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<br />"..,I,'.Jllly, Snowfall inCr"lyi"'notextrem~h.
<br />h,.",,,';. \\"ith Jlnn",,1 t"ulI,'r"nyi"y fr,,,,,:l:it',,
<br />77 i"dw,_ I;,'r,cl'al n,;" may ,.,,-,{.u,. o\'t',' tilt'
<br />Y1l11ltm Hil"'" !.l".in and eon\'t'~liw' tn'"
<br />eI,,,,,lIllLr,t ,Lorm, f,'t'quent!,' o~cur Ln
<br /><Umm",.
<br />VCIl"tati"" in the Yam)>a Hi,.,., Ba,in
<br />'.arle, aeeurdlns::- to Clt'""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"r1ler. mo<t of the <<"nual
<br />pn'cLpllatlon in thc Yampa Rlwr B".in
<br />occurs 2S snow and a deepsnuwpack accumu-
<br />lat~s In hiyh ,'I~vatlon are2,. Gelleral rain.
<br />.torm, coverinjl," larJl:e area> for extendcd
<br />l}{'rio<l,"anoeeurovertrlb\ltllrydralnagl'
<br />arca., from law.prin>>; throu!/,'hcarly fall. and
<br />eon"t'etivl' Iypf' cloudburst storms can be
<br />t'xpe<'t~r1 frc'lu<'ntlydurlnl< tbe ,ummel'.
<br />Major floo<1in>>; in thf' Cra;l<area has heen
<br />th,' r~,ult of rapidly meltinl< ."''''., ^omdimes
<br />aUf:mentf'dby!/,'eneralraln.uuringthf'p<-'rIO<!
<br />fr"m lI-I>\rehthmul(hJune.orpl"<'eip;tat~d by
<br />ice jam, in late winter Or ea.-ly spring,
<br />Snowmelt fl'xxlln~i'~haraeleri'.e<l bynmder-
<br />at<' l"-'uk fluws.l'l,."e vulum,' of runolf. Ion"
<br />duratior..lInd marlwd diunwl f1uNuat;"n of
<br />11011'. .\lajor flo.,din.o; from yenfr~1 rain alon~
<br />;< "01 knOJW" t" h"v" ()tt'urn'd in the Cra;y
<br />aF('a, but th('r~ io nu rt'3,OJ\ lo ~ondud~ that
<br />""'.,1' 11Ir~ flnod,r,-""Itinl( fromv.~nf'r"lr2In
<br />nfl' nut Ix)>;"jble in th.' Y"ml'x lIi"er flusln.
<br />Fh><lin~ frn", V'-'nrr~1 rain;s characlf'rlzed
<br />by hiv.h I)('uk flow"'lnil [lloden\t_<!du"atiOll"f
<br />n",,>Jnnw,. Fhl<lln>>; f,""In conv<,,-,tlvc Lype
<br />cioudbtJr't sturm, i~ ~h"ra"teriz,'d I,l' hil(1o
<br />peak flows,won clu,."tioll offlow,:\ntl,;mall
<br />
<br />FLOOD HISTORY
<br />
<br />IIj~tol'it"al ref~n'n"l'~ to floOl.l, 0:: Fortifira.
<br />ti,,,,Cr,,~knkJ\dl,,,('ktnI879.lnll,,tt\"<'ar ~
<br />maj"r fhxl in"ndalf,1 tiw f'lltil'<' an'~.wlw~c
<br />C,.otig L, rLo\,'I'-'Cal~,i. A 'Hin",. fI".-.d oceUlT,'d
<br />in I~% anri the fir&t m'~or flood "In"~ th~
<br />town was e<t~bli,lwd (X'~"".('(I In April 18!17,
<br />..l,v.rif'llltul""l ~I"<'''~ no\\' parI "f Ill<' eity. 211d
<br />.",id~ntIRI pr'\l~'rli," ""~l nf F~~t!r:"":;o,,
<br />Ct<.,.k W'T~ ,,'vN,-'I.\' dam"s::-~d I-'lnodflQ\\"8 "ul
<br />
<br />and th,> ,,:ui;'(' '."f:"\atinn ha< h",.'~ d,.a,tically
<br />",~,lifif'<I. In \.all,'.,. ""'.11' h~lo'-'" ~111j1l fO',,\ not
<br />,,,,,1 f<"."Itr'i,.ultu,.t',\'e>:NottlorL L"da"jf,('da<
<br />~"nh..r''' n,,-",,,rt ShrLlh: \hat i~, ><w<'hru'h,
<br />,'ahbitbrtlsb. ~nd \vlnlcrf"t with an \'ndt'r-
<br />,tot',. of '-"rious h"rdy ;>:ra',;;'';. :-;tlbalpi,,~
<br />I-"o,.e,t (a'pO'n, blit('jXlle pill", !Jou>>;:~" a"d
<br />"th~, liN. and Enl(I'':l\f'tl 'prllC€) l'Xlt"n,;,;
<br />[,,'m al.,ut Hi~!~ fe'.t lo timhcdine,
<br />
<br />th~,f', the 1!IH ljln, 1!J~{I, and Hl!i7 fl,~~l"
<br />"'('r,' ,.a,,,,'d h)" r~pl,ll,' mellln~ ,now Yamp"
<br />Kin'r ,nown",it flo", i~ 1!17,1 Wer<' au>>;'
<br />ment~d by rainfall. primar;ly on s""wl~"
<br />"n',~,b<.'lwe<'n Steamlm"tSprin>:,; and Cr"if(,
<br />Thf' 1921 cve"twa"panofwide'prp"drapld
<br />,n()\\'rl1t'lt'\ndy~neralrain,;inmanyh'aliti~,
<br />ofC(,lo,';vlothal,'"",-r.f'lo"of'<)n<lilion.on
<br />Fortifit'al;(", C,,~'k at that tin". ~Iso re"ultrd
<br />from "t1Owm~lt ~Hgmf'ntf'<ll>y rain and "'~rr
<br />int",,<lfi,,-tlby ieejams near the mouth ofthp
<br />cr<,,'k. The Iarl(eSl floodflQW of record on
<br />Fot.tlfl~"tionCreek.RII eubicft.etp""""C<Jn<1.
<br />()l'tu'r~d in ~'1art.b 1947. SIll,lle,; l"d;t"alC.
<br />ho..,.<,\"t'l'.thattheat"tualflo\\"lllayhavf'bef'n
<br />con,idf'r'ably ,,;,,'ata duc W o,.eo-I,,'nk flow,
<br />that WNe lIOt m~~,LJr<'d, '" to iet' tondition,
<br />thatca\\;cd inaccur~l~ ~a)(<' r~ading" AI<o, on
<br />tlw ba,i, of" hijl,"h water mark WClO(] dat"
<br />unknown). the Colo,.ado nepartm('ntofllil(h-
<br />w:'.\"~ eoml'utf'<1 a prak flow of I,S(~)~\tb;t. feet
<br />jwr st'~oml on Fortification CrN'k, In March
<br />1\)71, ~ 'nownwlt fl<~,,1 un Cedar Mountain
<br />
<br />volulnt' of runoff Beeausedoudbur.t.t"nll.
<br />ar" "m;.1l in "real extent and short in
<br />dLli.ation, th<',\.d""otf'On.tituteafhl<1 thr~at
<br />On ,tr<'~m' as la"I(" ", lhp Yampa Ri,'e,.,
<br />
<br />It"c jam< "oll;;titut~ a "if(nificant debrl~
<br />j".obl~m. parti"ularl,' alony Fortifi~atlon
<br />Crt'~k \\"h<'re. hi$toriclllly. Ice j~m, at th~
<br />hilthw",- and milt."a,] hrldK'~. have eau""d
<br />subn~ntial flood damage. ll<Jwever. chan"f'1
<br />jmprO"t''''~nt work, Iarl(t'ly aecompli,hed on
<br />~n {'m~'.I'Tne,. ba,is ill H!.19, alld improvenw"t
<br />"f Ihe hrid~f'S aPI~'ar to have ,.,,<lue,'d th~
<br />(){,~"'.Fl'nct'ofic<'jam,llttht'""lorationg.kcin
<br />tht' Yamp" Hi"<'r ""tithe an;ll".anch ehalln~1
<br />that carri,,, F"rtili"stlon ('",,-'k flow to the
<br />main $1,'.0 pan ~lso("-f'"t<'floo<l co",lltioll); in
<br />Crai!/,'. A sprt'i,,1 slynlfieanc~ of ice jam,; i,
<br />tha!:helocation,ofthciroceUrl'el,"""ndtlH,ir
<br />impa~lS Srt' I"d",,,rmlnaw. ".nr. Otlly i" it
<br />Imr~,"ihle to predict ",her" an if'f' jHm will
<br />"[.t'llr, th!' ar"" that ,",ulri be' "lfL."t~d by
<br />on,.!!,,\\, amI th~ rt\'1"ll;,n( dCJllh of fl,".I",~
<br />:Lf<' also du"i,"'. ~'Iowthat \\'''llld "tht'F\\'I,,, b,'
<br />,wn-ri""'a>>;iny('ould, if""""iatc'dwlthatl it.<.
<br />JaIlL. f]ovd al."'" ordinarii.,' co,,"ider~d flood
<br />frt'!',
<br />
<br />
<br />[1('''' ehannel, thr<llLr.h l'if'h "ll"l'l~ultu",\lland<
<br />in andarnundth"town,lrril!"li""diteh"'and
<br />h....d 1':"(('< Wt',~ \\":',,)wd uut. S"",." major
<br />fl.."l ,'".'nb{\\I(I,1. 11. 14, If" 17,21. :\n<!171
<br />a,,,1 fiw It''' tI~maKi"v: (;,,-"1 ,.\','nl.o{I\1()2, 00,
<br />22, 2'l. ",,,12B1h"'."'~'(,lIrn'don Fortification
<br />C",'pk"nn' lh,' tllrn "fth,.'t'entUI".\'. Six flood
<br />e'.~r,:o il~q l. 1" ~n, :!1, ,.,. ,.",! "II ,,,-,.,.,,, n.,1
<br />o~, tilt. y"",pa Hi""r ,1uri,,1.( thaI IX'I.i,"1 Of
<br />
<br />fi~u,..' 2
<br />
<br />(;"lrl1 innnrl"tprlrl('wlol'inV:"f'a< near the
<br />lhfh\\'", lfl ""iv..c\ ,...",;In)(, F1,"'llwatl'c
<br />1,..,,1.,'; l" ~ .;~ptb uf nw,.~ t;larL I; f,'ct "" the
<br />up"tn'arn <i,\c."ftlw t'ul\'t'rt, b\Lldid nntfl"",
<br />m.~.. the 10;> "I th., ro"d, On th.. ba,l, of th~
<br />Iimit,~J inl"l'm!l.tlon a,-"il~bl", It i" ",;timated
<br />that a p,'ak flo'" l".twfcn '2(H1 and :>00 cub;"
<br />f....1 !",r ~~e"nd ()('r"I""~1. ;";0 Inlnrmatio" on
<br />fI",~1 ,'.."nt, 0" Broth"rt"" snd l'lne Riclj(r
<br />I;"kh~, i, ~,.~ihhl~
<br />
<br />~'i"",1il\>>; from ,,,mnwr I'loudlmr,;t typ~
<br /><torm,ba,;o<'{'urrl'd;nandaroundCr;\I~.ll\lt
<br />litllf'ddiniti\'ed~taonthi>tYPt'orfloodf'v<'nt
<br />ar~ ~""ibbh A ~mall thunder>torm (.15
<br />Ine-h,', of r~in in 2', hour") "n July 20, 197.]
<br />r<',ull<:'! In ame,~,,,,.<'<l flow of l02c\lblcf<:el
<br />per sl't'oT\d on Ccd~l' ~-!ourltain Gulch. )'l"re
<br />than '2 inehe,of rain in I hour.)Hm'~v<'t'. ha'
<br />h,,<,n ,.t'COrded in Lhe Crall<an'a,
<br />Th,-' lollowln,,; photoj(rnph" and m'''''paper
<br />a,'ticl~< {~im\llatw from tbe orl!rinalsl illu~.
<br />trau' pUolt fhxl cv'-'nt, In an,1 around Crall<.
<br />
<br />
<br />Fi.",,'1
<br />
<br />,.o,,,r,,;<\,,,,, ,:.."" n..,t~."\<" in C"i., l-\""""'" 1"'1.1. l!"m.~ tho rl...",. ,c,i<i,'o.., "".I t" rl,~' thoi, ""Jr.," '" lhe
<br />>,...l.~:,. ur \1" ,,:.:.,,_ ,'",. h;..:'"" L.r~i" .,,c, ",._1.,-,] "~\ .,:..1 ~ :",,~::, .,,,:,,:,',>'1,,,.1 n"",:l ,'.',I<u: :"'''..,l,mo:i".d.
<br />"''''I~ .,1 F"~i""'''' Ill,' r~"'''~'''I,I\;_ ,",'1",1 ''''''<, 'J"k",~'" 1
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