Laserfiche WebLink
<br />ba~ins. Flood records from ga,~"" on the..e streams provi.de the majority "f <br />data for this region. <br /> <br />i.n the region, The Running Creek flood predictions are reasonable based On <br />this comparlson ~nd the fluod history of Running Creek, <br /> <br />Flood data for the reRion IS statistically analyzed to obtain a curve <br />relating the mean annual peak flood to the drainage area ane. The desired <br />10- and 100-year frequency flooda are computed USinR a set of ratios of <br />varlOus ftood frequencies to the mean annual peak flood. <br /> <br />After revie~ of the strengths and ~eakne"ses of each procedure, the <br />design hydrology was selected utilizing the result, frum the four methods. <br />The detailed computations for the different ~thods were sub~itted to the <br />Colorado Water Conservation Board as part of the technical addendum. The <br />.elected peak flow, in f(<11",ing Creek at specified deaign points for the 10- <br />and lOa-year frequency flood are presented in Table-4 belo~. <br /> <br />2. Technical Manual No. 1 - The Cotorado Water Conservation Board, in <br />cooperation ~ith the U.S. Geological Survey and others, hss developed a l:\anU- <br />at for estimating flood characteristics of Colorado streams. The manual <br />provides a simplified method for calculating floods in the Eastern Plains <br />arc a based On drainage basin geometry. Regression equations are dorived which <br />relate basin slope and drainage area to peak flows. The equations were devel- <br />oped by relating flood characteristics at gaged sites to basin and climatic <br />parameters. The least sensitive paramoters wcre eliminated in thc final <br />regression equations. <br /> <br />rABLE4 <br />RUNNING CREEK-PEAK DISCHARGES <br /> <br />3, Soil Conscrvation Service <br /> <br />National EnKineerin~ HandbOOk - the Soil <br /> <br /> REFERE1;CE.. DRAlNACEAREA Q" Q100 <br />LOCATION LINE StATION (Square )Jiles) (cis) (cis) <br />Upstream Study Limit 7/+00 50.2 5,000 12,600 <br />Tributary Confluence 62+00 51.8 5,080 12,790 <br />Slal<:lIigh..',-,y36 ilridge 28'00 53.0 5,130 12,930 <br />OownstrearnStudy Li];lit 1"'00 54.0 5,180 lJ,050 <br /> <br />Cons~rvation Service ha. developed n ~idely accepted proc~durc for predi.cting <br />floodflo"~ "sing r,~i"fal 1 ~ata and basin pnrnm"ter~. Roinfnll is appl icd to <br />thehasinandthercsultingrunoffiscomputedba.ed"nsoilinfiltr"tlon, <br />vcget" tion "nd terrain charnctcrist it'$, Thi. "",thod produce.~ 0 complete storm <br />hydrograph for the basin. <br /> <br />" 5eeFloodedArcaPlatcs(pages28through31J. <br /> <br />I,. Soil ConservationServie(--"Poak Fl"ws inColor"d 0 "-the Soil Con- <br />'crvatioll Service has also published a method sp~cificaLly for determining <br />peak flows in Colorado. The procedure is similar to that described in Method <br />j ahav". but it simplifies the application of rainhll data and does not pro- <br />vide the complete hydroRraph, <br /> <br />1'1w n<>od predictions hot'1 o'.leh of th<'sc fo"r meth"d. ~ere also compared <br />"ith data from other floodplain information reports and with histod~al Hoods <br /> <br />-22- <br /> <br />-23- <br />