FLOOD09478 - Laserfiche WebLink

Home Browse Search

Introduction This Spacl~l Flood H~z~~d Information Report for the South PI~tte River In Weld County, Colo~ado was prepared by the Omah~ District, Corps of Engineers, under continuing autho~lty provided bySeetlon Z060f the 1960 Flood Control Ad (Public Law B6-645J, as ~ded. The report was ra~uested by the Colo~ado Water COnser- vation Boa~d end Is the first of three volumes presenting Info~- tlon ralatlve to the South Platte Rjve~ and Its flood plain In Weld, Morgan, Washington, Logen, and Sedgwick Counties, Colo~ado. The pu~ose of this report Is to present Information desc~lblng the South Platte Rlve~ and Its flood plain In Weld County relatIve to past flooding as well as to potential future flooding. This ~eport basically shows the ~eletlonshlp of the 1973 flood on the South PllItte RIver In Weld County to the IOO-yell~ flood. Info~tlon on the 10-, 50-, end 500-yee~ floods Is also presented. The lnfor~- tlonprovldoWvarlesfrornstage-dlschllrgeralatlonshlpsate&Ch cro~ section In the ru~al areas to water surface profiles In the urban arelIS. Throughout the study ~each. flood widths h~e been Indicated at each cross section location. The Info~tlon In this ~eport Is Intended for use pr!ma~lly by planners conce~ned with the erell. This ~eport does not Imply lIny Federlll Interest or llutho~!ty to zone or ragulllte the use of t~e South Platte River flood plain in Weld County; this Is II loelll responsIbility. The ~eport provides a suitable basis for the lldop- tlon of Illnd use controls to guide flood plain development with con- sideration for environmental attributes, thereby preventIng Inten- sification of loss problems. Since It Identifies flood p~oblems, the report will stImulate the development of other flood d~ge ~eductlon technl~ues such as flood control, ramoval of obstructions, IInd flood proofing, which mlgnt be used In lIn overll" Flood Pla;n I4enllgement (FPMl program. Distribution of the report to offlclllls, lIgencles, and Indi- viduals conce~ned with planning In the lIrea covered Is ~de by Weld County. The Corps of Engineers wi II provide Interpratlltlon and , technical ass1stllnce, If requested, In lIppl1clltlon of tne report date. Other guldellMs lIvallable from the Corps of Englnee~s lI~e II pamphlet, "Guldellnes fo~ Reducing Flood DII~ges", and a booklat, "Introduction to Flood Proofing". 6asln and St~ellm Chllrllcterlstlcs The South Platte River In Weld County flows in II general norTh- e~ly dl~ectlon from the Adllms-Weld County line to lIbout Milliken, Colorado where It tu~ns and f lows In a no~theasterly dIrectIon. It continues In this direction to llbout Kersey, Colorado where It be- gins to flow In II general southellsterly dl~ectlon to the Weld-Mo~lIn County line. Th~ughout this ~eaeh the South PllItte River flows In erelatlvelywelldeflnedchannel. Thlschllnnellstyp1cally bralded end Is situated In a broad shallOW valley ~anglng In widTh fromllbout 3,000 feet to lIbout 9,000 foot lInd Is flanked by roltlng plains. The streambed slope of the South Platte River In Weld County Is ~ellltlvely unlfo~m. slowly transltlonlng from about 9 feet per mila In the upstrellm rellches to lIbout 6 feet pe~ mIle downstream. TlIble 1 gives additional streambed slope Information. hble , South Platte River St~eCfllbed SI,,?e Weld County, Colorado Location .........Jlope (feet per mllel 8.5 9.0 7.5 '.0 '.0 Adams-Weld County Line tQ Fort Lupton PI.,tteville LIISalle Kersey Sublette The drlllnage IIrell of the South Platte River In Weld County varies considerably from the Adams-Weld County line to the Weld-Morgan County line due ..alnly to the numbe~ of rellltlvely IlIrge t~lbutllrles 2