The acting head of the federal flood insurance program told Congress yesterday that his agency needs to be allowed to borrow $5 billion more just to cover claims it expects to pay by mid- to late November.

Congress recently increased the National Flood Insurance Program's borrowing authority by $2 billion -- to $3.5 billion -- but acting director David I. Maurstad said the agency expects claims from hurricanes Katrina and Rita to top $22 billion. That is more than the program has paid out in its entire history, which stretches back to 1968.

In contrast to past borrowings, Maurstad said after a hearing by the Senate Banking Committee, the insurance program has no hope of repaying debt of that magnitude out of premium income. This would mean that most funding necessary to pay claims would have to come from taxpayers, either as "borrowing" that won't be repaid by the agency or as an appropriation.

Until now, when the flood insurance agency has borrowed from the Treasury, it has repaid its loans with interest, Maurstad said.

The most debt the agency's premiums could service would be about $1 billion, he said, adding that boosting premiums sharply would likely cause homeowners and businesses to drop the coverage.

"We have to balance premiums with policy counts," Maurstad said. He said the program is meant to provide coverage for property owners in the event of a catastrophe, but it doesn't work if people don't buy the policies.

Maurstad called the $5 billion in increased borrowing "a stopgap" while fundamental questions about the future of the program are addressed. He said that he has been talking with members of the Banking Committee and their staffs and that "everything is on the table."

Congress last year enacted a number of changes to the program, but they have not been fully implemented, and Maurstad faced sharp, unhappy questions at the hearing from Sens. Jim Bunning (R-Ky.) and Paul S. Sarbanes (D-Md.), principal authors of last year's legislation.

Uncompleted actions include updates of flood-plain maps used to set premiums and to determine when flood insurance is required of mortgage borrowers, and the continuing lack of a formal appeals process for policyholders who think their claims have not been resolved properly.

"You have not got the job done," Bunning told Maurstad.

Witnesses at the hearing offered a number of suggestions as to how the National Flood Insurance Program might be made to work better, but they tended to focus either on how to encourage more people to buy the coverage or how to make the program more financially sound.

For example, several experts, including the Government Accountability Office, suggested ending the practice of setting premiums too low to cover actual losses, especially for older, more flood-prone properties and for "repetitive-loss" properties that have suffered repeated damage.

Others suggested extending and tightening mandatory coverage so that more owners would have to buy policies and that they would be harder to drop.

But less was said to address what panel Chairman Sen. Richard C. Shelby (R-Ala.) called "a big public policy question that faces us. . . . Are we going to keep bailing out people who build in a flood-prone area?"

"Have we learned anything?" he asked.

Witnesses noted that the flood insurance program establishes minimum construction standards, such as requiring that new buildings must be a certain height above projected 100-year flood levels and that badly damaged buildings must meet certain flood-resistance standards when repaired.

But it does not prohibit building in flood-prone areas. Localities can impose such provisions, but many do not, especially in vacation areas where the attraction is proximity to water. Indeed, many states have their own risk pools to cover wind damage and other perils that private insurers will not.

"There are hundreds of thousands of structures today that would never have been built were it not for the implicit guarantees of a myriad of government-run insurance enterprises, including the NFIP," said Robert P. Hartwig, chief economist of the Insurance Information Institute, an industry group.