Hal Jones thought he could sell his aunt and uncle's house to settle their estate, but now he's not so sure.

Federal flood insurance contacts

Find and view your local flood map and learn your flood zone at msc.fema.gov.

Find more information on the Biggert-Waters Flood Insurance Reform Act and download a homeowners guide to elevation certificates at fema.gov/bw12.

Call the National Flood Insurance Program Help Center at 800-427-4661.

"I'm very upset and frustrated about the whole thing," he said.

Jones said he lost a $420,000 sales contract on the home because of a steep price hike for federal flood insurance.

Before Oct. 1, Jones paid about $1,000 per year for flood protection of the property on Oak Island near Folly Beach. Now, estimates for flood coverage range from $12,000 to $18,000 because of the newly implemented Biggert-Waters Flood Insurance Reform Act.

Mark McKnight wanted to buy the house from Jones, but the cost of flood insurance was a deal breaker.

"That about blew my socks off," McKnight said.

Jones said he now doubts anyone would take out a mortgage on the property because of the cost of flood protection.

The same sort of thing has been happening on Sullivan's Island, said Town Councilman Pat O'Neill.

"There are a lot of people who are really getting some serious sticker shock from this. We've already got people walking away from contracts," O'Neill said.

Biggert-Waters aims to improve the finances of the National Flood Insurance Program, which is billions of dollars in debt in the wake of weather events, such as Hurricane Katrina and Super Storm Sandy.

Subsidized flood rates allowed financing for construction of millions of homes and businesses in flood-prone areas across the U.S.

O'Neill said most of downtown Charleston is in a flood zone and would therefore be affected by the provisions of the new law.

Winslow Hastie, Historic Charleston Foundation chief preservation officer, said the NFIP writes policies in all 50 states.

"This is a huge issue for so many property owners across the Lowcountry," he said in an e-mail to real estate and preservation colleagues.

"We really need to voice our concerns, loudly and repeatedly, so that Congress will defer the implementation of this disastrous bill until its purposes can be achieved with far less arbitrary, capricious and draconian effects," Hastie said.

Trademark Properties Realtor Carol Newman, who represented Jones in the derailed Oak Island deal, worried that the federal flood insurance changes will help trigger the next crash in real estate at a time when sales are increasing.

"This is just going to put the brakes on any type of housing recovery, in my opinion," Newman said.

The Federal Emergency Management Agency says on its website that some 20 percent of NFIP policies are subsidized. The structures they insure are known as "pre-FIRM," meaning they were built before a community adopted its first Flood Insurance Rate Map.

In Charleston County, FEMA said all homes built before April 1971 pre-date the first flood map. In Dorchester County, the date is January 1982, and in Berkeley County it's September 1983.

Homes built after flood maps were adopted will not see as much impact from the NFIP changes, but they could be affected by the new flood maps FEMA is developing for the entire United States, the agency said.

On Oct. 1, when parts of the new law kicked in, flood policies increased an average of 10 percent. Under the changes, subsidies are being removed from second homes, rentals and businesses, as well as dwellings that have had repeated flood losses. Homes sold in pre-FIRM areas are automatically required to have the much more expensive insurance that reflects the "true risk" of flooding.

There are nearly 104,000 flood insurance policies in Berkeley, Charleston and Dorchester counties.

Folly Beach Mayor Tim Goodwin expressed worries about how the new law will affect retirees. "Many may be forced to sell their homes," he said in a letter to Congress.

Goodwin said that if someone wanted to purchase his home, the buyer would face a new, $20,000 annual flood policy premium.

"That's going to really hurt the real estate market. Property is just going to be really hard to do anything with," he said.

Edisto Beach Town Administrator Iris Hill said the situation is affecting older residents who built homes before flood maps were drawn.

"It would devastate us economically. It's going to be tough to sell homes, second homes especially," said Edisto Mayor Burley Lyons.

Isle of Palms Mayor Dick Cronin wrote in a letter to the congressional delegation stating that because of Biggert-Waters, property values will fall and mortgages will go into foreclosure, which could create blighted areas.

Biggert-Waters dramatically increases the cost of $250,000 of flood insurance for a single-family IOP residence constructed in 1968. The annual price tag rises from $2,550 to $15,107, Cronin said.

IOP Council passed a resolution imploring Congress to delay Biggert-Waters, initiate an affordability study and consider a more gradual implementation of the act. Legislation has been introduced to postpone the law for four years.

The act will affect an estimated 1,400 IOP properties, which is more than 30 percent of the real estate on the island, Cronin said.

"It will dry up the real estate market," he said.