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The floodways presented in this study were computed for certain stream segments on the basis of equal conveyance reduction from each side of the flood plain. Floodway widths were computed at cross sections. Between cross sections, the floodway boundaries were interpolated. The results of the floodway computations are tabulated for selected cross sections (Table 2). In cases where the floodway and lOO-year flood plain boundaries are either close together or collinear, only the floodway boundary is shown. FOr Dry Creek and its tributaries, floodway data were not provided. The area between the floodway and laO-year flood plain boundaries is termed the floodway fringe. The floodway fringe encompasses the portion of the flood plain that could be completely obstructed without increasing the water-surface elevation of the lOO-year flo04 by more than 1.0 foot at any point. Typical relationships between the floodway and the floodway fringe and their significance to flood plain development are shown in Figure 2. I- ~ aD-YEAR FLOOD P....AIN -, FLCQDV~AV FRI~GE FLOOD\.it;AY ;:~OOD'.."AY FRI"'GE STREAM C'-iAN,\;EL FLOOD ELEVAT~ON V"J-tEN CONFIN:D ~':!THIf\; FLOOD\ra';AY ENC~OACHMEI\;T -r E"\oCROACHlI."ENT -r- (',r---- ..---- S~C~~E...:J -~--- _._-- I . --L AREA OF FLOOD ?:"'AIN Ti-!AT COL:LD 9:':: USED FOR ~EVELOP!\;~ENT BV ~AISING GPOUNC '\. --..........A",.....- FLOOD ::LE\!AT!Of\; B~FOA=ENCROACH~EN: O!\l F~OOC PLAIN LINE A81S THE F!...OO:) ELEVATIO~" BEFORE ENCROACHMENT_ LINE CD IS THE ;:LOOD E~EVAT!ON A;:TE~ E:\iCRCACHMEl'I:T. 'SURCHARGE IS :--;CTTO EXCEED 1.0 FOOT ,FEVA =lEGUIREMENT; OR LESSER AMOUr~T IF SPECIFIED 8Y STATE_ Figure 2. Floodway Schematic 21