The federal government has released new flood zone maps for York and Cumberland counties that could raise some residents’ insurance costs by thousands of dollars and restrict property owners’ rights to develop or expand properties in coastal locations.

The maps, which were released online Tuesday and will be available in city and town offices in the coming days, are expected to extend flood zones farther inland, putting more homes and businesses in zones considered high-risk.

The maps are not final. Individuals, businesses and municipalities can appeal flood zone classifications during a 90-day period. After appeals and final reviews, the maps are projected to take effect in the summer of 2015, according to the Federal Emergency Management Agency.

The maps are the basis for federal flood insurance, which is required for mortgages on properties in flood zones. The maps are supposed to account for topography, water depths and wind speeds, among other factors, to determine which areas are at risk for flooding so severe that it may come only once in a century.

When flood zones are expanded, property owners who never have had to purchase flood insurance may be required to buy it. And a home or business in a low- or moderate-risk zone may be reclassified as being in a high-risk zone, driving up the owner’s insurance costs.

“If flood zones are expanded, then new areas will have restrictions on what can be built or expanded,” said Robert Gerber, a senior engineer and geologist with Ransom Consulting.

Gerber, who specializes in computer modeling of environmental systems, is a consultant for 14 Maine cities and towns that are expected to appeal the new maps.

Charles Katz-Leavy, a real estate attorney with Verrill Dana in Portland, said, “For a property owner who has land that isn’t developed yet or is preparing for expansion, it could impact what you do with your property.

“If you have a project to build an office, hotel or restaurant on the water and were not previously under a flood zone and now you are, you will have to buy flood insurance,” he said. “You also may have to elevate any structure that is being built. The costs could be prohibitive and render your property undevelopable.”

A new map that puts a property into a “special hazard zone” can be devastating financially, even for a homeowner who has flood insurance, said Bob O’Brien, an insurance broker in South Portland.

“Being in a special hazard zone can increase your flood insurance by five to 10 times,” said O’Brien, vice president of Noyes, Hall & Allen Insurance.

O’Brien said the average homeowner in Maine who buys flood insurance for a home outside a high-risk zone pays $500 to $600 a year. If the property is reclassified as a flood hazard, that cost could easily hit $5,000 to $10,000 a year, he said.

The maps released Tuesday by FEMA will replace maps issued in 2009 that prompted an outcry from municipalities about mistakes and miscalculations. After hundreds of homeowners appealed their inclusion in flood zones, FEMA scrapped the maps in 2010 and restarted the analysis.

At the time, municipal officials and property owners said the maps didn’t accurately represent the terrain or account for the protection offered by Maine’s jagged coastline, including islands, protected harbors, artificial barriers and underwater ledges.

It’s impossible to know yet how many homeowners in Maine will be affected by the changes in the new flood maps, O’Brien said. FEMA officials will first notify flood insurance providers, who will then notify their clients of any changes to their premiums, he said.

Maine homeowners who don’t buy flood insurance now could be in for a rude awakening if the new boundaries put their properties in hazard zones, said Dennis Hilton, an insurance broker in Damariscotta.

“I’m sure that anyone at any moment can get a call from their (mortgage lender) saying they have to buy flood insurance,” said Hilton, president of Cheney Insurance.

Homeowners who don’t have mortgages may not find out about the boundary changes until they try to sell their homes, Hilton said. Any owner who isn’t sure whether their property has been reclassified as a flood hazard should contact their city or town, check the FEMA website or call a flood insurance broker, he said.

About 7,000 flood insurance policies are now in effect in Maine, with coverage totaling nearly $900 million, according to the state.

It’s crucial that property owners pay attention to the new maps and determine whether they will be affected, said Katz-Leavy, with Verrill Dana. Cities and towns may file appeals, but individual property owners may have more luck making their own appeals and hiring their own engineers and lawyers to dispute FEMA’s findings.

Disputes can escalate to the federal district court level, he said.

“Most property owners are not fully aware of what’s going on,” said Katz-Leavy. “There’s a limited time to respond, so don’t wait.”

Homeowners who had appeals of the 2009 maps pending and want to appeal their inclusion in the new maps will have to restart the appeals process, said Gerber, with Ransom Consulting.

Maine’s rate of flood plain appeals is three times the national average, according to the Maine Floodplain Management Program. In Maine, there is an appeal for every 3,763 people. The national average is one for every 10,209 people, according to FEMA.

In the past 20 years, there have been more than 3,400 flood plain map appeals in Maine, costing property owners more than $2.6 million, according to the State Planning Office.

For example, the city of Portland appealed the 2009 maps because much of the waterfront was designated a high-hazard zone. That would have halted construction on Portland’s piers and any rebuilding of structures that were more than half destroyed by storms.

Portland and its consultants worked with FEMA to look at other, more accurate data. That reduced the area that was designated as high-risk.

The issue of flood insurance is being addressed at the federal level. A bipartisan group of U.S. senators proposed the Homeowner Flood Insurance Affordability Act last month to delay many premium increases until FEMA completes a required study on the affordability of flood insurance.

Jessica Hall can be contacted at 791-6316 or at:

jhall@pressherald.com

J. Craig Anderson can be contacted at 791-6390 or at:

canderson@pressherald.com