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<br />GLOSSARY
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<br />flood Plain. The relativelY flat .......e. Or lo"lMd~ adj01n1ng the ch""lllel
<br />Or a river, .troMl Or ""'tOercour.e or ocean, l"ke, orotherbo~of
<br />ste.ndillg""ter.vh1chh"s been or llIay be covered by floodllater.
<br />
<br />Oesip;nated:FloodPle.1n. Tho ..ro..de9ign..tedas .. tloodPl9.inby otfic1als
<br />of HolYoke. Colorado, vith tho prlor concurrence of the Color..do Water
<br />Con"erv..tionBo..rd.
<br />
<br />rloodProrile. Agr..ph sholllngthe rel..t10nshipof""ter surface elevation
<br />toloe"t10n;'tOhol"ttergollorallYexpre9sedasdlstM.eeabovelllOuth
<br />for.. at.....Ml of "..tel' tlollingin811o:pon channel. It1agellerall.y
<br />dravntollholl"urt8.Coel"vationforthocr".tof...pec1f1ctloodor
<br />tloodfrequencY,butma,ybeprepe.redforcOlldition...tagiventi"",
<br />orst..g".
<br />
<br />Basin. An "nclosed or partlY enclosodllater are" Or depress1onon the
<br />aurface otthe earth.
<br />
<br />Fitty_Y"a..Flood. AtlOOdhavingan..ver..go:treqU<>ncyofocour.....neeonth"
<br />order ef enee in 50 yeara ..lthe"8h the flood IUY occur 1n MY yo..r or
<br />even ill 8uecollaive yo8.:t'a. It 10 b....ed oil ats.tlllt1cs.l s.ns.ly..ea of rain-
<br />faUs.ndrunoffchar"cteristic.inthegeneralregionofthellatershed.
<br />
<br />llood Protection Level.
<br />flcodelevationfcr
<br />
<br />Ale""l which ia e..tablhhed..bo"" the
<br />regulatingUlles1nhighhazard"reas.
<br />
<br />100_year
<br />
<br />FloodSt"ge. The stage Or elov"Uon at which overfloll of the ne.tura1
<br />blUlks of a stree.m or body of water begina In the res.ch er"rea in
<br />IIhlch the elevation 18 mes.aur<!d.
<br />
<br />Five_Hundred.-Yes.rFlood. Afloodh..vinga.naveragefrequoncyofoccurrence
<br />on the order of once in 500 ye..n a.lthough the f'loed may OCcUr in ar,;y
<br />rear Or even in ..ucce..aiyo yes.rs. It i. baaed on ats.tistlcal ans.lysea
<br />ofst....s..mflovrecorde ava.11s.ble tor the "atersheds.nd o.ns.lyaesof
<br />rll1nfalls.ndrunoffchs.racter1atica in the genersl region of the
<br />vderahed.
<br />
<br />t'lo,," Line. The minimum stage Or elevation s.t Which tlow occurs in stream.
<br />
<br />Flood. An oV<!rflO'W" on lands not nor:ns.llY covered by ""ter. Flooil,..h"ve
<br />-tvoessentis.lchs.racterhtlc.;theinundationotland1stempors.ry
<br />and,'tOhe ls.nd io s.djacent to and inundlltedbY overflw from..r1ver
<br />oratreamerMoces.n,ls.ke, er other body of stand1ng'll'll.ter.
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<br />Hes.dLess. Theertectofobstructlons,suohs.anarrollbridgeopellingsor
<br />buildings that licit the s.rea through vhich vs.ter mu..t flow, rahing
<br />the sur!"ce of the water upatree.m from the obstruc't010ns.
<br />
<br />LeftBs.nk. The bank on the left sldeofs.1'1ver, stream.orws.tercour.e,
<br />lookingdown.tres.m.
<br />
<br />Normally S. flood 1s conslder<ld..a any temporary riae in.tree.mflow
<br />oretage,butnotthepoundingof..urf"cewater.thatreaultllin..lg-
<br />n1t1cs.nt s.dverse effecta in the vic1,lity. Adverse effecta may include
<br />dtllnagea from overflo'l< Of ls.nd areas, temporary bs.ck_ter effect" in
<br />sewera o.ndlocs.l <l.r..lw.ge channels, cres.tlon of unsanit..ry condition "
<br />Or other unfavorable situations by depoii1tiono!ms.terhJ.sin stree.m
<br />cb.annel. durlngfloodrecess1ons, useofgroundvatorceinc1dent
<br />vithlncre..sed..t""....flo".s.ndotherprob1elll...
<br />
<br />Lew Hs.zs.rd ZOM. Ths.te.res.ofthedesign..tedfloodplain1nwhlchthe
<br />;rs.ter.. of an Intermed1s.te Regione.1 Flood (lOO-ye,ar flood) "Ulnot
<br />s.tts.1n..,,,.Il.:dmUlll depth greater than One IIndone-half feet.
<br />
<br />Lo"Steel. See "Undercle..rance."
<br />
<br />FloodCre..t.
<br />tloodat
<br />
<br />Thems.ximwnsts.georelevat1onres.chedbythevatersofa
<br />.. given loc"tion.
<br />
<br />Obstl"Uc'tOlen. Any dam. v811, ahart", emban"",<mt, 1e""e, dike. pile, sbut.."ont,
<br />projection, excavation, chanllel roctifica'tOion, bridge, conduit, culvert,
<br />bullding, w1re, fence, rock, grs.vel, rcfUlle, fill, structure or llllItter
<br />in, along, s.cross, or projectl....g lnto any ch,umel. watercourse. or
<br />regulatory floodhazard..res.which"'.... i<npede, retard. or change the
<br />dlreationofthe tlowofwater, elther in 1tself,orbycatehingor
<br />collectlngdebrh carrledby such "...ter, erth..t iB p1"cedvhere the
<br />flow efwater might c..rrythe S8lne dO'fflstre.....tothed"""'geofl1fe
<br />orpI"ope:rty. A."l o.:rtif1eis.lobstruct10n shall",e"" a.nyobstructior:.
<br />whlchhnots.n...turalob.truct1on. An..turalob.tructlonsh..ll
<br />means.r.:yrock,tree,gra.,el,orother=tterth..ths.sbeenleeated
<br />bya"en_h\llllMCllu.e.
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<br />Floodl'reQ.uency. The avers.ge frequency. at..thtl"allY determined. for
<br />\/hiche.spec1flcfloodtlOllms.gnitudemaybeequs.l1edoroxeeeded.
<br />(Frequency expree"ed as s.noccurrencewithin "spec1t1ednumberof
<br />reAr"h the o'luivs.lent of recurrence intorvalwb1ch ls the ..ver..ge
<br />time 1nterval bet~en actual occurrellceS cf ... flood event of s. given
<br />orgrederlllllg<l1tudeoftlO'o".)
<br />
<br />Flood Peak. The ,oe,:dll1Ulllinstantolneous d1..eh..rge ofat1oodat a given
<br />l<x>a'tOion. Itusuallyoccuroe.terne...rthetimeotthetlooderest.
<br />
<br />One_Hundred_Yearf'lood. AfloodhavingWle""r..gefrequencrofooeurrence
<br />or-theord.erofonceinl00ye..r6..ltho~thefloodmayoccurin.in:r
<br />y"..ror""en in successiveyeers. It is b&sod on ste.thtical=,,1y'08
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