Gulf Coast states have collected billions of dollars more in federal flood insurance claims than they have paid into the system over the past 30 years, while states like Florida and California have paid far more than they have received.

The disparity, according to a government audit, shows that the deficit-ridden program needs updating to better reflect risks in different parts of the country.

Residents and businesses in Louisiana got the most out of the program, taking in nearly $12 billion more in claims than they paid in premiums, according to the Government Accountability Office audit. The massive imbalance was linked to the 2005 hurricanes Katrina and Rita; Louisiana, however, had paid more into the system than it collected before those storms hit.

Other Gulf States — Alabama, Mississippi and Texas — had large net gains even before 2005. By 2007, Mississippi had a $2.5 billion advantage, Alabama’s was $746 million and Texas’ was $222 million. Other states with consistent surpluses include Missouri and West Virginia, which have seen heavy river flooding in recent years.

On the other extreme, Florida paid almost $10 billion more in premiums than it collected, California paid $2.4 billion more, and New Jersey paid $1.3 billion more.

George Riedel, deputy director for the Association of State Floodplain Managers, said he wasn’t surprised at the findings because the program only loosely uses sound actuarial rates.

Because major changes in federal flood insurance must ultimately be approved by Congress, he said a reluctance in Washington to increase premiums for the program’s 5.5 million customers is part of the problem.

“Nobody likes to see increases, but if people are going to choose to live along areas that are at risk they need to share some of the cost that goes along with that,” Riedel said. “Hopefully we will get a reform act at some point soon.”

Congress has been working on legislation for several years but has not been able to agree on a final bill. The program, meanwhile, is saddled with almost $18 billion in debt — mostly from Hurricane Katrina — with interest payments to the U.S. Treasury eating up a large chunk of its budget.

The audit reiterated earlier recommendations that the Federal Emergency Management Agency update the flood maps and other data it uses to assess risk and adjust premiums accordingly. The report noted that the agency sets rates based on national averages, for example, and has not begun analyzing the effects expected from climate change as private insurers have.

FEMA agreed with the major points of the audit but criticized parts of it. The agency said the audit painted an overly negative picture of the program and did not adequately account for progress the agency has made or for the complexities of setting rates.

The National Flood Insurance Program was created in 1968 to help homeowners and businesses in flood-prone regions get affordable insurance not usually available on the private market and to reduce federal costs in natural disasters.

On the Net:

National Flood Insurance Program: http://www.fema.gov/business/nfip/