will be able to keep them as long as coverage is maintained continuously, according to FEMA.

According to a representative of Farm Family Insurance, which has offices in North Andover and Topsfield, flood insurance can range from $200 to $300 for low-risk properties to as much as $4,000 in high-risk zones.

Homeowners on Plum Island are typically paying about $2,000. Flood insurance has a cap depending on the carrier, and usually does not cover the cost of replacing a house in the event of a disaster.

“I would say [residents] should talk to their insurance company to try to identify if they are or are not in a flood zone, and figure out whether they should buy insurance now,’’ Reilly said. “Some of these people don’t have any insurance because they weren’t in a high hazard zone, so it can get to be quite a bit more.’’

For some residents, the best rates may come after the new maps are in place if they go from a high-risk to a low-risk zone, or if they’re taken off the flood zone completely. The 90-day comment period also allows property owners to appeal FEMA’s flood plain determination.

According to FEMA, communities that are currently in the midst of the 90-day comment period are Andover, Beverly, Gloucester, Ipswich, Lawrence, Manchester-by-the-Sea, Marblehead, Nahant, Newbury, Newburyport, North Andover, Rowley, Salisbury, and Swampscott.

For more information, residents should visit their community websites as well as www.fema.gov.

Katheleen Conti can be reached at kconti@globe.com.