FLOOD11751

• County: Statewide
• Basin: Statewide
• Title: Floods in Colorado
• Date: 1/1/1948
• Floodplain - Doc Type: Educational/Technical/Reference Information

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IN COLORADO

FLOODS

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By ROBERT FOLLANSBEE AND LEON ~. SAWYER

The first records of floods in Colorado antedated the settlement of the State
by about 30 years. These were records of floods on the Arkansas and Republican
Rivers in 1826. Other floods noted by traders, hunters and emigrants, some
of whom were on their way to the Far West, occurred in 1844 on the Arkansas
River, and by inference on the South Platte River. Other early floods were those
on the Purgatoire, the Lower Arkansas, and the San Juan Rivers about 1859.
The most serious flood since settlement began was that on the Arkansas River
during June 1921, which caused the loss of about 100 lives and an estimated
property loss of $19,000,000. Many floods of lesser magnitude have occurred,
and some of these have caused loss of life and very considerable property damage.
Topography is the chief factor in determining the location of storms and re-
sulting floods. These occur most frequently on the eastern slope of the Front
Range. In the mountains farther west precipitation is insufficient to cause floods
except during periods of melting snow, in June. In the southwestern part of the
State, where precipitation during periods of melting snow is insufficient to cause
floods, the severest floods yet experienced resulted from heavy rains in September'
1909 and October 191L
In the eastern foothills region, usually beiow an altitude of about 7,500 feet
and extending for a distance of about 50 miles east of the mountains, is a zone
subject to rainfalls of great intensity known as cloudbursts. 'These cloudbursts
are of short duration and are confined to very small areas. At times the intensity,
is so great as to make breathing difficult for those exposed to a storm. The areas
of intense rainfall are so small that Weather Bureau precipitation stations have
not been located in them. Local residents, being cloudburst conscious, frequently
measure the rainfall, in receptacles in their yards, and such records constitute the
only source of information regarding the intensity.
A, flood resulting from a cloudburst rises so quickly that it is usually described
as a "wall of water." It has a pfJak duration of only a few minutes, followed by
a ra.pid subsidence. Nearly.90 cloudburst floods in Colorado are described in
varying detail in this report. The earliest recorded cloudburst-called at that
time a waterspout-occurred in Golden Gate Gulch, July 14, 1872. The "wall of
water" was described as a "perpendicular breast of 10 or 12 feet." A cloudburst
flood on Kiowa Creek in May.1878 caused the loss of a standard-gage locomotive,
and although search was made by means of long metallic rods, the locomotive was
never recovered, liS bedrock was about 50 feet below. the creek bed.,
All available information relative to floods in Colorado,beginning with the
flood of 1826 on the Arkansas River, is presented in this report, although for many
of the earlier floods estimates of discharge are lacking. '
Floods throughout a large part of the State have occurred in 1844, June 1864,
June 1884, May 1894, and June 1921.: The highest floods of record were on the

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ABSTRACT

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Major floods-Continued.
Arkansas River-Continued.
Huerfano River _ ____n.
Apishapa River_______
Purgatoire River _ _h_____
WoU Creek and Granada Creek
Two Butte Creek________u___
Wild Horse CreeL____u_____
Minor tributaries of Arkansas River_uu_.___uuuu__u__u

Rio Grande________________________________________________---
South Fork Rio Grande___________________~________________

Alamosa Creek____________________________________________
Conejos River _ _ _ _ __u ____ ___ __ ___________.
Colorado River _n__ ________________ ____ __ _____
Gunnison River _____n__-'_________________
Uncompahgre River _ _ ___________nU__
Dolores River___ ,____________~__ ____ __ _____
West Creek_________________..:_________
San Miguel River _ __ un__u___
San Juan River____________________
Animas Rivern_u______nu__~
La Plata Riverhnu_--u-n---
Summary of maximum flood discharges_~_____
Changes in channel capacity and development of
Index__

CONTENTS

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IV

flood-protection measures

City of Denver during the flood of May 19-20, 1864-n____~__
Damage to Denver & Rio Grande Railroad caused by flood of
June 1921: A, Bridge west of Pueblo; B, Railroad yards in

Pueblo___-'_~__________________________________________
Damage to tracks of Denver & Rio Grande Railroad caused by
flood of October 1911 on San Juan River near PagosaJunction_
Map of Colorado showing principal river systems and cities
mentio'ned in the text._______n___~..:_n_n________'_____
Typical stage hydrographs of cloudburst floods________~_____
Chart showing maximum flood discharge, in second-feet per
squa~..IDileJ' for various places given in. the summary table

ILLUSTRA TrONS

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FIGURE