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The area between the f100dway and 100-year flood plain boundaries is termed the f100dway fring~. The f100dway fringe encoDqlasses the portion of the flood p~ain that could be completely obstructed without increasing the water'-surface elevation of the 100-year flood by more than 1.0 foot at any point. Typical re~ationships between the f~oodway and the, f100dway fringe and their significance to f~ood plain peve10pment are shown in Figure 2. I ~ 100-YEAR fiLOOD PLAIN ~ I FLOODWA Y FRINGE FLOODWAY FLOODWAY FRINGE STREAM CHANNEL FLOOD ELEVATION WHEN CONFINED WITHIN FLOODWAV AREA OF FLOOD PLAIN THAT COULD BE USED FOR DEVELOPMENT BY RAISING GROUND o SURCHARGE- FLOOD ELEVATION BEFORE ENCROACHMENT ON FLOOD PLAIN LINE AS IS THE FLOOD ELEVATION BEFORE ENCROACH~ENT. LINE CD IS THE FLOOD ELEVATION AFTER ENCAOACHME,NT. .SURCHARGE ISNOTTO ExceeD 1,0 FOOT (FEMA AEQUIR,EMENT) OR LESSER AMOUNT IF SPECIFIED BY STATE. Figure 2. F100dway Schematic 5.0 INSURANCE APPLICATION For flood insurance rating purpos~s, flood insurance zone designations are assigned to a community based pn the results of the engineering analyses. These zones are as fo11;owsl Zone A Zone A is the flood insuranqe rate zone that corresponds to the 100-year flood plains that i\re determined in the Flood Insurance Study by approximate method.. Because detailed hydraulic analyses are not performed for such I\reas, no base f~ood elevations or depths are shown this zone. Zone AE Zone AE is the flood insurance rate zone that corresponds to the 100-year flood plains that are determined in the Flood Insurance Study by detailed methods. :Who~e-foot base flood elevations , derived from the detailed hlldraulic analyses are shown at selected intervals within this zone. ' 44