After three ''100 year'' floods hit the Phoenix, Ariz., area in the space of four years, some people there began wearing T-shirts that read: ''I survived the 100-year floods of 1979, 1980, and 1982.''
That, says David Cobb, spokesman for the Federal Emergency Management Agency, helps illustrate one of the problems about floods: There are a lot of misconceptions that can lead to a lack of preparation. This week, Mr. Cobb is in North Carolina, helping FEMA and its Federal Insurance Administration settle claims filed with the national flood insurance program after the onslaught of hurricane Diana.
A ''100 year'' flood, he explained, does not mean that one like it - or worse - cannot happen for another 100 years; it simply means there is a 1 percent likelihood that a particular geographical area will have a flood of such severity.
Although hurricanes in late summer and early fall as well as melting snow in the spring provide many of the high-water scenes on the evening TV news, floods of varying degrees occur somewhere in the country almost throughout the year, Cobb says. Floods can come from ocean storms, or from swollen rivers and lakes overflowing with rainwater.
The flood insurance program has been in existence since 1968, and it is the only source of flood insurance available. Ordinary property-casualty insurance policies do not include flood coverage, because ordinary insurance companies don't offer it, although their agents and brokers can sell the federal insurance , Cobb says.
About 6 to 8 million structures are exposed to some risk of flooding, he says , but there are only about 2 million flood-risk policyholders around the country today. And some of these have bought coverage for more than one structure, which leaves a lot of homes and businesses without flood insurance.
In the two North Carolina counties hardest hit by Diana, for example, only about 6,200 people had flood policies. And even among these folks, there will be some sorting out to do.
''One of the problems we have there,'' Cobb pointed out, ''is differentiating between flood damage and wind damage.'' The standard homeowners policy covers wind damage, while the homeowner needs the federal coverage to get reimbursed for flood damage. But then, water damage may have occurred because a wall or window was blown away. This could require some negotiation.
Not everyone, of course, needs flood insurance. FEMA has identified some 20, 000 communities with at least a minimal amount of flood danger. Some 17,000 of these communities participate in FEMA's flood-management program. For the most part, this means the community has agreed to use certain guidelines in approving future development, Cobb says. It does not mean that houses built before the community joined up are ineligible for flood insurance.
''We are trying to encourage new construction to be built in safe areas,'' Cobb notes. ''We are not trying to be punitive.''
There are three categories, or degrees of flood risk, that the agency considers. An ''A'' zone carries the highest risk, a ''B'' zone is moderate risk , and a ''C'' zone is minimal risk. Here, however, another misconception comes in:
''Over 40 percent of the claims we pay are for losses to property which are in minimal to moderate flood-hazard areas,'' Cobb says.
The cost of flood insurance varies greatly, but a loosely defined ''average'' annual premium would be about $185 for a $50,000 house. The exact number depends on several factors, including the hazard zone, the value of the property, and the size of the deductible.
In most cases, there is a $500 deductible, although this can be raised as high as $3,000, if the homeowner wants to absorb that much flood damage and pay lower premiums as long as there is no deluge.
There is a possibility these premiums could go up, Cobb says, since the insurance program has lost money every year but one since it was founded. Last year, flood insurance premiums amounted to $123 million, while claims totaled $ 450 million. The rest comes out of taxes. Cobb says the Reagan administration has expressed a desire that the program come closer to self-sufficiency in the future.
To find out whether your community is a participant in the national flood control program and, if it is, which of the three zones your home is in, contact your city or town hall. It should have information and maps you can use to find your house.
An easier way, Cobb says, is to call your insurance company. If the agent is authorized to sell flood insurance, he or she should have copies of the maps and information on premiums. The agent also collects the money, although the check is made out to the National Flood Insurance Program.
If you do not have flood insurance yet, don't wait until you see the water creeping up the road before applying for it. The first premium has to be received by the program at least five days before any claims can be made.
If it's a vacation home you want to cover, it will be more difficult. In 1982 the rules on vacation homes, or houses occupied less than 20 percent of the year , were changed. Now you cannot claim full coverage, only the original purchase price, less depreciation. This, of course, may be far less than the market value.
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