Preliminary flood-risk maps raise insurance and building code concerns along South Carolina coast

September 23, 2017 GMT

New Federal Emergency Management Agency flood-risk maps will change what some South Carolina residents pay for flood insurance, as properties are shown to have greater or lesser risk than previously thought.

In some cites along the coast, the still-pending maps have caused great concern, but for different reasons. In some areas, officials think the maps show too little flood risk; in others, too much.

On Isle of Palms, local officials were shocked to learn the preliminary maps show a lower flood risk for most properties on the barrier island near Charleston.

“I think everybody was a little surprised to learn that,” said Douglas Kerr, the city’s director of Building, Planning and Zoning. “The (required) elevations (for new construction) are pretty much dropping across the island.”

For properties with National Flood Insurance Program insurance, being mapped into a less-risky category could lower premiums.

Kerr said in some cases, properties in the second row from the beach are shown as having a less than a 1 percent annual chance of flooding — a classification that means a lender typically wouldn’t require flood insurance.

“It’s kind of a stunner,” he said.

Isle of Palms City Council will consider new building regulations to require new homes to have no floor lower than 14 feet above sea level, which is typically about 6 feet above ground on the island, so that the new flood maps don’t prompt risky construction practices.

Up the coast in Myrtle Beach, preliminary flood maps have raised the opposite concern.

“Sometimes FEMA mystifies us,” Horry County Councilman Gary Loftus said. “They are putting areas that never flooded into flood zones.”

He said some of the classifications are being appealed. Properties mapped into more-risky flood zones could face substantially higher NFIP insurance costs.

Most South Carolina counties have adopted new flood maps, but the new maps are still pending in most coastal counties. Those counties have the most to gain, or lose, from any changes. They account for most of the flood insurance coverage in the state, with more than 180,000 policies and $47 billion of flood insurance coverage.

Statewide, there are just under 200,000 NFIP policies in force.

Maria Cox Lamm, who oversees the S.C. Department of Natural Resources Flood Mitigation Program, said the new FEMA maps generally show lower flood risks “on the majority of the entire east coast.”

Some key aspects of flood maps are the height of a property in relation to sea level, and how high water would be expected to rise in a flood. Newer technology allowed for more precise elevation calculations.

“I think we’re among the last (S.C. county to adopt new flood maps) because we have major problems with it, and I know because I’m the one who had to tell them about the problems,” said Carl Simmons, Charleston County’s director of building inspection services.

Like other coastal counties, Charleston County is working through a list of concerns. Its new maps could be adopted late next year.