The NFIP is expected to be self-supporting (i.e., premiums are set at an actuarially sound level) in an average loss year, as reflected in past experience. In an extraordinary year, as Hurricane Katrina demonstrated, losses can greatly exceed premiums, leaving the NFIP with a huge debt to the U.S. Treasury that it is unlikely to be able to pay back. Hurricane Katrina losses and the percentage of flood damage that was uninsured led to calls for a revamping of the entire flood program.

Flood adjusters must be trained and certified to work on NFIP claims. NFIP general adjusters typically reexamine a sample of flood settlements. Insurers that fail to meet NFIP requirements must correct problems; otherwise they can be dropped from the program.

As with other types of insurance, rates for flood insurance are based on the degree of risk. FEMA assesses flood risk for all the participating communities, resulting in the publication of thousands of individual flood rate maps. High-risk areas are known as Special Flood Hazard Areas or SFHAs.

Flood plain maps are redrawn periodically, removing some properties previously designated as high hazard and adding new ones. New technology enables flood mitigation programs to more accurately pinpoint areas vulnerable to flooding. As development in and around flood plains increases, run off patterns can change, causing flooding in areas that were formerly not considered high risk and vice versa.

People tend to underestimate the risk of flooding. The highest-risk areas (Zone A) have an annual flood risk of 1 percent and a 26 percent chance of flooding over the lifetime of a 30-year mortgage, compared with a 9 percent risk of fire over the same period. In addition, people who live in areas adjacent to high-risk zones may still be exposed to floods on occasion. Ninety percent of all natural disasters in this country involve flooding, the NFIP says. Since the inception of the federal program, some 25 to 30 percent of all paid losses were for damage in areas not officially designated at the time of loss as special flood hazard areas. NFIP coverage is available outside high-risk zones at a lower premium.

Flood insurance covers direct physical losses by flood and losses resulting from flood-related erosion caused by heavy or prolonged rain, coastal storm surge, snow melt, blocked storm drainage systems, levee dam failure or other similar causes. To be considered a flood, waters must cover at least two acres or affect two properties. Homes are covered for up to $250,000 on a replacement cost basis and the contents for up to $100,000 on an actual cash value basis. Replacement cost coverage pays to rebuild the structure as it was before the damage. Actual cash value is replacement cost minus the depreciation in value that occurs over time. (Excess flood insurance is available in all risk zones from some private insurers for NFIP policyholders who want additional coverage or where the homeowner’s community does not participate in the NFIP.) Coverage for the contents of basements is limited. Coverage limits for commercial property are $500,000 for the structure and another $500,000 for its contents.

To prevent people putting off the purchase of coverage until waters are rising and flooding is inevitable, policyholders must wait 30 days before their policy takes effect. In 1993, 7,800 policies purchased at the last minute resulted in $48 million in claims against only $625,000 in premiums.