Zone A
Zone A is the flood insurance rate zone that corresponds to the 100-year floodplains that are determined in the Flood Insurance Study (FIS) by approximate methods. Because detailed hydraulic analyses are not performed for such areas, no BFEs or depths are shown within this zone. Mandatory flood insurance purchase requirements apply.

Zone AE and A1-A30
Zones AE and A1-A30 are the flood insurance rate zones that correspond to the 100-year floodplains that are determined in the FIS by detailed methods. In most instances, BFEs derived from the detailed hydraulic analyses are shown at selected intervals within this zone. Mandatory flood insurance purchase requirements apply.

Zone AH
Zone AH is the flood insurance rate zone that corresponds to the areas of 100-year shallow flooding with a constant water-surface elevation (usually areas of ponding) where average depths are between 1 and 3 feet. The BFEs derived from the detailed hydraulic analyses are shown at selected intervals within this zone. Mandatory flood insurance purchase requirements apply.

Zone AO
Zone AO is the flood insurance rate zone that corresponds to the areas of 100-year shallow flooding (usually sheet flow on sloping terrain) where average depths are between 1 and 3 feet. The depth should be averaged along the cross section and then along the direction of flow to determine the extent of the zone. Average flood depths derived from the detailed hydraulic analyses are shown within this zone. In addition, alluvial fan flood hazards are shown as Zone AO on the FIRM. Mandatory flood insurance purchase requirements apply.

Zone A99
Zone A99 is the flood insurance rate zone that corresponds to areas of the 100-year floodplains that will be protected by a Federal flood protection system where construction has reached specified statutory milestones. No BFEs or depths are shown within this zone. Mandatory flood insurance purchase requirements apply.

Zones B, C, and X
Zones B, C, and X are the flood insurance rate zones that correspond to areas outside the 100-year floodplains, areas of 100-year sheet flow flooding where average depths are less than 1 foot, areas of 100-year stream flooding where the contributing drainage area is less than 1 square mile, or areas protected from the 100-year flood by levees. No BFEs or depths are shown within this zone.

What is a Flood Insurance Study (FIS)?

A Flood Insurance Study (FIS) is a book that contains information regarding flooding in a community and is developed in conjunction with the Flood Insurance Rate Map (FIRM). The FIS, also known as a flood elevation study, frequently contains a narrative of the flood history of a community and discusses the engineering methods used to develop the FIRMs. The study also contains flood profiles for studied flooding sources and can be used to determine Base Flood Elevations for some areas.

What is the "100-year flood"?

The term "100-year flood" is misleading. It is not the flood that will occur once every 100 years. Rather, it is the flood elevation that has a 1- percent chance of being equaled or exceeded each year. Thus, the 100-year flood could occur more than once in a relatively short period of time. The 100-year flood, which is the standard used by most Federal and state agencies, is used by the NFIP as the standard for floodplain management and to determine the need for flood insurance. A structure located within a special flood hazard area shown on an NFIP map has a 26 percent chance of suffering flood damage during the term of a 30 year mortgage.

What is a Flood Insurance Rate Map (FIRM)?

A Flood Insurance Rate Map (FIRM) is an insurance and floodplain management map issued by FEMA that identifies areas of 1-percent annual chance flood hazard in a community. In some areas, the map also shows Base Flood Elevations and 0.2-percent annual chance floodplain boundaries and, occasionally, regulatory floodway boundaries.

What is a Base Flood Elevation (BFE)?

A Base Flood Elevation (BFE) is the height of the base flood, usually in feet, in relation to the National Geodetic Vertical Datum of 1929, the North American Vertical Datum of 1988, or other datum referenced in the Flood Insurance Study report, or average depth of the base flood, usually in feet, above the ground surface.

I have lived here forever and have never been flooded. Why do I need flood insurance?

The flood hazards shown on NFIP maps are based on the best information available at the time the maps were prepared. In many areas, hydraulic and hydrologic studies were conducted to reflect the long-term projection of flood risk. Because of the infrequent occurrence of flood events and the relatively short history of the NFIP, Special Flood Hazard Areas (SFHAs) are not based only on the past flooding occurrences. The fact that a flood hasn't occurred within memory doesn't mean one won't happen soon.

The 100-year flood is a relatively rare event (1-percent chance in any given year), but structures located in the floodplain have a significant chance (26%) of suffering flood damage during the term of a 30-year mortgage. For these reasons, flood insurance is required as a condition of receiving Federal or federally-backed financial assistance.

How and when do I get a refund for canceling my flood insurance?

If you were required to get insurance by a lender and then you got a Letter of Map Amendment (LOMA) from FEMA, you may request a refund. The lender is not required to waive the requirement; the lender may decide that flood insurance coverage is still required.

To get a refund, the lender must agree to waive it. Present the written waiver to the insurance agent who sold you the policy and request a refund. Refunds are not available if a claim has been made or is pending against the policy.

What elevation is used when rating a structure for a flood insurance policy?

The difference between the lowest floor elevation (including basement) of your structure and the 1% annual chance flood elevation is used to determine the insurance rating. Note: Only buildings are insurable, other structures are not.

My family has lived in our house for many years, and we had a big flood that was called the "100-year flood." We weren't damaged. Why do I need flood insurance?

The term "100-year flood" is often incorrectly used and can be misleading. It does not mean that only one flood of that size will occur every 100 years. The term is a statement of probability that scientists and engineers use to describe how one flood compares to others that are likely to occur. Today, we use the phrase "1% annual chance flood." What it means is that there is a 1% chance of a flood of that size happening in any year. Over a 100-year period, it has a 63.5% chance of occurring. Even more surprising is that over a 30-year period (typical mortgage period) the 1% annual chance flood has a 26% chance of occurring. This means a home in the mapped flood hazard area is five times more likely to be damaged by flood than to have a major fire!

To answer your question about why you need flood insurance, you would need to look very carefully at what caused the flood and how high the water near your home rose. Because rainfall amounts are different when a storm moves across an area, a "100-year flood" may occur in some places but not others. There are many factors that can add to flooding, including debris in the waterway, small road culverts and bridges, frozen or saturated ground, and others.

If your area had a major storm and your home was not flooded, you may want to check with your community's engineering or planning office. If other areas didn't flood, it may mean that the FIRMs should be revised. You may also want to check to see if your home is eligible for a Letter of Map Amendment (LOMA) which FEMA uses when homeowners submit Elevation Certificates showing that their homes are out of the mapped floodplain. With a LOMA, your lender may choose to not require flood insurance.

My bank said I'm in the floodplain and have to buy insurance. I don't believe it. What can I do?

If a lending institution is federally regulated or making federally-backed loans, it must review the NFIP maps to determine if the building is located in a Special Flood Hazard Area. The SFHA is the area that is expected to be inundated by a 1% annual chance flood. If the bank makes such a determination, it must require the borrower to purchase flood insurance. Please note, these determinations are purely in/out and do not involve the vertical elevation of the structure.

If you disagree with the lending institution's determination, you may request that FEMA review the lender's determination. FEMA will then review the information that the lending institution used, and issue a letter that states whether we agree with the determination. Your request must be postmarked no later than 45 days after the lending institution notifies you of the flood insurance requirement and the submittal must be complete. The request must include all of the information and fees listed in the Letter of Determination Review (LODR) information sheet. If your request is postmarked after the 45-day limit has expired, or if we do not receive all of the information within the 45-day limit, we will not be able to review the determination and the flood insurance requirement stands.

FEMA's responses to these requests are called LODRs, and offer two basic dispositions: (1) the lender's determination stands or (2)it is overturned. FEMA's determination is based on the technical data submitted. If the lender's evidence is inconclusive or the request is incomplete FEMA can disagree with the lender's determination. FEMA's response does not amend or revise the NFIP map for your community. It only states that FEMA agrees or disagrees with your lender's determination.

Occasionally a lending institution may require insurance if it determines that a part of your lot is in the SFHA. The NFIP does not insure land. However, even if you submit evidence that your building is out of the floodplain, the bank may still decide to require insurance on your building.

Who can prepare an Elevation Certificate?

Elevation Certificates must be prepared and certified by either a land surveyor, engineer, or architect who is authorized by commonwealth, state, or local law to certify elevation information. Community officials who are authorized by local law or ordinance to provide floodplain management information may also sign the certificate.

What are some of the common acronyms used in the National Flood Insurance Program?

ACRONYM	STANDS FOR...
ANI	Area Not Included
BFE	Base Flood Elevation
CLOMA	Conditional Letter of Map Amendment
CLOMR	Conditional Letter of Map Revision
CLOMR-F	Conditional Letter of Map Revision based on Fill
ERM	Elevation Reference Mark
FEMA	Federal Emergency Management Agency
FHBM	Flood Hazard Boundary Map
FIRM	Flood Insurance Rate Map
FIS	Flood Insurance Study
LAG	Lowest Adjacent Grade (to a structure)
LOMA	Letter of Map Amendment
LOMC	Letter of Map Change
LOMR	Letter of Map Revision
LOMR-F	Letter of Map Revision based on Fill
NFIP	National Flood Insurance Program
SFHA	Special Flood Hazard Area

Back to Top