The Mississippi Department of Insurance has filed a lawsuit against the federal government to try to block rates from increasing Oct. 1 in the National Flood Insurance Program.

State Insurance Commissioner Mike Chaney said that unless something changes, some customers could see their rates rise by more than 3,000 percent because of a 2012 federal law.

“Today, many consumers face loss of their property due to the increases,” Chaney said in a news release last Thursday. “Many of the new flood elevation maps are riddled with errors and consumers must pay for new elevation certificates to prove they are not in a flood zone.”

The lawsuit is against the U.S. Department of Homeland Security and one of its divisions, the Federal Emergency Management Agency.

The 2012 law, known as the Biggert-Waters Flood Insurance Reform Act, was intended to keep the flood insurance program solvent after a large number of claims following Hurricane Katrina, which struck in 2005. The law removes federal subsidies from properties in flood zones.

FEMA says the phase-out of subsidies will affect fewer than 20 percent of flood policyholders nationwide. In Mississippi, 14 percent of flood insurance policies are subsidized, according to the National Flood Insurance Program.

The 2012 law reauthorized the flood insurance program for five years and set a strategy for updating flood zone maps across the U.S. The Mississippi lawsuit says that according to FEMA, Mississippi and Louisiana are the first states to include post-Hurricane Katrina statistics in their rating methodology.

“This means that Mississippi’s citizens will be among the first in the nation to have these drastic rate increases imposed, and that Mississippi’s citizens will pay for them many years before citizens of other states are required to do likewise,” the lawsuit says.

Chaney had asked the state’s attorney general, Jim Hood, to support him in his lawsuit but Hood declined.

About 17.4 million households in the U.S. live in areas where flood insurance is mandatory, and 41 percent of those have low to median income levels, the lawsuit says. It says the 2012 law requires an affordability study for flood insurance, but that hasn’t been completed.

The lawsuit asks a federal judge to find that FEMA was obligated to deliver an affordability study to Congress by this past April, and that it failed to do so. The suit asks the judge to block rate increases until FEMA has done everything the law requires.

U.S. senators from Florida, Louisiana and New Jersey filed legislation Wednesday to try to delay implementation of the Biggert-Waters Act by one year.

During a visit to Florida’s Emergency Operations Center in August, FEMA Director Craig Fugate acknowledged residents in coastal areas are feeling “sticker shock,” but he said eliminating subsidies means the federal government won’t have to continue to borrow money to pay for the insurance.

“The true cost” of insurance “has been provided at below-market rate,” Fugate said.

Fugate said rate hikes will be phased in over time for those with primary residencies, but larger hikes will take effect for those insuring secondary homes or homes that have recently sold.

Fugate told a Senate panel last week that he does not have the authority under the law to delay the rate increases.

Associated Press writer Gary Fineout contributed to this report from Florida.