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<br />Flooded area ond flood dar:nges - \1otor surfilCC profiles for
<br />tho Ir.Termeoi~te Rogiondl ~~d Stande~d Proj~c'r Floods wore develope~ lor
<br />toe length of tho study reach usinq backwater C<Y'1putationsby the $tand ard
<br />St"p I'bthod. The prof i le5, on r lafos ii tllrough la, 5~"'" tho elevation 0' the
<br />'.ater .5Ur~<lCes Jnd wClfer derths re I af I ve. fO fh" ch<lnncl hed. HeJd IO~56S
<br />~f bridges '~ere cJlculated usi~g "Hydr~\Jlks of Bridge ,I~fe""ay~" pulJlished
<br />o y t~e 'J. S. rJep<lrtment of CQf'1l'l1('rce. The watf'r surface e I ev~t ions were .Jsed
<br />to dotermlne flood limits on thElcross sections and topographic maps and in
<br />turn the flood bound~rif)S were loc~ted o~ toe af)rj~1 photQ(Jraphs. The re~ults
<br /><Ire sh,-" n on tile f looded ~r"a maps, plates 3 through 7. ,~n I ndex to the
<br />Hoodoo e~o:l plate~ i~ on plaTe 2. RoprC5ont~tlvc erc5\> snction5 ere i Ilu5-
<br />trateoon:'Jl"tcsllthrOlJgh 15. Th"cro5ssectlonssh<;warOlJndelovation5
<br />ac~OSS the vol ley on both sidf'5 of the ch~nMel i1nd Jerths of overb~ni<. flood lng,
<br />Reference poi nts, coinc iding with the location of s~rvcy",d oros.',; seotlo~~, aro
<br />provided to loc~te flood elevotlons at Inte~v~ls JlonJ T~e river. The referenoe
<br />pol nt locations are shewn on flooded ar<N ,",ps, prof i le5, and c~oss sections
<br />fo~ bett"r corr"'lation b",t~~"n dr""'io'JS. T"blf' 5 ~rDv;d",~ d~t~ at r",fer,,~n
<br />point loc~ti(}o", incbJirYj dl~tanr,;<J from rr.outh ~n~ cl(wdtlons for "!"rc ~tro"",
<br />~oo ond the lotormedla~e f'O<JioMI and St~ndMd F'rojoct FlOOdS, A bwrlng
<br />;s c~cvin&O for or;en"!"atlon of tho crD~~ 5flG"!"jDn tnroug" the refer('oce rnint.
<br />r 100<1 olevntlons for the t.'o lilr<]e poto~tia I floods cnn be chta i ned I~om the
<br />
<br />
<br />Figure II. Potentia I rlood Heights, Hlg.~.ay 23
<br />Grioge,8ellv"c.
<br />
<br />~"o;';'('~, ",r",~" ,,,c,+;,,,n5, ",r r~'"r~n.,,, +"~'''. .-;-r ~ '~pro;';'" ';+'I~+;",n
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<br />'/Ill"...., <lccwr/lCY 01 floode<.l ",reil is required, tho eprropriato flood elevation
<br />canbeiound IrCf:1oneof theaoovo sourcosand that elevation located by
<br />~"rv"y Oll till. r I<X)d p 1,,1 n w; : I e5f,1l, I hit t~" r I()o,j I imi t5. PhotO<J~aphs on
<br />P,190S 20 "nd 21 i Ilustr~te potentid I f ICXJd depths at 5f'cci I led Io<:"tions
<br />in the study ~eoch.
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<br />
<br />UpstFea~ Irom Laoo~t", ~reos su~jBCt to II00ding by larse
<br />1100<.15 on the Cacho la Pow~re River 'Ire lilrg~ly undeveloped, and us~d for
<br />c~o:>l"nd or past"re. lI~stF"i!m In"" R.efnrcnce f>oin~ 32 the lelt ~~llk is
<br />;;Q5tlv. ab(>ve 11000 le''-c I~. r., I 1 ~h h,,'ch<Jrv. '5 located on +~e r ;'l~+ IHln,
<br />
<br />-....
<br />...~.:.-
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<br />'"~
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<br />Figure 12. l'o"!"er,'Ii11 F loo~ II"'i')ht5, ']ver I~od Trili I
<br />:'O<l~ 8r 1.;'1c'. L~norto.
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