Laserfiche WebLink
<br />I- <br /> <br />lOO.YEAR FLOODPLAIN <br /> <br />-I <br /> <br />FLOODWAY <br />FRINGE <br /> <br />.. <br /> <br />FLOODWAY <br /> <br />FLOODWAY <br />FRINGE <br /> <br />STREAM <br />CHANNEL <br /> <br />FLOOD ELEVATION WHEN <br />CONFINED WITHIN FLOODWAY <br /> <br /> <br />ENCROACHMENT <br /> <br />ENCROACHMENT <br /> <br />AREA OF FLOODPLAIN THAT COULD BE UseD <br />FOR DEVELOPMENT BV RAISING GROUND <br /> <br />FLOOD ELEVATION BEFORE <br />ENCROACHMENT ON FLOODPLAIN <br /> <br />UNE AB IS THE FLOOD ELEVATION BEFORE ENCROACHMENT. <br />LINE CD IS THE FLOOD ELEVATION AFTER ENCROACHMENT. <br />'SURCHARGE IS NOT TO EXCEeo 1.0 FOOT (FIA REQUIREMENT) OR LESSER AMOUNT IF SPECIFIED BY STATE. <br /> <br />Figure 9. Floodway Schematic <br /> <br />greater than that indicated in the following table for more than 20 percent <br />of the reach: <br /> <br />Average Difference Between <br />10- and 100-Year Floods <br /> <br />Variation <br /> <br />Less than 2 feet <br />2 to 7 feet <br />7.1 to 12 feet <br />More than 12 feet <br /> <br />0.5 foot <br />1.0 foot <br />2.0 feet <br />3.0 feet <br /> <br />5.2 Flood Hazard Factors <br /> <br />The Flood Hazard Factor (FHF) is used to establish relationships <br />between depth and frequency of flooding in any reach. This rela- <br />tionship is then used with depth-damage relationships for various <br />classes of structures to establish actuarial insurance rate tables. <br /> <br />The FHF for a reach is the average weighted difference between tbe <br />10- and lOO-year flood water-surfac'e elevations rounded to the <br /> <br />27 <br />