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<br />standards limit such increases to 1.0 foot, provided that hazardous <br />velocities are not produced. The floodways in this study are <br />presented to local agencies as minimum standards that can be adopted <br />directly or that can be used as a basis for additional floodway <br />studies. <br /> <br />The floodways presented in this study <br />equal conveyance reduction from each <br />results of these computations were <br />sections for each stream segment for <br />(Table 3). <br /> <br />were computed on the basis of <br />side of the floodplain. The <br />tabulated at selected cross <br />which a floodway is computed <br /> <br />The floodways at the confluence of Nissen Reservoir Channel and <br />City Park Channel incorporate sheetflow diversion areas common to <br />both channels. The floodways were delineated through these sheet <br />flow areas after analyzing two HEC-2 computer runs: (1) with the <br />total flow confined to the channels, and (2) with partial flow. <br />confined to the channel. If the change in WSEL between these <br />computer runs was greater than allowable with encroachment <br />{i. e., greater than 1.0 feet), then the floodway was shown routed <br />through the sheet flow diversion areas. <br /> <br />As shown on the FBFM (Exhibit 2), the floodway boundaries were <br />computed at cross sections. Between cross sections, the boundaries <br />were interpolated. In cases where the floodway and lOO-year <br />floodplain boundaries are either close together or collinear, only <br />the floodway boundary has bee- shown. <br /> <br />The area between the floodway and lOO-year floodplain boundaries is <br />t'e'rm-e~d-th~e-fro-odway fringe. T~flooaway' frInge encompasses the <br />portion of the floodplain that could be completely obstructed <br />without increasing the WSEL of the lOa-year flood by more than <br />1.0 foot at any point. Typical relationships between the floodway <br />and the floodway fringe and their significance to floodplain <br />development are shown in Figure 8. <br /> <br />5.0 INSURANCE APPLICATION <br /> <br />For flood insurance rating purposes, flood insurance zone designations are <br />assigned to a community based on the results of the engineering analyses. <br />These zones are as follows: <br /> <br />Zone A <br /> <br />Zone A is the flood insurance rate zone that corresponds to the lOO-year <br />floodplains that are determined in the FIS by approximate methods. <br />Because detailed hydraulic analyses are not performed for such areas, no <br />base (lOa-year) flood elevations (BFEs) or depths are shown. within this <br />zone. <br /> <br />14 <br />