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<br />The highest recorded floods for Morrison occurred on July 24, 1896; July 7, 1933; and <br />September 2 and 3, 1938. The peak flows estimated for the 1896 and 1933 floods above <br />Mount Vernon Creek are 8,600 cfs and 8,110 efs, respectively. The 1938 flood was caused <br />by a cloudburst that centered on the divide between Mount Vernon and Bear Creeks near the <br />top of Genesee Mountain. The highest peak for Bear Creek at Morrison, above Mount <br />Vernon Creek, was only 6,200 cfs; however, the peak for Mount Vernon Creek at Morrison <br />was 9,230 cfs (Reference 28). Other floods of lesser magnitude occurred on Bear Creek in <br />1934,1957,1965, and 1969 (Reference 36). <br /> <br />In the City of Westminster, the streams that flow into Standley Lake and Great Western <br />Reservoir, along with Big Dry and Little Dry Creeks, are generally well defined with <br />relatively narrow channels. The tributaries to Big Dry and Little Dry Creeks are not very <br />well defined and at times, are generally shallow with low banks. Industrial and residential <br />developments exist along portions of the streams, especially below the reservoirs. <br /> <br />Generally, the streams are intermittent, having little or no flow most of the time. Flooding in <br />the Westminster area is caused by heavy local rainstorms. Flooding occurred in May 1973, <br />especially in the vicinity of Big Dry Creek at Huron Street. <br /> <br />2.4 Flood Protection Measures <br /> <br />There are numerous dams, reservoirs, and channel improvements within Jefferson County. <br />Many of these flood protection measures affect flood peaks on the streams included in this <br />study. In addition to an active floodplain management program, the major flood protection <br />measures are listed below: <br /> <br />Bear Creek - Evergreen Lake, located just upstream of Evergreen, is primarily used for water <br />supply and recreation and provides little routing effect to the flood peak. Mt. Carbon Dam <br />and the Bear Creek Lake were designed by the USACE for the purpose of flood control. Peak <br />flows from the 1 DO-year event have been reduced from 30,000 cfs to approximately 1,000 cfs <br />through storage in the reservoir. However, because of its location, there is little protection <br />provided for other areas in Jefferson County. <br /> <br />Bear Creek Tributaries No.1 and No.3 - Storm sewers have been constructed at various <br />places along these streams. During a flood event, these storm sewers will overtop, and <br />damage caused by the resultant flooding may be greater than before the storm sewers were <br />installed. <br /> <br />Bergen Creek - Channel improvements have been constructed immediately downstream from <br />State Highway 74. These improvements provide significant protection to the adjacent <br />buildings, but are overtopped during extreme flood events. <br /> <br />Buffalo Creek - Wellington Lake is located near the headwaters of Buffalo Creek. This lake <br />is used for water supply and recreation and provides negligible flood protection. <br /> <br />Clear Creek - There are few flood protection measures for Clear Creek that cover areas in <br />Jefferson County. Some channelization work has been done in and near Golden, but this has <br />little effect during a flood peak. Additional channel improvements have been constructed <br />between Marshall Street and Wadsworth Boulevard. <br /> <br />21 <br />