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<br />HYDROLQGICANDHYDRAtJLICDF.HRMINAT!O;;S
<br />
<br />Tabl..3:
<br />
<br />USGS GAGING STATIONS
<br />
<br />Flood Characteristics
<br />
<br />Station Identification
<br />
<br />Drainage Area
<br />(s'l1\ar" mUca)
<br />
<br />Period of Record
<br />
<br />Floods in the mOUn lain arca of the Front Ran~.. "an result h"m rain_
<br />
<br />17195 Clear Creek near
<br />C"lden
<br />
<br />""
<br />
<br />1888.1970
<br />(intermittently)
<br />
<br />fallorralnfallincombinMionwith.nowmelt.
<br />
<br />Gencrally,thcsmailerthe
<br />
<br />North Clear Creek near
<br />Blac!:.lIawk{2.3mile;
<br />upstream from mouth and
<br />4\ mile; southeast of
<br />Black Haw!:..)
<br />
<br />55.8
<br />
<br />1951-1955
<br />
<br />watershed, themore!ikclylthth"tfloodswillbel'rimurlye"usedbyin_
<br />
<br />tense thunderstorms.
<br />
<br />Floods in thc arca are generally caused by intense cloudbursts or
<br />
<br />thunderstorms during the perlod of Hay through AUHU.t. The steep and narrow
<br />
<br />HydroloHtcAnaly.is
<br />
<br />atorms r..aul to in floods with ~ high peak and lasting only" short time.
<br />
<br />I
<br />I
<br />I
<br />I
<br />I
<br />
<br />A hydrologIc "nalysia was carried out by the Colorado Water Conservation
<br />
<br />nature of the topography combined wtlh the high intenslty, .hortduratlon
<br />
<br />Board to eat"hli"h thep,,"kdlacharHe_frequency relationship" forfl oods
<br />
<br />Wi t:h development co"",entrated irunedtately adj "cent ~o the ",,"terw"y", thIs
<br />
<br />of 10-, 50-. 100_, and 500_year recurrenCe intervals for each "tream in the
<br />
<br />leAv"s little time (nr flood warninfl and no opportunity tOllvoid f!oo d
<br />
<br />9tudyarell.
<br />
<br />d~~re onCe r"infall be~ina.
<br />
<br />^ r..vlew of flol>d d~ta and information in the '/ieinity nf Black fi"wk f"r
<br />
<br />Thc p,'''k snowfall month h April. \"'hih "pring "nowrnc1t l1"d""bt~dly
<br />
<br />North CliOar Cre"k, Gregory Gulch and Chaae Gulch lndicated an in"uHictent
<br />
<br />"onlrlb"t..~ to full_flowing .lre.>ms, it is not the primary c.'"se of fl""ding.
<br />
<br />record of mea"ured titreamtlow 1.0 d..rlve th...,.al'ective fll>od fL ow peaks for
<br />
<br />Tl,,, sno,,",elt r,,~.,)ff Ls char~et~rlz,,~ h,' pH lad" of ~i~:, flc.w and m.lr~ed
<br />
<br />the varl""s <~curr,'n~~ Int"r"a! flood". Therefore, a rovi~_~' of r~gion..lized
<br />
<br />diurnal fluctuation.
<br />
<br />flood data a"d other informat10nwa. conducted to determine the' oostapl"-c;-
<br />
<br />priatemeans of ardvLn!\ at the baain flood peaks. Publicatlona conBulted
<br />
<br />A short term record of stream flow has beenmainta1ned on North Clear
<br />
<br />included th".e 1iate~ In the Bibliof';raphy for chi" report. Rdercnce55,
<br />
<br />Cr",'k near Black fjawk and a long"r term 8tationwaa On Clear Creek near
<br />
<br />10 and 12 dill not pn.>duee Q conslstel\t or "ppropriate hydrol<ll\lc dHcrmlnatl"n
<br />
<br />C~lden, a~ .hown in Table 3, hbwev~r, nQither of th"s~ station's records
<br />
<br />for thi> ~eQll.r"phical area.
<br />
<br />It wa" dedded to use" 6torm ~e"erated .u1\off
<br />
<br />wer" u.ed in the flo"d anatysi. "s they contained Insufficient information
<br />
<br />~naly~ls to prod\lce p"..k f I"od flows. Thia involved.. dcLe",,,.i,,..t""f\ of tl,~
<br />
<br />c>n flo"~ [wsks to permit a 8t<\llattc31 6nalysi" for I>rejectlon of f100rl fl"wH.
<br />
<br />storm pre~!pitatlon ch"r~d.,'rIAtlc. which, in cum~ln"t1on ~-ith th.. ",,1
<br />
<br />cloncaclcri"tiC". "0; 1 molsl"r" ~<lf\("nl dnd gruund ""v"r, I'rud\lC~.r .. propor
<br />
<br />,.,,,~or<,,[\c~ inl~rv"l fl""d. Thb r"I..\i<l!\s!<ip (B .imply t~"t pr~cLpHation
<br />
<br />(thc [,om ,,[ ,.. ;"f..' 1) m\:\u~ lo,.~,," produce. r'~nofi or f l',od p~ak. Tr.I"
<br />
<br />"
<br />
<br /><8
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