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<br />FLOO9$ITI;ATION
<br />
<br />is generally op'.n ar>d free of bl!ildin<)s and trees; thC)exci!ntion<; are
<br />at Li.l~nrt') and in toe ~r"a of t~e Colle,;e Avenue bridge ""here there are
<br />
<br />SOurCes of Data and Records
<br />
<br />nu-'C"-Ou5 resi~(),"tii! i and cC/"r'lorcia! blli Id i nss.
<br />
<br />FIe>! ~ccrcs for the study roach of
<br />River ere ava i lab 10 from a U. s. r.eologic~1 Survey
<br />'Jago locatodil.5milas north,;estof Fort Collins.
<br />
<br />thc Ca~he la "oudre
<br />~ater sfage recorder
<br />The rlraiM'Je area at
<br />
<br />F l(")Cd da""'<Jc recuct ion moasures ~ Trrore are no 'Ioac
<br />control struct~res on the Cache i" Poudre ~ iver in the study rea.eh.
<br />Thore are t<lO deC'ls on the Norti For". each" I" Pnudra Rivt\r. The '1" II i~..n
<br />DaM and Resorvoir, located ~out 24...i le<; oortrwest of Fort rolli"s, ",~s
<br />bu\ It in IglO lor irri~at ion s~or<l~e and is ""ned i>v the '.Iorth Poudre
<br />I rr I g<lt i on 2cnJa ny" The ~.'i I ton Searm n D~rn and Rcservo i r, bu i It bv the
<br />city of (f-eeley in 1947 tor mun icipa I ",ater supp Iv, is loc~ted ~bout
<br />One rni 10 upstream from the ~orth ForI;; cont luence w it~ tho Cache la Pnudre
<br />River" The flood control offect of either d~rn is considered ncgliglJle
<br />In this stl!dv. Thoro is nosDocificrogulationordlnancoaopllootothe
<br />I lcod ~ I,)in In the stu<Jy roaeh at the present tiroe, al thoug" loea I gover.....
<br />r.ent can rO<]ulatt> to 5(:<7\6 extent by control of buIlding oo.....lts. The
<br />city of Fort Coil \ ns hilS 8cqui red 50me flood rrono land~ for '"oDe~ srace"'
<br />u~a", sud J~ ~~rL~. Theca i~ nc evidecco of flood ~~oofi~g of "x:sti~q
<br />
<br />"tho gage is 1,055 5<"1uare mi le~, <)nd it5 loc<ltion marks w!;era the river
<br />leaves toe ~ountJln canyons and enter~ the high olains toooqrao~y.
<br />
<br />Tho Urirner~lojcld Regional Planning C""""issinn rrovld'Jd
<br />the cl"05s soction SlJr"VE>Y rl~t., '~hich \faS used to conmute hy<jr~u I ic nro-
<br />f 11% and to dd ine I looderl ~rOG limIts. The cross section s~rvevs '''ere
<br />'f\adebyphotograrnrnetricmethods in 1972, Thcuor;cll photogranhg used as
<br />11 bao,e for the flooded ar,.,i\ m"rs wer~ t Icwn In Ju Iy 1911CJ.
<br />
<br />Flood Season and FlOod Ch~r~c"terlstics
<br />
<br />,',"nUill ~e.,k flcws on t~" Co>::he Ii! "oudr<' 'liver In t~e
<br />study reach nnrro" Ily {}Cn;r in thi) ~crioo Ih." thro"r:h ~cpt[""'~"r, ',I~ll
<br />ooout70 rnrc<"ntoccurrin'] in Jun". Alth0U'lh"1Ostfloodsr.ogultfrC'1l
<br />I~"t"ns,., rRlnlol1 I~ o-he b~sln. .sna-Imolt rllnoff is ~ faco-(}r ,1nd 'I,p' ',;or~t
<br />ontcnt ia I t lood irIG Cond itinn i<; that of h",~vy r" In" "t " tiM<' '. h"" ~n"..-
<br />
<br />structures in th.. flOQd plain.
<br />
<br />Other f1ctors Jnd heir ;r-rilds - "ort ('Alli"S 'i'lS not
<br />~ad 0 larqe flooc in the ~omorv of C'1Ost ~r~5ent resident~ of the city and
<br />
<br />,.,-,,;j~' "ur",rr i~ Ili~II..~I, in I,;'y vr' Jun",
<br />
<br />noi; ~"d ";,,. "'aVl, ea,.,€<o ,) cc,.r,p:.J~;;~C''' or ~.:;ck of 'l~yrC~C:>~ c! Dc~c~tl"l:
<br />
<br />FactorsAiloctin'JFloodir'9"nd Itslmp<1ct
<br />
<br />f 1000 i ng ~y rc" i~"nt;:; neilr t~o rivor. Local off ;ci~ I s are eaqcr to have
<br />the flood pi,,;" defined as fln i~portant oid to future ola~nlnq, Othor
<br />factors t"r reduction <.>1 f lood ~azH""1 are I IOOd ",arn I "q, f 1000 ;>"1E'rgerlCY
<br />~Ians, ~nd tM ,,,'~norln9 of ~a~<Jri~1 e,t{"Jre~ on t'w floOO rl~I~.
<br />
<br />0:Js1'ructions-<-ofloodflcws-Rridges."lcr05sth<Jcl,annel.
<br />rlllsed emb"nkm~nt" at r();'J~S clnJ rai IrOi'lds, ~n'('s ,jn" "the,- ve!",€btion.
<br />1'()US<lS dr>d other bu i IJ i ns~, ,1tid lonc;"s ar" "I i d.,);/ruct Ion,; 10 'la., alcnq
<br />t),,, C""he L~ P"urlr(' Piv..r in TO,(> d"dv r"~rh" -""rp ~r" 1"\ hrirl,:"~ In
<br />ti" study roaco: torA" railrOC3d ~ri~~,,;:; anJ ter. r~~ b~lrlq<,s. SC'I"ral
<br />roaC'<ldy ~nJ rili I'.;ay ",.rbJnkir.€nt~ cross thu 'load nlain aM in ';0/'1(' CaQ)5
<br />such d),;tructinns c"u~e pondi"~ 01 flOOd 110;~ o~ tilt) lJ'"lstr",,'ll siC".
<br />rosulti~~1 In hiJh,,~ ",'"t"r surface,. T'l" I I ()(X! ~Iai~ in t'le ~tu.1v r~~co.
<br />
<br />F 100<1 worn In<; iJnd foreca5ti~~ - The l1a~ iona I Gce",i, and
<br />,~-<-ccosrher i C ,~C'" i n i strat lor, ~;"ti ona I ~'~aher ~erv I ce ~rov ides 11 q"ner~ I
<br />"Iert to the (jdn~or at t lash flood Inq on the Cache 10 Poodro Rive" in the
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