Zoning & Building Safety:

Zoning and Building Safety Department
Flood Information

Frequently Asked Questions:

Please remember that all of the Questions and Answers only apply to properties in Unincorporated Rock Island County. If you live in a city or village please check with their Floodplain Manager for rules and regulations.

What does the "100-year flood" mean?
The term "100-year flood" is misleading. News media has a tendency to call every minor flood a "100 year flood" even though it is not. As stated above, 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.
My home is in a floodplain. Am I at high risk for flooding?
Yes. Buildings in floodplains, or Special Flood Hazard Areas (SFHAs), are at high risk for flood damage. Some floodplains experience frequent flooding, while others are affected by only the severest of storms. As a homeowner in a floodplain, it's not so much a question of if a flood will damage your property as when. That's why the law requires you to have flood insurance. Did you know that an SFHA home has a 26% chance of being flooded over a 30-year period? That means that you're five times more likely to be damaged by a flood than a fire!
If I read a Flood Insurance Rate Map (FIRM), what are the different flood hazard zone designations and what do they mean?
  • 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 Base Flood Elevations (BFE) 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 AR Zone AR is the flood insurance rate zone used to depict areas protected from flood hazards by flood control structures, such as a levee, that are being restored. FEMA will consider using the Zone AR designation for a community if the flood protection system has been deemed restorable by a Federal agency in consultation with a local project sponsor; a minimum level of flood protection is still provided to the community by the system; and restoration of the flood protection system is scheduled to begin within a designated time period and in accordance with a progress plan negotiated between the community and FEMA. Mandatory purchase requirements for flood insurance will apply in Zone AR, but the rate will not exceed the rate for unnumbered A zones if the structure is built in compliance with Zone AR floodplain management regulations.

    For floodplain management in Zone AR areas, elevation is not required for improvements to existing structures. However, for new construction, the structure must be elevated (or flood proofed for non-residential structures) such that the lowest floor, including basement, is a maximum of 3 feet above the highest adjacent existing grade if the depth of the Base Flood Elevation (BFE) does not exceed 5 feet at the proposed development site. For infill sites, rehabilitation of existing structures, or redevelopment of previously developed areas, there is a 3-foot elevation requirement regardless of the depth of the BFE at the project site.

    The Zone AR designation will be removed and the restored flood control system shown as providing protection from the 1% annual chance flood on the NFIP map upon completion of the restoration project and submittal of all the necessary data to FEMA.

  • 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.
  • Zone D The Zone D designation on NFIP maps is used for areas where there are possible but undetermined flood hazards. In areas designated as Zone D, no analysis of flood hazards has been conducted. Mandatory flood insurance purchase requirements do not apply, but coverage is available. The flood insurance rates for properties in Zone D are commensurate with the uncertainty of the flood risk.
  • 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.
The Flood Insurance Rate Map (FIRM) shows that my parcel is in the mapped floodplain, but the ground my house is on is higher. I believe I shouldn't be shown in the floodplain. What are FEMA's requirements for being removed from the 1% annual chance flood hazard area?
To be removed from the floodplain shown on the Flood Insurance Rate Map, a structure must be on land that is not subject to flooding by the 1% annual chance flood. Remember, more severe floods can and do happen, so even if your home is found to be on high ground, it may still be damaged by an extreme flood event.

If your lot or building site is on natural ground that is higher than the Base Flood Elevation shown on the FIRM, then you may request a Letter of Map Amendment (LOMA). To support your request, you will have to get a surveyor to determine the elevation of the Lowest Adjacent Grade (LAG) of your building and complete an Elevation Certificate. If the ground is higher than the Base Flood Elevation, then FEMA will issue a LOMA. With a LOMA, your lender may choose to not require flood insurance. The easiest way to file this type of LOMA is with the form MT-EZ. You may download the MT-EZ form and instructions from the downloads section of our pages.

If your home was built on fill that was placed after the FIRM was prepared, you may request a Letter of Map Revision Based on Fill (LOMR-F). As with a LOMA, you will need to get an Elevation Certificate completed by a land surveyor. If the filled ground is higher than the Base Flood Elevation, and if you do not have a basement, then FEMA may issue a LOMR-F, and your lender may choose to not require flood insurance.

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 floodpain 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.

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. So, 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 I have to buy flood 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 do determinations of floodplain maps?
Remember, a flood determination is just an interpretation of maps provided to us by FEMA. These determinations are purely in/out and do not involve the vertical elevation of the structure. Rock Island County does offer flood determinations, for specific properties, but your lending institution may not except it. This service is available to any resident, lender or insurance agent within unincorporated Rock Island County. This office does determinations for properties located within unincorporated Rock Island County, and the Villages of Andalusia, Hillsdale and Oak Grove. If you have a question about a property within another municipality please contact the appropriate city or village.

We will provide, in writing, a determination based on the FIRM for our community. These letters do not imply that the referenced property will or will not be free from flooding or damage. A property not in a Special Flood Hazard Area may be damaged by a flood greater than predicted on the FIRM or from a local drainage problem not shown on the map. Even with one of these determination letters, your financial institution may still require you to carry flood insurance.

How can I find my community number and/or panel number?
All residents within unincorporated Rock Island County are in Community Number 170582. If you are in a city or village, your community number is different, please check with your local city or village.

Mapping is done digitally now. Visit FEMA's Flood Map Service Center and search by address. This will provide you with all of your informational needs. .

Who can prepare an elevation certificate?
Elevation Certificates must be prepared and certified by 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 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.
What do I need to know if my building is in the floodplain?
Buildings in special flood hazard areas shown on FIRMs may be damaged when flooding occurs. Some buildings flood frequently, while others get damaged by only the more severe events.

If your home is in the 1% annual chance floodplain it has a 26% chance of getting flooded over a 30-year period. This means it is about five times more likely to get damaged by flood than by a severe fire!

You should know that usually you can get flood insurance, if available, by contacting your regular homeowners insurance agent. FEMA and others recommend that everyone in special flood hazard areas buy flood insurance. If you buy a home or refinance your home your mortgage lender or banker may require flood insurance. But, even if not required, it is a good investment especially in areas that flood frequently or where flood forces are likely to cause major damage.

Another thing you should know is that Rock Island County requires permits for remodeling, improving, expanding, or rebuilding any structure over 70 square feet. In order to reduce long-term flood damage, the NFIP requires that buildings that are substantially improved or substantially damaged become compliant. This means if the cost of the improvements or repairs is more than 50% of the market value of the building, you will have to make it compliant with the rules for floodplain construction. Usually this means lifting if off the foundation and elevating it above the predicted flood level. If you carry a flood insurance policy and have major flood damage, you may be eligible for up to $30,000 more to help pay for the cost of this work.

I bought a house near the river; I had no idea that it floods there, what do I do?
This is an actual question we receive in our office. Please understand that if you purchase a residence near a body of water, there is a chance it can be damaged by a flood. A flood can damage many properties that are not determined to be in a Special Flood Hazard Area (SFHA).
How can I be considered to be in a floodplain, I only get water when it floods?
Again this is an actual question we get in this office. A floodplain is the area that has been determined by FEMA or other flood studies, where water will go if we receive excessive amounts of water in a short period of time. This usually only happens when we get heavy rainfall or in the spring when snow is melting, but can happen at other times also.
Five years ago my neighbor did something I want to do now, why can't I do it?
Every year floodplain regulations are getting stricter and will continue to do so. Regulations are set by FEMA, the State of Illinois and by local government. These are constantly changing to adapt to a changing environment.
The mean local official says that my property has been substantially damaged, what does that mean?
This means that a flood has damaged your property, and the damage exceeds more than 50% of your properties assessed value. Your local assessor sets the assessed value and you pay taxes based on this value every year. The damage amount is based on local values of replacement. These are set values based on nationwide building valuations. Materials and labor are included even If you do the work yourself.

This also means that you cannot move back into your property until it is brought into compliance with our building codes and meets floodplain regulations. This could mean elevation, flood proofing, relocation, or demolition. If substantially damaged by flooding events, up to $30,000 may be available to assist you from a rider on your flood insurance policy. This rider does not apply to damage from other means (fire, wind, etc). Because flood insurance does not cover damage from fire, wind, etc.

What happens if I move back into my house, even though it has been declared substantially damaged?
Again this is an actual question we get. So there are procedures in place to deal with this. First, Rock Island County will file a notice of violation on the deed to your property, which may prevent you from selling the property and all future owners will know of the violation.

Then we will notify your insurance company of the violation, which will lead to your insurance premiums to possibly increase to $25 per $100 of assessed value per year. So a $100,000 house would pay flood insurance of $25,000 a year, because you wanted to move back into your house. Or the insurance company could decide to drop your flood insurance and then you would be expected to payoff your mortgage in 30 days.

And finally, this is a violation of the Zoning Ordinance, which has potential fines of $500 per day.

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Rock Island County Office Building (map ExternalLink.gif)
1504 Third Avenue, Room 305, Rock Island IL 61204-8624
Phone: (309) 558-3771      Fax: (309) 786-4456

      Hours: 8:00 AM to 10:00 AM and 3:00 PM to 4:30 PM - Monday thru Friday
Inspectors are in the field from 10:00 AM until 3:00 PM