The Legend Slideshow

The Legend provides information for identifying the flood risk zones and floodways on the flood map.

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Flood map panel with legend identified. A blowup of the legend shows that there are pattern keys, terms and symbols and explanation, however, the text is not legible.Partial section of a legend, including Legend title. Shaded rectangle is the key for Special Flood Hazard Areas Subject to inundation by the 1% annual Change Flood Event. The 1-percent annual chance flood (100-year flood) also known as the base flood, is the flood that has a 1% chance of being equaled or exceeded I any given year. The Special Flood Hazard Area is the area subject to flooding by the 1% annual change flood. Areas of Special Flood Hazard include Zones A, AE, AH, AO, AR, AO, AR, A99, V and VE. The Base Flood Elevation is the water surface elevation of the 1% annual change flood. ZONE A: No base flood elevations determined. Zone AE: Base flood elevations determined. Zone AH: Flood depths of 1 to 3 feet (usually areas of ponding); base flood elevations determined. ZONE AO: Flood of 1 to 3 feet (usually sheet flow on sloping terrain); average depths determined. For areas of alluvial fan flooding. Velocities also determined. Zone AR: Area of special flood hazard formerly protected from the 1% annual chance flood event by a flood control system that was subsequently decertified. Zone AR indicates that the former flood control system is being restored to provide protection from the 1% annual change or greater flood event. Zone A99: Area to be protected from the 1% annual change flood evet by a Federal flood protection system under construction; no base flood elevations determined. Zone V: Coastal flood zone with velocity hazard (wave action); no base flood elevations determined. Zone VE: Coastal flood zone with velocity hazard (wave action); base flood elevations determined.Partial section of the Legend: Dark gray pattern: Floodway Areas In Zone AE. The floodway is the channel of a stream plus any adjacent floodplain areas that must be kept free of encroachment so that the 1% annual chance flood can be carried without substantial increases in flood heights. Light gray pattern: Other Flood Areas. Zone X: Areas of 0.2% annual chance flood; areas of 1% annual chance flood with average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas protected by levees from 1% annual chance flood. White, no pattern: Other Areas. Zone X: Areas determined to be outside the 0.2% annual chance floodplain. Zone D: Areas in which flood hazards are undetermined, but possible. Diagonal line pattern: Coastal Barrier Resources System (CBRS) Areas. Broken Diagonal line pattern: Otherwise Protected Areas (OPAs). CBRS areas and OPAs are normally located within or adjacent to Special Flood Hazard Areas.
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Note: Floodways are not calculated in all riverine flood studies.Note: Flood Hazard Boundary Maps (FHBMs) will not have floodways.Note: On pre-1986 FIRM/Flood Boundary and Floodway Maps (FBFMs) the floodway will be shown on the FBFM panel in white.