|
<br />"",I,',Joly, Snowfall inCr"lyionOlextrem~h'
<br />h,.",,,';' \\'ith Jlnn",,1 t"ulI,'r"nyi"y fr,,,,,:l:il',,
<br />77 i"dw,_ I;,'r.cl'al n,;" may ,..,-,{.u,. o\'t',' tilt'
<br />Y1l11ltm Hil"'" U".in and {'on\'t'~liw' t,l')>('
<br />do,,,lIllLr,t ,Lorm, f""quent!,' o~cur Ln
<br /><Umm",.
<br />VCIl"tati"" in the Yam)>a Hi",., Ba,in
<br />.'arle, a{'curdins::- to Cit'""llon. ~Iu"h of lh"
<br />\'ail",\' a""" i, tl<<v"l~d w l"..xlu~:ion of ha\',
<br />
<br />NATURE OF FLOOD PROBLEMS
<br />
<br />As noted e"r1lel'. mo<t of the <<"nual
<br />pn'cLpltatlon in thc Yampa Rlwr B".in
<br />occurs as snow and a deepsnuwpack accumu-
<br />lat~s In hiyh ,'I~vatlon area,. Gelleral rain.
<br />.torm, coverinjl," larjl;e area> for extendcd
<br />l}{'ri()(l,canoeeurovertrlb\ltllrydralnagl'
<br />arca., from law.prin>>; throul<hcarly fall. and
<br />eon"t'etivl' Iyp... cloudburst storms can be
<br />,'xpe<'t~r1 frc'lu<'ntlydurlnj(' tbe ,Ummel'.
<br />Major floo<1in>>; in th... Cra;j('area has heen
<br />thc' r~,ult of rapidly meltinj(' .Ilt"", ^omdimes
<br />aUf:ment...dbYl<eneralraln.uuringth"'p<-'rlod
<br />fr"m lI-I>\rehthmul(hJune.orp,,'eipltat~d by
<br />ice jam, in late ",Inter Or ea.-ly spring,
<br />Snowmelt fl(xxlln~i'~haraeleri'.e<l bynmder-
<br />at<' !>f'uk fluws.l'l";;e vulumc. of runolf. Ion;;
<br />duratior..lInd marlwd diunwl nUNuatl"n of
<br />11011'. .\lajor flo.,din.o; from yenfr~] rain alon~
<br />;< llO1 knOJW" to h"v" ()tt'urn'd in th" Craly
<br />aF('a, but th('r~ io nu rt'a,OJ\ lo ~ondud~ that
<br />"",.,1' 11Ir~ flnod,r,-""Itinl( fromv.~n"'r"lraln
<br />nfl' nut Ix)>;"jble in th.' Y"ml'x lIi"er flusln.
<br />I-'h><lin~ frn", V'-'nrr~1 rain Is characl...rlzed
<br />by hiv.h I)('uk flow"'lnil rnoden\t_<!du"atiOllof
<br />n",,>Jnnw,. Fhl<lln>>; f,""In conv('('tivc Lype
<br />cioudbtJr't sturm, i~ ~h"l'acteriZc'd 1,)-' hiKIo
<br />peak flows,won clu,."tioll orflow,:\nt!,;mall
<br />
<br />FLOOD HISTORY
<br />
<br />IIj~tol'it'al ref~n'ncl'~ to floml, 0:: Fortifira.
<br />ti,,,,Cr,,~knkJ\dl,,,('ktnI879.lnll,,tt""ar ~
<br />maj"r fhxl in"ndalf,1 tiw ..."til'l' an,~'wlw~c
<br />Cro<ig L, rL,,\,'local~,i. A 'Hin",' flo.-.d oceUlT,'d
<br />in I~% anri the fir&t m'~or flood "In"~ th~
<br />town was e<tabJi,lwd ot'~ll,,'('<1 In April 18!17,
<br />..l,v.ri...nltlll'"l al"<'''~ no\\' parI "f till' eity. alld
<br />.",id~ntIRI pr'\l~'rli," ""~l nf F~~t!r:c":;o,,
<br />Ct<.(.k W'T~ ,,'vN<,'I.\' dam"s::-~d I-'lnodflQ\\"8 "ul
<br />
<br />and In,> ,,:Ui;'(' ""f:"tatinn ha< h",.'~ d,'a,tically
<br />",~,lifif,tI. In \'all".,' a""lI' h~lo'-" ~111j1l fO','! not
<br />,,,,,1 f<"'''Itr'i,'ultu''C',Yt'>:NatlorL L"da"jf,,-'da<
<br />~"nh..r''' Dc"""rt ShrLlh: that i~, >;Wc'hru'h,
<br />,'ahbitbr"sb. ~nd \vlnl"rr"l with an \'ndC'r"
<br />'lot',. of '-"rious h~rdy ;>:ra',;;'';. :';tlbalpi,,~
<br />h,,'e,t (a'ppn, bJ,.:<"jXlle pill", [Jou>>;:as a"d
<br />"th~, liN, and Enl(I,':l\"''' sprllC€) extt'nds
<br />[,,'m al.,ut Hi~!~ fet'l lo timh"dine,
<br />
<br />th~,..., th~ 1!IH ljln, 1!J~{I, and Hl!i7 fl,~\ds
<br />"'('r,' ,'a,,,,''; h)" r~pl,ll,' mellln~ ,now Yamp"
<br />Kin'r ,nownwit flo", i~ 1!17,1 Werl' ~u>>;'
<br />ment~d by rainfall. primarily on st",wl~,;,
<br />an',~,b<.'lwel'n SteamlmalSprin>:,; and Cr"if(,
<br />'l'h... 1921 cv~nt wa, pan of wide'prp"d rapid
<br />,no\"'l",lt ,lnd y~neral rain,; in many h'aliti~,
<br />or C"lo,';vlo that ,',,",-r, f'lo,,<I Nmtlition. on
<br />I'ortifit'all(m Crt~'k at thai tin'" also re,ultrd
<br />from "nowm~lt >tHgm...ntf'<ll>y rain and "'~rr
<br />int",.,lfi",lby ieejams near the mouth ofthp
<br />cr<,,'k. The Iarl(eSl floodfl"w of record on
<br />Fot.tlfl~"ti"nCreek.Rlleubicft.etp""""'C{)ml.
<br />"l'tu'r~d in ~'1art'b 1947. SIll,lle,; Indlt'atc.
<br />ho,,"l'''''l'.thattheat'tualflO\\"lllayhav...be...n
<br />con,id...rably ,,-",,'atel' duc W o"eo-I",nk flow,
<br />that WNe lint m~a,LJr<'';, '" to jet' rondition,
<br />thatca\\;cd inaccur~l~ ~a)(.' r~ading" AI,o, on
<br />tlw ha,i, of a hijl,"h water mark WClO(] dat"
<br />unknown). the Colorado nepal'tm('ntoflliKh-
<br />"':'.I'~eoml'utr'd a peak flow of I,S(~'c\tblt'fl'<'t
<br />jwr ,;;'~oml on Fortification Cr""k, In March
<br />1\'71, a "lOwmdt fl<x><] un Cedar Mountain
<br />
<br />volumt' of runoff Beeaus~ <'iuudbur.t .tnn".
<br />art' "m;.1l in "real extent and short in
<br />dLli'ation, thl',\'dollotf'On.tituteafhl<1 thr~at
<br />On ,t,,'am, as la"K~ a, lhp Yampa Ri.'er,
<br />
<br />It'c jam< "oll;;titut~ a "if(nificant debrl~
<br />j".obl~m. particularl,' alony Fortification
<br />Crt'~k whl'r~. hi$toriclllly. Ice jam, at th~
<br />hilthwa,- and milt'va,] hrldK'~. have eau""d
<br />subn~ntial flood damage. llo"'ev~r, ehan"...1
<br />jmprO"t''''~nt work, IarK"ly aecompli,h~d on
<br />an{'m~"I,:<,ne,.ba,;isill H).19,alldimprovenw"t
<br />"f Ihe hrid~", aPI~'ar to have redUC<,'d th~
<br /><X'nn'Fl'nc"nfiCl'jam,llttht'""lorations.kcin
<br />tnt' Yamp" Hi",'r and th~ an:ll"'anch ehalln~1
<br />thaI carri,,, F"rtili"atlon C,,'C'k flow to the
<br />main M,'rn pan also ("-...atl'flow comlltio",; in
<br />Crail<. A sped,,1 "Iynlfieanc~ of ice jam,; i,
<br />th,,! :he location, of their ()CeUrl'~I,"~ and th"il'
<br />impa~lS "r<' I",;",,,rmlnaw. ,,"nr. only i" il
<br />Imr~,"ihle to predit't ",her,. an i...... jHm will
<br />,,[.t'llr, lh!' art'fC that t",uiri b., "If.."t~d I,,'
<br />Q\'l'rfjo\\' amI th~ "''''1"ll"nt dCJllh of fl,".I",~
<br />:Lf<' also du,i,"'. ~'Io\\' that \\'''llld "tht'F\\'I", b,'
<br />non-ri""'a>>;iny!'ould, if",,,,,,iatc'dwlthatl it'l'
<br />JaIlL. fJovd al',.,,, ordinarii." comider~d flood
<br />frt'!',
<br />
<br />
<br />m''''ehannel,thr<llLr.hl'i...hall"l'lcullUnllland<
<br />in and around lh"town,lrrill"alio" diteh~, and
<br />h""d I,:a(", Wt',e w:l"lwd uut. S"",." major
<br />fl..xl ,'".'nb{\\I(I,1. 11. 14, If., 17,21. :\nd171
<br />a'HI(iwl",",hmaKi"v;fj"..I,'\','nl.;{I!102,Oo,
<br />2~, 2'l. ",HI 2M h",'" '~'''"rrc'd nn Fortificatiot!
<br />C".'Pk"rlCl'lh..tllrn"rth,-'t'entul'.I'. Six flood
<br />e"~r,:o il~q l. 17, ~O, :!1, ,.7, ,.",! ~,II ,,,,.,.,,, n.,1
<br />o~, tilt. y"",pa Hi""r ,luri,,1.( thaI IX'I'i,"1 Of
<br />
<br />fi~u,,' 2
<br />
<br />(;,,1011 innnrlatprl rlpvpl~l'inv :""'a< near the
<br />lhfh\\'a, lfl ..,,1\-..,.( 'T",;ln)(, F1("'llwatl'r
<br />1,,,,,1.,'; l" ~ ,;~ptb uf nw,.~ lil:L" I; f,'ct "" the
<br />up"tn'arn <i,\c'"ftlw t'ul\'t'rt, b\Lldid n"tfl"",
<br />m'~r the 10;.> "I th., ro"d, On th.. b",I. of th~
<br />Iimit,~J inl"l'mfltlon a.-"il"bl", It i"",;tirnated
<br />that a p,'ak flo\\' l".twfcn '2(H1 and :>00 ~ublc
<br />f....t !>('r ~~e"nd ()('r"I""~1. ;";0 Inlnrmatioll ot!
<br />fI",~1 ,'.'"nt, 0" Broth"rt"" and l'lne l-1iclj(r
<br />I;"kh~, i, ~,'~iIaIM
<br />
<br />~'iO<J{1il\>>; from ,,,mnwr I'loudlmr,;t type
<br /><torm,ba,;o<'{'urrl'd;nandaroundCn\I~,ll\lt
<br />litll...ddilliti\'ed"taonthi,tYPt'offlood",vl'nt
<br />ar~ av"ilabh A ~mall thunder>wrm {.45
<br />Inl'hc',ofrninin2',hour"J"nJuIY20,197.j
<br />rc',ull<:'! In a me'~'lll'c'd flow of 102ct,bl~ f<:el
<br />per ",,<,o1\d on Cedar ~-!ountain Gul~h. )'Iore
<br />than '2 inehe, of rain in I hour, hm"~v<'", ha'
<br />hc,<,n t"t'COrtlcd in Lhe Cralj('an'a,
<br />Th<' 101l0\\'ln,,-" photoj(rnph" and m'w'paper
<br />'ll'ticl~< {~im\llatw from tbe nrl!rinalsl illu~"
<br />trau' pao!t fhxl cvent, In an,1 "r()undCr~Ij('.
<br />
<br />
<br />Fi.",.'1
<br />
<br />,'o,,,r,,;<\,,,,, t:"." n..,t~."\<" in C"i., ,....",,"',. t"'I.1. l!"",.~'h' n"''''.,c,i<i,'o'"",,d ,,, n", thoi, """"",,"lho
<br />>,...:,~:,. ur \1" ,,:.:.,,_ ,'",. h;..:'"" L.r~i", .,,c, ",._1.,-,] "~\ ,,:..1 ~ :",,~::, .""":",d,".1 n..,:l ,'.',ll"u: :"''''.,i,mo:i"d,
<br />"''''I~ "I F"~i""'" Ill,' r~"'''~'''I,I\;_ ,",'1",1 ''''''<, 'J"k",~'" 1
<br />
<br />4
<br />
<br />,
<br />
|