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IntroductIon The Initial Flood Plain InformatIon report, Volume II, for Sand, Toll Gllte, and Lower Cherry Creeks WIIS putJllshed in April 1964. The torrential rains and dlsasterous floods in the Denver area In June 1965, the greatest flood to date there, made necessary the revisIon of the prior study to Include the 1965 data and Its effect cn probable rainfall occurrence, ..unoff amounts, "nd "re<lS flooded. This report desc..ibes the ..esults of the revised study, The basin and stream cha..acteristlcs, flood hIstories, <lnd the p..obable effects of major floodIng are described. Two potential floods, the Intermediate Regional and Standard Project Floods, a..e usedtodatinethefloodh<lzan1s. These two floods are defined in the Glossary, page 18, and should be given appropriate consideration In developing controls and future planning. Thea..eas flooded by these two floods ara shown on plates at the end of this report. Profiles show the probable depths of floodwater relative to the chan- nel tJedandbanksandalsoshowfloodelevatlonsacrosstheflood plain. The Qm<Iha Dlst..lct, Corps of Engineers, will p..ovide upon request technical assistance to Federal, State and loclll agencies In the InterpretatIon and use of the InformatIon cont"ined In thIs raport. tfOWeve.., zoning or otc.",r r..guldtion 01 the flood plaIn Is a loea: responsIbility. Ap.3mphlat, "Guidelines for Reducing Flood Oamages," and a booket "Introduction to Flood Proofing," C<ln be supplied. The InformatIon given in this report does not imply any Federal Inte..est of authority to zone or regulate use of the flood plains in +tw study re<lches. The InfOl'matlonpresentedhere is b<lsed on field conditions th<lt are constantly ch~nging and Is ~ reason~tJle r<lthe~ than precise delineation of tho flood h~zards. The use to which flood plain info.."",tion will be put is the responslbi I ity of loe~1 autho..lties. Basin Characteristics Cherry Creek flows northweSTerly for 65 miles <lnd d..alns 409 square miles. Theb<lsln is <lbout 54 miles long and averages IOmiles wide. The study redch is 11.7 miles froo the Cherry Creek D~m to the creek mouth. Cherry Creek O<lm and Reservol.. controls the runoff f..oo 385 square miles; of the..emaining uncontrolled 24 squ<lromiles ,7.8 squaromilesiscontributedby<lmajortrlbutary,GoldsmlthGulcn-Y. SandCre"k<lnd its tributary Toll Gate C..eek drain anare<l of 191 squa~e miles with 42 sqU<lre mi les bei ng In the Toll Gate C..eek drain<lge <lrea. The S<lnd C..eek b<lsln <ldjolns Cherry Creek to the northe<lstand is32mileslongandave..ages6mlles in width. S<lnd Creek is 38 miles long; ttwstudyextendsfromthemouth 13.1 miles upstream. Toll Gate Creek Is 15 miles long but only the downst..eilm 6.8milas Is In the study reach. TheSandC..eekv<llleyupstre<lmf..om Tol I Gilte C~eek ranges f..om 1/2 to I mIle In width. The Tol.l Gate Creel<.v<llley..angesfrom 1/4 to 1/3 mile In width. A basin map of Cher..y C..eek, Sand C..eek <lnd Toll G<lte Creek I s shown on I' I~te I. Flood Ch<l~acteristlcs A zone of frequent cloudbursts extends ovor highlands <It 6,000 to 7,000 feet elcv<ltion for <lbOut 75 mi les eastw<lr<.l from the Rocky Mountains. This zone covers the major portions of the Cherry. Sand an~ Tol: Cdte Creek basins. Such cloudburst sto..ms are the cause 01 floods that occur during the poriod M<ly through August. The Cherry Creek channel Is alluvial, flat-bottomed, and fol lows a meandering course. Channel slopes downst..eam f..om the Che....y Creek Dam arc about 25 feot per mllo. From the dam to Goldsmith GulCh the channell1asrMl<llned Intnenaturalcondltlonexceptforchannel Imp..ovements downstream from Cherry Creek D~m to Havana Street ~nd a fow lac<ll levocs. In Its natural statcthochannel..angesf..om50to 150 feet wide and from 2 to 10 feet deep. Ch<lonel capacity from the I/GOldsmlthGulchls Includod (n "Flood Plain Infor",<ltion, Volu",,, VI, Denver' Metropolitdn Rogion," published in October 1971. ,