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Cross section data for Kiowa Creek near the study area were obtained from field surveys~ All bridges and backwater-producing structures were surveyed to obtain elevation data and structural geometry. Locations of selected cross sections used in the hydraulic analyses are shown on the Flood Profiles (Exhibit 1). For stream segments for which a floodway is computed (Section 4.2), selected cross section locations are also shown on the Flood Boundary and Floodway Map (Exhibit 2). Roughness coefficients (Manning's "n"} for Kiowa Creek were estimated by field inspection. The channel "n" value used for Kiowa Creek was 0.03, and the overbank values ranged from 0.04 to 0.05. Starting elevations for backwater computations were determined by using the slope area method. Water-surface profiles were computed for the 10-, 50-, 100-, and 500-year floods using the U.S. Army Corps of Engineer's HEC-2 computer program (Reference 8). Flood profiles were dr~wn to an accuracy of 0.5 foot for floods of the selected recurrenqe"intervals (Exhibit 1). All elevations are referenced to the National Geodetic Vertical Datum of 1929 (NGVD). Elevation reference marks used in the study are shown on the maps. 4.0 FLOOD PLAIN MANAGEMENT APPLICATIONS A prime purpose of the National Flood Insurance Program is to encourage state and local governments to adopt sound flood plain management pro- grams. Each Flood Insurance study, therefore, includes a flood boundary map designed to assist communities in developing sound flood plain management measures. 4.1 Flood Boundaries In order to provide a national standard without regional discrimina- tion, the 100-year flood has been adopted by the Federal Insurance Administration as the base flood for purposes of flood plain manage- ment measures. The SOO-year flood is employed to indicate additional areas of flood risk in the community. For each stream studied in detail, the boundaries of the 100- and the 500-year floods have been delineated using the flood elevations determined at each cross section; between cross sections, the boundaries were interpolated using topographic maps at scale of 1:24,000, with a contour interval of 10 feet (Reference 9). In cases where the 100- and 500-year flood boundaries are close together, only the 100-year boundary has been shown.