<br />18 THE ARKANSAS mVlm lfLOOD OF JUNE 3-5, 1921.
<br />
<br />traversed a distance 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 second-feet at a point 1 mile above its mouth. Although this
<br />discharge is extremely high, it is entirely reasonable, as the mean
<br />discharge required to empty the reservoir in 30 minute~ would have
<br />been 87,100 second-feet. (rSee PI. III, E.)
<br />At, Pueblo the maximum discharge of the river caused by this
<br />flood, which lasted from 3 t~ 4 p. m. on June 5, was 31,000 second-feet.
<br />Before and after the flood the discharge of the river was about 15,000
<br />, second-feet, and the difference, 16,000second-fe€t, represents the flood'
<br />I crest from Beaver Creek as it reached Pueblo. Thus in traverSing 25
<br />r 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 Slmguay reservoir is formed by a dam across the channel of
<br />West Beaver Creek. The dam is a 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 buse. The top
<br />width is 20 feet. The steel...hced upstream slope stands at an angle
<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 parallel channels
<br />by concrete and timber partitions. (See PI. IV, B.) The steel plates
<br />are sheets measuring 5 by 15 feet and decreasing in thickness from
<br />,half an inch at the bottom to a quarte'r of, an inch at the top. This
<br />, dam successfully withstood the flood, although the water ran qver it
<br />,in the low places. To stop this overflow lIashboards in the spillway
<br />were blown out with dynamite, and the consequent sudden release of
<br />; water into the channel below the dam washed out 50 feet of wood-
<br />'. ,.stave pipe-line leading to the power hous{~, 5 miles below.,
<br />" . - The Teller reservoir 7 is formed by the construction across Turkey
<br />, , Creek of an earth darn 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 />',' ' .' ,that form the abutments of the dam are very steep, and near the top
<br />, Othe dam abuts against rock cliffs 'at both ends. The embankment has
<br />a crest width of 22 feet, an outside slope o':E 1! 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 concrete plugs 6
<br />inches in diameter and 2 feet long, spaced 12 feet, apart. This con-
<br />crete pavement is connected with n roncrete toe wall, which is carrie,l
<br />to bedrock across the creek bottom. Concrete cnt-off wnlls were nl80
<br />provided where the embanlunent 'nbuts ag'llin8t the rock cliffs at
<br />the ends. The outlet consists of a concrete tunnel 7 feet wide IlncI
<br />
<br />, COlorado State Engineer Fifteenth Blenn, Rept,. p.. 119, 1911,
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