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<br />THE ARKANSAS RIVER l!'LOOD OF 'JUNE :a-6, 1921.
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<br />tmversed a distmce of 25 miles in '3! hours, an average rate of 7.1
<br />miles an hour. , "
<br />The maximum discharge of Beaver Creek was determined as
<br />153,000 sccund-fect at a point 1 'mile above its mouth. .Although this
<br />discharge is extremely high, it is entirely reasonable, as the mem
<br />discharge required to empty the reservoir in 30 minuW$ would have
<br />been Si,IOO second-feet, (ISee I'l. III, B,)
<br />.At Pueblo the maximum discharge of the river eaused by this
<br />,flood, which lasted from 3 t~ 4 p. Ill. on June 5, was 31,000 second-feet.
<br />Before and after the flood the discharge of the river was a.bout 15,000
<br />t second-feet, ap.d the difference, 16,000' second-fCilt, represents the flood'
<br />I crest from Beaver Creek as it reached Pueblo. Thus in traverSin~ 25
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<br />1 miles, of river that was at. medium flood stage'the crest decrellsed
<br />from 153,000 second-feet to 16,000 second-feet. ,
<br />The Skllguay reservoir is formed by a dam across the channel of
<br />" West Beaver Creek: The dam is 0. steel-faced granite back-filled
<br />structure, having a maximum height of 70 feet to the spillway level.
<br />Its length is 405 feet on the crest and 220 feet at the, base. The top
<br />width is 20 feet. The steel-faced upstream slope stands at an a.ngle
<br />of 300 with the vertical, and the downstream slope at an angle of 500.
<br />The spillway is 60 feet wide and is cut through , granite beyond the
<br />northwest end of the dam. It is divided into six para~cl chllnnels
<br />by concrete and timber partitions. (See PI. IV, E.) .The ,steel plates
<br />are sheets measuring 5 by 15 feet and decreasing in thickness from
<br />"'..,.,,..>....,haIf an inch at the bottom to a quarter of.an inch at the top, This
<br />:,:::';{:i-\:.,:: d~m stlccessfully withstood the flood, although the water ranqver it
<br />.:;:;',.,,',<' :'in the low places. To stop this overflow tlashboards in the spillway
<br />;:} '/'" were bloWn out with dynamite, and the consequent sudden release of
<br />'::.!..'::,:,...i:water into the channel below the dam washed out 50 foot' of wood- ,.
<br />;'(:~::<::;.:~::~stave pipe-line leading to the power hO,use, 5. miles be1-ow.'. .,. .-', .'-,
<br />\: "\:\:~;.': The Teller reservoir 1 is formed by. the ,construction across Turkey ",::'
<br />':'::>;/';Creek of an earth dam having a maximum height of 106 feet, a crest : ,{,~
<br />" _::-, ',;. :", , length of 770 feet, and a bottom length of about 500 feet. The hills ';' ':;,
<br />;;;,::: '~:'~:(":J~that form the abutments of the dam are very Steep, a.nd near the top:' .'
<br />":<.;:, .."'the dam abuts against rock cliffs 'at both ends. The embankment hIlS "
<br />a crest width of 22 feet, an outside slope of I! to 1, and an inside slope
<br />of 3 to 1. The inner slope is protected by a reinforced-concrete pave-
<br />ment 4 inches thick. anchored to the earthwork by concretc plugs 6
<br />inches in diameter and 2 feet Ion!!:, spaced 12 feet, apart.. This con-
<br />crete pavement is connected with a concrete toe wall, which is carrie(l
<br />to bedrock across the creek bottom. Concrete cut-off walls werc also
<br />provided w,here the embankment' abuts al!ainst the. rock cliffs at
<br />the ends. The outlet consists of a concrete tunnel 7 feet wide and
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<br />'Colorado State Engineer Fifteenth Blelln. Rept" p. 111l, 11l11.
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