Laserfiche WebLink
<br />3-03. The mountainous areas above Canon City are not conducive <br />to high peak floodflows. Although the drainage area at Canon City com- <br />prises 3,117 square miles, the largest recorded peak flow during 77 years <br />of record is 19,000 c.f.s. The high plains area below Canon City and the <br />steep tributaries characteristically produce peak flows of substantially <br />greater magnitude. Generally, during major floods there is attenuation <br />of flood waves in the reach between La Junta and Las Animas. This attenua- <br />tion is due primarily to the valley storage in the flood plain and reser- <br />voir storage on the intervening tributary streams of Horse and Adobe. Creeks. <br />The peak flow at Pueblo for 72 years of record is 103,000 c.f.s. The peak <br />flow at La Junta for 56 years of record is 200,000 c.f.s. The peak flow <br />at Las Animas for 27 years of record is 44,000 c.f.s. The authorized <br />Pueblo Dam would affect these peaks. Listed below are peak flows at <br />Pueblo, La Junta, and Las Animas for the June 1921, May 1955, and June <br />1965 floods on the Arkansas River with and without Pueblo Reservoir in <br />operation. <br /> <br /> Pueb 1 0 La Junta Las Animas <br /> With With With <br /> Existing Pueblo Existing Pueblo Existing Pueblo <br />Flood Conditions Reservoir Conditions Reservoir Conditions Reservoir <br />Date (c.f.s.) (c.f.s.) (c.f.s.) (c.f.s.) (c.f.s.) (c.f.s.) <br />Jun '1911' 150,000 20,000 2152,700 121,000 3140,000 108,000 <br />May 1955 11,100 4,800 50,000 49,600 44,000 38,000 <br />Jun 1965 9,260 500 31,700 27,200 22,100 19,300 <br /> <br />1103,000 c.f.s. without Barrier Dam. <br />2200,000 c.f.s. without Barrier Dam. <br />3187,000 c.f.s. without Barrier Dam. <br /> <br />j ~r <br />A <br />" <br /> <br />3-04. Channel capacity.- The <br />River at Las Animas is 6,500 c.f.s. <br />discharge of about 10,000 c.f.s. <br /> <br />present channel capacity of the Arkansas <br />Flooding of the urban area begins at a <br /> <br />3-05. Stpeamfl~ pecopds.- A stream gaging station is located on the <br />left bank of the Arkansas River at Las Animas. It is 0.4 mile downstream <br />from the U.S. Highway 50 bridge. Records of discharge at this station are <br />available for the period May 1939 through September 1965. The average <br />annual flow volume at the station for 26 complete years of record has been <br />167,850 acre-feet. About 77 percent of this annual flow has occurred in the <br />5-month period, April through August. The maximum annual flow volume was <br />1,022,000 acre-feet and occurred in Water Year 1942. The minimum annual <br />flow volume was 20,340 acre-feet and occurred in Water Year 1959. The <br />maximum monthly flow volume was 298,600 acre-feet and occurred in May 1942. <br />The minimum monthly flow volume was 260 acre-feet and occurred in October <br />1956. Records of monthly and annual flow vollDDes for the Arkansas River at <br />Canon City, Pueblo, Nepesta, La Junta, and Las Animas for the entire period <br /> <br /> <br />11 <br /> <br />