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<br />HJVESTlGATH1'{S A."r> ANAlYSIS
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<br />lOO-Year Flood Event
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<br />Interpretation and Use uf Report
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<br />The iOQ-Year flood eVen~ may also be used fur on"ine"ri<<< desl!l"
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<br />,.
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<br />Fr..~u"ncy and Dhcharlle
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<br />purposes where a luwer risk of failure than the 10- or 50-year flood ia
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<br />'"c ,,, S^ ,M 'S....n_v"ar ,'".,d events are used as the floud
<br />,,,e "'''-, ,,..., ''''-. an vu,~ ...
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<br />desired. Howeve.r,the",osti"'portantuaeofth"IOo-yearfl<l,xleventlles
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<br />frequencies for thts flood plain analysis. Thus the data develuped in this
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<br />in fluo~ plain "",nal':e",,,nt and land uSe olanninl': as set forth in the state
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<br />report will he compatible not only for rel'(utationpurposes, andfl .B.1041
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<br />statutes. The State of Colorado considers the loo-year frequency flood as
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<br />designation but also for pederal Inaurance Ad~inistration flood insurance
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<br />the flood evenC to be used in desil(nln~ and protectin;: structures and
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<br />r..testudies.
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<br />dwellings for humsn occupation. Therefore, all flood plsin regulations are
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<br />These v!lri",..s flood events have Sn avera",e occurrence of once in the
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<br />haseduponthe IOCl-year flood.
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<br />number of years as indicated. For example, the 100-year flood occurs, on
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<br />50Cl-Yeer Flood Event
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<br />the average, onc.. ina 100 year perlod, and has "cmepercent chance of
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<br />The 5ClO-year flood event ie u""ful tn making the p\lbl1c aware that
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<br />being equaled or e~ceeded in any ",iven year.
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<br />floods l"-rger than the 100-year flood can and do occur. Just hecause a
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<br />The particular llses for the various flood events in sdd1tion to thos e
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<br />person is liv1nl': above the 100-year flood boundary does not mean that he is
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<br />stated above are as followa:
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<br />completely ade fro", fLoodin",. The SOCl-year flood ev"nt can also he used
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<br />lO-Year and 50-Year Flood Events
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<br />for teg\llat1ng high risk developments within the flood plain such as nuclear
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<br />Information reg.rdlng tbese luwer frequency floods Is especially useful
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<br />puwer plants, or the stora.o:e "r manufacture of to~1c or explosive
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<br />for f\lture "n>(1occr1"1': st",IiC6 a"d land "s" olannl,,;: purpc>ses ~elated tc>
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<br />[IIatertals.
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<br />..inor road
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<br />svste~s minur channel improvements. the locatioo
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<br />ufp"rband
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<br />FlOQdElevat!on
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<br />~c"rc"~in,,,,1 hcil!~lcs, al':ric'"ltural hno:l~, ..,~ ~rn"rtPM", "t~"c.t"res.
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<br />The exhibits and tablcs diapl"y s~udy reault. by stream reach, as shown
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<br />For structure. and uaes of thi. type Qn the stllaller tributaries or i ",or,,,..
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<br />on the inde" map. flood crest el""ations tor the 10-, 50-, 100-, ~nd
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<br />where the hl>(h risk of structural fallure Is ecooomlcnlly feaslble, and the
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<br />.s()()-yc~r n<lods "s d('tennlned at each cross 6"ctlon ~ay hc found in the
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<br />h"-,,,,-rd of life and propcrty nonexistent, th~ ,,"e <>f the luwer freq\lency
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<br />Fluod Freq\lency-Elevation and Dlacharl':e Dat8 tahIe, Table 1. The Cross
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<br />noodsmaybeconsir\ere<l.
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<br />~ectlon Exhibits, B-1 thro\ll':h B-9, SMW a I':r~phic~l repr",s<>ntstion "f the
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<br />high wster elevations ~t typical valley ~ross seetiu"6 throll>(huut the study
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<br />re"-ch. W"t,'r ",,,faoe ele".t1(,ns at the cross sections ....,re lIwd ~lI prepare
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<br />the flood pr"f11es, ""hi~1 ts A-I thr"u!l:h A-9d, whi eh ..h."" ~hc "trea",bed
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<br />elevation in relation to Ill~h ~'atH elevatluns for ti,e !(]-\lear '\n-y~"-r,
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<br />100-ycar. and 500-year frequency flouds.
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