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Type III distribution (Reference 8). The entire period of record was not used because Blue Mesa Dam, completed in 1965, significantly affects downstream flows. The results of flood flow frequency analysis performed for the period 1966 to 1985 are shown in Table 2. A comparison of the flood hydrographs for the Colorado and Gunnison Rivers was made. It can be assumed that flood peaks on the Colorado and Gunnison Rivers occur at the same time since the hydrographs are nearly parallel. Thus, for study reaches downstream of the mouth of the Gunnison River, the peak discharges on the Colorado River are added to the flood peaks computed for the Gunnison River. Resul ts of hydrologic analyses for Big Salt Wash and Li t tIe Sal t Wash presented in the 1976 COE Flood Hazard Information Reports (References 10 and 11) were used in this study. The Flood Hazard Information report for Fruita, 1976 (Reference 10), di scusses the hydrologic studies conducted by the COE, Sacramento District on Big Salt Wash and Little Salt Wash. Because streamflow gaging information was not available for these two streams, the COE derived unit hydrographs by the S-graph method, based on an S-graph developed for Rifle Creek at Rifle. A Standard Project Storm was developed for the washes from a compilation of precipitation records. The Standard Project Storm is defined as the storm resulting from the most severe combination meteorological conditions that are considered reasonably characteristic of the geographical area in which the stream basin is located. The Standard Project Storm was centered over the enti re Li t tIe Sal t Wash bas in and the Standard Pro ject Flood was derived from it. Using frequency curves developed for other regional drainage basins similar in size to the study area drainages, ratios of 100- and 500-year floods to the Standard Project Flood were determined. The 1976 hydrologic studies also developed information on 10- and 50-year flood events but the design discharges are not listed in the report. The Flood Insurance Study for Fruita (Reference 1) lists the 10- and 50-year discharges for only Little Salt Wash. To determine peak discharges for Big Salt Wash for these frequencies, the 100- and 500-year discharges were plotted on probability paper and values for the 10- and 50-year floods were extrapolated. Peak discharge-drainage area relationships for the streams studied by detailed methods are shown in Table 2. 3.2 Hydraulic Analyses Analyses of the hydraulic characteristics of flooding sources studied were carried out to provide estimates elevations of floods of the selected recurrence intervals. from of the the 12