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<br />016
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<br />rLVOi);S 01' 1965 l~ THi<; t:'~!TED STATES
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<br />sOuTH FLATTE RIVER BASIN, COLORADO; .J"0NE 19G5
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<br />BI7
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<br />,,:ho had Ji\"ed in the area for ;,5 years, stated that the flood in 1965 was
<br />the highest he had seen, including the 19;15 flood. At a site about 20
<br />miles upstream from Burncsdlle, erO\\- Creek crested at 0700 hours
<br />on .Tune 15, and the estimated pen.k discharge was 4,000 cis. Coal Creek
<br />(>nters Crow Creek in the 20-mile reach abm'e Barnesyille and con-
<br />trilmted a. pe:lk flow of 5,a-t-O cfs, measured west of Briggsflale.
<br />); 0 prenol!~ Hood records exist for the Pa WHee Creek basin .,H'st. of
<br />~IPrlin;!: thrrefore (,olllpari~olls \yith prC\-iOllS floods cannot be made.
<br />The (Te~t of !.\~S() ef:-; nIl Xort'h PaWll('f.' Creek ii('~tr Xpw IbYllH'r
<br />OCCUlTed at- ~-LOO hours on .Tunp 1-4-. HUllOff from thp intrl'H'ning- an'a
<br />011 :\orth Fawnee C,'pek :md that from South Pa\\"ilt'e Creek increased
<br />
<br />
<br />..~~
<br />--t
<br />~l:-~
<br />"14
<br />-~
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<br />the discharge to ~G,700 t'fs at O:WO 1101ll":-;.1 Hill..' }.; on P;t\nlPf' CI'('ek IW;U.
<br />Stolleharn. Locally, there was some baekwatel' from jams of floating
<br />hailstone::::. Pawnee Creek peaked at ;')5,:200 ('fs at the bridge on State
<br />Highway l+~ l~j miles wC'stof Sterling.
<br />. \t .r UlrSbll1'P-, 63 miles down:;.tream frolll Pa WHee Creek, flood-
<br />waters fropl Pawnee Creek illcreased the flow of the South Platt~
<br />Ri'-[,r" from :WO to ;~,If>O cfs, the higlll'st since .June 10, 1961..it descrip-
<br />tion of higlH". fioods in .TUlle IDG;") on the South Platte Hiycr starts
<br />011 page B~:!.
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<br />PLF:lf CHEEK AXD CHERHY CREEK BASINS
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<br />High intensity, hea\.y rains occurred near three centers ill the Plum
<br />Creek basin on the afternoon of .June 16. O,.er 12 inches fell near
<br />Castle Rock and o\-er 14 inches fen near Palmer Lake and near Lark-
<br />spur in auont 4 hours. These rains caused the disastrous flood (fig. fi)
<br />that scarreel the lanelscape (fig. )l) and caused the great amount of
<br />damage in the Deu\-er metropolitan area.
<br />East and "'est Plum Creeks crested at 126.000 and ;)6,800 ds, respee-
<br />ti\-ely, during the afterlloon of .Tulle Hi. The unit runoff abo,-c the site
<br />on East Plulll Creek just downstream from Castle Rock was 1,170 ds
<br />pPl' ~quare mile for a dl'ain~i:.;e area of 10S square miles. "Test ern tribu-
<br />taries of 'Yest Plum Creek and all tributaries of Plum Creek down-
<br />stream from Sedalia were out. of the- high rainfall areas and COIl-
<br />tributed little or no runoi!' durin/! the flood. .
<br />The Plum Creek gaging station 1I(":1r Tft"HI\"jers was destroyed, hut
<br />obsen-atious indicated that the flo,,' incrPased a thonsandfold, from
<br />ahout 150 cfs to 154,000 cfs, in less than ~ h01lrs. The recession was also
<br />rapid; a Illeasurement of nss ds was made by wading at 1200 honrs
<br />on (June 17, only 18 hours from the peale Streamflow records haye been
<br /><.'oIlected on Plum Creek eitlwr Ileal' Spdalia or He-ar T.A:)(l\-iers since
<br />1!l-J.2,-and the maximum dischnrge prior to June 16, 1965, was 7,700
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<br />FIGnu,~ :i.-Vie". downstrf:>am on East Plum Cre(>k south of ~('dalia. Colo., late
<br />aft("rlloou uf .lUlU' ]6. Deun'r Po~t llh(lt(l~r;lph I,:" LO\n'lI (:('org-ia.
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<br />cis in August. 1945. The peak discharge on .J H11e 1H, 1065, was 20 t iHle~
<br />the pre\.i~us 1~1aXinlUm discharge in 2;3 years_ , .. .
<br />The slope of PImn Creek near Louders is :-~:~ feet per mIlt,. I he ("Oln~
<br />hi nation of this steep slope, the sand und gl':l\-el stl1..~.uHbe~l, and r:la-
<br />tin".'" open and straig-ht rt':whes of ('hannel W:lS cOIHlu.C'I.\"e .to lugh
<br />\'elocities and standing wan's. The compnted mean \"elocIOe::; III se\-en
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