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increases to 1.0 foot, provided that hazardous velocities are not produced. The floodways in this study are presented to local agencies as minimum standards that can be adopted directly or that can be used as a basis for additional floodway studies. 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 flood way computations are tabulated for selected cross sections (Table 2). The computed floodways are shown on the Flood Insurance Rate Map (Exhibit 2). In cases where the floodway and 100-year flood plain boundaries are either close together or collinear, only the floodway boundary is shown. The area between the floodway and 100-year flood plain .boundaries is termed the floodway fr inge. The floodway fr inge encompasses the portion of the flood plain 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 relationships between the floodway and the floodway fringe and their significance to flood plain development are shown in Figure 2. I- 1 OQ.YEAR FLOOD PLAIN " F LOODWA Y FRINGE F LOOOWA Y FLOOaWAY FRINGE STREAM CHANNEL FLOOD ELEVATION WHEN CONFINED WITHIN FLQODWAY AREA OF FLOOD PLAIN THAT COULD BE USED FOR DEVELOPMENT BY RAISING GROUND "" FLOOD ELEVATION BEFORE ENCROACHMENT ON FLOOD PLAIN LINE AS 15 THE FLOOD ELEVATION BEFORE ENCROACHMENT. LINE CD IS THE FLOOD ELEVATION AFTER ENCROACHMENT. .SU RCHARGE IS NOT TO EXCEe 0 1.0 FOOT (FEMA REQUIREMENT) OR LESSE R AMOUNT IF SPECIF IE 0 BY STATE. Figure 2. Floodway Schematic 11