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.

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.

The 1% annual chance standard was chosen after considering various alternatives. The standard constitutes a reasonable compromise between the need for building restrictions to minimize potential loss of life and property and the economic benefits to be derived from floodplain development. Development may take place within the SFHA, provided that development complies with local floodplain management ordinances, which must meet the minimum Federal requirements. Flood insurance is required for insurable structures within the SFHA to protect federally funded or federally backed investments and assistance used for acquisition and/or construction purposes within communities participating in the NFIP.

FEMA publishes maps indicating a community’s flood hazard areas and the degree of risk in those areas. Flood insurance maps are on file in the Greenville County Office of the Floodplain Manager and at the County library. A property owner may consult these maps as a first step in determining if the property is in a special flood hazard area (SFHA). For a specific determination, Greenville County residents should contact the Floodplain Manager (467.7523) to determine if property located in the unincorporated areas of the County is within the 1% SFHA. You will need to provide a tax parcel number and may request the information in person or by fax, e-mail or regular mail.

In addition, maps may be viewed online by accessing the FEMA Flood Map Service Center at http://msc.fema.gov/portal

To be removed 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 ground next to your building and complete an application form. 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. 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 of April 1, 2023, FEMA fully implemented the National Flood Insurance Program's (NFIP) pricing approach, Risk Rating 2.0. Mitigation efforts, community programs and other discounts can help reduce flood damage and, potentially, the cost of flood insurance. Because of the efforts of your Greenville County Floodplain Management and the participation of the Community Rating System (CRS); the residents in the unincorporated areas of Greenville County will receive a 15% discount, which is applied uniformly on their cost of flood insurance.

The difference between the lowest floor elevation (including basement) of your structure and the 1-percent annual chance flood elevation is used to determine the insurance rating.

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. Elevations must be certified by a licensed engineer or surveyor if the elevation certificate is intended to support an application for a Letter of Map Amendment or a Letter of Map Revision based on Fill.