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<br />The profiles of the St~nd~rd Project flood and the <br />Intermediate Regional flood depend in part upon the degree of <br />structural obstruction and clogging that may occur at the various <br />bridgee during the flood. Theae factors cannot be accurately <br />forecast, and sOme ologging is to be expected ~hich may change <br />Astimeted flood limit~. It We' aseumed that the bridge struc. <br />tures would stand intact. <br />On the three tributaries studied, the difference <br />bet~een the Standard Project flood end Intermediate Regional <br />flood water surface profiles, along most of each stream, averages <br /><I to 5 feet on liIild Horae.Dry Creek, and leu than 1 foot on Dry <br />Creek and Goodnight Arroyo. Stage comparisons with historical <br />floode cannot be made due to tho lack of reliable past. flood <br />date on these streams. <br /> <br />TA8LEIO <br />INTtRr~WIATE REGIONAL fLOOD <br /> <br />~AXIMU~ VELOCITIES <br /> <br />St!'eam <br /> <br />Loc~tion <br />Mile <br /> <br />Max~m~m <br />C'l~nnel <br />ft.paresc. <br /> <br />Velocities <br />IJvert"nk <br />ft. per sec. <br /> <br />Wild Horse-Dry Creek <br /> <br />1.52 <br />2.55 <br /> <br />20.0 <br />18.4 <br /> <br />3.3 <br />e,2 <br /> <br />Dry Creek <br /> <br />0.39 <br /> <br />11.6 <br /> <br />Goodnight Ar!'oyo <br /> <br />1.66 <br /> <br />12.8 <br /> <br />,,' <br /> <br />Figu!'es 9 through 11 show the heights that would be <br />reaohed by the Standard Project Flood and the Intermediate Regional <br />Flood on select facilities presently existing ~ithin the flood <br />plaine considered in the study. <br /> <br />TA8LE11 <br /> <br />So A~DARD PROJECT fLOOO <br /> <br />Velo~itias. R~tas of Rise. ~nd O~te~ion <br />Weter velodties during floode depend i~rgely upon <br />the aila, ahape, and slope of the streambed. and the condition <br />of the channel. These factors vary on diffe~ent atreame and at <br />different locations and timos on the same stream. <br />T~bles 10 and 11 show the maximum velocities that <br /> <br />MAXIMU~ VELOCITIES <br /> <br />St!'~"m <br /> <br />Loc"Uon <br />Mile <br /> <br />maximum <br />Chann~l <br />ft.peresc. <br /> <br />Veiocities <br />Ovo~b"nk <br />ft. per ~ec. <br /> <br />Wild Hnf"n-O,y Cr~~k <br /> <br />1.52 <br />2.55 <br /> <br />23.8 <br /> <br />1.9 <br />;.; <br /> <br />2'2.7 <br /> <br />would occur in the m~in channel and overbank areas of the !'eaches <br /> <br />studied during the lntar~edi~te Regional flood ~nd St~nd"rd <br />Project flcod, respectively. <br /> <br />OryCresl< <br /> <br />0.39 <br /> <br />12.2 <br /> <br />~oodnight Arroyo <br /> <br />1.66 <br /> <br />13.2 <br /> <br />'.0 <br /> <br />" <br /> <br />Tables 12 and 13 shaw the total hei9ht of riae. the <br />moxi~m rote of ri36. and the duration abov~ b~nkrull stdge of the <br />Intermediate Regional Flood and Standa!'d PrnJect FlOOd, reopectively, <br />for tYpic~l flood plain sections on the .eachas studied. <br /> <br />" <br />