FLOOD04722

• County: Las Animas
• Basin: Arkansas
• Title: Storm and Flood of July2-3, 1981 Frijole Creek Basin
• Date: 9/1/1982
• Prepared For: Colorado and Southern Railway
• Prepared By: Bishop Associates, Inc.
• Floodplain - Doc Type: Flood Documentation Report

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SECTION II
INTRODUCTION

During the night and early morning hours of July 2-3, 1981, a

thunderstorm of unusual intensity occurred centered over the upper

region of Frijole Creek, approximately 7 miles southeast of Trinidad,

Colorado. The flash flood produced by the runoff from this storm caused

failure of the Colorado and Southern Railway bridge over Frijole Creek

resulting in the derailment of s train. Flood damage within the basin,

except to the railway bridge and train, was relatively light becauae of

the few residences in the area. Damage was limited to wsshing out of

local roads and bridges, and erosion damage to the lands.

The purpose of this
,
storm of July 2-3, 1981.
following:

report is to describe the hydrology of the
The scope of the investigation included the

1. Site inspections and personal interviews on July 9, 1981, and

November 13, 1981, including aerial observation of the drainage

basin.

2. Analysis of field survey data provided by Burlington Northern

of high water marks at the railway bridge and a reach of

channel downstream from the bridge.

3. Review of USGS reports of the discharges in Frijole Creek at
the U.S. Highway 160 bridge near the confluence of Frijole
Creek and the Purgatoire River during this and previous major
flood events.

4. Review of meteorological data from the weather station at

Trinidad Airport and Limon radar station for the period July 2

and 3.

5. Hydrologic and hydraulic analyses to determine the runoff

characteristics of the storm and its estimated recurrence

interval.

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