FLOOD10506

• County: Statewide
• Basin: Statewide
• Title: State of Colorado - 2006 Flood Documentation Reports
• Date: 6/1/2007
• Prepared For: CWCB
• Prepared By: ICON Engineering
• Floodplain - Doc Type: Floodplain Report/Masterplan

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

FLOOD DOCUMENTATION REPORT - CHAPTER 1

Penrose, Colorado Flood of July 5_6th, 2006
Brush Hollow Creek; Eightmile Creek; Beaver Creek
(Fremont County)

On Wednesday night and continuing into
Thursday, July 5-6th, 2006, a large storm front
extending along the foothills/plains interface of
EI Paso, Fremont, and Pueblo counties produced
a significant amount of rainfall that impacted
the un-incorporated town of Penrose and
surrounding Fremont County area. There were
confirmed reports indicating rainfall amounts in
excess of 6 inches in eastern Fremont County,
with rainfall of up to 2 inches reported west of
Colorado Springs (Manitou Springs and Garden
of the Gods area) in EI Paso County. Several
other rainfall amounts were reported from this
storm including 1.79 inches in Florence and 1.65 inches in Canyon City. According to
Bill Fortune, meteorologist in charge at the National Weather Service in Pueblo, the rain
started around 7 p.m. Wednesday and continued well past midnight with the heaviest and
most damaging rainfall occuring between 7 and 10 p.m. This event was preceeded on the
previous day by a thunderstorm that reportedly dropped 1.4 inches of rain at the Pueblo
Memorial Airport which is approximately 30 miles east ofthe Penrose area.

Introduction

Figure 1.1 - Fremont County Location in
the State of Colorado.
Map courtesy of the Colorado Herpetological
Society.

Flooding was reported along Eightmile Creek, Brush Hollow Creek, and Beaver Creek,
all of which are north-bank tributaries to the Arkansas River. USGS gaging stations on
Beaver Creek and the Arkansas River recorded signficant flow increases. Damage
occurred to several county roads and culvertlbridge crossings including severe damage to
Highway 115 and Highway 50. In particular, the Brush Hollow Creek culvert crossing of
Highway 115 approximately 1.5 miles south of Penrose overtopped and failed which
resulted in the closure ofthe highway. Brush Hollow Reservoir, which is located
appromately 4 miles north of the Highway 115 crossing, totally contained all flows
upstream of the reservoir resulting in a reported water-surface elevation rise of
approximately 6.7 feet in one day with a corresponding estimated increase in water
storage of 516 acre-feet. A house on Eightmile Creek near County Road 123 was
partially inundated as were several structures near the Eightmile crossing at County Road
132. Additionally, flooding from local drainage damaged an apartment complex in
Penrose as well as several local roads in the surrounding area.

ICON Engineering, Inc

1

September 2006