A proposed moratorium on federal flood insurance reform because of homeowner worries about costly new policies has the backing of Republican South Carolina Senators Tim Scott and Lindsey Graham.

"A temporary delay will allow for a halt in burdensome rate increases while the problem is addressed," Scott said.

The Homeowner Flood Insurance Affordability Act (S. 1846) would delay for four years flood insurance increases resulting from the Biggert-Waters Flood Insurance Reform Act of 2012, which aims to make the debt-ridden National Flood Insurance Program solvent by shifting the cost of subsidized policies to homeowners.

Graham said the issue is "critically important" for South Carolina. "We need to ensure that the National Flood Insurance Program is affordable, accessible and sustainable," he said.

Elected officials on Sullivan's Island, Isle of Palms, Folly Beach and Edisto Beach have expressed worries about the effect of Biggert-Waters on the real estate market.

Hal Jones of James Island said he recently lost a $420,000 deal to sell his aunt and uncle's 1966 home to settle their estate because the new law caused the flood policy to rise from $1,000 per year to more than $12,000 annually. The concrete slab house is on Oak Island near Folly Beach.

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, the Federal Emergency Management Agency says at its web site.

"Pre-FIRM is where the current issue lies," said Jim Kempson, associate broker at Sea Island Realty.

Most homes are not affected if built according to FEMA guidelines, Kempson said.

"So far, the Biggert-Waters Act only adversely impacts a very small percentage of coastal homes - those built pre-1971 that do not meet flood elevation guidelines," he said.

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 that FEMA is developing for the entire United States, the agency said.

Sen. Mary Landrieu, a Louisiana Democrat and co-sponsor of S. 1846, said the bill will delay the Biggert-Waters flood insurance rate increases until FEMA has "implemented a flood mapping approach that, when applied, results in technically credible flood hazard data."

The bill also requires FEMA to conduct a study of the affordability of the rate increases, according to news reports.

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

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.

On Oct. 1, when parts of Biggert-Waters 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.

Subsidized flood rates allowed financing for construction of millions of homes and businesses in flood-prone areas across the U.S. The NFIP is billions of dollars in debt in the wake of weather events such as Hurricane Katrina and Super Storm Sandy.