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<br />H
<br /> TABLEx_l TABLEX_2
<br /> lOW FLOW HYDROLOGY
<br /> SOUTH PLATTE RIVER
<br /> FLOOD HYDROLOGY Littleton Denver Hefid~~SOfi
<br /> Gage Gag!' Gage
<br /> Discharge (cfs) Month (cfs) (cfs) lefs)
<br /> January 3" 78 153
<br /> Recurrence Interval
<br />Location 2-Year IO-Year 50-Year lOO-Year February 44 84 119
<br />a/SDutch Cree~ ~~rch 56 95 168
<br /> . . 5,060 1;,400
<br />S. Platte @ Littleton 3,100 6,170 7,940 April 51 102 1"
<br />.
<br />DfS Big Dry Creek . 4,350 9,500 12,600 '" " 118 <05
<br />O/S L itt 1e Or y Cree~ . 5,750 12,200 16,000 June 164 119 m
<br />CIS Cherry Creek 3,580 9,700 18.000 22,500 July 174 204 519
<br />S.Plattelil19th Ave. 3,580 9,700 18,000 22,400 August 146 197 311
<br />U/SSandCreek 3,580 9,700 17,400 21,700 5ept!'rl1ber 53 88 115
<br />O/SC1",arCreek 3,550 13,000 28,600 38,000 October 42 67 144
<br />0/5 first Creek 3,550 12,700 27,500 36,000 November 60 116 173
<br />S. Platte @ Henderson 3,400 12,300 2,700 35,500 [)ecember ]6 " 2n
<br />Baseline Road 3,130 11,400 ?5,500 33,60()
<br />
<br />Hydraulic Roughness. Hydraul ic computations fo~ the flow in the South
<br />Platte River channel utilizes the follow1ng Manning's"n" rouqhnesseoeftl-
<br />e i ents wtl1 eh are based an US,\Cf and Wr ight Water Eng ineer~ cali brat ions.
<br />
<br />~ Snowmelt and dam releases predominate
<br />
<br />Normal flood period releases from Chatfiel<i, Bear Creek, and Cherry Creek
<br />Reservoirs ,nay be up to 5,000 cfs. $uehreleasesforplanninqanddesign
<br />are Mt to be added to floo<is generated downstream of tht~ dams du!' to
<br />rainfall occurrences.
<br />
<br /> TASLE '_J
<br /> MANNING'S ROUGHNESS VALUES
<br /> Mannino's n
<br />R~ach Location Ch,lnnel bverbanks
<br />~, thatfH,ld to ColL.O'l1biM .030 .06 .07
<br />1 Columbine to Oxford .030 .045 .0$
<br />3 Oxford to Bates .030 .045 .05
<br />4 Bates toCo1fax .030 .045 .055
<br />5 (,(llf~x to Chl'rryCrl'ek .030 .04 .05
<br />6 Cherry Creek to23rd .035 .04 J15
<br /> 23rd to Franklin .030 .04 .055
<br />, Fran~l in to Sanrl Crl';f'k .035 .04 .055
<br />8 Sand Creek " Basel in~ .035 .06 .n3
<br />
<br />Low Flow Hydroloqy. Average monthly low flows in the South Platte River,
<br />nased on a ::!ry year anal ysi s, for near term pl anni ng ~nd design purposes
<br />are shown 1n Tanle X-2.
<br />
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