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<br />The floodways presented in this study were computed on the <br />bases of equal conveyance reduction from each side of tne <br />floodplain. Sound engineeri ng judgment prevailed in case ,:)f <br />any departure from this approach. The results of blese <br />computations are tabulated at selected cross sections for each <br />stream segment: for which a flood'.ay is computed (Table 2). <br /> <br />As shown on the Flood Boundary and Floodway Map (Exhibit 2), <br />the floodway boundaries were determined at cross sections; <br />between cross sections, the ::)ollndaries were interpolated. In <br />cases where the floodway and IOO-year flood boundaries are <br />close together, only the floodway boundary has been shown. <br /> <br />The area between the floodway and the boundary of the 100-year <br />flood is termed the floodway fringe. The floodway fringe th~s <br />encompasses the pOl:tion of the floodplain that could be <br />completely obstructed without increasing the water-surface <br />elevation of the 100-year flood more than 1.0 foot at anyone <br />point. Typical relationships between the floodway and the <br />floodway fringe and the it: :o'ignificance to floodplain <br />development aJ:e shown in F'igu:ce 2. <br /> <br />f--- <br /> <br />---100 n:AH FLOOD PlA1M--.-------1 <br /> <br />Fl.OOQWAY <br />FRINGE <br /> <br /> <br />--------.J"l.'JOOWAV--._.__ <br /> <br />HODaWAY <br />FAI"lGE <br /> <br />STREAM <br />,.- <br />CHANNEL <br /> <br /> <br />FLOOD ELEVATION WHEN <br />CONFINED WHHIN FlOOOWAY <br /> <br />'NC"OAOHM'NT ~ iENCROAC4d' <br /> <br />_f-~ C_ :~-;~~~____, ~- .1-F:7""~ <br />~ -==- I ~,~~ .- i_ <br />_l. _.....~~..'\ - .--" ",,<, ~ <br /> <br />AREA OF FLOOO PLA'N THAT COULD \...._,// FLOOO ELEVAT'ON <br />BE USED FOA DEVELOPMENT BV SUQR!: ENCI~OACHMENl <br />RAISING GROUND ON FLOOD PLAIN <br /> <br />1.INE A - 8 IS THE FLOOD l:lI:VA.TlON BEFORE ENCROACHMENT <br />LINE C. 0 IS THE FLOOD 1,I.I;VATION AFTER ENCROACHMENT <br /> <br />I <br />, <br />i <br />I <br />--.----..-------.----______.____________J <br /> <br />Figure 2. <br /> <br />Floodway Schematic <br /> <br />-7- <br />