FLOOD05562 - Laserfiche WebLink

Home Browse Search

, I I 16 THE ARKANSAS RIVER..ELOOD OF JUNE' H, 1921. The statements of local residents and the measured maximum dis- charges of the tributary streams indicate two principal areas of intense rainfall. (See Pl. I.) The larger area, which is roughly ellip- tical, extends from the northern boundary of Pueblo County to the top of the 'Wet Mountains near Beulah, a distance of 30 miles, and from a point a short distance above the mouth of Rush Creek nearly to Pueblo, a distance of 15 milt's. The smaller area covers the south slope of the Pikes Peak uplift, which forms the northern part of tIle m?untain valley, nnd e:'i:tends from a point above Skaguay reser- voir to a point 3 or 4 miles south of the river, a distance of 25 miles, and from Oil Creek to Beaver Creek, a distance of 11 miles. The two areas coyer ~5'p square miles. . . EFFECT OF RESERVOIRS ON THE FLOOD. Considerahlt! misinformation relat,ive to the effect of reser.oirs upon the flood was dis.<;elllinated hy thl) hrt)n',n'1I1 iuul lcdlllical press at the time of its O<:f'UITI'JU:t'. There 111'1) three reservoirs of con- siderable size within the areas 0 r intense rainfltll, antlnone of these contributed to the main flood of .June 3. The Schaeffer reservoir, on Beaver Creek, failed 011 June 5,causing the flood of that date, which was very severe in the yalley immedi!1tely below the mouth of , Beaver Creek but flattened Gut farther downstream. The other two reservoirs, the Skaguay reservoir, on Beaver Creek, and the Teller reservoir, on Turkey Creek, safely withstood the flood. At the time of the main flood the three reservoirs helped in a slight degree to reduce its magnitude by holding back a portion of the run-off above them. The Schaeffer reservoir, which had a capacity of 3,190 acre-feet, was formed by an earth dam across Beaver Creek in sec. 9, T. 18 S" R 68 W. The dam had a maximum height of 100 feet above the bottom of the outIet and a length on the: crest of 1,100 feet. ; Its average height was about 90 feet for the middle 500 feet of'its length. The width on the crest was ,15 feet, the outside slope 2 to 1, ",and the inside slope 3 to 1. .A freeboard of 10 feet was provided. ..A concrete cut-off wall ,",,'as provided in the middle portion of the dam, and a timber cut-off wall for the remainder, The inlet was a concrete tunnel'{ feet wide and 5 feet high, t'onstructedon bedrock. The dam was built to a height of 20 to 30 feet by the hydraulie- fill method when it was ohscrn:d tllat the 1I1aterial deposited in the center of the dam retained water aml dill not cOllsolidate, being more nearly liquid than solid. The liquid material ,\-as replaceu by dry earth,' and the dam was finisher1 by depositing the earth by wagons, sprinkling, and rolling in thin layers. The inner slope was rip- rapped to the top. A spillway 100 feet wide was providell beyond . .