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r lX-5 [ [ GEOMOOPHOLOGY The South Pl atte River reg ime, cha~nel and floodpl ain character! sties were controlled by alternative periods of drought and ~t cycles. Its width, depth, bends, bank height and slope were constantly readjusting to Mtural phenonHma. Sand Creek to East 104th Avenue From Sand Creek to East to4thAvenue, the river 6.8 miles. The sinuosity of the ch,lnnel is 1.18. low levees on one or both banks of the river over channel falls 54 feet in lnthisreach,thereare most of the distance. I I I I , Through Denver, the river was fixed between permanent b,mks and ch,mnel_ i~ed. The U. S. Army Corps of Engineers Channel i lation project will fix the bed and banks of the r;ver from Colunbine Valleyto Oxford Street. East l04th Avenue to BaselilleRoad Thedolo\1stream reach of the South Platte River is rural inform. It falls 92 feet in a river distance of 11.4 miles. The sinuosity is 1.26. The Adc\llls County portion of the South Platte River will be fixedbetoleen protected bdnks with the bottom e1 evat i on of the stream contro 11 ed ~ i a drops. The South Pl atte River is acti~ely eroding its bed dI1d b,mks where~er it is free to do so with the absence of controlled drops and adequatebankr1p- rap. For purposes of morphological description of the South Platte River, the study area has beendivfded into five reaches. I Chatfield Reservoir to Columbine Valley This reach is ch<lr<lcterized by the Littleton Floodpl<lin Pdrk dnd gravel pits. It is 3.7 <niles long with a slope of lO.87feet/mile fora total drop of 40 feet. Columbine Valley to West Hampden Avenue In this 5.6 mile reach which drops 17feet, the South Platte ls a suburban river. The sinuosity is 1.25. West Hampden Avenue to Sand Creek ThiS is the urban reach of the South Platte River. Over its length of 13.8 ml1es, the river falls 159 feet. The river has been straightened so that it~ sinuosity is only 1.09. Th~re are numerous rlrops in th~ riverbed level through the urban reach. NEEDEOCORfl.ECTlVEI.lJRK. Erosion of the riverside berm in this old Little- ton area gravel pit allows the river to flo~' into the 1 ake, and out of the lakedo\>Tlstredll. The bermmllst be reconstructed so that river borne sedi- mf'nts ilre not 10~ t to the river 1 n order to contro 1 the head cut ti ng '.h ich is occurring.