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Computed standard proj~ct floods were used in conjunction with the log-Pearson Type III method statistical analysis (Reference 2) of available streamflow data to develop flow-frequency curves for seven locations. Average stream gradients in the study area, together with approximate drainage areas are shown in the tabulation that follows: StK~ ~~~_<:t~_~?n Approxima te Drainage Area square miles Average Gradient feet/mile Yampa River Gaging Station (At Steamboat Springs) 604 20 Soda Creek Corporate Limit 20 70 Butcherknife Creek Corporate Limit 4 90 Spring Creek Corporate Limit 8 140 Gaging S ta tion (Upper Station near 25 160 Steamboat Springs) Gaging Station (Near Steamboat Springs) 42 15 Near Storm Meadows Drive 4 150 Fish Creek Walton Creek Burgess Creek Ratios of the computed standard project flood developed from the flow-frequency curves were used to determine the 10-, SO-, 100-, and SOO-year flood events in areas where stream gage data were not available. One hundred-year peak flows for streams studied by approximate methods were based on a Frequency-Discharge, Drainage Area Curve prepared from computed standard project floods. Standard project floods from the curve were reduced by approximate percentages to approximate the lOa-year flood event. The computational methods and techniques used are generally accepted for hydrologic analyses and produced results considered reasonable for the Steamboat Springs area. Unexpected findings were not encountered in carrying out the hydro- logic analyses for this Flood Insurance Study. Frequency-Discharge, Drainage Area Curves for the streams under study are shown in Figure 22. 3.2 Hydraulic Analyses Analyses of the hydraulic characteristics of streams in the community were carried out to provide estimates of the elevations of floods of the selected recurrence intervals along each stream studied in detail 19