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<br />study, the peak. discharges along the Colorado River from DeBeque <br />Canyon to the Utah State line were analyzed. <br /> <br />There are several U.S. <br />on the Colorado River <br />following is a list of <br /> <br />Geological Survey stre,mflow gaging stations <br />and tributaries in the project area. The <br />the gages used in the hydrologic analysis: <br /> <br />Gaging Station <br /> <br />Period of Record <br /> <br />Colorado River: <br />near Cameo <br />near Palisade <br />near Fruita <br />near Colorado-Utah State Line <br /> <br />1934 - 1985 <br />1902 - 1933 <br />1911 - 1923 <br />1951 - 1985 <br /> <br />Gunnison River: <br />near Grand Junction <br />(after Blue Mesa Dam) <br /> <br />1965 - 1985 <br /> <br />The frequency analysis was performed using the log-Pearson Type III <br />Method, in accordance with criteria outlined 10 Bulletin 17B <br />(Reference 12). <br /> <br />The peak flow series that were analyzed represent primarily <br />snowmelt floods which peak between late April and June. Following <br />COE guide1 ines, a regional skew of zero was used for the Cameo <br />gage. The results of the computation compared favorably with the <br />results of the COE hydrology report and are shown in Table 2. <br /> <br />To estimate peak discharges for the various recurrence intervals on <br />the Gunnison River near Grand Junction, records from the long-term <br />gage on the Gunnison were analyzed, using the log-Pearson Type III <br />distribution (Reference 12). The entire period of record was not <br />used because Blue Mesa Dam, completed in 1965, significantly <br />affects downstream flows. The results of flood flow frequency <br />analysis performed for the period 1966 to 1985 are shown in <br />Table 2. <br /> <br />A comparison of the flood hydrographs for the Colorado and Gunnison <br />Rivers was made. It Chn be assumed that flood peaks on the <br />Colorado and Gunnison Rivers occur at the same time since the <br />hydrographs are nearly parallel. Thus. for study reaches <br />downstream of the mouth of the Gunnison River, the peak discharges <br />on the Colorado River are added to the flood peak.s computed for the <br />Gunnison River. <br /> <br />For Indian Wash, the principal cause of flooding has resulted from <br />intense cloudburst storms. Snowmelt flooding is relatively <br />insignificant due to the low altitude. As no stream gage data are <br />available for Indian Wash and few are available for the general <br />area, and, also, due to the presence of the flood-retention <br />structure, a rainfall-runoff analysis was conducted on the <br /> <br />15 <br />