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<br />
<br />FLOODS IN COLORADO
<br />
<br />flowed its banks in a. number of places, had reached West Firxt S~rcct in the
<br />city and covered a large portion of ground occupied by road-making machinery.
<br />The cement paving south of l..oveland is covered with water to a. depth of over a
<br />foot. The Estes Park road and the valley near the plaster mills are covered.
<br />
<br />The water commissioner estimated that the flow of the river below
<br />the canyon was 7,000 second-feet, of which 5,000 second-feet was
<br />being diverted into storage reservoirs.
<br />One of the areas of heaviest precipitation during the general storm
<br />of September 1938 was the foothills part of the Thompson River Basin
<br />as far east as Fort Collins. Records of precipitation in or near the
<br />Thompson River Basin for thc period September 1-4, as reported by
<br />the Wenther Bureau arc given below.
<br />
<br />Precipitation, in inches, in Thompson River Ba8in, Sept. 1-4. 1938
<br />
<br /> September
<br />Station Altitude 'l'oto.l
<br />(feet)
<br /> 1 2 3 4
<br /> - - --
<br />Estes Pllrkn_n__.-:.__.____________._______ 8,000 0.12 0.71 1.93 0.19 2.95
<br />N<>.ar 1.011gS Peakun_.u_________________ 8,956 .09 .30 2.50 .2' 3.16
<br />Wa.wnlahL_._..._________.__._.__.nhh' &,206 u----~32- 5.:15 :1.22 ." 9.04
<br />Fort COIHM. h_ ._______n___ _._.__ -. - -- -- 4,985 1.14 3." .09 5.0~
<br />
<br />The operator at the Loveland filter plant, 7~ miles west of Love-
<br />land and 2 miles west of Waterdale, had a small rain gage formerly
<br />used by the Weather Bureau. He reported precipitation as follows:
<br />
<br />Precipitation at Loveland filter plant
<br />
<br />Inchu
<br />Sept. 1,4.15 p. m. to 7:15 p. m...____.___.._____________ 3.25
<br />Sept. 1, 7:15p. In., to Sept. 2, 6 8. m___h__ ____________ 2.00
<br />Sept. 2, 6 t\. m. to Sept. 3, 68. m________________________ 2.90
<br />Sept. 4____..________.__.____.___....__.___..__...____. .58
<br />
<br />8. 73
<br />
<br />A second storm, consisting chiefly of a series of cloudbursts, occurred
<br />in tho foothills area Scptmnber 10, In8. Like the storm earlier in
<br />September, its cffect was chiefly on the tributary streams, where
<br />sharp flood flows of short duration resulted. At a point on Redstone
<br />Creek, 6ll miles above Masonville, a rancher stated that during this
<br />storm a lO-inch bucket in the yard was filled and ran over, In spite
<br />of the heavy precipitation, no outstanding flood occurred on thc
<br />Thompson River; the peak dischargc at the gaging station near the
<br />mouth of the canyon was 5,600 second-fcct, ami at the gaging station
<br />near the mouth of the rivcr 3,000 second-feet. This was due partly
<br />to tJ>e fnct that the extensive reservoir system in the Thompson Valley
<br />diverted the water during this period, The chief damage from flood
<br />
<br />T
<br />
<br />MAJOR FLOODB--1l0UTH PLATTE RIVER
<br />
<br />49
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<br />was to the recently completed highway in the canyon, which was
<br />washed out in 10 places. In its lower course the river overflowed its
<br />banks, particularly below thc mouth of Little Thompson River.
<br />The intcnse precipitation causcd floods on several tributary streams
<br />in the foothills, and these were investigated by the Geological Survey.
<br />Dixon Gulch, draining nn area of 2.15 square miles, enters Thompson
<br />River at the head of Loveland Oanyon 2 miles above the canyon
<br />gaging station and 3 ~ miles above the Loveland Reservoir filter beds.
<br />Heavy precipitation caused a sharp rise at 7 p. m. September 1, which
<br />lasted only about 10 minutes. A slope-area measurement made near
<br />the mouth of Loveland Canyon showed a peak flow of 3,620 second-
<br />feet, or 1,680 second-feet per square mile. This flood undoubtedly
<br />was a contributing factor to the peak flow of 5,600 second-feet at
<br />8 p. m. on the Thompson River at the canyon station. Green Ridge
<br />Glade, a small gulch that enters Thompson River at the filter beds,
<br />had a peak discharge of 980 second-feet at 7:15 p. m. Scptember 1, as
<br />determined from high-wnter marks of discharge through a 7 -foot con-
<br />crete pipe. . This rcpre.sented a unit run-olf of 778 second-feet per
<br />square mile. Two slightly smaller peaks occulTed during the night of
<br />Scptember 1-2; thcse were estimated at about 950 second-feet each.
<br />Dry Crcck, ordinarily a very small stream draining the foothills south
<br />of Thompson River, which it enters midway between Buckhorn Creek
<br />and Lovcland, was reported by the Water Commissioner to have had a
<br />discharge of 1,500 second-feet.
<br />Cedar Crcek, which enters Thompson River tlrree-quarters of a mile
<br />ahovc Dixon Gulch, had a flood about 7 p. m. September 3, of sufficient.
<br />volume to wash out the bridges ovcr the creek. The rainfall was very
<br />hcav:\: near the mouth of the creek but did not extend very far up
<br />Thompson Rivcr above it. A sccond flood on Cedar Creek about 7
<br />p. m., September 10, was higher than that of Septembcr 3. A slopc-
<br />area measuremcnt of this flood at the mouth of the creek in sec. 8,
<br />T. 5 N., R. 70 W., showcd a peak discharge of 2,940 second-feet, or
<br />156 second-feet per square mile from a drainage area of 18.9 square
<br />miles.
<br />
<br />BUCKHORN CREEK
<br />The lowcr part of the area drained by Buckhorn Creek, consists of
<br />three narrow troughlike valleys lying in the foothills west of Loveland.
<br />This part is subject to cloudbursts, Buckhorn Creck has a fall of 42
<br />fcct per mile from its mouth to Redstone Creck, and 93 feet per mile
<br />for a distance of 8 miles above Redstone Creek. Redstone Creek has
<br />a fall of 99 feet per mile, for a distance of 7 miles above its mouth.
<br />Missouri Canyon which enters Buckhorn Creek 3 miles below Mason-
<br />ville, has an average fnll of 147 feet per mile.
<br />Subsequent to the general storm over the Thompson River Basin,
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